• FluTrackers.com Inc. does not provide medical advice. Information on this web site is collected from various internet resources, and the FluTrackers board of directors makes no warranty to the safety, efficacy, correctness or completeness of the information posted on this site by any author or poster. The information collated here is for instructional and/or discussion purposes only and is NOT intended to diagnose or treat any disease, illness, or other medical condition. Every individual reader or poster should seek advice from their personal physician/healthcare practitioner before considering or using any interventions that are discussed on this website. By continuing to access this website you agree to consult your personal physican before using any interventions posted on this website, and you agree to hold harmless FluTrackers.com Inc., the board of directors, the members, and all authors and posters for any effects from use of any medication, supplement, vitamin or other substance, device, intervention, etc. mentioned in posts on this website, or other internet venues referenced in posts on this website.
  • We are not asking for any donations. Do not donate to any entity who says they are raising funds for us.

US - FluView: 2016-2017 Influenza Season

sharon sanders

Editor-in-Chief & President
[h=3]2016-2017 Influenza Season Week 40 ending October 8, 2016[/h] [FONT=&quot]All data are preliminary and may change as more reports are received.[/FONT]
[h=3]Background:[/h] [FONT=&quot]The Centers for Disease Control and Prevention?s (CDC) Influenza Division collects, compiles, and analyzes information on influenza activity year-round in the United States and produces FluView, a weekly influenza surveillance report, and FluView Interactive , which allows for more in-depth exploration of influenza surveillance data. The U.S. influenza surveillance system provides information in five categories collected from eight data sources. This is the first report of the 2016-2017 influenza season, which began on October 2, 2016.[/FONT]
[FONT=&quot]The five categories and eight data components of CDC influenza surveillance are:[/FONT]
  • Viral Surveillance: U.S. World Health Organization (WHO) collaborating laboratories, the National Respiratory and Enteric Virus Surveillance System (NREVSS), and human infection with novel influenza A virus case reporting;
  • Mortality: National Center for Health Statistics (NCHS) Mortality Surveillance System and influenza-associated pediatric deaths;
  • Hospitalizations: Influenza Hospitalization Network (FluSurv-NET) including the Emerging Infections Program (EIP) and three additional states;
  • Outpatient Illness Surveillance: U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet);
  • Geographic Spread of Influenza: State and territorial epidemiologists? reports.
[FONT=&quot]An overview of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component, is available at: http://www.cdc.gov/flu/weekly/overview.htm.[/FONT]
[h=3]Synopsis:[/h] [FONT=&quot]During week 40 (October 2-8, 2016), influenza activity was low in the United States.[/FONT]
  • Viral Surveillance: The most frequently identified influenza virus type reported by public health laboratories during week 40 was influenza A. The percentage of respiratory specimens testing positive for influenza in clinical laboratories is low.
  • Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was below the system-specific epidemic threshold in the National Center for Health Statistics (NCHS) Mortality Surveillance System.
  • Influenza-associated Pediatric Deaths: No influenza-associated pediatric deaths were reported.
  • Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 1.1%, which is below the national baseline of 2.2%. All 10 regions reported ILI below region-specific baseline levels. New York City and 50 states experienced minimal ILI activity and the District of Columbia and Puerto Rico had insufficient data.
  • Geographic Spread of Influenza: The geographic spread of influenza in Guam was reported as widespread; Puerto Rico and one state reported local activity; the U.S. Virgin Islands and 36 states reported sporadic activity; and the District of Columbia and 13 states reported no activity.
[h=3]National and Regional Summary of Select Surveillance Components[/h]
[FONT=&quot] [TABLE="class: table table-bordered opt-in"]
[TR]
[/TR]
[TR]
HHS Surveillance Regions* Data for current week Data cumulative since October 2, 2016 (week 40) [/TR]
[TR]
Out-patient ILI[SUP]?[/SUP] Number of jurisdictions reporting regional or widespread activity[SUP]?[/SUP] % respiratory specimens positive for flu in clinical laboratories[SUP]?[/SUP] A(H1N1)pdm09 A (H3) A (Subtyping not Performed) B Victoria lineage B Yamagata lineage B lineage not performed Pediatric Deaths [/TR]
[TR]
Influenza test results from public health laboratories only [/TR]
[TR]
Nation [TD]Normal[/TD]
[TD]1 of 54[/TD]
[TD]1.7%[/TD]
[TD]4[/TD]
[TD]28[/TD]
[TD]5[/TD]
[TD]1[/TD]
[TD]0[/TD]
[TD]2[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 1 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]0.5%[/TD]
[TD]0[/TD]
[TD]4[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 2 [TD]Normal[/TD]
[TD]0 of 4[/TD]
[TD]0.6%[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 3 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]0.5%[/TD]
[TD]2[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 4 [TD]Normal[/TD]
[TD]0 of 8[/TD]
[TD]4.2%[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 5 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]0.8%[/TD]
[TD]0[/TD]
[TD]5[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 6 [TD]Normal[/TD]
[TD]0 of 5[/TD]
[TD]1.9%[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 7 [TD]Normal[/TD]
[TD]0 of 4[/TD]
[TD]0.1%[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]2[/TD]
[TD]1[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 8 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]0.5%[/TD]
[TD]2[/TD]
[TD]2[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 9 [TD]Normal[/TD]
[TD]1 of 4[/TD]
[TD]1.2%[/TD]
[TD]0[/TD]
[TD]7[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 10 [TD]Normal[/TD]
[TD]0 of 4[/TD]
[TD]2.4%[/TD]
[TD]0[/TD]
[TD]10[/TD]
[TD]1[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[/TABLE]
[/FONT]
[FONT=&quot]*HHS regions (Region 1 CT, ME, MA, NH, RI, VT; Region 2: NJ, NY, Puerto Rico, US Virgin Islands; Region 3: DE, DC, MD, PA, VA, WV; Region 4: AL, FL, GA, KY, MS, NC, SC, TN; Region 5: IL, IN, MI, MN, OH, WI; Region 6: AR, LA, NM, OK, TX; Region 7: IA, KS, MO, NE; Region 8: CO, MT, ND, SD, UT, WY; Region 9: AZ, CA, Guam, HI, NV; and Region 10: AK, ID, OR, WA).
? Elevated means the % of visits for ILI is at or above the national or region-specific baseline
? Includes all 50 states, the District of Columbia, Guam, Puerto Rico, and U.S. Virgin Islands
? National data are for current week; regional data are for the most recent three weeks

[/FONT]

[h=2]U.S. Virologic Surveillance:[/h] [FONT=&quot]WHO and NREVSS collaborating laboratories, which include both public health and clinical laboratories located in all 50 states, Puerto Rico, and the District of Columbia, report to CDC the total number of respiratory specimens tested for influenza and the number positive for influenza by virus type. In addition, public health laboratories also report the influenza A subtype (H1 or H3) and influenza B lineage information of the viruses they test and the age or age group of the persons from whom the specimens were collected.[/FONT]
[FONT=&quot]Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html and http://gis.cdc.gov/grasp/fluview/flu_by_age_virus.html.[/FONT]
[FONT=&quot]The results of tests performed by clinical laboratories during the current week are summarized below.[/FONT]
[TABLE="class: table table-bordered table-condensed opt-in"]
[TR]
[TD] [/TD]
Week 40 [/TR]
[TR]
No. of specimens tested [TD]9,799[/TD]
[/TR]
[TR]
No. of positive specimens (%) [TD]170 (1.7%)[/TD]
[/TR]
[TR]
Positive specimens by type [TD] [/TD]
[/TR]
[TR]
Influenza A [TD]88 (51.8%)[/TD]
[/TR]
[TR]
Influenza B [TD]82 (48.2%)[/TD]
[/TR]
[/TABLE]


View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation
[FONT=&quot]The results of tests performed by public health laboratories, as well as the age group distribution of influenza positive tests, during the current week are summarized below.[/FONT]
[TABLE="class: table table-bordered table-condensed opt-in"]
[TR]
[TD] [/TD]
Week 40 [/TR]
[TR]
No. of specimens tested [TD]403[/TD]
[/TR]
[TR]
No. of positive specimens [TD]40[/TD]
[/TR]
[TR]
Positive specimens by type/subtype [TD] [/TD]
[/TR]
[TR]
Influenza A [TD]37 (92.5%)[/TD]
[/TR]
[TR]
A(H1N1)pmd09 [TD]4 (10.8%)[/TD]
[/TR]
[TR]
H3 [TD]28 (75.7%)[/TD]
[/TR]
[TR]
Subtyping not performed [TD]5 (13.5%)[/TD]
[/TR]
[TR]
Influenza B [TD]3 (7.5%)[/TD]
[/TR]
[TR]
Yamagata lineage [TD]0 (0%)[/TD]
[/TR]
[TR]
Victoria lineage [TD]1 (33.3%)[/TD]
[/TR]
[TR]
Lineage not performed [TD]2 (66.7%)[/TD]
[/TR]
[/TABLE]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation


View Interactive Application | View Full Screen
[h=2]Influenza Virus Characterization:[/h] [FONT=&quot]CDC characterizes influenza viruses through one or more tests including genomic sequencing, hemagglutination inhibition (HI) and/or neutralization assays. These data are used to compare how similar currently circulating influenza viruses are to the reference viruses used for developing influenza vaccines, and to monitor for changes in circulating influenza viruses. Historically, HI data have been used most commonly to assess the similarity between reference viruses and circulating viruses to suggest how well the vaccine may work until such a time as vaccine effectiveness estimates are available.[/FONT]
[FONT=&quot]For nearly all virus positive surveillance samples received at CDC, next-generation sequencing is performed to ascertain genomic data of circulating influenza viruses. Viruses can be classified into genetic groups/clades based on analysis of their HA gene segments using phylogenetics and key amino acid changes (Klimov Vaccine 2012).[/FONT]
[FONT=&quot]No characterization data is currently available for specimens collected after October 1, 2016.[/FONT]
[h=2]Genetic Characterization[/h] [FONT=&quot]During May 22 ? October 8, 2016, 1,148 influenza positive specimens were reported by public health laboratories in the United States (figure, left). CDC genetically characterized 192 influenza viruses [15 influenza A (H1N1)pdm09, 111 influenza A (H3N2), and 66 influenza B viruses] collected by U.S. laboratories. The HA gene segment of all influenza A (H1N1)pdm09 viruses analyzed belonged to genetic group 6B.1. Influenza A (H3N2) virus HA gene segments analyzed belonged to genetic groups 3C.2a, 3C.2a1 or 3C.3a. The HA of influenza B/Victoria-lineage viruses all belonged to genetic group V1A. The HA of influenza B/Yamagata-lineage viruses analyzed all belonged to genetic group Y3.[/FONT]
[FONT=&quot]The majority of U.S. viruses submitted for characterization come from state and local public health laboratories. Specimen submission guidance issued to the laboratories request that, if available, 2 influenza A (H1N1), 2 A influenza (H3N2), and 2 influenza B viruses be submitted every other week. Because of this, the number of each virus type/subtype characterized should be approximately equal. In the figure below, the results of tests performed by public health labs are presented on the left and sequence results by genetic group of specimens submitted to CDC are presented on the right.[/FONT]
Genetic40_small.gif

View Chart Data | View Full Screen | View PowerPoint Presentation
[h=2]Antigenic Characterization[/h] [FONT=&quot]During May 22 ? September 30, 2016, CDC antigenically characterized 120 influenza viruses [8 influenza A (H1N1)pdm09, 53 influenza A (H3N2), and 59 influenza B viruses] collected by U.S. laboratories.[/FONT]
[FONT=&quot]Influenza A Virus [61][/FONT]
  • A (H1N1)pdm09 [8]: All 8 (100%) influenza A (H1N1)pdm09 viruses were antigenically characterized using ferret post-infection antisera as A/California/7/2009-like, the influenza A (H1N1) component of the 2016-2017 Northern Hemisphere vaccine.
  • A (H3N2) [53]: 44 (83%) of 53 influenza A (H3N2) viruses were antigenically characterized as A/Hong Kong/4801/2014-like, a virus that belongs in genetic group 3C.2a and is the influenza A (H3N2) component of the 2016-2017 Northern Hemisphere vaccine, by HI testing or neutralization testing. Among the viruses that reacted poorly with ferret antisera raised against A/Hong Kong/4801/2014-like viruses, 8 of 9 (90%) are more closely related to A/Switzerland/9715293/2013, a virus belonging to genetic group 3C.3a.
[FONT=&quot]Influenza B Virus [59][/FONT]
  • Victoria Lineage [26]: All 26 (100%) B/Victoria-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Brisbane/60/2008-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere trivalent and quadrivalent influenza vaccines.
  • Yamagata Lineage [33]: All 33 (100%) B/Yamagata-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Phuket/3073/2013-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere quadrivalent influenza vaccines.
[h=2]Antiviral Resistance:[/h] [FONT=&quot]No antiviral resistance data is available for specimens collected after October 1, 2016.[/FONT]
[FONT=&quot]During May 22-Septemer 30, 2016, 159 specimens (14 influenza A (H1N1)pdm09, 84 influenza A (H3N2), and 61 influenza B viruses) collected in the United States were tested for susceptibility to the neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir). Among the 14 influenza A (H1N1)pdm09 viruses tested for oseltamivir and peramivir, one (7.1%) was resistant to both drugs. A total of 12 influenza A (H1N1)pdm09 viruses were tested for zanamivir susceptibility and all were susceptible. None of the 84 influenza A (H3) and 61 influenza B viruses were found to be resistant to either oseltamivir, zanamivir, or peramivir.[/FONT]
[FONT=&quot]The majority of recently circulating influenza viruses are susceptible to the neuraminidase inhibitor antiviral medications, oseltamivir, zanamivir, and peramivir; however, rare sporadic instances of oseltamivir-resistant and peramivir-resistant influenza A (H1N1)pdm09 viruses and oseltamivir-resistant influenza A (H3N2) viruses have been detected worldwide. Antiviral treatment as early as possible is recommended for patients with confirmed or suspected influenza who have severe, complicated, or progressive illness; who require hospitalization; or who are at high risk for serious influenza-related complications. Additional information on recommendations for treatment and chemoprophylaxis of influenza virus infection with antiviral agents is available at http://www.cdc.gov/flu/antivirals/index.htm.[/FONT]



[h=2]Pneumonia and Influenza (P&I) Mortality Surveillance:[/h] [FONT=&quot]Based on National Center for Health Statistics (NCHS) mortality surveillance data available on October 12, 2016, 5.4% of the deaths occurring during the week ending September 24, 2016 (week 38) were due to P&I. This percentage is below the epidemic threshold of 6.3% for week 38.[/FONT]
[FONT=&quot]P&I percentages for recent weeks may be artificially low due to a backlog of records requiring manual processing. Percentages will likely increase to levels more similar to the baseline as more data becomes available.[/FONT]
[FONT=&quot]Beginning in the week ending October 8, 2016, data from the National Center for Health Statistics (NCHS) Mortality Surveillance System will replace the information reported in FluView and Table III of the Morbidity and Mortality Weekly Report and the 122 Cities Mortality Reporting System will be retired. For more information, please see Notice to Readers: Update to Reporting of Pneumonia and Influenza Mortality. For a final complete set of data reported to the 122 Cities Mortality Reporting System, please see Deaths in 122 U.S. Cities ? 1962-2016. 122 Cities Mortality Reporting System.[/FONT]
[FONT=&quot]Region and state-specific data are available at http://gis.cdc.gov/grasp/fluview/mortality.html.[/FONT]
NCHS40_small.gif

View Regional and State Level Data | View Chart Data | View Full Screen

[h=2]Influenza-Associated Pediatric Mortality:[/h] [FONT=&quot]No influenza-associated pediatric deaths were reported to CDC during week 40.[/FONT]
[FONT=&quot]Additional data can be found at: [/FONT]http://gis.cdc.gov/GRASP/Fluview/PedFluDeath.html[FONT=&quot].[/FONT] [FONT=&quot] [/FONT]

View Interactive Application | View Full Screen | View PowerPoint Presentation


[h=2]Influenza-Associated Hospitalizations:[/h] [FONT=&quot]The Influenza Hospitalization Surveillance Network (FluSurv-NET) conducts population-based surveillance for laboratory-confirmed influenza-related hospitalizations in select counties in the Emerging Infections Program (EIP) states and Influenza Hospitalization Surveillance Project (IHSP) states. FluSurv-NET estimated hospitalization rates will be updated weekly starting later this season. Additional FluSurv-NET data can be found at: http://gis.cdc.gov/GRASP/Fluview/FluHospRates.html and http://gis.cdc.gov/grasp/fluview/FluHospChars.html.[/FONT]



[h=2]Outpatient Illness Surveillance:[/h] [FONT=&quot]Nationwide during week 40, 1.1% of patient visits reported through the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) were due to influenza-like illness (ILI). This percentage is below the national baseline of 2.2%.[/FONT]
[FONT=&quot](ILI is defined as fever (temperature of 100?F [37.8?C] or greater) and cough and/or sore throat.)[/FONT]
[FONT=&quot]Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html.[/FONT]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation
[FONT=&quot]On a regional level, the percentage of outpatient visits for ILI ranged from 0.4% to 1.8% during week 40. All 10 regions reported a proportion of outpatient visits for ILI below their region-specific baseline levels.[/FONT]
[FONT=&quot]

[/FONT]

[h=2]ILINet State Activity Indicator Map:[/h] [FONT=&quot]Data collected in ILINet are used to produce a measure of ILI activity* by state. Activity levels are based on the percent of outpatient visits in a state due to ILI and are compared to the average percent of ILI visits that occur during weeks with little or no influenza virus circulation. Activity levels range from minimal, which would correspond to ILI activity from outpatient clinics being below, or only slightly above, the average, to high, which would correspond to ILI activity from outpatient clinics being much higher than average.[/FONT]
[FONT=&quot]During week 40, the following ILI activity levels were experienced:[/FONT]
  • New York City and all 50 states experienced minimal ILI activity.
  • Data were insufficient to calculate an ILI activity level from the District of Columbia and Puerto Rico.
[FONT=&quot][/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]Click on map to launch interactive tool[/FONT]
[FONT=&quot]*This map uses the proportion of outpatient visits to health care providers for ILI to measure the ILI activity level within a state. It does not, however, measure the extent of geographic spread of flu within a state. Therefore, outbreaks occurring in a single city could cause the state to display high activity levels.
Data collected in ILINet may disproportionally represent certain populations within a state, and therefore, may not accurately depict the full picture of influenza activity for the whole state.
Data displayed in this map are based on data collected in ILINet, whereas the State and Territorial flu activity map is based on reports from state and territorial epidemiologists. The data presented in this map is preliminary and may change as more data are received.
Differences in the data presented here by CDC and independently by some state health departments likely represent differing levels of data completeness with data presented by the state likely being the more complete.[/FONT]



[h=2]Geographic Spread of Influenza as Assessed by State and Territorial Epidemiologists[/h] [FONT=&quot]The influenza activity reported by state and territorial epidemiologists indicates geographic spread of influenza viruses, but does not measure the severity of influenza activity.[/FONT]
[FONT=&quot]During week 40, the following influenza activity was reported:[/FONT]
  • Widespread influenza activity was reported by Guam.
  • Local influenza activity was reported by Puerto Rico and one state (New Hampshire).
  • Sporadic influenza activity was reported by the U.S. Virgin Islands and 36 states (Alaska, Arizona, California, Colorado, Connecticut, Florida, Georgia, Hawaii, Idaho, Iowa, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nevada, New Jersey, New Mexico, New York, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, South Dakota, Tennessee, Texas, Utah, Washington, West Virginia, Wisconsin, and Wyoming).
  • No activity was reported by the District of Columbia and 13 states (Alabama, Arkansas, Delaware, Illinois, Indiana, Kansas, Mississippi, Nebraska, North Carolina, Rhode Island, South Carolina, Vermont, and Virginia).
[FONT=&quot][/FONT]


[FONT=&quot] [/FONT]
[h=2]Additional National and International Influenza Surveillance Information[/h] [FONT=&quot]FluView Interactive: FluView includes enhanced web-based interactive applications that can provide dynamic visuals of the influenza data collected and analyzed by CDC. These FluView Interactive applications allow people to create customized, visual interpretations of influenza data, as well as make comparisons across flu seasons, regions, age groups and a variety of other demographics. To access these tools, visit http://www.cdc.gov/flu/weekly/fluviewinteractive.htm.[/FONT]
[FONT=&quot]U.S. State and local influenza surveillance: Click on a jurisdiction below to access the latest local influenza information.[/FONT]
[FONT=&quot] [/FONT]

[TD="width: 139"] Alabama
[/TD]
[TD="width: 139"] Alaska
[/TD]
[TD="width: 139"] Arizona
[/TD]
[TD="width: 139"] Arkansas
[/TD]
[TD="width: 139"] California
[/TD]

[TD="width: 139"] Colorado
[/TD]
[TD="width: 139"] Connecticut
[/TD]
[TD="width: 139"] Delaware
[/TD]
[TD="width: 139"] District of Columbia
[/TD]
[TD="width: 139"] Florida
[/TD]

[TD="width: 139"] Georgia
[/TD]
[TD="width: 139"] Hawaii
[/TD]
[TD="width: 139"] Idaho
[/TD]
[TD="width: 139"] Illinois
[/TD]
[TD="width: 139"] Indiana
[/TD]

[TD="width: 139"] Iowa
[/TD]
[TD="width: 139"] Kansas
[/TD]
[TD="width: 139"] Kentucky
[/TD]
[TD="width: 139"] Louisiana
[/TD]
[TD="width: 139"] Maine
[/TD]

[TD="width: 139"] Maryland
[/TD]
[TD="width: 139"] Massachusetts
[/TD]
[TD="width: 139"] Michigan
[/TD]
[TD="width: 139"] Minnesota
[/TD]
[TD="width: 139"] Mississippi
[/TD]

[TD="width: 139"] Missouri
[/TD]
[TD="width: 139"] Montana
[/TD]
[TD="width: 139"] Nebraska
[/TD]
[TD="width: 139"] Nevada
[/TD]
[TD="width: 139"] New Hampshire
[/TD]

[TD="width: 139"] New Jersey
[/TD]
[TD="width: 139"] New Mexico
[/TD]
[TD="width: 139"] New York
[/TD]
[TD="width: 139"] North Carolina
[/TD]
[TD="width: 139"] North Dakota
[/TD]

[TD="width: 139"] Ohio
[/TD]
[TD="width: 139"] Oklahoma
[/TD]
[TD="width: 139"] Oregon
[/TD]
[TD="width: 139"] Pennsylvania
[/TD]
[TD="width: 139"] Rhode Island
[/TD]

[TD="width: 139"] South Carolina
[/TD]
[TD="width: 139"] South Dakota
[/TD]
[TD="width: 139"] Tennessee
[/TD]
[TD="width: 139"] Texas
[/TD]
[TD="width: 139"] Utah
[/TD]

[TD="width: 139"] Vermont
[/TD]
[TD="width: 139"] Virginia
[/TD]
[TD="width: 139"] Washington
[/TD]
[TD="width: 139"] West Virginia
[/TD]
[TD="width: 139"] Wisconsin
[/TD]

[TD="width: 139"] Wyoming
[/TD]
[TD="width: 139"] New York City
[/TD]
[TD="width: 139"] Puerto Rico
[/TD]
[TD="width: 139"] Virgin Islands
[/TD]
[TD="width: 139"] [/TD]

[FONT=&quot]Google Flu Trends: Google Flu Trends uses aggregated Google search data in a model created in collaboration with CDC to estimate influenza activity in the United States. For more information and activity estimates from the United States and worldwide, see http://www.google.org/flutrends/[/FONT]
[FONT=&quot]World Health Organization: Additional influenza surveillance information from participating WHO member nations is available through FluNet and the Global Epidemiology Reports.[/FONT]
[FONT=&quot]WHO Collaborating Centers for Influenza located in Australia, China, Japan, the United Kingdom, and the United States (CDC in Atlanta, Georgia).[/FONT]
[FONT=&quot]Europe: for the most recent influenza surveillance information from Europe, please see WHO/Europe at http://www.flunewseurope.org/ and visit the European Centre for Disease Prevention and Control at http://ecdc.europa.eu/en/publicatio...s/weekly_influenza_surveillance_overview.aspx[/FONT]
[FONT=&quot]Public Health Agency of Canada: The most up-to-date influenza information from Canada is available at http://www.phac-aspc.gc.ca/fluwatch/[/FONT]
[FONT=&quot]Public Health England: The most up-to-date influenza information from the United Kingdom is available at https://www.gov.uk/government/statistics/weekly-national-flu-reports[/FONT]
[FONT=&quot] [/FONT]

[FONT=&quot] [/FONT]
Any links provided to non-Federal organizations are provided solely as a service to our users. These links do not constitute an endorsement of these organizations or their programs by CDC or the Federal Government, and none should be inferred. CDC is not responsible for the content of the individual organization web pages found at these links. [FONT=&quot] [/FONT]
[FONT=&quot]In addition to the eight data components of CDC influenza surveillance for the 2016-2017 influenza season, the use of National Center for Health Statistics (NCHS) pneumonia and influenza mortality surveillance data for the rapid assessment of influenza-associated mortality will be piloted. An overview of influenza surveillance, including a description of the NCHS mortality surveillance data, is available here.

http://www.cdc.gov/flu/weekly/weeklyarchives2016-2017/Week40.htm
[/FONT]
 
[h=3]2016-2017 Influenza Season Week 41 ending October 15, 2016[/h] [FONT=&quot]All data are preliminary and may change as more reports are received.[/FONT]
[h=3]Synopsis:[/h] [FONT=&quot]During week 41 (October 9-15, 2016), influenza activity was low in the United States.[/FONT]
  • Viral Surveillance: The most frequently identified influenza virus type reported by public health laboratories during week 41 was influenza A. The percentage of respiratory specimens testing positive for influenza in clinical laboratories is low.
  • Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was below the system-specific epidemic threshold in the National Center for Health Statistics (NCHS) Mortality Surveillance System.
  • Influenza-associated Pediatric Deaths: No influenza-associated pediatric deaths were reported.
  • Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 1.2%, which is below the national baseline of 2.2%. All 10 regions reported ILI below region-specific baseline levels. Puerto Rico experienced low ILI activity, New York City and 50 states experienced minimal ILI activity, and the District of Columbia had insufficient data.
  • Geographic Spread of Influenza: The geographic spread of influenza in Guam was reported as widespread; one state reported local activity; the District of Columbia, the U.S. Virgin Islands and 41 states reported sporadic activity; eight states reported no activity; and Puerto Rico did not report.
[h=3]National and Regional Summary of Select Surveillance Components[/h]
[FONT=&quot] [TABLE="class: table table-bordered opt-in"]
[TR]
[/TR]
[TR]
HHS Surveillance Regions* Data for current week Data cumulative since October 2, 2016 (week 40) [/TR]
[TR]
Out-patient ILI[SUP]?[/SUP] Number of jurisdictions reporting regional or widespread activity[SUP]?[/SUP] % respiratory specimens positive for flu in clinical laboratories[SUP]?[/SUP] A(H1N1)pdm09 A (H3) A (Subtyping not Performed) B Victoria lineage B Yamagata lineage B lineage not performed Pediatric Deaths [/TR]
[TR]
Influenza test results from public health laboratories only [/TR]
[TR]
Nation [TD]Normal[/TD]
[TD]1 of 54[/TD]
[TD]1.3%[/TD]
[TD]9[/TD]
[TD]54[/TD]
[TD]7[/TD]
[TD]1[/TD]
[TD]0[/TD]
[TD]5[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 1 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]0.7%[/TD]
[TD]0[/TD]
[TD]8[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 2 [TD]Normal[/TD]
[TD]0 of 4[/TD]
[TD]0.7%[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 3 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]0.6%[/TD]
[TD]2[/TD]
[TD]1[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 4 [TD]Normal[/TD]
[TD]0 of 8[/TD]
[TD]4.0%[/TD]
[TD]0[/TD]
[TD]4[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]2[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 5 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]0.5%[/TD]
[TD]0[/TD]
[TD]8[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 6 [TD]Normal[/TD]
[TD]0 of 5[/TD]
[TD]0.7%[/TD]
[TD]1[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 7 [TD]Normal[/TD]
[TD]0 of 4[/TD]
[TD]<0.1%[/TD]
[TD]0[/TD]
[TD]2[/TD]
[TD]1[/TD]
[TD]1[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 8 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]0.9%[/TD]
[TD]6[/TD]
[TD]3[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 9 [TD]Normal[/TD]
[TD]1 of 4[/TD]
[TD]1.0%[/TD]
[TD]0[/TD]
[TD]16[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 10 [TD]Normal[/TD]
[TD]0 of 4[/TD]
[TD]2.0%[/TD]
[TD]0[/TD]
[TD]12[/TD]
[TD]6[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]0[/TD]
[/TR]
[/TABLE]
[/FONT]
[FONT=&quot]*HHS regions (Region 1 CT, ME, MA, NH, RI, VT; Region 2: NJ, NY, Puerto Rico, US Virgin Islands; Region 3: DE, DC, MD, PA, VA, WV; Region 4: AL, FL, GA, KY, MS, NC, SC, TN; Region 5: IL, IN, MI, MN, OH, WI; Region 6: AR, LA, NM, OK, TX; Region 7: IA, KS, MO, NE; Region 8: CO, MT, ND, SD, UT, WY; Region 9: AZ, CA, Guam, HI, NV; and Region 10: AK, ID, OR, WA).
? Elevated means the % of visits for ILI is at or above the national or region-specific baseline
§ Includes all 50 states, the District of Columbia, Guam, Puerto Rico, and U.S. Virgin Islands
? National data are for current week; regional data are for the most recent three weeks

[/FONT]

[h=2]U.S. Virologic Surveillance:[/h] [FONT=&quot]WHO and NREVSS collaborating laboratories, which include both public health and clinical laboratories located in all 50 states, Puerto Rico, and the District of Columbia, report to CDC the total number of respiratory specimens tested for influenza and the number positive for influenza by virus type. In addition, public health laboratories also report the influenza A subtype (H1 or H3) and influenza B lineage information of the viruses they test and the age or age group of the persons from whom the specimens were collected.[/FONT]
[FONT=&quot]Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html and http://gis.cdc.gov/grasp/fluview/flu_by_age_virus.html.[/FONT]
[FONT=&quot]The results of tests performed by clinical laboratories during the current week are summarized below.[/FONT]
[TABLE="class: table table-bordered table-condensed opt-in"]
[TR]
[TD="width: 200"] [/TD]
Week 41 Data Cumulative since
October 2, 2016 (Week 40) [/TR]
[TR]
No. of specimens tested [TD]9,677[/TD]
[TD]21,483[/TD]
[/TR]
[TR]
No. of positive specimens (%) [TD]128 (1.3%)[/TD]
[TD]327 (1.5%)[/TD]
[/TR]
[TR]
Positive specimens by type [TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
Influenza A [TD]77 (60.2%)[/TD]
[TD]185 (56.6%)[/TD]
[/TR]
[TR]
Influenza B [TD]51 (39.8%)[/TD]
[TD]142 (43.4%)[/TD]
[/TR]
[/TABLE]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation
[FONT=&quot]The results of tests performed by public health laboratories, as well as the age group distribution of influenza positive tests, during the current week are summarized below.[/FONT]
[TABLE="class: table table-bordered table-condensed opt-in"]
[TR]
[TD] [/TD]
Week 41 Data Cumulative since
October 2, 2016 (Week 40) [/TR]
[TR]
No. of specimens tested [TD]404[/TD]
[TD]1,049[/TD]
[/TR]
[TR]
No. of positive specimens [TD]23[/TD]
[TD]76[/TD]
[/TR]
[TR]
Positive specimens by type/subtype [TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
Influenza A [TD]20 (87.0%)[/TD]
[TD]70 (92.1%)[/TD]
[/TR]
[TR]
A(H1N1)pmd09 [TD]4 (20.0%)[/TD]
[TD]9 (13.0%)[/TD]
[/TR]
[TR]
H3 [TD]10 (50.0%)[/TD]
[TD]54 (77.1%)[/TD]
[/TR]
[TR]
Subtyping not performed [TD]6 (30.0%)[/TD]
[TD]7 (10.0%)[/TD]
[/TR]
[TR]
Influenza B [TD]3 (13.0%)[/TD]
[TD]6 (7.9%)[/TD]
[/TR]
[TR]
Yamagata lineage [TD]0 (0%)[/TD]
[TD]0 (0%)[/TD]
[/TR]
[TR]
Victoria lineage [TD]0 (0%)[/TD]
[TD]1 (16.7%)[/TD]
[/TR]
[TR]
Lineage not performed [TD]3 (100%)[/TD]
[TD]5 (83.3%)[/TD]
[/TR]
[/TABLE]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation


View Interactive Application | View Full Screen
[h=2]Influenza Virus Characterization:[/h] [FONT=&quot]CDC characterizes influenza viruses through one or more tests including genomic sequencing, hemagglutination inhibition (HI) and/or neutralization assays. These data are used to compare how similar currently circulating influenza viruses are to the reference viruses used for developing influenza vaccines, and to monitor for changes in circulating influenza viruses. Historically, HI data have been used most commonly to assess the similarity between reference viruses and circulating viruses to suggest how well the vaccine may work until such a time as vaccine effectiveness estimates are available.[/FONT]
[FONT=&quot]For nearly all virus positive surveillance samples received at CDC, next-generation sequencing is performed to ascertain genomic data of circulating influenza viruses. Viruses can be classified into genetic groups/clades based on analysis of their HA gene segments using phylogenetics and key amino acid changes (Klimov Vaccine 2012).[/FONT]
[FONT=&quot]No characterization data is currently available for specimens collected after October 1, 2016.[/FONT]
[h=2]Genetic Characterization[/h] [FONT=&quot]During May 22 – October 15, 2016, 1,214 influenza positive specimens were collected and reported by public health laboratories in the United States (figure, left). CDC genetically characterized 195 influenza viruses [18 influenza A (H1N1)pdm09, 111 influenza A (H3N2), and 66 influenza B viruses] collected by U.S. laboratories. The HA gene segment of all influenza A (H1N1)pdm09 viruses analyzed belonged to genetic group 6B.1. Influenza A (H3N2) virus HA gene segments analyzed belonged to genetic groups 3C.2a or 3C.3a. Genetic group 3C.2a includes a newly emerging subgroup known as 3C.2a1. The HA of influenza B/Victoria-lineage viruses all belonged to genetic group V1A. The HA of influenza B/Yamagata-lineage viruses analyzed all belonged to genetic group Y3.[/FONT]
[FONT=&quot]The majority of U.S. viruses submitted for characterization come from state and local public health laboratories. Specimen submission guidance issued to the laboratories request that, if available, 2 influenza A (H1N1), 2 A influenza (H3N2), and 2 influenza B viruses be submitted every other week. Because of this, the number of each virus type/subtype characterized should be approximately equal. In the figure below, the results of tests performed by public health labs are presented on the left and sequence results by genetic group of specimens submitted to CDC are presented on the right.[/FONT]
Genetic41_small.gif

View Chart Data | View Full Screen | View PowerPoint Presentation
[h=2]Antigenic Characterization[/h] [FONT=&quot]During May 22 – September 30, 2016, CDC has antigenically characterized 133 influenza viruses [8 influenza A (H1N1)pdm09, 62 influenza A (H3N2), and 63 influenza B viruses] collected by U.S. laboratories.[/FONT]
[FONT=&quot]Influenza A Virus [70][/FONT]
  • A (H1N1)pdm09 [8]: All 8 (100%) influenza A (H1N1)pdm09 viruses were antigenically characterized using ferret post-infection antisera as A/California/7/2009-like, the influenza A (H1N1) component of the 2016-2017 Northern Hemisphere vaccine.
  • A (H3N2) [62]: 50 (80.1%) of 62 influenza A (H3N2) viruses were antigenically characterized as A/Hong Kong/4801/2014-like, a virus that belongs in genetic group 3C.2a and is the influenza A (H3N2) component of the 2016-2017 Northern Hemisphere vaccine, by HI testing or neutralization testing. Among the viruses which reacted poorly with ferret antisera raised against A/Hong Kong/4801/2014-like viruses, 11 of 12 (91.7%) are more closely related to A/Switzerland/9715293/2013), a virus belonging to genetic group 3C.3a.
[FONT=&quot]Influenza B Virus [63][/FONT]
  • Victoria Lineage [30]: All 30 (100%) B/Victoria-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Brisbane/60/2008-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere trivalent and quadrivalent influenza vaccines.
  • Yamagata Lineage [33]: All 33 (100%) B/Yamagata-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Phuket/3073/2013-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere quadrivalent influenza vaccines.
[h=2]Antiviral Resistance:[/h] [FONT=&quot]No antiviral resistance data is available for specimens collected after October 1, 2016.[/FONT]
[FONT=&quot]During May 22-Septemer 30, 2016, 191 specimens (18 influenza A (H1N1)pdm09, 107 influenza A (H3N2), and 66 influenza B viruses) collected in the United States were tested for susceptibility to the neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir). Among the 18 influenza A (H1N1)pdm09 viruses tested for oseltamivir and peramivir, one (5.6%) was resistant to both drugs. A total of 14 influenza A (H1N1)pdm09 viruses were tested for zanamivir susceptibility and all were susceptible. None of the 107 influenza A (H3) and 66 influenza B viruses were found to be resistant to either oseltamivir, zanamivir, or peramivir.[/FONT]
[FONT=&quot]The majority of recently circulating influenza viruses are susceptible to the neuraminidase inhibitor antiviral medications, oseltamivir, zanamivir, and peramivir; however, rare sporadic instances of oseltamivir-resistant and peramivir-resistant influenza A (H1N1)pdm09 viruses and oseltamivir-resistant influenza A (H3N2) viruses have been detected worldwide. Antiviral treatment as early as possible is recommended for patients with confirmed or suspected influenza who have severe, complicated, or progressive illness; who require hospitalization; or who are at high risk for serious influenza-related complications. Additional information on recommendations for treatment and chemoprophylaxis of influenza virus infection with antiviral agents is available at http://www.cdc.gov/flu/antivirals/index.htm.[/FONT]



[h=2]Pneumonia and Influenza (P&I) Mortality Surveillance:[/h] [FONT=&quot]Based on National Center for Health Statistics (NCHS) mortality surveillance data available on October 19, 2016, 5.4% of the deaths occurring during the week ending October 1, 2016 (week 39) were due to P&I. This percentage is below the epidemic threshold of 6.4% for week 39.[/FONT]
[FONT=&quot]P&I percentages for recent weeks may be artificially low due to a backlog of records requiring manual processing. Percentages will likely increase to levels more similar to the baseline as more data becomes available.[/FONT]
[FONT=&quot]Region and state-specific data are available at http://gis.cdc.gov/grasp/fluview/mortality.html.[/FONT]
NCHS41_small.gif

View Regional and State Level Data | View Chart Data | View Full Screen

[h=2]Influenza-Associated Pediatric Mortality:[/h] [FONT=&quot]No influenza-associated pediatric deaths were reported to CDC during week 41.[/FONT]
[FONT=&quot]Additional data can be found at: [/FONT]http://gis.cdc.gov/GRASP/Fluview/PedFluDeath.html[FONT=&quot].[/FONT] [FONT=&quot] [/FONT]

View Interactive Application | View Full Screen | View PowerPoint Presentation


[h=2]Influenza-Associated Hospitalizations:[/h] [FONT=&quot]The Influenza Hospitalization Surveillance Network (FluSurv-NET) conducts population-based surveillance for laboratory-confirmed influenza-related hospitalizations in select counties in the Emerging Infections Program (EIP) states and Influenza Hospitalization Surveillance Project (IHSP) states. FluSurv-NET estimated hospitalization rates will be updated weekly starting later this season. Additional FluSurv-NET data can be found at: http://gis.cdc.gov/GRASP/Fluview/FluHospRates.html and http://gis.cdc.gov/grasp/fluview/FluHospChars.html.[/FONT]



[h=2]Outpatient Illness Surveillance:[/h] [FONT=&quot]Nationwide during week 41, 1.2% of patient visits reported through the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) were due to influenza-like illness (ILI). This percentage is below the national baseline of 2.2%.[/FONT]
[FONT=&quot](ILI is defined as fever (temperature of 100°F [37.8°C] or greater) and cough and/or sore throat.)[/FONT]
[FONT=&quot]Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html.[/FONT]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation
[FONT=&quot]On a regional level, the percentage of outpatient visits for ILI ranged from 0.5% to 2.1% during week 41. All 10 regions reported a proportion of outpatient visits for ILI below their region-specific baseline levels.[/FONT]
[FONT=&quot]

[/FONT]

[h=2]ILINet State Activity Indicator Map:[/h] [FONT=&quot]Data collected in ILINet are used to produce a measure of ILI activity* by state. Activity levels are based on the percent of outpatient visits in a state due to ILI and are compared to the average percent of ILI visits that occur during weeks with little or no influenza virus circulation. Activity levels range from minimal, which would correspond to ILI activity from outpatient clinics being below, or only slightly above, the average, to high, which would correspond to ILI activity from outpatient clinics being much higher than average.[/FONT]
[FONT=&quot]During week 41, the following ILI activity levels were experienced:[/FONT]
  • Puerto Rico experienced low ILI activity.
  • New York City and all 50 states experienced minimal ILI activity.
  • Data were insufficient to calculate an ILI activity level from the District of Columbia.
[FONT=&quot][/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]Click on map to launch interactive tool[/FONT]
[FONT=&quot]*This map uses the proportion of outpatient visits to health care providers for ILI to measure the ILI activity level within a state. It does not, however, measure the extent of geographic spread of flu within a state. Therefore, outbreaks occurring in a single city could cause the state to display high activity levels.
Data collected in ILINet may disproportionally represent certain populations within a state, and therefore, may not accurately depict the full picture of influenza activity for the whole state.
Data displayed in this map are based on data collected in ILINet, whereas the State and Territorial flu activity map is based on reports from state and territorial epidemiologists. The data presented in this map is preliminary and may change as more data are received.
Differences in the data presented here by CDC and independently by some state health departments likely represent differing levels of data completeness with data presented by the state likely being the more complete.[/FONT]



[h=2]Geographic Spread of Influenza as Assessed by State and Territorial Epidemiologists[/h] [FONT=&quot]The influenza activity reported by state and territorial epidemiologists indicates geographic spread of influenza viruses, but does not measure the severity of influenza activity.[/FONT]
[FONT=&quot]During week 41, the following influenza activity was reported:[/FONT]
  • Widespread influenza activity was reported by Guam.
  • Local influenza activity was reported by one state (New Hampshire).
  • Sporadic influenza activity was reported by the District of Columbia, the U.S. Virgin Islands and 41 states (Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Florida, Georgia, Hawaii, Idaho, Indiana, Iowa, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nevada, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, and Wyoming).
  • No activity was reported by eight states (Alabama, Delaware, Illinois, Kansas, Mississippi, Nebraska, Rhode Island, and South Carolina).
  • Puerto Rico did not report.
[FONT=&quot][/FONT]


[FONT=&quot] [/FONT]
[h=2]Additional National and International Influenza Surveillance Information[/h] [FONT=&quot]FluView Interactive: FluView includes enhanced web-based interactive applications that can provide dynamic visuals of the influenza data collected and analyzed by CDC. These FluView Interactive applications allow people to create customized, visual interpretations of influenza data, as well as make comparisons across flu seasons, regions, age groups and a variety of other demographics. To access these tools, visit http://www.cdc.gov/flu/weekly/fluviewinteractive.htm.[/FONT]
[FONT=&quot]U.S. State and local influenza surveillance: Click on a jurisdiction below to access the latest local influenza information.[/FONT]
[FONT=&quot] [/FONT]

[TD="width: 139"] Alabama
[/TD]
[TD="width: 139"] Alaska
[/TD]
[TD="width: 139"] Arizona
[/TD]
[TD="width: 139"] Arkansas
[/TD]
[TD="width: 139"] California
[/TD]

[TD="width: 139"] Colorado
[/TD]
[TD="width: 139"] Connecticut
[/TD]
[TD="width: 139"] Delaware
[/TD]
[TD="width: 139"] District of Columbia
[/TD]
[TD="width: 139"] Florida
[/TD]

[TD="width: 139"] Georgia
[/TD]
[TD="width: 139"] Hawaii
[/TD]
[TD="width: 139"] Idaho
[/TD]
[TD="width: 139"] Illinois
[/TD]
[TD="width: 139"] Indiana
[/TD]

[TD="width: 139"] Iowa
[/TD]
[TD="width: 139"] Kansas
[/TD]
[TD="width: 139"] Kentucky
[/TD]
[TD="width: 139"] Louisiana
[/TD]
[TD="width: 139"] Maine
[/TD]

[TD="width: 139"] Maryland
[/TD]
[TD="width: 139"] Massachusetts
[/TD]
[TD="width: 139"] Michigan
[/TD]
[TD="width: 139"] Minnesota
[/TD]
[TD="width: 139"] Mississippi
[/TD]

[TD="width: 139"] Missouri
[/TD]
[TD="width: 139"] Montana
[/TD]
[TD="width: 139"] Nebraska
[/TD]
[TD="width: 139"] Nevada
[/TD]
[TD="width: 139"] New Hampshire
[/TD]

[TD="width: 139"] New Jersey
[/TD]
[TD="width: 139"] New Mexico
[/TD]
[TD="width: 139"] New York
[/TD]
[TD="width: 139"] North Carolina
[/TD]
[TD="width: 139"] North Dakota
[/TD]

[TD="width: 139"] Ohio
[/TD]
[TD="width: 139"] Oklahoma
[/TD]
[TD="width: 139"] Oregon
[/TD]
[TD="width: 139"] Pennsylvania
[/TD]
[TD="width: 139"] Rhode Island
[/TD]

[TD="width: 139"] South Carolina
[/TD]
[TD="width: 139"] South Dakota
[/TD]
[TD="width: 139"] Tennessee
[/TD]
[TD="width: 139"] Texas
[/TD]
[TD="width: 139"] Utah
[/TD]

[TD="width: 139"] Vermont
[/TD]
[TD="width: 139"] Virginia
[/TD]
[TD="width: 139"] Washington
[/TD]
[TD="width: 139"] West Virginia
[/TD]
[TD="width: 139"] Wisconsin
[/TD]

[TD="width: 139"] Wyoming
[/TD]
[TD="width: 139"] New York City
[/TD]
[TD="width: 139"] Puerto Rico
[/TD]
[TD="width: 139"] Virgin Islands
[/TD]
[TD="width: 139"] [/TD]

[FONT=&quot]Google Flu Trends: Google Flu Trends uses aggregated Google search data in a model created in collaboration with CDC to estimate influenza activity in the United States. For more information and activity estimates from the United States and worldwide, see http://www.google.org/flutrends/[/FONT]
[FONT=&quot]World Health Organization: Additional influenza surveillance information from participating WHO member nations is available through FluNet and the Global Epidemiology Reports.[/FONT]
[FONT=&quot]WHO Collaborating Centers for Influenza located in Australia, China, Japan, the United Kingdom, and the United States (CDC in Atlanta, Georgia).[/FONT]
[FONT=&quot]Europe: for the most recent influenza surveillance information from Europe, please see WHO/Europe at http://www.flunewseurope.org/ and visit the European Centre for Disease Prevention and Control at http://ecdc.europa.eu/en/publicatio...s/weekly_influenza_surveillance_overview.aspx[/FONT]
[FONT=&quot]Public Health Agency of Canada: The most up-to-date influenza information from Canada is available at http://www.phac-aspc.gc.ca/fluwatch/[/FONT]
[FONT=&quot]Public Health England: The most up-to-date influenza information from the United Kingdom is available at https://www.gov.uk/government/statistics/weekly-national-flu-reports[/FONT]
[FONT=&quot] [/FONT]

[FONT=&quot] [/FONT]
Any links provided to non-Federal organizations are provided solely as a service to our users. These links do not constitute an endorsement of these organizations or their programs by CDC or the Federal Government, and none should be inferred. CDC is not responsible for the content of the individual organization web pages found at these links. [FONT=&quot] [/FONT]
[FONT=&quot]An overview of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component, is available at: http://www.cdc.gov/flu/weekly/overview.htm.[/FONT]


http://www.cdc.gov/flu/weekly/weeklyarchives2016-2017/Week41.htm
 
[h=3]2016-2017 Influenza Season Week 42 ending October 22, 2016[/h] [FONT=&quot]All data are preliminary and may change as more reports are received.[/FONT]
[h=3]Synopsis:[/h] [FONT=&quot]During week 42 (October 16-22, 2016), influenza activity was low in the United States.[/FONT]
  • Viral Surveillance: The most frequently identified influenza virus type reported by public health laboratories during week 42 was influenza A. The percentage of respiratory specimens testing positive for influenza in clinical laboratories was low.
  • Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was below the system-specific epidemic threshold in the National Center for Health Statistics (NCHS) Mortality Surveillance System.
  • Influenza-associated Pediatric Deaths: No influenza-associated pediatric deaths were reported.
  • Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 1.3%, which is below the national baseline of 2.2%. All 10 regions reported ILI below region-specific baseline levels. New York City, Puerto Rico, and all 50 states experienced minimal ILI activity and the District of Columbia had insufficient data.
  • Geographic Spread of Influenza: The geographic spread of influenza in Guam was reported as widespread; Puerto Rico reported regional activity; one state reported local activity; the District of Columbia, the U.S. Virgin Islands and 41 states reported sporadic activity; and eight states reported no activity.
[h=3]National and Regional Summary of Select Surveillance Components[/h]
[FONT=&quot] [TABLE="class: table table-bordered opt-in"]
[TR]
[/TR]
[TR]
HHS Surveillance Regions* Data for current week Data cumulative since October 2, 2016 (week 40) [/TR]
[TR]
Out-patient ILI[SUP]?[/SUP] Number of jurisdictions reporting regional or widespread activity[SUP]?[/SUP] % respiratory specimens positive for flu in clinical laboratories[SUP]?[/SUP] A(H1N1)pdm09 A (H3) A (Subtyping not Performed) B Victoria lineage B Yamagata lineage B lineage not performed Pediatric Deaths [/TR]
[TR]
Influenza test results from public health laboratories only [/TR]
[TR]
Nation [TD]Normal[/TD]
[TD]2 of 54[/TD]
[TD]1.6%[/TD]
[TD]17[/TD]
[TD]92[/TD]
[TD]13[/TD]
[TD]3[/TD]
[TD]4[/TD]
[TD]5[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 1 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]0.6%[/TD]
[TD]0[/TD]
[TD]10[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 2 [TD]Normal[/TD]
[TD]1 of 4[/TD]
[TD]0.9%[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 3 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]0.6%[/TD]
[TD]2[/TD]
[TD]1[/TD]
[TD]1[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 4 [TD]Normal[/TD]
[TD]0 of 8[/TD]
[TD]3.8%[/TD]
[TD]0[/TD]
[TD]10[/TD]
[TD]5[/TD]
[TD]1[/TD]
[TD]2[/TD]
[TD]2[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 5 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]0.7%[/TD]
[TD]0[/TD]
[TD]18[/TD]
[TD]1[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 6 [TD]Normal[/TD]
[TD]0 of 5[/TD]
[TD]1.6%[/TD]
[TD]2[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 7 [TD]Normal[/TD]
[TD]0 of 4[/TD]
[TD]<0.1%[/TD]
[TD]0[/TD]
[TD]4[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 8 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]0.9%[/TD]
[TD]11[/TD]
[TD]5[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 9 [TD]Normal[/TD]
[TD]1 of 4[/TD]
[TD]1.0%[/TD]
[TD]2[/TD]
[TD]22[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]1[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 10 [TD]Normal[/TD]
[TD]0 of 4[/TD]
[TD]2.2%[/TD]
[TD]0[/TD]
[TD]22[/TD]
[TD]6[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]0[/TD]
[/TR]
[/TABLE]
[/FONT]
[FONT=&quot]*HHS regions (Region 1 CT, ME, MA, NH, RI, VT; Region 2: NJ, NY, Puerto Rico, US Virgin Islands; Region 3: DE, DC, MD, PA, VA, WV; Region 4: AL, FL, GA, KY, MS, NC, SC, TN; Region 5: IL, IN, MI, MN, OH, WI; Region 6: AR, LA, NM, OK, TX; Region 7: IA, KS, MO, NE; Region 8: CO, MT, ND, SD, UT, WY; Region 9: AZ, CA, Guam, HI, NV; and Region 10: AK, ID, OR, WA).
? Elevated means the % of visits for ILI is at or above the national or region-specific baseline
§ Includes all 50 states, the District of Columbia, Guam, Puerto Rico, and U.S. Virgin Islands
? National data are for current week; regional data are for the most recent three weeks

[/FONT]

[h=2]U.S. Virologic Surveillance:[/h] [FONT=&quot]WHO and NREVSS collaborating laboratories, which include both public health and clinical laboratories located in all 50 states, Puerto Rico, and the District of Columbia, report to CDC the total number of respiratory specimens tested for influenza and the number positive for influenza by virus type. In addition, public health laboratories also report the influenza A subtype (H1 or H3) and influenza B lineage information for the viruses they test and the age or age group of the persons from whom the specimens were collected.[/FONT]
[FONT=&quot]Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html and http://gis.cdc.gov/grasp/fluview/flu_by_age_virus.html.[/FONT]
[FONT=&quot]The results of tests performed by clinical laboratories during the current week are summarized below.[/FONT]
[TABLE="class: table table-bordered table-condensed opt-in"]
[TR]
[TD="width: 200"] [/TD]
Week 42 Data Cumulative since
October 2, 2016 (Week 40) [/TR]
[TR]
No. of specimens tested [TD]10,837[/TD]
[TD]35,844[/TD]
[/TR]
[TR]
No. of positive specimens (%) [TD]176 (1.6%)[/TD]
[TD]555 (1.6%)[/TD]
[/TR]
[TR]
Positive specimens by type [TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
Influenza A [TD]94 (53.4%)[/TD]
[TD]311 (56.0%)[/TD]
[/TR]
[TR]
Influenza B [TD]82 (46.6%)[/TD]
[TD]244 (44.0%)[/TD]
[/TR]
[/TABLE]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation
[FONT=&quot]The results of tests performed by public health laboratories, as well as the age group distribution of influenza positive tests, during the current week are summarized below.[/FONT]
[TABLE="class: table table-bordered table-condensed opt-in"]
[TR]
[TD] [/TD]
Week 42 Data Cumulative since
October 2, 2016 (Week 40) [/TR]
[TR]
No. of specimens tested [TD]400[/TD]
[TD]1,691[/TD]
[/TR]
[TR]
No. of positive specimens [TD]27[/TD]
[TD]134[/TD]
[/TR]
[TR]
Positive specimens by type/subtype [TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
Influenza A [TD]25 (92.6%)[/TD]
[TD]122 (91.0%)[/TD]
[/TR]
[TR]
A(H1N1)pmd09 [TD]6 (24.0%)[/TD]
[TD]17 (13.9%)[/TD]
[/TR]
[TR]
H3 [TD]18 (72.0%)[/TD]
[TD]92 (75.4%)[/TD]
[/TR]
[TR]
Subtyping not performed [TD]1 (4.0%)[/TD]
[TD]13 (10.7%)[/TD]
[/TR]
[TR]
Influenza B [TD]2 (7.4%)[/TD]
[TD]12 (9.0%)[/TD]
[/TR]
[TR]
Yamagata lineage [TD]1 (50.0%)[/TD]
[TD]4 (33.3%)[/TD]
[/TR]
[TR]
Victoria lineage [TD]1 (50.0%)[/TD]
[TD]3 (25.0%)[/TD]
[/TR]
[TR]
Lineage not performed [TD]0 (0%)[/TD]
[TD]5 (41.7%)[/TD]
[/TR]
[/TABLE]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation


View Interactive Application | View Full Screen
[h=2]Influenza Virus Characterization:[/h] [FONT=&quot]CDC characterizes influenza viruses through one or more tests including genomic sequencing, hemagglutination inhibition (HI) and/or neutralization assays. These data are used to compare how similar currently circulating influenza viruses are to the reference viruses used for developing influenza vaccines, and to monitor for changes in circulating influenza viruses. Historically, HI data have been used most commonly to assess the similarity between reference viruses and circulating viruses to suggest how well the vaccine may work until such a time as vaccine effectiveness estimates are available.[/FONT]
[FONT=&quot]For nearly all virus positive surveillance samples received at CDC, next-generation sequencing is performed to ascertain genomic data of circulating influenza viruses. Viruses can be classified into genetic groups/clades based on analysis of their HA gene segments using phylogenetics and key amino acid changes (Klimov Vaccine 2012).[/FONT]
[h=2]Genetic Characterization[/h] [FONT=&quot]During May 22 – October 22, 2016, 1,297 influenza positive specimens were collected and reported by public health laboratories in the United States (figure, left). CDC genetically characterized 250 influenza viruses [21 influenza A (H1N1)pdm09, 152 influenza A (H3N2), and 77 influenza B viruses] collected by U.S. laboratories. The HA gene segment of all influenza A (H1N1)pdm09 viruses analyzed belonged to genetic group 6B.1. Influenza A (H3N2) virus HA gene segments analyzed belonged to genetic groups 3C.2a or 3C.3a. Genetic group 3C.2a includes a newly emerging subgroup known as 3C.2a1. The HA of influenza B/Victoria-lineage viruses all belonged to genetic group V1A. The HA of influenza B/Yamagata-lineage viruses analyzed all belonged to genetic group Y3.[/FONT]
[FONT=&quot]The majority of U.S. viruses submitted for characterization come from state and local public health laboratories. Specimen submission guidance issued to the laboratories request that, if available, 2 influenza A (H1N1), 2 A influenza (H3N2), and 2 influenza B viruses be submitted every other week. Because of this, the number of each virus type/subtype characterized should be approximately equal. In the figure below, the results of tests performed by public health labs are presented on the left and sequence results by genetic group of specimens submitted to CDC are presented on the right.[/FONT]
Genetic42_small.gif

View Chart Data | View Full Screen | View PowerPoint Presentation
[h=2]Antigenic Characterization[/h] [FONT=&quot]During May 22 – October 22, 2016, CDC has antigenically characterized 150 influenza viruses [10 influenza A (H1N1)pdm09, 77 influenza A (H3N2), and 63 influenza B viruses] collected by U.S. laboratories.[/FONT]
[FONT=&quot]Influenza A Virus [87][/FONT]
  • A (H1N1)pdm09 [10]: All 10 (100%) influenza A (H1N1)pdm09 viruses were antigenically characterized using ferret post-infection antisera as A/California/7/2009-like, the influenza A (H1N1) component of the 2016-2017 Northern Hemisphere vaccine.
  • A (H3N2) [77]: 65 (84.4%) of 77 influenza A (H3N2) viruses were antigenically characterized as A/Hong Kong/4801/2014-like, a virus that belongs in genetic group 3C.2a and is the influenza A (H3N2) component of the 2016-2017 Northern Hemisphere vaccine, by HI testing or neutralization testing. Among the viruses which reacted poorly with ferret antisera raised against A/Hong Kong/4801/2014-like viruses, 11 of 12 (91.7%) are more closely related to A/Switzerland/9715293/2013), a virus belonging to genetic group 3C.3a.
[FONT=&quot]Influenza B Virus [63][/FONT]
  • Victoria Lineage [30]: All 30 (100%) B/Victoria-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Brisbane/60/2008-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere trivalent and quadrivalent influenza vaccines.
  • Yamagata Lineage [33]: All 33 (100%) B/Yamagata-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Phuket/3073/2013-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere quadrivalent influenza vaccines.
[FONT=&quot]
[/FONT]

[h=2]Antiviral Resistance:[/h] [FONT=&quot]No antiviral resistance data is available for specimens collected after October 1, 2016.[/FONT]
[FONT=&quot]During May 22-Septemer 30, 2016, 228 specimens (26 influenza A (H1N1)pdm09, 128 influenza A (H3N2), and 74 influenza B viruses) collected in the United States were tested for susceptibility to the neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir). Among the 26 influenza A (H1N1)pdm09 viruses tested for oseltamivir and peramivir, one (3.8%) was resistant to both drugs. A total of 22 influenza A (H1N1)pdm09 viruses were tested for zanamivir susceptibility and all were susceptible. None of the 128 influenza A (H3) and 74 influenza B viruses were found to be resistant to either oseltamivir, zanamivir, or peramivir.[/FONT]
[FONT=&quot]The majority of recently circulating influenza viruses are susceptible to the neuraminidase inhibitor antiviral medications, oseltamivir, zanamivir, and peramivir; however, rare sporadic instances of oseltamivir-resistant and peramivir-resistant influenza A (H1N1)pdm09 viruses and oseltamivir-resistant influenza A (H3N2) viruses have been detected worldwide. Antiviral treatment as early as possible is recommended for patients with confirmed or suspected influenza who have severe, complicated, or progressive illness; who require hospitalization; or who are at high risk for serious influenza-related complications. Additional information on recommendations for treatment and chemoprophylaxis of influenza virus infection with antiviral agents is available at http://www.cdc.gov/flu/antivirals/index.htm.[/FONT]



[h=2]Pneumonia and Influenza (P&I) Mortality Surveillance:[/h] [FONT=&quot]Based on National Center for Health Statistics (NCHS) mortality surveillance data available on October 26, 2016, 5.3% of the deaths occurring during the week ending October 8, 2016 (week 40) were due to P&I. This percentage is below the epidemic threshold of 6.5% for week 40.[/FONT]
[FONT=&quot]P&I percentages for recent weeks may be artificially low due to a backlog of records requiring manual processing. Percentages will likely increase to levels more similar to the baseline as more data becomes available.[/FONT]
[FONT=&quot]Region and state-specific data are available at http://gis.cdc.gov/grasp/fluview/mortality.html.[/FONT]
NCHS42_small.gif

View Regional and State Level Data | View Chart Data | View Full Screen | View PowerPoint Presentation

[h=2]Influenza-Associated Pediatric Mortality:[/h] [FONT=&quot]No influenza-associated pediatric deaths were reported to CDC during week 42.[/FONT]
[FONT=&quot]Additional data can be found at: [/FONT]http://gis.cdc.gov/GRASP/Fluview/PedFluDeath.html[FONT=&quot].[/FONT] [FONT=&quot] [/FONT]

View Interactive Application | View Full Screen | View PowerPoint Presentation


[h=2]Influenza-Associated Hospitalizations:[/h] [FONT=&quot]The Influenza Hospitalization Surveillance Network (FluSurv-NET) conducts population-based surveillance for laboratory-confirmed influenza-related hospitalizations in select counties in the Emerging Infections Program (EIP) states and Influenza Hospitalization Surveillance Project (IHSP) states. FluSurv-NET estimated hospitalization rates will be updated weekly starting later this season. Additional FluSurv-NET data can be found at: http://gis.cdc.gov/GRASP/Fluview/FluHospRates.html and http://gis.cdc.gov/grasp/fluview/FluHospChars.html.[/FONT]



[h=2]Outpatient Illness Surveillance:[/h] [FONT=&quot]Nationwide during week 42, 1.3% of patient visits reported through the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) were due to influenza-like illness (ILI). This percentage is below the national baseline of 2.2%.[/FONT]
[FONT=&quot](ILI is defined as fever (temperature of 100°F [37.8°C] or greater) and cough and/or sore throat.)[/FONT]
[FONT=&quot]Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html.[/FONT]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation
[FONT=&quot]On a regional level, the percentage of outpatient visits for ILI ranged from 0.5% to 1.8% during week 42. All 10 regions reported a proportion of outpatient visits for ILI below their region-specific baseline levels.[/FONT]
[FONT=&quot]

[/FONT]

[h=2]ILINet State Activity Indicator Map:[/h] [FONT=&quot]Data collected in ILINet are used to produce a measure of ILI activity* by state. Activity levels are based on the percent of outpatient visits in a state due to ILI and are compared to the average percent of ILI visits that occur during weeks with little or no influenza virus circulation. Activity levels range from minimal, which would correspond to ILI activity from outpatient clinics being below, or only slightly above, the average, to high, which would correspond to ILI activity from outpatient clinics being much higher than average.[/FONT]
[FONT=&quot]During week 42, the following ILI activity levels were experienced:[/FONT]
  • New York City, Puerto Rico, and all 50 states experienced minimal ILI activity.
  • Data were insufficient to calculate an ILI activity level from the District of Columbia.
[FONT=&quot][/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]Click on map to launch interactive tool[/FONT]
[FONT=&quot]*This map uses the proportion of outpatient visits to health care providers for ILI to measure the ILI activity level within a state. It does not, however, measure the extent of geographic spread of flu within a state. Therefore, outbreaks occurring in a single city could cause the state to display high activity levels.
Data collected in ILINet may disproportionally represent certain populations within a state, and therefore, may not accurately depict the full picture of influenza activity for the whole state.
Data displayed in this map are based on data collected in ILINet, whereas the State and Territorial flu activity map is based on reports from state and territorial epidemiologists. The data presented in this map is preliminary and may change as more data are received.
Differences in the data presented here by CDC and independently by some state health departments likely represent differing levels of data completeness with data presented by the state likely being the more complete.[/FONT]



[h=2]Geographic Spread of Influenza as Assessed by State and Territorial Epidemiologists[/h] [FONT=&quot]The influenza activity reported by state and territorial epidemiologists indicates geographic spread of influenza viruses, but does not measure the severity of influenza activity.[/FONT]
[FONT=&quot]During week 42, the following influenza activity was reported:[/FONT]
  • Widespread influenza activity was reported by Guam.
  • Regional influenza activity was reported by Puerto Rico.
  • Local influenza activity was reported by one state (Alabama).
  • Sporadic influenza activity was reported by the District of Columbia, the U.S. Virgin Islands and 41 states (Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nevada, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, Utah, Virginia, Washington, Wisconsin, and Wyoming).
  • No activity was reported by eight states (Idaho, Illinois, Mississippi, Nebraska, New Hampshire, Rhode Island, Vermont, and West Virginia).
[FONT=&quot][/FONT]


[FONT=&quot] [/FONT]
[h=2]Additional National and International Influenza Surveillance Information[/h] [FONT=&quot]FluView Interactive: FluView includes enhanced web-based interactive applications that can provide dynamic visuals of the influenza data collected and analyzed by CDC. These FluView Interactive applications allow people to create customized, visual interpretations of influenza data, as well as make comparisons across flu seasons, regions, age groups and a variety of other demographics. To access these tools, visit http://www.cdc.gov/flu/weekly/fluviewinteractive.htm.[/FONT]
[FONT=&quot]U.S. State and local influenza surveillance: Click on a jurisdiction below to access the latest local influenza information.[/FONT]
[FONT=&quot] [/FONT]

[TD="width: 139"] Alabama
[/TD]
[TD="width: 139"] Alaska
[/TD]
[TD="width: 139"] Arizona
[/TD]
[TD="width: 139"] Arkansas
[/TD]
[TD="width: 139"] California
[/TD]

[TD="width: 139"] Colorado
[/TD]
[TD="width: 139"] Connecticut
[/TD]
[TD="width: 139"] Delaware
[/TD]
[TD="width: 139"] District of Columbia
[/TD]
[TD="width: 139"] Florida
[/TD]

[TD="width: 139"] Georgia
[/TD]
[TD="width: 139"] Hawaii
[/TD]
[TD="width: 139"] Idaho
[/TD]
[TD="width: 139"] Illinois
[/TD]
[TD="width: 139"] Indiana
[/TD]

[TD="width: 139"] Iowa
[/TD]
[TD="width: 139"] Kansas
[/TD]
[TD="width: 139"] Kentucky
[/TD]
[TD="width: 139"] Louisiana
[/TD]
[TD="width: 139"] Maine
[/TD]

[TD="width: 139"] Maryland
[/TD]
[TD="width: 139"] Massachusetts
[/TD]
[TD="width: 139"] Michigan
[/TD]
[TD="width: 139"] Minnesota
[/TD]
[TD="width: 139"] Mississippi
[/TD]

[TD="width: 139"] Missouri
[/TD]
[TD="width: 139"] Montana
[/TD]
[TD="width: 139"] Nebraska
[/TD]
[TD="width: 139"] Nevada
[/TD]
[TD="width: 139"] New Hampshire
[/TD]

[TD="width: 139"] New Jersey
[/TD]
[TD="width: 139"] New Mexico
[/TD]
[TD="width: 139"] New York
[/TD]
[TD="width: 139"] North Carolina
[/TD]
[TD="width: 139"] North Dakota
[/TD]

[TD="width: 139"] Ohio
[/TD]
[TD="width: 139"] Oklahoma
[/TD]
[TD="width: 139"] Oregon
[/TD]
[TD="width: 139"] Pennsylvania
[/TD]
[TD="width: 139"] Rhode Island
[/TD]

[TD="width: 139"] South Carolina
[/TD]
[TD="width: 139"] South Dakota
[/TD]
[TD="width: 139"] Tennessee
[/TD]
[TD="width: 139"] Texas
[/TD]
[TD="width: 139"] Utah
[/TD]

[TD="width: 139"] Vermont
[/TD]
[TD="width: 139"] Virginia
[/TD]
[TD="width: 139"] Washington
[/TD]
[TD="width: 139"] West Virginia
[/TD]
[TD="width: 139"] Wisconsin
[/TD]

[TD="width: 139"] Wyoming
[/TD]
[TD="width: 139"] New York City
[/TD]
[TD="width: 139"] Puerto Rico
[/TD]
[TD="width: 139"] Virgin Islands
[/TD]
[TD="width: 139"] [/TD]

[FONT=&quot]World Health Organization: Additional influenza surveillance information from participating WHO member nations is available through FluNet and the Global Epidemiology Reports.[/FONT]
[FONT=&quot]WHO Collaborating Centers for Influenza located in Australia, China, Japan, the United Kingdom, and the United States (CDC in Atlanta, Georgia).[/FONT]
[FONT=&quot]Europe: For the most recent influenza surveillance information from Europe, please see WHO/Europe and the European Centre for Disease Prevention and Control at http://www.flunewseurope.org/.[/FONT]
[FONT=&quot]Public Health Agency of Canada: The most up-to-date influenza information from Canada is available at http://www.phac-aspc.gc.ca/fluwatch/[/FONT]
[FONT=&quot]Public Health England: The most up-to-date influenza information from the United Kingdom is available at https://www.gov.uk/government/statistics/weekly-national-flu-reports[/FONT]
[FONT=&quot] [/FONT]

[FONT=&quot] [/FONT]
Any links provided to non-Federal organizations are provided solely as a service to our users. These links do not constitute an endorsement of these organizations or their programs by CDC or the Federal Government, and none should be inferred. CDC is not responsible for the content of the individual organization web pages found at these links. [FONT=&quot] [/FONT]
[FONT=&quot]An overview of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component, is available at: http://www.cdc.gov/flu/weekly/overview.htm.

http://www.cdc.gov/flu/weekly/weeklyarchives2016-2017/Week42.htm
[/FONT]
 
[h=3]2016-2017 Influenza Season Week 43 ending October 29, 2016[/h] [FONT=&quot]All data are preliminary and may change as more reports are received.[/FONT]
[h=3]Synopsis:[/h] [FONT=&quot]During week 43 (October 23-29, 2016), influenza activity was low in the United States.[/FONT]
  • Viral Surveillance: The most frequently identified influenza virus subtype reported by public health laboratories during week 43 was influenza A (H3). The percentage of respiratory specimens testing positive for influenza in clinical laboratories was low.
  • Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was below the system-specific epidemic threshold in the National Center for Health Statistics (NCHS) Mortality Surveillance System.
  • Influenza-associated Pediatric Deaths: Two influenza-associated pediatric deaths were reported that occurred during the 2015-2016 season.
  • Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 1.3%, which is below the national baseline of 2.2%. All 10 regions reported ILI below region-specific baseline levels. Puerto Rico experienced high ILI activity, New York City and all 50 states experienced minimal ILI activity, and the District of Columbia had insufficient data.
  • Geographic Spread of Influenza: The geographic spread of influenza in Guam was reported as widespread; Puerto Rico reported regional activity; three states reported local activity; the District of Columbia, the U.S. Virgin Islands and 39 states reported sporadic activity; and eight states reported no activity.
[h=3]National and Regional Summary of Select Surveillance Components[/h]
[FONT=&quot] [TABLE="class: table table-bordered opt-in"]
[TR]
[/TR]
[TR]
HHS Surveillance Regions* Data for current week Data cumulative since October 2, 2016 (week 40) [/TR]
[TR]
Out-patient ILI[SUP]?[/SUP] Number of jurisdictions reporting regional or widespread activity[SUP]?[/SUP] % respiratory specimens positive for flu in clinical laboratories[SUP]?[/SUP] A(H1N1)pdm09 A (H3) A (Subtyping not Performed) B Victoria lineage B Yamagata lineage B lineage not performed Pediatric Deaths [/TR]
[TR]
Influenza test results from public health laboratories only [/TR]
[TR]
Nation [TD]Normal[/TD]
[TD]2 of 54[/TD]
[TD]1.6%[/TD]
[TD]25[/TD]
[TD]184[/TD]
[TD]8[/TD]
[TD]3[/TD]
[TD]7[/TD]
[TD]12[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 1 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]0.4%[/TD]
[TD]0[/TD]
[TD]14[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 2 [TD]Normal[/TD]
[TD]1 of 4[/TD]
[TD]0.8%[/TD]
[TD]0[/TD]
[TD]2[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]2[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 3 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]0.4%[/TD]
[TD]2[/TD]
[TD]9[/TD]
[TD]1[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 4 [TD]Normal[/TD]
[TD]0 of 8[/TD]
[TD]3.6%[/TD]
[TD]1[/TD]
[TD]19[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]2[/TD]
[TD]6[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 5 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]0.7%[/TD]
[TD]0[/TD]
[TD]23[/TD]
[TD]4[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]1[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 6 [TD]Normal[/TD]
[TD]0 of 5[/TD]
[TD]1.2%[/TD]
[TD]3[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]3[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 7 [TD]Normal[/TD]
[TD]0 of 4[/TD]
[TD]0.2%[/TD]
[TD]0[/TD]
[TD]5[/TD]
[TD]1[/TD]
[TD]1[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 8 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]0.9%[/TD]
[TD]16[/TD]
[TD]25[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 9 [TD]Normal[/TD]
[TD]1 of 4[/TD]
[TD]1.2%[/TD]
[TD]3[/TD]
[TD]39[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]1[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 10 [TD]Normal[/TD]
[TD]0 of 4[/TD]
[TD]3.7%[/TD]
[TD]0[/TD]
[TD]48[/TD]
[TD]2[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]2[/TD]
[TD]0[/TD]
[/TR]
[/TABLE]
[/FONT]
[FONT=&quot]*HHS regions (Region 1 CT, ME, MA, NH, RI, VT; Region 2: NJ, NY, Puerto Rico, US Virgin Islands; Region 3: DE, DC, MD, PA, VA, WV; Region 4: AL, FL, GA, KY, MS, NC, SC, TN; Region 5: IL, IN, MI, MN, OH, WI; Region 6: AR, LA, NM, OK, TX; Region 7: IA, KS, MO, NE; Region 8: CO, MT, ND, SD, UT, WY; Region 9: AZ, CA, Guam, HI, NV; and Region 10: AK, ID, OR, WA).
? Elevated means the % of visits for ILI is at or above the national or region-specific baseline
§ Includes all 50 states, the District of Columbia, Guam, Puerto Rico, and U.S. Virgin Islands
? National data are for current week; regional data are for the most recent three weeks

[/FONT]

[h=2]U.S. Virologic Surveillance:[/h] [FONT=&quot]WHO and NREVSS collaborating laboratories, which include both public health and clinical laboratories located in all 50 states, Puerto Rico, and the District of Columbia, report to CDC the total number of respiratory specimens tested for influenza and the number positive for influenza by virus type. In addition, public health laboratories also report the influenza A subtype (H1 or H3) and influenza B lineage information for the viruses they test and the age or age group of the persons from whom the specimens were collected.[/FONT]
[FONT=&quot]Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html and http://gis.cdc.gov/grasp/fluview/flu_by_age_virus.html.[/FONT]
[FONT=&quot]The results of tests performed by clinical laboratories during the current week are summarized below.[/FONT]
[TABLE="class: table table-bordered table-condensed opt-in"]
[TR]
[TD="width: 200"] [/TD]
Week 43 Data Cumulative since
October 2, 2016 (Week 40) [/TR]
[TR]
No. of specimens tested [TD]10,890[/TD]
[TD]49,484[/TD]
[/TR]
[TR]
No. of positive specimens (%) [TD]177 (1.6%)[/TD]
[TD]761 (1.5%)[/TD]
[/TR]
[TR]
Positive specimens by type [TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
Influenza A [TD]116 (65.5%)[/TD]
[TD]444 (58.3%)[/TD]
[/TR]
[TR]
Influenza B [TD]61 (34.5%)[/TD]
[TD]317 (41.7%)[/TD]
[/TR]
[/TABLE]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation
[FONT=&quot]The results of tests performed by public health laboratories, as well as the age group distribution of influenza positive tests, during the current week are summarized below.[/FONT]
[TABLE="class: table table-bordered table-condensed opt-in"]
[TR]
[TD] [/TD]
Week 43 Data Cumulative since
October 2, 2016 (Week 40) [/TR]
[TR]
No. of specimens tested [TD]493[/TD]
[TD]2,822[/TD]
[/TR]
[TR]
No. of positive specimens [TD]33[/TD]
[TD]239[/TD]
[/TR]
[TR]
Positive specimens by type/subtype [TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
Influenza A [TD]28 (84.8%)[/TD]
[TD]217 (90.8%)[/TD]
[/TR]
[TR]
A(H1N1)pmd09 [TD]6 (21.4%)[/TD]
[TD]25 (11.5%)[/TD]
[/TR]
[TR]
H3 [TD]21 (75.0%)[/TD]
[TD]184 (84.8%)[/TD]
[/TR]
[TR]
Subtyping not performed [TD]1 (3.6%)[/TD]
[TD]8 (3.7%)[/TD]
[/TR]
[TR]
Influenza B [TD]5 (15.2%)[/TD]
[TD]22 (9.2%)[/TD]
[/TR]
[TR]
Yamagata lineage [TD]1 (20.0%)[/TD]
[TD]7 (31.8%)[/TD]
[/TR]
[TR]
Victoria lineage [TD]0 (0%)[/TD]
[TD]3 (13.6%)[/TD]
[/TR]
[TR]
Lineage not performed [TD]4 (80.0%)[/TD]
[TD]12 (54.5%)[/TD]
[/TR]
[/TABLE]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation


View Interactive Application | View Full Screen
[h=2]Influenza Virus Characterization:[/h] [FONT=&quot]CDC characterizes influenza viruses through one or more tests including genomic sequencing, hemagglutination inhibition (HI) and/or neutralization assays. These data are used to compare how similar currently circulating influenza viruses are to the reference viruses used for developing influenza vaccines, and to monitor for changes in circulating influenza viruses. Historically, HI data have been used most commonly to assess the similarity between reference viruses and circulating viruses to suggest how well the vaccine may work until such a time as vaccine effectiveness estimates are available.[/FONT]
[FONT=&quot]For nearly all virus positive surveillance samples received at CDC, next-generation sequencing is performed to ascertain genomic data of circulating influenza viruses. Viruses can be classified into genetic groups/clades based on analysis of their HA gene segments using phylogenetics and key amino acid changes (Klimov Vaccine 2012).[/FONT]
[h=2]Genetic Characterization[/h] [FONT=&quot]During May 22 – October 29, 2016, 1,415 influenza positive specimens were collected and reported by public health laboratories in the United States (figure, left). CDC genetically characterized 270 influenza viruses [22 influenza A (H1N1)pdm09, 171 influenza A (H3N2), and 77 influenza B viruses] collected by U.S. laboratories. The HA gene segment of all influenza A (H1N1)pdm09 viruses analyzed belonged to genetic group 6B.1. Influenza A (H3N2) virus HA gene segments analyzed belonged to genetic groups 3C.2a or 3C.3a. Genetic group 3C.2a includes a newly emerging subgroup known as 3C.2a1. The HA of influenza B/Victoria-lineage viruses all belonged to genetic group V1A. The HA of influenza B/Yamagata-lineage viruses analyzed all belonged to genetic group Y3.[/FONT]
[FONT=&quot]The majority of U.S. viruses submitted for characterization come from state and local public health laboratories. Specimen submission guidance issued to the laboratories request that, if available, 2 influenza A (H1N1), 2 A influenza (H3N2), and 2 influenza B viruses be submitted every other week. Because of this, the number of each virus type/subtype characterized should be approximately equal. In the figure below, the results of tests performed by public health labs are presented on the left and sequence results by genetic group of specimens submitted to CDC are presented on the right.[/FONT]
Genetic43_small.gif

View Chart Data | View Full Screen | View PowerPoint Presentation
[h=2]Antigenic Characterization[/h] [FONT=&quot]During May 22 – October 29, 2016, CDC has antigenically characterized 173 influenza viruses [19 influenza A (H1N1)pdm09, 86 influenza A (H3N2), and 68 influenza B viruses] collected by U.S. laboratories.[/FONT]
[FONT=&quot]Influenza A Virus [105][/FONT]
  • A (H1N1)pdm09 [19]: All 19 (100%) influenza A (H1N1)pdm09 viruses were antigenically characterized using ferret post-infection antisera as A/California/7/2009-like, the influenza A (H1N1) component of the 2016-2017 Northern Hemisphere vaccine.
  • A (H3N2) [86]: 73 (84.9%) of 86 influenza A (H3N2) viruses were antigenically characterized as A/Hong Kong/4801/2014-like, a virus that belongs in genetic group 3C.2a and is the influenza A (H3N2) component of the 2016-2017 Northern Hemisphere vaccine, by HI testing or neutralization testing. Among the viruses which reacted poorly with ferret antisera raised against A/Hong Kong/4801/2014-like viruses, 12 of 13 (92.3%) are more closely related to A/Switzerland/9715293/2013), a virus belonging to genetic group 3C.3a.
[FONT=&quot]Influenza B Virus [68][/FONT]
  • Victoria Lineage [31]: All 31 (100%) B/Victoria-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Brisbane/60/2008-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere trivalent and quadrivalent influenza vaccines.
  • Yamagata Lineage [37]: All 37 (100%) B/Yamagata-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Phuket/3073/2013-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere quadrivalent influenza vaccines.
[FONT=&quot]
[/FONT]

[h=2]Antiviral Resistance:[/h] [FONT=&quot]Testing of influenza A (H1N1)pdm09, influenza A (H3N2), and influenza B virus isolates for resistance to neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) is performed at CDC using a functional assay. Additional influenza A (H1N1)pdm09 and influenza A (H3N2) clinical samples are tested for mutations of the virus known to confer oseltamivir resistance. The data summarized below combine the results of both testing methods. These samples are routinely obtained for surveillance purposes rather than for diagnostic testing of patients suspected to be infected with antiviral-resistant virus.[/FONT]
[FONT=&quot]High levels of resistance to the adamantanes (amantadine and rimantadine) persist among influenza A (H1N1)pdm09 and influenza A (H3N2) viruses (the adamantanes are not effective against influenza B viruses). Therefore, data from adamantane resistance testing are not presented below.[/FONT]
[TABLE="class: table, align: center, border: 0, cellpadding: 3, cellspacing: 0"]
[h=3]Neuraminidase Inhibitor Resistance Testing Results on Samples Collected Since October 1, 2016[/h] [/TABLE]
[TABLE="class: table table-bordered opt-in"]
[TR]
[TD] [/TD]
Oseltamivir
Zanamivir
Peramivir
[/TR]
[TR]
[TD] [/TD]
Virus Samples tested (n)
Resistant Viruses, Number (%)
Virus Samples tested (n)
Resistant Viruses, Number (%)
Virus Samples tested (n)
Resistant Viruses, Number (%)
[/TR]
[TR]
Influenza A(H1N1)pdm09
[TD] [/TD]
[TD] 0 (0.0)
[/TD]
[TD] [/TD]
[TD] 0 (0.0)
[/TD]
[TD] [/TD]
[TD] 0 (0.0)
[/TD]
[/TR]
[TR]
Influenza A (H3N2)
[TD] 7
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 7
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 7
[/TD]
[TD] 0 (0.0)
[/TD]
[/TR]
[TR]
Influenza B
[TD] 3
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 3
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 3
[/TD]
[TD] 0 (0.0)
[/TD]
[/TR]
[/TABLE]
[FONT=&quot]The majority of recently circulating influenza viruses are susceptible to the neuraminidase inhibitor antiviral medications, oseltamivir, zanamivir, and peramivir; however, rare sporadic instances of oseltamivir-resistant and peramivir-resistant influenza A (H1N1)pdm09 viruses and oseltamivir-resistant influenza A (H3N2) viruses have been detected worldwide. Antiviral treatment as early as possible is recommended for patients with confirmed or suspected influenza who have severe, complicated, or progressive illness; who require hospitalization; or who are at high risk for serious influenza-related complications. Additional information on recommendations for treatment and chemoprophylaxis of influenza virus infection with antiviral agents is available at http://www.cdc.gov/flu/antivirals/index.htm.[/FONT]


[h=2]Pneumonia and Influenza (P&I) Mortality Surveillance:[/h] [FONT=&quot]Based on National Center for Health Statistics (NCHS) mortality surveillance data available on November 2, 2016, 5.6% of the deaths occurring during the week ending October 15, 2016 (week 41) were due to P&I. This percentage is below the epidemic threshold of 6.5% for week 41.[/FONT]
[FONT=&quot]P&I percentages for recent weeks may be artificially low due to a backlog of records requiring manual processing. Percentages will likely increase to levels more similar to the baseline as more data becomes available.[/FONT]
[FONT=&quot]Region and state-specific data are available at http://gis.cdc.gov/grasp/fluview/mortality.html.[/FONT]
NCHS43_small.gif

View Regional and State Level Data | View Chart Data | View Full Screen | View PowerPoint Presentation

[h=2]Influenza-Associated Pediatric Mortality:[/h] [FONT=&quot]Two influenza-associated pediatric deaths that occurred during the 2015-2016 season were reported to CDC during week 43. Both deaths were associated with an influenza A virus for which no subtyping was performed. These deaths bring the total number of reported influenza-associated pediatric deaths occurring during that season to 87.[/FONT]
[FONT=&quot]No influenza-associated pediatric deaths for the 2016-2017 season have been reported to CDC.[/FONT]
[FONT=&quot]Additional data can be found at: [/FONT]http://gis.cdc.gov/GRASP/Fluview/PedFluDeath.html[FONT=&quot].[/FONT] [FONT=&quot] [/FONT]

View Interactive Application | View Full Screen | View PowerPoint Presentation


[h=2]Influenza-Associated Hospitalizations:[/h] [FONT=&quot]The Influenza Hospitalization Surveillance Network (FluSurv-NET) conducts population-based surveillance for laboratory-confirmed influenza-related hospitalizations in select counties in the Emerging Infections Program (EIP) states and Influenza Hospitalization Surveillance Project (IHSP) states. FluSurv-NET estimated hospitalization rates will be updated weekly starting later this season. Additional FluSurv-NET data can be found at: http://gis.cdc.gov/GRASP/Fluview/FluHospRates.html and http://gis.cdc.gov/grasp/fluview/FluHospChars.html.[/FONT]



[h=2]Outpatient Illness Surveillance:[/h] [FONT=&quot]Nationwide during week 43, 1.3% of patient visits reported through the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) were due to influenza-like illness (ILI). This percentage is below the national baseline of 2.2%.[/FONT]
[FONT=&quot](ILI is defined as fever (temperature of 100°F [37.8°C] or greater) and cough and/or sore throat.)[/FONT]
[FONT=&quot]Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html.[/FONT]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation
[FONT=&quot]On a regional level, the percentage of outpatient visits for ILI ranged from 0.5% to 2.3% during week 43. All 10 regions reported a proportion of outpatient visits for ILI below their region-specific baseline levels.[/FONT]
[FONT=&quot]

[/FONT]

[h=2]ILINet State Activity Indicator Map:[/h] [FONT=&quot]Data collected in ILINet are used to produce a measure of ILI activity* by state. Activity levels are based on the percent of outpatient visits in a state due to ILI and are compared to the average percent of ILI visits that occur during weeks with little or no influenza virus circulation. Activity levels range from minimal, which would correspond to ILI activity from outpatient clinics being below, or only slightly above, the average, to high, which would correspond to ILI activity from outpatient clinics being much higher than average.[/FONT]
[FONT=&quot]During week 43, the following ILI activity levels were experienced:[/FONT]
  • Puerto Rico experienced high ILI activity.
  • New York City and all 50 states experienced minimal ILI activity.
  • Data were insufficient to calculate an ILI activity level from the District of Columbia.
[FONT=&quot][/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]Click on map to launch interactive tool[/FONT]
[FONT=&quot]*This map uses the proportion of outpatient visits to health care providers for ILI to measure the ILI activity level within a state. It does not, however, measure the extent of geographic spread of flu within a state. Therefore, outbreaks occurring in a single city could cause the state to display high activity levels.
Data collected in ILINet may disproportionally represent certain populations within a state, and therefore, may not accurately depict the full picture of influenza activity for the whole state.
Data displayed in this map are based on data collected in ILINet, whereas the State and Territorial flu activity map is based on reports from state and territorial epidemiologists. The data presented in this map is preliminary and may change as more data are received.
Differences in the data presented here by CDC and independently by some state health departments likely represent differing levels of data completeness with data presented by the state likely being the more complete.[/FONT]



[h=2]Geographic Spread of Influenza as Assessed by State and Territorial Epidemiologists[/h] [FONT=&quot]The influenza activity reported by state and territorial epidemiologists indicates geographic spread of influenza viruses, but does not measure the severity of influenza activity.[/FONT]
[FONT=&quot]During week 43, the following influenza activity was reported:[/FONT]
  • Widespread influenza activity was reported by Guam.
  • Regional influenza activity was reported by Puerto Rico.
  • Local influenza activity was reported by three states (Alabama, Maine, and New Hampshire).
  • Sporadic influenza activity was reported by the District of Columbia, the U.S. Virgin Islands and 39 states (Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Indiana, Iowa, Kansas, Louisiana, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nevada, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, South Dakota, Tennessee, Texas, Utah, Virginia, Washington, West Virginia, and Wisconsin).
  • No activity was reported by eight states (Illinois, Kentucky, Mississippi, Nebraska, Rhode Island, South Carolina, Vermont, and Wyoming).
[FONT=&quot][/FONT]


[FONT=&quot] [/FONT]
[h=2]Additional National and International Influenza Surveillance Information[/h] [FONT=&quot]FluView Interactive: FluView includes enhanced web-based interactive applications that can provide dynamic visuals of the influenza data collected and analyzed by CDC. These FluView Interactive applications allow people to create customized, visual interpretations of influenza data, as well as make comparisons across flu seasons, regions, age groups and a variety of other demographics. To access these tools, visit http://www.cdc.gov/flu/weekly/fluviewinteractive.htm.[/FONT]
[FONT=&quot]U.S. State and local influenza surveillance: Click on a jurisdiction below to access the latest local influenza information.[/FONT]
[FONT=&quot] [/FONT]

[TD="width: 139"] Alabama
[/TD]
[TD="width: 139"] Alaska
[/TD]
[TD="width: 139"] Arizona
[/TD]
[TD="width: 139"] Arkansas
[/TD]
[TD="width: 139"] California
[/TD]

[TD="width: 139"] Colorado
[/TD]
[TD="width: 139"] Connecticut
[/TD]
[TD="width: 139"] Delaware
[/TD]
[TD="width: 139"] District of Columbia
[/TD]
[TD="width: 139"] Florida
[/TD]

[TD="width: 139"] Georgia
[/TD]
[TD="width: 139"] Hawaii
[/TD]
[TD="width: 139"] Idaho
[/TD]
[TD="width: 139"] Illinois
[/TD]
[TD="width: 139"] Indiana
[/TD]

[TD="width: 139"] Iowa
[/TD]
[TD="width: 139"] Kansas
[/TD]
[TD="width: 139"] Kentucky
[/TD]
[TD="width: 139"] Louisiana
[/TD]
[TD="width: 139"] Maine
[/TD]

[TD="width: 139"] Maryland
[/TD]
[TD="width: 139"] Massachusetts
[/TD]
[TD="width: 139"] Michigan
[/TD]
[TD="width: 139"] Minnesota
[/TD]
[TD="width: 139"] Mississippi
[/TD]

[TD="width: 139"] Missouri
[/TD]
[TD="width: 139"] Montana
[/TD]
[TD="width: 139"] Nebraska
[/TD]
[TD="width: 139"] Nevada
[/TD]
[TD="width: 139"] New Hampshire
[/TD]

[TD="width: 139"] New Jersey
[/TD]
[TD="width: 139"] New Mexico
[/TD]
[TD="width: 139"] New York
[/TD]
[TD="width: 139"] North Carolina
[/TD]
[TD="width: 139"] North Dakota
[/TD]

[TD="width: 139"] Ohio
[/TD]
[TD="width: 139"] Oklahoma
[/TD]
[TD="width: 139"] Oregon
[/TD]
[TD="width: 139"] Pennsylvania
[/TD]
[TD="width: 139"] Rhode Island
[/TD]

[TD="width: 139"] South Carolina
[/TD]
[TD="width: 139"] South Dakota
[/TD]
[TD="width: 139"] Tennessee
[/TD]
[TD="width: 139"] Texas
[/TD]
[TD="width: 139"] Utah
[/TD]

[TD="width: 139"] Vermont
[/TD]
[TD="width: 139"] Virginia
[/TD]
[TD="width: 139"] Washington
[/TD]
[TD="width: 139"] West Virginia
[/TD]
[TD="width: 139"] Wisconsin
[/TD]

[TD="width: 139"] Wyoming
[/TD]
[TD="width: 139"] New York City
[/TD]
[TD="width: 139"] Puerto Rico
[/TD]
[TD="width: 139"] Virgin Islands
[/TD]
[TD="width: 139"] [/TD]

[FONT=&quot]World Health Organization: Additional influenza surveillance information from participating WHO member nations is available through FluNet and the Global Epidemiology Reports.[/FONT]
[FONT=&quot]WHO Collaborating Centers for Influenza located in Australia, China, Japan, the United Kingdom, and the United States (CDC in Atlanta, Georgia).[/FONT]
[FONT=&quot]Europe: For the most recent influenza surveillance information from Europe, please see WHO/Europe and the European Centre for Disease Prevention and Control at http://www.flunewseurope.org/.[/FONT]
[FONT=&quot]Public Health Agency of Canada: The most up-to-date influenza information from Canada is available at http://www.phac-aspc.gc.ca/fluwatch/[/FONT]
[FONT=&quot]Public Health England: The most up-to-date influenza information from the United Kingdom is available at https://www.gov.uk/government/statistics/weekly-national-flu-reports[/FONT]
[FONT=&quot] [/FONT]

[FONT=&quot] [/FONT]
Any links provided to non-Federal organizations are provided solely as a service to our users. These links do not constitute an endorsement of these organizations or their programs by CDC or the Federal Government, and none should be inferred. CDC is not responsible for the content of the individual organization web pages found at these links. [FONT=&quot] [/FONT]
[FONT=&quot]An overview of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component, is available at: http://www.cdc.gov/flu/weekly/overview.htm.[/FONT]
[FONT=&quot]--------------------------------------------------------------------------------[/FONT]

http://www.cdc.gov/flu/weekly/weeklyarchives2016-2017/Week43.htm
 
[h=3]2016-2017 Influenza Season Week 45 ending November 12, 2016[/h] All data are preliminary and may change as more reports are received.
[h=3]Synopsis:[/h] During week 45 (November 6-12, 2016), influenza activity remained low in the United States.
  • Viral Surveillance: The most frequently identified influenza virus subtype reported by public health laboratories during week 45 was influenza A (H3). The percentage of respiratory specimens testing positive for influenza in clinical laboratories was low.
  • Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was below the system-specific epidemic threshold in the National Center for Health Statistics (NCHS) Mortality Surveillance System.
  • Influenza-associated Pediatric Deaths: No influenza-associated pediatric deaths were reported.
  • Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 1.6%, which is below the national baseline of 2.2%. One region reported ILI at their region-specific baseline level. Puerto Rico experienced high ILI activity, two states experienced low ILI activity, New York City and 48 states experienced minimal ILI activity, and the District of Columbia had insufficient data.
  • Geographic Spread of Influenza: The geographic spread of influenza in Guam was reported as widespread; Puerto Rico, the U.S. Virgin Islands and one state reported regional activity; five states reported local activity; the District of Columbia and 40 states reported sporadic activity; and four states reported no activity.
[h=3]National and Regional Summary of Select Surveillance Components[/h]
[TABLE="class: table table-bordered opt-in, width: 100%"]
[TR]
[/TR]
[TR]
HHS Surveillance Regions* Data for current week Data cumulative since October 2, 2016 (week 40) [/TR]
[TR]
Out-patient ILI? Number of jurisdictions reporting regional or widespread activity? % respiratory specimens positive for flu in clinical laboratories? A(H1N1)pdm09 A (H3) A (Subtyping not Performed) B Victoria lineage B Yamagata lineage B lineage not performed Pediatric Deaths [/TR]
[TR]
Influenza test results from public health laboratories only [/TR]
[TR]
Nation [TD]Normal[/TD]
[TD]4 of 54[/TD]
[TD]1.7%[/TD]
[TD]49[/TD]
[TD]412[/TD]
[TD]18[/TD]
[TD]13[/TD]
[TD]14[/TD]
[TD]19[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 1 [TD]Normal[/TD]
[TD]1 of 6[/TD]
[TD]0.6%[/TD]
[TD]0[/TD]
[TD]25[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 2 [TD]Normal[/TD]
[TD]2 of 4[/TD]
[TD]0.7%[/TD]
[TD]0[/TD]
[TD]9[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]0[/TD]
[TD]2[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 3 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]0.3%[/TD]
[TD]4[/TD]
[TD]17[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]1[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 4 [TD]Elevated[/TD]
[TD]0 of 8[/TD]
[TD]3.6%[/TD]
[TD]2[/TD]
[TD]37[/TD]
[TD]3[/TD]
[TD]2[/TD]
[TD]2[/TD]
[TD]9[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 5 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]0.6%[/TD]
[TD]2[/TD]
[TD]41[/TD]
[TD]9[/TD]
[TD]3[/TD]
[TD]1[/TD]
[TD]2[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 6 [TD]Normal[/TD]
[TD]0 of 5[/TD]
[TD]1.4%[/TD]
[TD]6[/TD]
[TD]9[/TD]
[TD]0[/TD]
[TD]2[/TD]
[TD]5[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 7 [TD]Normal[/TD]
[TD]0 of 4[/TD]
[TD]0.2%[/TD]
[TD]0[/TD]
[TD]7[/TD]
[TD]1[/TD]
[TD]2[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 8 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]1.6%[/TD]
[TD]23[/TD]
[TD]57[/TD]
[TD]1[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 9 [TD]Normal[/TD]
[TD]1 of 4[/TD]
[TD]1.7%[/TD]
[TD]11[/TD]
[TD]118[/TD]
[TD]4[/TD]
[TD]1[/TD]
[TD]5[/TD]
[TD]3[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 10 [TD]Normal[/TD]
[TD]0 of 4[/TD]
[TD]5.9%[/TD]
[TD]1[/TD]
[TD]92[/TD]
[TD]0[/TD]
[TD]2[/TD]
[TD]0[/TD]
[TD]2[/TD]
[TD]0[/TD]
[/TR]
[/TABLE]
*HHS regions (Region 1 CT, ME, MA, NH, RI, VT; Region 2: NJ, NY, Puerto Rico, US Virgin Islands; Region 3: DE, DC, MD, PA, VA, WV; Region 4: AL, FL, GA, KY, MS, NC, SC, TN; Region 5: IL, IN, MI, MN, OH, WI; Region 6: AR, LA, NM, OK, TX; Region 7: IA, KS, MO, NE; Region 8: CO, MT, ND, SD, UT, WY; Region 9: AZ, CA, Guam, HI, NV; and Region 10: AK, ID, OR, WA).
? Elevated means the % of visits for ILI is at or above the national or region-specific baseline
? Includes all 50 states, the District of Columbia, Guam, Puerto Rico, and U.S. Virgin Islands
? National data are for current week; regional data are for the most recent three weeks


[h=2]U.S. Virologic Surveillance:[/h] WHO and NREVSS collaborating laboratories, which include both public health and clinical laboratories located in all 50 states, Puerto Rico, and the District of Columbia, report to CDC the total number of respiratory specimens tested for influenza and the number positive for influenza by virus type. In addition, public health laboratories also report the influenza A subtype (H1 or H3) and influenza B lineage information for the viruses they test and the age or age group of the persons from whom the specimens were collected.
Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html and http://gis.cdc.gov/grasp/fluview/flu_by_age_virus.html.
The results of tests performed by clinical laboratories during the current week are summarized below.
[TABLE="class: table table-bordered table-condensed opt-in, width: 100%"]
[TR]
[TD="width: 200"] [/TD]
Week 45 Data Cumulative since
October 2, 2016 (Week 40) [/TR]
[TR]
No. of specimens tested [TD]11,841[/TD]
[TD]79,913[/TD]
[/TR]
[TR]
No. of positive specimens (%) [TD]199 (1.7%)[/TD]
[TD]1,302 (1.6%)[/TD]
[/TR]
[TR]
Positive specimens by type [TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
Influenza A [TD]163 (81.9%)[/TD]
[TD]822 (63.1%)[/TD]
[/TR]
[TR]
Influenza B [TD]36 (18.1%)[/TD]
[TD]480 (36.9%)[/TD]
[/TR]
[/TABLE]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation The results of tests performed by public health laboratories, as well as the age group distribution of influenza positive tests, during the current week are summarized below.
[TABLE="class: table table-bordered table-condensed opt-in, width: 100%"]
[TR]
[TD] [/TD]
Week 45 Data Cumulative since
October 2, 2016 (Week 40) [/TR]
[TR]
No. of specimens tested [TD]547[/TD]
[TD]5,278[/TD]
[/TR]
[TR]
No. of positive specimens [TD]35[/TD]
[TD]525[/TD]
[/TR]
[TR]
Positive specimens by type/subtype [TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
Influenza A [TD]34 (97.1%)[/TD]
[TD]479 (91.2%)[/TD]
[/TR]
[TR]
A(H1N1)pmd09 [TD]1 (2.9%)[/TD]
[TD]49 (10.2%)[/TD]
[/TR]
[TR]
H3 [TD]30 (88.2%)[/TD]
[TD]412 (86.0%)[/TD]
[/TR]
[TR]
Subtyping not performed [TD]3 (8.8%)[/TD]
[TD]18 (3.8%)[/TD]
[/TR]
[TR]
Influenza B [TD]1 (2.9%)[/TD]
[TD]46 (8.8%)[/TD]
[/TR]
[TR]
Yamagata lineage [TD]0 (0%)[/TD]
[TD]14 (30.4%)[/TD]
[/TR]
[TR]
Victoria lineage [TD]0 (0%)[/TD]
[TD]13 (28.3%)[/TD]
[/TR]
[TR]
Lineage not performed [TD]1 (100%)[/TD]
[TD]19 (41.3%)[/TD]
[/TR]
[/TABLE]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation
View Interactive Application | View Full Screen [h=2]Influenza Virus Characterization:[/h] CDC characterizes influenza viruses through one or more tests including genomic sequencing, hemagglutination inhibition (HI) and/or neutralization assays. These data are used to compare how similar currently circulating influenza viruses are to the reference viruses used for developing influenza vaccines, and to monitor for changes in circulating influenza viruses. Historically, HI data have been used most commonly to assess the similarity between reference viruses and circulating viruses to suggest how well the vaccine may work until such a time as vaccine effectiveness estimates are available.
For nearly all virus positive surveillance samples received at CDC, next-generation sequencing is performed to ascertain genomic data of circulating influenza viruses. Viruses can be classified into genetic groups/clades based on analysis of their HA gene segments using phylogenetics and key amino acid changes (Klimov Vaccine 2012).
[h=2]Genetic Characterization[/h] During May 22 ? November 12, 2016, 1,702 influenza positive specimens were collected and reported by public health laboratories in the United States (figure, left). CDC genetically characterized 332 influenza viruses [31 influenza A (H1N1)pdm09, 211 influenza A (H3N2), and 90 influenza B viruses] collected by U.S. laboratories. The HA gene segment of all influenza A (H1N1)pdm09 viruses analyzed belonged to genetic group 6B.1. Influenza A (H3N2) virus HA gene segments analyzed belonged to genetic groups 3C.2a or 3C.3a. Genetic group 3C.2a includes a newly emerging subgroup known as 3C.2a1. The HA of influenza B/Victoria-lineage viruses all belonged to genetic group V1A. The HA of influenza B/Yamagata-lineage viruses analyzed all belonged to genetic group Y3.
The majority of U.S. viruses submitted for characterization come from state and local public health laboratories. Specimen submission guidance issued to the laboratories request that, if available, 2 influenza A (H1N1), 2 A influenza (H3N2), and 2 influenza B viruses be submitted every other week. Because of this, the number of each virus type/subtype characterized should be approximately equal. In the figure below, the results of tests performed by public health labs are presented on the left and sequence results by genetic group of specimens submitted to CDC are presented on the right.
Genetic45_small.gif

View Chart Data | View Full Screen | View PowerPoint Presentation [h=2]Antigenic Characterization[/h] During May 22 ? November 12, 2016, CDC has antigenically characterized 194 influenza viruses [20 influenza A (H1N1)pdm09, 99 influenza A (H3N2), and 75 influenza B viruses] collected by U.S. laboratories.
Influenza A Virus [119]
  • A (H1N1)pdm09 [20]: All 20 (100%) influenza A (H1N1)pdm09 viruses were antigenically characterized using ferret post-infection antisera as A/California/7/2009-like, the influenza A (H1N1) component of the 2016-2017 Northern Hemisphere vaccine.
  • A (H3N2) [99]: 85 (85.9%) of 99 influenza A (H3N2) viruses were antigenically characterized as A/Hong Kong/4801/2014-like, a virus that belongs in genetic group 3C.2a and is the influenza A (H3N2) component of the 2016-2017 Northern Hemisphere vaccine, by HI testing or neutralization testing. Among the viruses which reacted poorly with ferret antisera raised against A/Hong Kong/4801/2014-like viruses, 13 of 14 (92.9%) are more closely related to A/Switzerland/9715293/2013, a virus belonging to genetic group 3C.3a.
Influenza B Virus [75]
  • Victoria Lineage [36]: All 36 (100%) B/Victoria-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Brisbane/60/2008-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere trivalent and quadrivalent influenza vaccines.
  • Yamagata Lineage [39]: All 39 (100%) B/Yamagata-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Phuket/3073/2013-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere quadrivalent influenza vaccines.

[h=2]Antiviral Resistance:[/h] Testing of influenza A (H1N1)pdm09, influenza A (H3N2), and influenza B virus isolates for resistance to neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) is performed at CDC using a functional assay. Additional influenza A (H1N1)pdm09 and influenza A (H3N2) clinical samples are tested for mutations of the virus known to confer oseltamivir resistance. The data summarized below combine the results of both testing methods. These samples are routinely obtained for surveillance purposes rather than for diagnostic testing of patients suspected to be infected with antiviral-resistant virus.
High levels of resistance to the adamantanes (amantadine and rimantadine) persist among influenza A (H1N1)pdm09 and influenza A (H3N2) viruses (the adamantanes are not effective against influenza B viruses). Therefore, data from adamantane resistance testing are not presented below.
[TABLE="class: table, align: center, border: 0, cellpadding: 3, cellspacing: 0, width: 100%"]
[h=3]Neuraminidase Inhibitor Resistance Testing Results on Samples Collected Since October 1, 2016[/h] [/TABLE]
[TABLE="class: table table-bordered opt-in, width: 100%"]
[TR]
[TD] [/TD]
Oseltamivir​
Zanamivir​
Peramivir​
[/TR]
[TR]
[TD] [/TD]
Virus Samples tested (n)
Resistant Viruses, Number (%)​
Virus Samples tested (n)
Resistant Viruses, Number (%)​
Virus Samples tested (n)
Resistant Viruses, Number (%)​
[/TR]
[TR]
Influenza A(H1N1)pdm09
[TD]
6​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
6​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
6​
[/TD]
[TD]
0 (0.0)​
[/TD]
[/TR]
[TR]
Influenza A(H3N2)
[TD]
33​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
33​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
23​
[/TD]
[TD]
0 (0.0)​
[/TD]
[/TR]
[TR]
Influenza B
[TD]
14​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
14​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
14​
[/TD]
[TD]
0 (0.0)​
[/TD]
[/TR]
[/TABLE]
The majority of recently circulating influenza viruses are susceptible to the neuraminidase inhibitor antiviral medications, oseltamivir, zanamivir, and peramivir; however, rare sporadic instances of oseltamivir-resistant and peramivir-resistant influenza A (H1N1)pdm09 viruses and oseltamivir-resistant influenza A (H3N2) viruses have been detected worldwide. Antiviral treatment as early as possible is recommended for patients with confirmed or suspected influenza who have severe, complicated, or progressive illness; who require hospitalization; or who are at high risk for serious influenza-related complications. Additional information on recommendations for treatment and chemoprophylaxis of influenza virus infection with antiviral agents is available at http://www.cdc.gov/flu/antivirals/index.htm.


[h=2]Pneumonia and Influenza (P&I) Mortality Surveillance:[/h] Based on National Center for Health Statistics (NCHS) mortality surveillance data available on November 16, 2016, 5.4% of the deaths occurring during the week ending October 29, 2016 (week 43) were due to P&I. This percentage is below the epidemic threshold of 6.7% for week 43.
P&I percentages for recent weeks may be artificially low due to a backlog of records requiring manual processing. Percentages will likely increase to levels more similar to the baseline as more data become available.
Region and state-specific data are available at http://gis.cdc.gov/grasp/fluview/mortality.html.
NCHS45_small.gif

View Regional and State Level Data | View Chart Data | View Full Screen | View PowerPoint Presentation

[h=2]Influenza-Associated Pediatric Mortality:[/h] No influenza-associated pediatric deaths were reported to CDC during week 45.
Additional data can be found at: http://gis.cdc.gov/GRASP/Fluview/PedFluDeath.html.

View Interactive Application | View Full Screen | View PowerPoint Presentation


[h=2]Influenza-Associated Hospitalizations:[/h] The Influenza Hospitalization Surveillance Network (FluSurv-NET) conducts population-based surveillance for laboratory-confirmed influenza-related hospitalizations in select counties in the Emerging Infections Program (EIP) states and Influenza Hospitalization Surveillance Project (IHSP) states. FluSurv-NET estimated hospitalization rates will be updated weekly starting later this season. Additional FluSurv-NET data can be found at:http://gis.cdc.gov/GRASP/Fluview/FluHospRates.html and http://gis.cdc.gov/grasp/fluview/FluHospChars.html.



[h=2]Outpatient Illness Surveillance:[/h] Nationwide during week 45, 1.6% of patient visits reported through the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) were due to influenza-like illness (ILI). This percentage is below the national baseline of 2.2%.
(ILI is defined as fever (temperature of 100?F [37.8?C] or greater) and cough and/or sore throat.)
Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html.

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation On a regional level, the percentage of outpatient visits for ILI ranged from 0.6% to 2.5% during week 45. One region (Region 4) reported a proportion of outpatient visits for ILI at their region-specific baseline levels.



[h=2]ILINet State Activity Indicator Map:[/h] Data collected in ILINet are used to produce a measure of ILI activity* by state. Activity levels are based on the percent of outpatient visits in a state due to ILI and are compared to the average percent of ILI visits that occur during weeks with little or no influenza virus circulation. Activity levels range from minimal, which would correspond to ILI activity from outpatient clinics being below, or only slightly above, the average, to high, which would correspond to ILI activity from outpatient clinics being much higher than average.
During week 45, the following ILI activity levels were experienced:
  • Puerto Rico experienced high ILI activity.
  • Two states (Georgia and Oklahoma) experienced low ILI activity.
  • New York City and 48 states (Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, and Wyoming) experienced minimal ILI activity.
  • Data were insufficient to calculate an ILI activity level from the District of Columbia.
Click on map to launch interactive tool
*This map uses the proportion of outpatient visits to health care providers for ILI to measure the ILI activity level within a state. It does not, however, measure the extent of geographic spread of flu within a state. Therefore, outbreaks occurring in a single city could cause the state to display high activity levels.
Data collected in ILINet may disproportionally represent certain populations within a state, and therefore, may not accurately depict the full picture of influenza activity for the whole state.
Data displayed in this map are based on data collected in ILINet, whereas the State and Territorial flu activity map is based on reports from state and territorial epidemiologists. The data presented in this map is preliminary and may change as more data are received.
Differences in the data presented here by CDC and independently by some state health departments likely represent differing levels of data completeness with data presented by the state likely being the more complete.


[h=2]Geographic Spread of Influenza as Assessed by State and Territorial Epidemiologists[/h] The influenza activity reported by state and territorial epidemiologists indicates geographic spread of influenza viruses, but does not measure the severity of influenza activity.
During week 45, the following influenza activity was reported:
  • Widespread influenza activity was reported by Guam.
  • Regional influenza activity was reported by Puerto Rico, the U.S. Virgin Islands, and one state (New Hampshire).
  • Local influenza activity was reported by five states (Hawaii, Maryland, Massachusetts, Oklahoma, and Oregon).
  • Sporadic influenza activity was reported by the District of Columbia and 40 states (Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Michigan, Minnesota, Mississippi, Missouri, Montana, Nevada, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Pennsylvania, South Carolina, South Dakota, Texas, Utah, Virginia, Washington, West Virginia, Wisconsin, and Wyoming).
  • No activity was reported by four states (Nebraska, Rhode Island, Tennessee, and Vermont).



[h=2]Additional National and International Influenza Surveillance Information[/h] FluView Interactive: FluView includes enhanced web-based interactive applications that can provide dynamic visuals of the influenza data collected and analyzed by CDC. These FluView Interactive applications allow people to create customized, visual interpretations of influenza data, as well as make comparisons across flu seasons, regions, age groups and a variety of other demographics. To access these tools, visithttp://www.cdc.gov/flu/weekly/fluviewinteractive.htm.
U.S. State and local influenza surveillance: Click on a jurisdiction below to access the latest local influenza information.

[TABLE="width: 100%"]
[TR]
[TD="width: 139"] Alabama
[/TD]
[TD="width: 139"] Alaska
[/TD]
[TD="width: 139"] Arizona
[/TD]
[TD="width: 139"] Arkansas
[/TD]
[TD="width: 139"] California
[/TD]
[/TR]
[TR]
[TD="width: 139"] Colorado
[/TD]
[TD="width: 139"] Connecticut
[/TD]
[TD="width: 139"] Delaware
[/TD]
[TD="width: 139"] District of Columbia
[/TD]
[TD="width: 139"] Florida
[/TD]
[/TR]
[TR]
[TD="width: 139"] Georgia
[/TD]
[TD="width: 139"] Hawaii
[/TD]
[TD="width: 139"] Idaho
[/TD]
[TD="width: 139"] Illinois
[/TD]
[TD="width: 139"] Indiana
[/TD]
[/TR]
[TR]
[TD="width: 139"] Iowa
[/TD]
[TD="width: 139"] Kansas
[/TD]
[TD="width: 139"] Kentucky
[/TD]
[TD="width: 139"] Louisiana
[/TD]
[TD="width: 139"] Maine
[/TD]
[/TR]
[TR]
[TD="width: 139"] Maryland
[/TD]
[TD="width: 139"] Massachusetts
[/TD]
[TD="width: 139"] Michigan
[/TD]
[TD="width: 139"] Minnesota
[/TD]
[TD="width: 139"] Mississippi
[/TD]
[/TR]
[TR]
[TD="width: 139"] Missouri
[/TD]
[TD="width: 139"] Montana
[/TD]
[TD="width: 139"] Nebraska
[/TD]
[TD="width: 139"] Nevada
[/TD]
[TD="width: 139"] New Hampshire
[/TD]
[/TR]
[TR]
[TD="width: 139"] New Jersey
[/TD]
[TD="width: 139"] New Mexico
[/TD]
[TD="width: 139"] New York
[/TD]
[TD="width: 139"] North Carolina
[/TD]
[TD="width: 139"] North Dakota
[/TD]
[/TR]
[TR]
[TD="width: 139"] Ohio
[/TD]
[TD="width: 139"] Oklahoma
[/TD]
[TD="width: 139"] Oregon
[/TD]
[TD="width: 139"] Pennsylvania
[/TD]
[TD="width: 139"] Rhode Island
[/TD]
[/TR]
[TR]
[TD="width: 139"] South Carolina
[/TD]
[TD="width: 139"] South Dakota
[/TD]
[TD="width: 139"] Tennessee
[/TD]
[TD="width: 139"] Texas
[/TD]
[TD="width: 139"] Utah
[/TD]
[/TR]
[TR]
[TD="width: 139"] Vermont
[/TD]
[TD="width: 139"] Virginia
[/TD]
[TD="width: 139"] Washington
[/TD]
[TD="width: 139"] West Virginia
[/TD]
[TD="width: 139"] Wisconsin
[/TD]
[/TR]
[TR]
[TD="width: 139"] Wyoming
[/TD]
[TD="width: 139"] New York City
[/TD]
[TD="width: 139"] Puerto Rico
[/TD]
[TD="width: 139"] Virgin Islands
[/TD]
[TD="width: 139"] [/TD]
[/TR]
[/TABLE]
World Health Organization: Additional influenza surveillance information from participating WHO member nations is available through FluNet and the Global Epidemiology Reports.
WHO Collaborating Centers for Influenza located in Australia, China, Japan, the United Kingdom, and the United States (CDC in Atlanta, Georgia).
Europe: For the most recent influenza surveillance information from Europe, please see WHO/Europe and the European Centre for Disease Prevention and Control at http://www.flunewseurope.org/.
Public Health Agency of Canada: The most up-to-date influenza information from Canada is available at http://www.phac-aspc.gc.ca/fluwatch/
Public Health England: The most up-to-date influenza information from the United Kingdom is available athttps://www.gov.uk/government/statistics/weekly-national-flu-reports


Any links provided to non-Federal organizations are provided solely as a service to our users. These links do not constitute an endorsement of these organizations or their programs by CDC or the Federal Government, and none should be inferred. CDC is not responsible for the content of the individual organization web pages found at these links.
An overview of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component, is available at: http://www.cdc.gov/flu/weekly/overview.htm.
--------------------------------------------------------------------------------









[h=5]File Formats Help:[/h] How do I view different file formats (PDF, DOC, PPT, MPEG) on this site?

[/COLOR]

  • Page last reviewed: November 18, 2016
  • Page last updated: November 18, 2016
http://www.cdc.gov/flu/weekly/


 
[h=3]2016-2017 Influenza Season Week 47 ending November 26, 2016[/h] All data are preliminary and may change as more reports are received.
[h=3]Synopsis:[/h] During week 47 (November 20-26, 2016), influenza activity increased slightly, but remained low in the United States.
  • Viral Surveillance: The most frequently identified influenza virus subtype reported by public health laboratories during week 47 was influenza A (H3). The percentage of respiratory specimens testing positive for influenza in clinical laboratories increased slightly, but remained low.
  • Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was below the system-specific epidemic threshold in the National Center for Health Statistics (NCHS) Mortality Surveillance System.
  • Influenza-associated Pediatric Deaths: No influenza-associated pediatric deaths were reported.
  • Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 1.8%, which is below the national baseline of 2.2%. Three regions reported ILI at or above their region-specific baseline levels. Puerto Rico experienced high ILI activity, one state experienced moderate ILI activity, New York City and five states experienced low ILI activity, 44 states experienced minimal ILI activity, and the District of Columbia had insufficient data.
  • Geographic Spread of Influenza:The geographic spread of influenza in Guam, Puerto Rico, the U.S. Virgin Islands, and one state was reported as regional; 12 states reported local activity; the District of Columbia and 36 states reported sporadic activity; and one state reported no activity.
[h=3]National and Regional Summary of Select Surveillance Components[/h]
[TABLE="class: table table-bordered opt-in, width: 100%"]
[TR]
[/TR]
[TR]
HHS Surveillance Regions* Data for current week Data cumulative since October 2, 2016 (week 40) [/TR]
[TR]
Out-patient ILI? Number of jurisdictions reporting regional or widespread activity? % respiratory specimens positive for flu in clinical laboratories? A(H1N1)pdm09 A (H3) A (Subtyping not Performed) B Victoria lineage B Yamagata lineage B lineage not performed Pediatric Deaths [/TR]
[TR]
Influenza test results from public health laboratories only [/TR]
[TR]
Nation [TD]Normal[/TD]
[TD]4 of 54[/TD]
[TD]3.6%[/TD]
[TD]65[/TD]
[TD]731[/TD]
[TD]53[/TD]
[TD]34[/TD]
[TD]21[/TD]
[TD]40[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 1 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]1.1%[/TD]
[TD]0[/TD]
[TD]34[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 2 [TD]Elevated[/TD]
[TD]2 of 4[/TD]
[TD]1.3%[/TD]
[TD]0[/TD]
[TD]67[/TD]
[TD]0[/TD]
[TD]14[/TD]
[TD]4[/TD]
[TD]3[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 3 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]0.7%[/TD]
[TD]6[/TD]
[TD]42[/TD]
[TD]1[/TD]
[TD]1[/TD]
[TD]1[/TD]
[TD]4[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 4 [TD]Elevated[/TD]
[TD]1 of 8[/TD]
[TD]5.8%[/TD]
[TD]4[/TD]
[TD]58[/TD]
[TD]4[/TD]
[TD]3[/TD]
[TD]2[/TD]
[TD]25[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 5 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]1.1%[/TD]
[TD]2[/TD]
[TD]60[/TD]
[TD]29[/TD]
[TD]6[/TD]
[TD]3[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 6 [TD]Normal[/TD]
[TD]0 of 5[/TD]
[TD]2.1%[/TD]
[TD]8[/TD]
[TD]16[/TD]
[TD]0[/TD]
[TD]5[/TD]
[TD]5[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 7 [TD]Normal[/TD]
[TD]0 of 4[/TD]
[TD]0.9%[/TD]
[TD]0[/TD]
[TD]12[/TD]
[TD]5[/TD]
[TD]2[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 8 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]2.2%[/TD]
[TD]28[/TD]
[TD]80[/TD]
[TD]2[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 9 [TD]Normal[/TD]
[TD]1 of 5[/TD]
[TD]2.1%[/TD]
[TD]16[/TD]
[TD]188[/TD]
[TD]11[/TD]
[TD]1[/TD]
[TD]6[/TD]
[TD]4[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 10 [TD]Elevated[/TD]
[TD]0 of 4[/TD]
[TD]8.3%[/TD]
[TD]1[/TD]
[TD]174[/TD]
[TD]1[/TD]
[TD]2[/TD]
[TD]0[/TD]
[TD]4[/TD]
[TD]0[/TD]
[/TR]
[/TABLE]
*HHS regions (Region 1 CT, ME, MA, NH, RI, VT; Region 2: NJ, NY, Puerto Rico, US Virgin Islands; Region 3: DE, DC, MD, PA, VA, WV; Region 4: AL, FL, GA, KY, MS, NC, SC, TN; Region 5: IL, IN, MI, MN, OH, WI; Region 6: AR, LA, NM, OK, TX; Region 7: IA, KS, MO, NE; Region 8: CO, MT, ND, SD, UT, WY; Region 9: AZ, CA, Guam, HI, NV; and Region 10: AK, ID, OR, WA).
? Elevated means the % of visits for ILI is at or above the national or region-specific baseline
? Includes all 50 states, the District of Columbia, Guam, Puerto Rico, and U.S. Virgin Islands
? National data are for current week; regional data are for the most recent three weeks


[h=2]U.S. Virologic Surveillance:[/h] WHO and NREVSS collaborating laboratories, which include both public health and clinical laboratories located in all 50 states, Puerto Rico, and the District of Columbia, report to CDC the total number of respiratory specimens tested for influenza and the number positive for influenza by virus type. In addition, public health laboratories also report the influenza A subtype (H1 or H3) and influenza B lineage information for the viruses they test and the age or age group of the persons from whom the specimens were collected.
Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html and http://gis.cdc.gov/grasp/fluview/flu_by_age_virus.html.
The results of tests performed by clinical laboratories during the current week are summarized below.
[TABLE="class: table table-bordered table-condensed opt-in, width: 100%"]
[TR]
[TD="width: 200"] [/TD]
Week 47 Data Cumulative since
October 2, 2016 (Week 40) [/TR]
[TR]
No. of specimens tested [TD]14,787[/TD]
[TD]119,242[/TD]
[/TR]
[TR]
No. of positive specimens (%) [TD]525 (3.6%)[/TD]
[TD]2,510 (2.1%)[/TD]
[/TR]
[TR]
Positive specimens by type [TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
Influenza A [TD]372 (70.9%)[/TD]
[TD]1,626 (64.8%)[/TD]
[/TR]
[TR]
Influenza B [TD]153 (29.1%)[/TD]
[TD]884 (35.2%)[/TD]
[/TR]
[/TABLE]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation The results of tests performed by public health laboratories, as well as the age group distribution of influenza positive tests, during the current week are summarized below.
[TABLE="class: table table-bordered table-condensed opt-in, width: 100%"]
[TR]
[TD] [/TD]
Week 47 Data Cumulative since
October 2, 2016 (Week 40) [/TR]
[TR]
No. of specimens tested [TD]541[/TD]
[TD]7,728[/TD]
[/TR]
[TR]
No. of positive specimens* [TD]62[/TD]
[TD]944[/TD]
[/TR]
[TR]
Positive specimens by type/subtype [TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
Influenza A [TD]54 (87.1%)[/TD]
[TD]849 (89.9%)[/TD]
[/TR]
[TR]
A(H1N1)pmd09 [TD]2 (3.7%)[/TD]
[TD]65 (7.7%)[/TD]
[/TR]
[TR]
H3 [TD]31 (57.4%)[/TD]
[TD]731 (86.1%)[/TD]
[/TR]
[TR]
Subtyping not performed [TD]21 (38.9%)[/TD]
[TD]53 (6.2%)[/TD]
[/TR]
[TR]
Influenza B [TD]8 (12.9%)[/TD]
[TD]95 (10.1%)[/TD]
[/TR]
[TR]
Yamagata lineage [TD]1 (12.5%)[/TD]
[TD]21 (22.1%)[/TD]
[/TR]
[TR]
Victoria lineage [TD]0 (0%)[/TD]
[TD]34 (35.8%)[/TD]
[/TR]
[TR]
Lineage not performed [TD]7 (87.5%)[/TD]
[TD]40 (42.1%)[/TD]
[/TR]
[/TABLE]
*The percent of specimens testing positive for influenza is not reported because public health laboratories often receive samples that have already tested positive for influenza at a clinical laboratory and therefore percent positive would not be a valid indicator of influenza activity. Additional information is available at http://www.cdc.gov/flu/weekly/overview.htm.


View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation
View Interactive Application | View Full Screen

[h=2]Influenza Virus Characterization:[/h] CDC characterizes influenza viruses through one or more tests including genomic sequencing, hemagglutination inhibition (HI) and/or neutralization assays. These data are used to compare how similar currently circulating influenza viruses are to the reference viruses used for developing influenza vaccines, and to monitor for changes in circulating influenza viruses. Historically, HI data have been used most commonly to assess the similarity between reference viruses and circulating viruses to suggest how well the vaccine may work until such a time as vaccine effectiveness estimates are available.
For nearly all virus positive surveillance samples received at CDC, next-generation sequencing is performed to ascertain genomic data of circulating influenza viruses. Viruses can be classified into genetic groups/clades based on analysis of their HA gene segments using phylogenetics and key amino acid changes (Klimov Vaccine 2012).
A proportion of influenza A (H3N2) viruses don?t yield sufficient hemagglutination titers for antigenic characterization using the hemagglutination inhibition test. Therefore, CDC selects a subset of influenza A (H3N2) viruses to test using a focus reduction assay for supplementary antigenic characterization.
[h=2]Genetic Characterization[/h] During the 2016-2017 season, 944 influenza positive specimens have been collected and reported by public health laboratories in the United States (figure, left). CDC genetically characterized 111 influenza viruses [12 influenza A (H1N1)pdm09, 84 influenza A (H3N2), and 15 influenza B viruses] collected by U.S. laboratories. The HA gene segment of all influenza A (H1N1)pdm09 viruses analyzed belonged to genetic group 6B.1. Influenza A (H3N2) virus HA gene segments analyzed belonged to genetic groups 3C.2a or 3C.3a. Genetic group 3C.2a includes a newly emerging subgroup known as 3C.2a1. The HA of influenza B/Victoria-lineage viruses all belonged to genetic group V1A. The HA of influenza B/Yamagata-lineage viruses analyzed all belonged to genetic group Y3.
The majority of U.S. viruses submitted for characterization come from state and local public health laboratories. Due to Right Size Roadmapconsiderations, specimen submission guidance issued to the laboratories request that, if available, 2 influenza A (H1N1), 2 A influenza (H3N2), and 2 influenza B viruses be submitted every other week. Because of this, the number of each virus type/subtype characterized should be approximately equal. In the figure below, the results of tests performed by public health labs are presented on the left and sequence results by genetic group of specimens submitted to CDC are presented on the right.
Genetic47_small.gif

View Chart Data | View Full Screen | View PowerPoint Presentation [h=2]Antigenic Characterization[/h] CDC has antigenically characterized 34 influenza viruses [7 influenza A (H1N1)pdm09, 15 influenza A (H3N2), and 12 influenza B viruses] collected by U.S. laboratories since October 1, 2016.
Influenza A Virus [22]
  • A (H1N1)pdm09 [7]: All 7 (100%) influenza A (H1N1)pdm09 viruses were antigenically characterized using ferret post-infection antisera as A/California/7/2009-like, the influenza A (H1N1) component of the 2016-2017 Northern Hemisphere vaccine.
  • A (H3N2) [15]: All 15 (100%) influenza A (H3N2) viruses were antigenically characterized as A/Hong Kong/4801/2014-like, a virus that belongs in genetic group 3C.2a and is the influenza A (H3N2) component of the 2016-2017 Northern Hemisphere vaccine, by HI testing or neutralization testing.
Influenza B Virus [12]
  • Victoria Lineage [5]: All 5 (100%) B/Victoria-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Brisbane/60/2008-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere trivalent and quadrivalent influenza vaccines.
  • Yamagata Lineage [7]: All 7 (100%) B/Yamagata-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Phuket/3073/2013-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere quadrivalent influenza vaccines.

[h=2]Antiviral Resistance:[/h] Testing of influenza A (H1N1)pdm09, influenza A (H3N2), and influenza B virus isolates for resistance to neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) is performed at CDC using a functional assay. Additional influenza A (H1N1)pdm09 and influenza A (H3N2) clinical samples are tested for mutations of the virus known to confer oseltamivir resistance. The data summarized below combine the results of both testing methods. These samples are routinely obtained for surveillance purposes rather than for diagnostic testing of patients suspected to be infected with antiviral-resistant virus.
High levels of resistance to the adamantanes (amantadine and rimantadine) persist among influenza A (H1N1)pdm09 and influenza A (H3N2) viruses (the adamantanes are not effective against influenza B viruses). Therefore, data from adamantane resistance testing are not presented below.
[TABLE="class: table, align: center, border: 0, cellpadding: 3, cellspacing: 0, width: 100%"]
[h=3]Neuraminidase Inhibitor Resistance Testing Results on Samples Collected Since October 1, 2016[/h] [/TABLE]
[TABLE="class: table table-bordered opt-in, width: 100%"]
[TR]
[TD] [/TD]
Oseltamivir​
Zanamivir​
Peramivir​
[/TR]
[TR]
[TD] [/TD]
Virus Samples tested (n)
Resistant Viruses, Number (%)​
Virus Samples tested (n)
Resistant Viruses, Number (%)​
Virus Samples tested (n)
Resistant Viruses, Number (%)​
[/TR]
[TR]
Influenza A(H1N1)pdm09
[TD]
17​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
17​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
17​
[/TD]
[TD]
0 (0.0)​
[/TD]
[/TR]
[TR]
Influenza A(H3N2)
[TD]
79​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
79​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
61​
[/TD]
[TD]
0 (0.0)​
[/TD]
[/TR]
[TR]
Influenza B
[TD]
20​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
20​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
20​
[/TD]
[TD]
0 (0.0)​
[/TD]
[/TR]
[/TABLE]
The majority of recently circulating influenza viruses are susceptible to the neuraminidase inhibitor antiviral medications, oseltamivir, zanamivir, and peramivir; however, rare sporadic instances of oseltamivir-resistant and peramivir-resistant influenza A (H1N1)pdm09 viruses and oseltamivir-resistant influenza A (H3N2) viruses have been detected worldwide. Antiviral treatment as early as possible is recommended for patients with confirmed or suspected influenza who have severe, complicated, or progressive illness; who require hospitalization; or who are at high risk for serious influenza-related complications. Additional information on recommendations for treatment and chemoprophylaxis of influenza virus infection with antiviral agents is available at http://www.cdc.gov/flu/antivirals/index.htm.


[h=2]Pneumonia and Influenza (P&I) Mortality Surveillance:[/h] Based on National Center for Health Statistics (NCHS) mortality surveillance data available on November 30, 2016, 5.2% of the deaths occurring during the week ending November 12, 2016 (week 45) were due to P&I. This percentage is below the epidemic threshold of 6.9% for week 45.
Weekly mortality surveillance data includes a combination of machine coded and manually coded causes of death collected from death certificates. A backlog of data requiring manual coding continues to exist within NCHS mortality surveillance data. The percentages of deaths due to P&I are higher among manually coded records than more rapidly available machine coded records and may result in initially reported P&I percentages that are lower than percentages calculated from final data. Efforts continue to reduce and monitor the number of records awaiting manual coding. During week 47, it was determined that data from the summer months were sufficient to allow re-calculation of seasonal baseline and epidemic threshold values. Those modified values are used in the current report and will be used going forward.
Beginning in the week ending October 8, 2016 (week 40), CDC retired the 122 Cities Mortality Reporting System and uses only the NCHS Mortality Surveillance System.
Region and state-specific data are available at http://gis.cdc.gov/grasp/fluview/mortality.html.
NCHS47_small.gif

View Regional and State Level Data | View Chart Data | View Full Screen | View PowerPoint Presentation

[h=2]Influenza-Associated Pediatric Mortality:[/h] No influenza-associated pediatric deaths were reported to CDC during week 47.
Additional data can be found at: http://gis.cdc.gov/GRASP/Fluview/PedFluDeath.html.

View Interactive Application | View Full Screen | View PowerPoint Presentation


[h=2]Influenza-Associated Hospitalizations:[/h] The Influenza Hospitalization Surveillance Network (FluSurv-NET) conducts population-based surveillance for laboratory-confirmed influenza-related hospitalizations in select counties in the Emerging Infections Program (EIP) states and Influenza Hospitalization Surveillance Project (IHSP) states. FluSurv-NET estimated hospitalization rates will be updated weekly starting later this season. Additional FluSurv-NET data can be found at:http://gis.cdc.gov/GRASP/Fluview/FluHospRates.html and http://gis.cdc.gov/grasp/fluview/FluHospChars.html.



[h=2]Outpatient Illness Surveillance:[/h] Nationwide during week 47, 1.8% of patient visits reported through the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) were due to influenza-like illness (ILI). This percentage is below the national baseline of 2.2%.
(ILI is defined as fever (temperature of 100?F [37.8?C] or greater) and cough and/or sore throat.)
Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html.

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation On a regional level, the percentage of outpatient visits for ILI ranged from 0.8% to 3.5% during week 47. Three regions (regions 2, 4, and 10) reported a proportion of outpatient visits for ILI at or above their region-specific baseline levels.



[h=2]ILINet State Activity Indicator Map:[/h] Data collected in ILINet are used to produce a measure of ILI activity* by state. Activity levels are based on the percent of outpatient visits in a state due to ILI and are compared to the average percent of ILI visits that occur during weeks with little or no influenza virus circulation. Activity levels range from minimal, which would correspond to ILI activity from outpatient clinics being below, or only slightly above, the average, to high, which would correspond to ILI activity from outpatient clinics being much higher than average.
During week 47, the following ILI activity levels were experienced:
  • Puerto Rico experienced high ILI activity.
  • One state (Georgia) experienced moderate ILI activity.
  • New York City and five states (Mississippi, North Carolina, Oklahoma, South Carolina, and Virginia) experienced low ILI activity.
  • 44 states (Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Dakota, Ohio, Oregon, Pennsylvania, Rhode Island, South Dakota, Tennessee, Texas, Utah, Vermont, Washington, West Virginia, Wisconsin, and Wyoming) experienced minimal ILI activity.
  • Data were insufficient to calculate an ILI activity level from the District of Columbia.
Click on map to launch interactive tool
*This map uses the proportion of outpatient visits to health care providers for ILI to measure the ILI activity level within a state. It does not, however, measure the extent of geographic spread of flu within a state. Therefore, outbreaks occurring in a single city could cause the state to display high activity levels.
Data collected in ILINet may disproportionally represent certain populations within a state, and therefore, may not accurately depict the full picture of influenza activity for the whole state.
Data displayed in this map are based on data collected in ILINet, whereas the State and Territorial flu activity map is based on reports from state and territorial epidemiologists. The data presented in this map is preliminary and may change as more data are received.
Differences in the data presented here by CDC and independently by some state health departments likely represent differing levels of data completeness with data presented by the state likely being the more complete.


[h=2]Geographic Spread of Influenza as Assessed by State and Territorial Epidemiologists[/h] The influenza activity reported by state and territorial epidemiologists indicates geographic spread of influenza viruses, but does not measure the severity of influenza activity.
During week 47, the following influenza activity was reported:
  • Regional influenza activity was reported by Guam, Puerto Rico, the U.S. Virgin Islands, and one state (North Carolina).
  • Local influenza activity was reported by 12 states (Alabama, Connecticut, Georgia, Indiana, Louisiana, Maine, Massachusetts, Nevada, New Hampshire, Oregon, Texas, and Washington).
  • Sporadic influenza activity was reported by the District of Columbia and 36 states (Alaska, Arizona, Arkansas, California, Colorado, Delaware, Florida, Hawaii, Idaho, Illinois, Iowa, Kansas, Kentucky, Maryland, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Jersey, New Mexico, New York, North Dakota, Ohio, Oklahoma, Pennsylvania, South Carolina, South Dakota, Tennessee, Utah, Vermont, Virginia, West Virginia, Wisconsin, and Wyoming).
  • No activity was reported by one state (Rhode Island).



[h=2]Additional National and International Influenza Surveillance Information[/h] FluView Interactive: FluView includes enhanced web-based interactive applications that can provide dynamic visuals of the influenza data collected and analyzed by CDC. These FluView Interactive applications allow people to create customized, visual interpretations of influenza data, as well as make comparisons across flu seasons, regions, age groups and a variety of other demographics. To access these tools, visithttp://www.cdc.gov/flu/weekly/fluviewinteractive.htm.
U.S. State and local influenza surveillance: Click on a jurisdiction below to access the latest local influenza information.

[TABLE="width: 100%"]
[TR]
[TD="width: 139"] Alabama
[/TD]
[TD="width: 139"] Alaska
[/TD]
[TD="width: 139"] Arizona
[/TD]
[TD="width: 139"] Arkansas
[/TD]
[TD="width: 139"] California
[/TD]
[/TR]
[TR]
[TD="width: 139"] Colorado
[/TD]
[TD="width: 139"] Connecticut
[/TD]
[TD="width: 139"] Delaware
[/TD]
[TD="width: 139"] District of Columbia
[/TD]
[TD="width: 139"] Florida
[/TD]
[/TR]
[TR]
[TD="width: 139"] Georgia
[/TD]
[TD="width: 139"] Hawaii
[/TD]
[TD="width: 139"] Idaho
[/TD]
[TD="width: 139"] Illinois
[/TD]
[TD="width: 139"] Indiana
[/TD]
[/TR]
[TR]
[TD="width: 139"] Iowa
[/TD]
[TD="width: 139"] Kansas
[/TD]
[TD="width: 139"] Kentucky
[/TD]
[TD="width: 139"] Louisiana
[/TD]
[TD="width: 139"] Maine
[/TD]
[/TR]
[TR]
[TD="width: 139"] Maryland
[/TD]
[TD="width: 139"] Massachusetts
[/TD]
[TD="width: 139"] Michigan
[/TD]
[TD="width: 139"] Minnesota
[/TD]
[TD="width: 139"] Mississippi
[/TD]
[/TR]
[TR]
[TD="width: 139"] Missouri
[/TD]
[TD="width: 139"] Montana
[/TD]
[TD="width: 139"] Nebraska
[/TD]
[TD="width: 139"] Nevada
[/TD]
[TD="width: 139"] New Hampshire
[/TD]
[/TR]
[TR]
[TD="width: 139"] New Jersey
[/TD]
[TD="width: 139"] New Mexico
[/TD]
[TD="width: 139"] New York
[/TD]
[TD="width: 139"] North Carolina
[/TD]
[TD="width: 139"] North Dakota
[/TD]
[/TR]
[TR]
[TD="width: 139"] Ohio
[/TD]
[TD="width: 139"] Oklahoma
[/TD]
[TD="width: 139"] Oregon
[/TD]
[TD="width: 139"] Pennsylvania
[/TD]
[TD="width: 139"] Rhode Island
[/TD]
[/TR]
[TR]
[TD="width: 139"] South Carolina
[/TD]
[TD="width: 139"] South Dakota
[/TD]
[TD="width: 139"] Tennessee
[/TD]
[TD="width: 139"] Texas
[/TD]
[TD="width: 139"] Utah
[/TD]
[/TR]
[TR]
[TD="width: 139"] Vermont
[/TD]
[TD="width: 139"] Virginia
[/TD]
[TD="width: 139"] Washington
[/TD]
[TD="width: 139"] West Virginia
[/TD]
[TD="width: 139"] Wisconsin
[/TD]
[/TR]
[TR]
[TD="width: 139"] Wyoming
[/TD]
[TD="width: 139"] New York City
[/TD]
[TD="width: 139"] Puerto Rico
[/TD]
[TD="width: 139"] Virgin Islands
[/TD]
[TD="width: 139"] [/TD]
[/TR]
[/TABLE]
World Health Organization: Additional influenza surveillance information from participating WHO member nations is available through FluNet and the Global Epidemiology Reports.
WHO Collaborating Centers for Influenza located in Australia, China, Japan, the United Kingdom, and the United States (CDC in Atlanta, Georgia).
Europe: For the most recent influenza surveillance information from Europe, please see WHO/Europe and the European Centre for Disease Prevention and Control at http://www.flunewseurope.org/.
Public Health Agency of Canada: The most up-to-date influenza information from Canada is available at http://www.phac-aspc.gc.ca/fluwatch/
Public Health England: The most up-to-date influenza information from the United Kingdom is available athttps://www.gov.uk/government/statistics/weekly-national-flu-reports


Any links provided to non-Federal organizations are provided solely as a service to our users. These links do not constitute an endorsement of these organizations or their programs by CDC or the Federal Government, and none should be inferred. CDC is not responsible for the content of the individual organization web pages found at these links.
An overview of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component, is available at: http://www.cdc.gov/flu/weekly/overview.htm.
--------------------------------------------------------------------------------









[h=5]File Formats Help:[/h] How do I view different file formats (PDF, DOC, PPT, MPEG) on this site?

[/COLOR]

  • Page last reviewed: December 2, 2016
  • Page last updated: December 2, 2016


http://www.cdc.gov/flu/weekly/
 
[h=3]2016-2017 Influenza Season Week 48 ending December 3, 2016[/h] [FONT=&quot]All data are preliminary and may change as more reports are received.[/FONT]
[h=3]Synopsis:[/h] [FONT=&quot]During week 48 (November 27 - December 3, 2016), influenza activity increased slightly, but remained low in the United States.[/FONT]
  • Viral Surveillance:The most frequently identified influenza virus subtype reported by public health laboratories during week 48 was influenza A (H3). The percentage of respiratory specimens testing positive for influenza in clinical laboratories remained low.
  • Pneumonia and Influenza Mortality: Due to data processing problems, the National Center for Health Statistics (NCHS) mortality surveillance data for the week ending November 19, 2016 (week 46) will not be published this week.
  • Influenza-associated Pediatric Deaths: No influenza-associated pediatric deaths were reported.
  • Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 1.8%, which is below the national baseline of 2.2%. Two regions reported ILI at or above their region-specific baseline levels. Puerto Rico experienced high ILI activity, New York City and four states experienced low ILI activity, 46 states experienced minimal ILI activity, and the District of Columbia had insufficient data.
  • Geographic Spread of Influenza:The geographic spread of influenza in Puerto Rico was reported as widespread; Guam and two states were reported as regional; 19 states reported local activity; the U.S. Virgin Islands and 28 states reported sporadic activity; one state reported no activity; and the District of Columbia did not report.
[h=3]National and Regional Summary of Select Surveillance Components[/h]
[FONT=&quot] [TABLE="class: table table-bordered opt-in"]
[TR]
[/TR]
[TR]
HHS Surveillance Regions* Data for current week Data cumulative since October 2, 2016 (week 40) [/TR]
[TR]
Out-patient ILI[SUP]?[/SUP] Number of jurisdictions reporting regional or widespread activity[SUP]?[/SUP] % respiratory specimens positive for flu in clinical laboratories[SUP]?[/SUP] A(H1N1)pdm09 A (H3) A (Subtyping not Performed) B Victoria lineage B Yamagata lineage B lineage not performed Pediatric Deaths [/TR]
[TR]
Influenza test results from public health laboratories only [/TR]
[TR]
Nation [TD]Normal[/TD]
[TD]4 of 54[/TD]
[TD]3.5%[/TD]
[TD]73[/TD]
[TD]899[/TD]
[TD]78[/TD]
[TD]37[/TD]
[TD]23[/TD]
[TD]50[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 1 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]1.9%[/TD]
[TD]0[/TD]
[TD]41[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 2 [TD]Elevated[/TD]
[TD]1 of 4[/TD]
[TD]2.0%[/TD]
[TD]0[/TD]
[TD]70[/TD]
[TD]2[/TD]
[TD]16[/TD]
[TD]4[/TD]
[TD]3[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 3 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]0.9%[/TD]
[TD]7[/TD]
[TD]66[/TD]
[TD]9[/TD]
[TD]1[/TD]
[TD]2[/TD]
[TD]7[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 4 [TD]Elevated[/TD]
[TD]2 of 8[/TD]
[TD]6.1%[/TD]
[TD]5[/TD]
[TD]76[/TD]
[TD]10[/TD]
[TD]3[/TD]
[TD]2[/TD]
[TD]29[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 5 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]1.4%[/TD]
[TD]3[/TD]
[TD]68[/TD]
[TD]41[/TD]
[TD]7[/TD]
[TD]4[/TD]
[TD]2[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 6 [TD]Normal[/TD]
[TD]0 of 5[/TD]
[TD]2.0%[/TD]
[TD]11[/TD]
[TD]24[/TD]
[TD]0[/TD]
[TD]5[/TD]
[TD]5[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 7 [TD]Normal[/TD]
[TD]0 of 4[/TD]
[TD]1.6%[/TD]
[TD]0[/TD]
[TD]22[/TD]
[TD]1[/TD]
[TD]2[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 8 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]2.7%[/TD]
[TD]28[/TD]
[TD]89[/TD]
[TD]2[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 9 [TD]Normal[/TD]
[TD]1 of 5[/TD]
[TD]3.0%[/TD]
[TD]18[/TD]
[TD]241[/TD]
[TD]11[/TD]
[TD]1[/TD]
[TD]6[/TD]
[TD]5[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 10 [TD]Normal[/TD]
[TD]0 of 4[/TD]
[TD]8.7%[/TD]
[TD]1[/TD]
[TD]202[/TD]
[TD]2[/TD]
[TD]2[/TD]
[TD]0[/TD]
[TD]4[/TD]
[TD]0[/TD]
[/TR]
[/TABLE]
[/FONT]
[FONT=&quot]*HHS regions (Region 1 CT, ME, MA, NH, RI, VT; Region 2: NJ, NY, Puerto Rico, US Virgin Islands; Region 3: DE, DC, MD, PA, VA, WV; Region 4: AL, FL, GA, KY, MS, NC, SC, TN; Region 5: IL, IN, MI, MN, OH, WI; Region 6: AR, LA, NM, OK, TX; Region 7: IA, KS, MO, NE; Region 8: CO, MT, ND, SD, UT, WY; Region 9: AZ, CA, Guam, HI, NV; and Region 10: AK, ID, OR, WA).
? Elevated means the % of visits for ILI is at or above the national or region-specific baseline
? Includes all 50 states, the District of Columbia, Guam, Puerto Rico, and U.S. Virgin Islands
? National data are for current week; regional data are for the most recent three weeks

[/FONT]

[h=2]U.S. Virologic Surveillance:[/h] [FONT=&quot]WHO and NREVSS collaborating laboratories, which include both public health and clinical laboratories located in all 50 states, Puerto Rico, and the District of Columbia, report to CDC the total number of respiratory specimens tested for influenza and the number positive for influenza by virus type. In addition, public health laboratories also report the influenza A subtype (H1 or H3) and influenza B lineage information for the viruses they test and the age or age group of the persons from whom the specimens were collected.[/FONT]
[FONT=&quot]Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html and http://gis.cdc.gov/grasp/fluview/flu_by_age_virus.html.[/FONT]
[FONT=&quot]The results of tests performed by clinical laboratories during the current week are summarized below.[/FONT]
[TABLE="class: table table-bordered table-condensed opt-in"]
[TR]
[TD="width: 200"] [/TD]
Week 48 Data Cumulative since
October 2, 2016 (Week 40) [/TR]
[TR]
No. of specimens tested [TD]15,262[/TD]
[TD]135,871[/TD]
[/TR]
[TR]
No. of positive specimens (%) [TD]535 (3.5%)[/TD]
[TD]3,087 (2.3%)[/TD]
[/TR]
[TR]
Positive specimens by type [TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
Influenza A [TD]390 (72.9%)[/TD]
[TD]2,052 (66.5%)[/TD]
[/TR]
[TR]
Influenza B [TD]145 (27.1%)[/TD]
[TD]1,035 (33.5%)[/TD]
[/TR]
[/TABLE]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation
[FONT=&quot]The results of tests performed by public health laboratories, as well as the age group distribution of influenza positive tests, during the current week are summarized below.[/FONT]
[TABLE="class: table table-bordered table-condensed opt-in"]
[TR]
[TD] [/TD]
Week 48 Data Cumulative since
October 2, 2016 (Week 40) [/TR]
[TR]
No. of specimens tested [TD]783[/TD]
[TD]9,049[/TD]
[/TR]
[TR]
No. of positive specimens* [TD]154[/TD]
[TD]1,160[/TD]
[/TR]
[TR]
Positive specimens by type/subtype [TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
Influenza A [TD]141 (91.6%)[/TD]
[TD]1,050 (90.5%)[/TD]
[/TR]
[TR]
A(H1N1)pmd09 [TD]6 (4.3%)[/TD]
[TD]73 (7.0%)[/TD]
[/TR]
[TR]
H3 [TD]112 (79.4%)[/TD]
[TD]899 (85.6%)[/TD]
[/TR]
[TR]
Subtyping not performed [TD]23 (16.3%)[/TD]
[TD]78 (7.4%)[/TD]
[/TR]
[TR]
Influenza B [TD]13 (8.4%)[/TD]
[TD]110 (9.5%)[/TD]
[/TR]
[TR]
Yamagata lineage [TD]2 (15.4%)[/TD]
[TD]23 (20.9%)[/TD]
[/TR]
[TR]
Victoria lineage [TD]2 (15.4%)[/TD]
[TD]37 (33.6%)[/TD]
[/TR]
[TR]
Lineage not performed [TD]9 (69.2%)[/TD]
[TD]50 (45.5%)[/TD]
[/TR]
[/TABLE]
[FONT=&quot]*The percent of specimens testing positive for influenza is not reported because public health laboratories often receive samples that have already tested positive for influenza at a clinical laboratory and therefore percent positive would not be a valid indicator of influenza activity. Additional information is available at http://www.cdc.gov/flu/weekly/overview.htm.
[/FONT]


View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation


View Interactive Application | View Full Screen

[h=2]Influenza Virus Characterization:[/h] [FONT=&quot]CDC characterizes influenza viruses through one or more tests including genomic sequencing, hemagglutination inhibition (HI) and/or neutralization assays. These data are used to compare how similar currently circulating influenza viruses are to the reference viruses used for developing influenza vaccines, and to monitor for changes in circulating influenza viruses. Historically, HI data have been used most commonly to assess the similarity between reference viruses and circulating viruses to suggest how well the vaccine may work until such a time as vaccine effectiveness estimates are available.[/FONT]
[FONT=&quot]For nearly all virus positive surveillance samples received at CDC, next-generation sequencing is performed to ascertain genomic data of circulating influenza viruses. Viruses can be classified into genetic groups/clades based on analysis of their HA gene segments using phylogenetics and key amino acid changes (Klimov Vaccine 2012).[/FONT]
[FONT=&quot]A proportion of influenza A (H3N2) viruses don?t yield sufficient hemagglutination titers for antigenic characterization using the hemagglutination inhibition test. Therefore, CDC selects a subset of influenza A (H3N2) viruses to test using a focus reduction assay for supplementary antigenic characterization.[/FONT]
[h=2]Genetic Characterization[/h] [FONT=&quot]During the 2016-2017 season, 1,160 influenza positive specimens have been collected and reported by public health laboratories in the United States (figure, left). CDC genetically characterized 141 influenza viruses [17 influenza A (H1N1)pdm09, 101 influenza A (H3N2), and 23 influenza B viruses] collected by U.S. laboratories. The HA gene segment of all influenza A (H1N1)pdm09 viruses analyzed belonged to genetic group 6B.1. Influenza A (H3N2) virus HA gene segments analyzed belonged to genetic groups 3C.2a or 3C.3a. Genetic group 3C.2a includes a newly emerging subgroup known as 3C.2a1. The HA of influenza B/Victoria-lineage viruses all belonged to genetic group V1A. The HA of influenza B/Yamagata-lineage viruses analyzed all belonged to genetic group Y3.[/FONT]
[FONT=&quot]The majority of U.S. viruses submitted for characterization come from state and local public health laboratories. Due to Right Size Roadmap considerations, specimen submission guidance issued to the laboratories request that, if available, 2 influenza A (H1N1), 2 A influenza (H3N2), and 2 influenza B viruses be submitted every other week. Because of this, the number of each virus type/subtype characterized should be approximately equal. In the figure below, the results of tests performed by public health labs are presented on the left and sequence results by genetic group of specimens submitted to CDC are presented on the right.[/FONT]
Genetic48_small.gif

View Chart Data | View Full Screen | View PowerPoint Presentation
[h=2]Antigenic Characterization[/h] [FONT=&quot]CDC has antigenically characterized 38 influenza viruses [8 influenza A (H1N1)pdm09, 16 influenza A (H3N2), and 14 influenza B viruses] collected by U.S. laboratories since October 1, 2016.[/FONT]
[FONT=&quot]Influenza A Virus [24][/FONT]
  • A (H1N1)pdm09 [8]: All 8 (100%) influenza A (H1N1)pdm09 viruses were antigenically characterized using ferret post-infection antisera as A/California/7/2009-like, the influenza A (H1N1) component of the 2016-2017 Northern Hemisphere vaccine.
  • A (H3N2) [16]: All 16 (100%) influenza A (H3N2) viruses were antigenically characterized as A/Hong Kong/4801/2014-like, a virus that belongs in genetic group 3C.2a and is the influenza A (H3N2) component of the 2016-2017 Northern Hemisphere vaccine, by HI testing or neutralization testing.
[FONT=&quot]Influenza B Virus [14][/FONT]
  • Victoria Lineage [6]: 5 of 6 (83%) B/Victoria-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Brisbane/60/2008-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere trivalent and quadrivalent influenza vaccines.
  • Yamagata Lineage [8]: All 8 (100%) B/Yamagata-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Phuket/3073/2013-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere quadrivalent influenza vaccines.
[FONT=&quot]
[/FONT]

[h=2]Antiviral Resistance:[/h] [FONT=&quot]Testing of influenza A (H1N1)pdm09, influenza A (H3N2), and influenza B virus isolates for resistance to neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) is performed at CDC using a functional assay. Additional influenza A (H1N1)pdm09 and influenza A (H3N2) clinical samples are tested for mutations of the virus known to confer oseltamivir resistance. The data summarized below combine the results of both testing methods. These samples are routinely obtained for surveillance purposes rather than for diagnostic testing of patients suspected to be infected with antiviral-resistant virus.[/FONT]
[FONT=&quot]High levels of resistance to the adamantanes (amantadine and rimantadine) persist among influenza A (H1N1)pdm09 and influenza A (H3N2) viruses (the adamantanes are not effective against influenza B viruses). Therefore, data from adamantane resistance testing are not presented below.[/FONT]
[TABLE="class: table, align: center, border: 0, cellpadding: 3, cellspacing: 0"]
[h=3]Neuraminidase Inhibitor Resistance Testing Results on Samples Collected Since October 1, 2016[/h] [/TABLE]
[TABLE="class: table table-bordered opt-in"]
[TR]
[TD] [/TD]
Oseltamivir
Zanamivir
Peramivir
[/TR]
[TR]
[TD] [/TD]
Virus Samples tested (n)
Resistant Viruses, Number (%)
Virus Samples tested (n)
Resistant Viruses, Number (%)
Virus Samples tested (n)
Resistant Viruses, Number (%)
[/TR]
[TR]
Influenza A (H1N1)pdm09
[TD] 24
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 24
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 24
[/TD]
[TD] 0 (0.0)
[/TD]
[/TR]
[TR]
Influenza A (H3N2)
[TD] 104
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 104
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 80
[/TD]
[TD] 0 (0.0)
[/TD]
[/TR]
[TR]
Influenza B
[TD] 28
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 28
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 28
[/TD]
[TD] 0 (0.0)
[/TD]
[/TR]
[/TABLE]
[FONT=&quot]The majority of recently circulating influenza viruses are susceptible to the neuraminidase inhibitor antiviral medications, oseltamivir, zanamivir, and peramivir; however, rare sporadic instances of oseltamivir-resistant and peramivir-resistant influenza A (H1N1)pdm09 viruses and oseltamivir-resistant influenza A (H3N2) viruses have been detected worldwide. Antiviral treatment as early as possible is recommended for patients with confirmed or suspected influenza who have severe, complicated, or progressive illness; who require hospitalization; or who are at high risk for serious influenza-related complications. Additional information on recommendations for treatment and chemoprophylaxis of influenza virus infection with antiviral agents is available athttp://www.cdc.gov/flu/antivirals/index.htm.[/FONT]


[h=2]Pneumonia and Influenza (P&I) Mortality Surveillance:[/h] [FONT=&quot]Due to data processing problems, the National Center for Health Statistics (NCHS) mortality surveillance data for the week ending November 19, 2016 (week 46) will not be published this week. Instead, updated data through the week ending November 12, 2016 (week 45) is presented below.[/FONT]
[FONT=&quot]Background: Weekly mortality surveillance data includes a combination of machine coded and manually coded causes of death collected from death certificates. There is a backlog of data requiring manual coding within NCHS mortality surveillance data. The percentages of deaths due to P&I are higher among manually coded records than more rapidly available machine coded records and may result in initially reported P&I percentages that are lower than percentages calculated from final data. Efforts continue to reduce and monitor the number of records awaiting manual coding.[/FONT]
[FONT=&quot]Beginning in the week ending October 8, 2016 (week 40), CDC retired the 122 Cities Mortality Reporting System and uses only the NCHS Mortality Surveillance System.[/FONT]
[FONT=&quot]Region and state-specific data are available at http://gis.cdc.gov/grasp/fluview/mortality.html.[/FONT]
NCHS48_small.gif

View Regional and State Level Data | View Chart Data | View Full Screen | View PowerPoint Presentation

[h=2]Influenza-Associated Pediatric Mortality:[/h] [FONT=&quot]No influenza-associated pediatric deaths were reported to CDC during week 48.[/FONT]
[FONT=&quot]Additional data can be found at: [/FONT]http://gis.cdc.gov/GRASP/Fluview/PedFluDeath.html[FONT=&quot].[/FONT] [FONT=&quot] [/FONT]

View Interactive Application | View Full Screen | View PowerPoint Presentation


[h=2]Influenza-Associated Hospitalizations:[/h] [FONT=&quot]The Influenza Hospitalization Surveillance Network (FluSurv-NET) conducts population-based surveillance for laboratory-confirmed influenza-related hospitalizations in select counties in the Emerging Infections Program (EIP) states and Influenza Hospitalization Surveillance Project (IHSP) states. FluSurv-NET estimated hospitalization rates will be updated weekly starting later this season. Additional FluSurv-NET data can be found at: http://gis.cdc.gov/GRASP/Fluview/FluHospRates.html and http://gis.cdc.gov/grasp/fluview/FluHospChars.html.[/FONT]



[h=2]Outpatient Illness Surveillance:[/h] [FONT=&quot]Nationwide during week 48, 1.8% of patient visits reported through the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) were due to influenza-like illness (ILI). This percentage is below the national baseline of 2.2%.[/FONT]
[FONT=&quot](ILI is defined as fever (temperature of 100?F [37.8?C] or greater) and cough and/or sore throat.)[/FONT]
[FONT=&quot]Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html.[/FONT]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation
[FONT=&quot]On a regional level, the percentage of outpatient visits for ILI ranged from 0.8% to 3.5% during week 48. Two regions (regions 2 and 4) reported a proportion of outpatient visits for ILI at or above their region-specific baseline levels.[/FONT]
[FONT=&quot]

[/FONT]

[h=2]ILINet State Activity Indicator Map:[/h] [FONT=&quot]Data collected in ILINet are used to produce a measure of ILI activity* by state. Activity levels are based on the percent of outpatient visits in a state due to ILI and are compared to the average percent of ILI visits that occur during weeks with little or no influenza virus circulation. Activity levels range from minimal, which would correspond to ILI activity from outpatient clinics being below, or only slightly above, the average, to high, which would correspond to ILI activity from outpatient clinics being much higher than average.[/FONT]
[FONT=&quot]During week 48, the following ILI activity levels were experienced:[/FONT]
  • Puerto Rico experienced high ILI activity.
  • New York City and four states (Colorado, Georgia, Louisiana, and Nevada) experienced low ILI activity.
  • 46 states (Alabama, Alaska, Arizona, Arkansas, California, Connecticut, Delaware, Florida, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, and Wyoming) experienced minimal ILI activity
  • Data were insufficient to calculate an ILI activity level from the District of Columbia.
[FONT=&quot][/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]Click on map to launch interactive tool[/FONT]
[FONT=&quot]*This map uses the proportion of outpatient visits to health care providers for ILI to measure the ILI activity level within a state. It does not, however, measure the extent of geographic spread of flu within a state. Therefore, outbreaks occurring in a single city could cause the state to display high activity levels.
Data collected in ILINet may disproportionally represent certain populations within a state, and therefore, may not accurately depict the full picture of influenza activity for the whole state.
Data displayed in this map are based on data collected in ILINet, whereas the State and Territorial flu activity map is based on reports from state and territorial epidemiologists. The data presented in this map is preliminary and may change as more data are received.
Differences in the data presented here by CDC and independently by some state health departments likely represent differing levels of data completeness with data presented by the state likely being the more complete.[/FONT]



[h=2]Geographic Spread of Influenza as Assessed by State and Territorial Epidemiologists[/h] [FONT=&quot]The influenza activity reported by state and territorial epidemiologists indicates geographic spread of influenza viruses, but does not measure the severity of influenza activity.[/FONT]
[FONT=&quot]During week 48, the following influenza activity was reported:[/FONT]
  • Widespread influenza activity was reported by Puerto Rico.
  • Regional influenza activity was reported by Guam and two states (Alabama and North Carolina).
  • Local influenza activity was reported by 19 states (Arizona, Connecticut, Delaware, Indiana, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Minnesota, Nevada, New Hampshire, Ohio, Oklahoma, Oregon, Pennsylvania, Texas, Virginia, and Washington).
  • Sporadic influenza activity was reported by the U.S. Virgin Islands and 28 states (Alaska, Arkansas, California, Colorado, Florida, Georgia, Hawaii, Idaho, Illinois, Iowa, Kansas, Michigan, Mississippi, Missouri, Montana, Nebraska, New Jersey, New Mexico, New York, North Dakota, South Carolina, South Dakota, Tennessee, Utah, Vermont, West Virginia, Wisconsin, and Wyoming).
  • No activity was reported by one state (Rhode Island).
  • The District of Columbia did not report.
[FONT=&quot][/FONT]


[FONT=&quot] [/FONT]
[h=2]Additional National and International Influenza Surveillance Information[/h] [FONT=&quot]FluView Interactive: FluView includes enhanced web-based interactive applications that can provide dynamic visuals of the influenza data collected and analyzed by CDC. These FluView Interactive applications allow people to create customized, visual interpretations of influenza data, as well as make comparisons across flu seasons, regions, age groups and a variety of other demographics. To access these tools, visit http://www.cdc.gov/flu/weekly/fluviewinteractive.htm.[/FONT]
[FONT=&quot]U.S. State and local influenza surveillance: Click on a jurisdiction below to access the latest local influenza information.[/FONT]
[FONT=&quot] [/FONT]

[TD="width: 139"] Alabama
[/TD]
[TD="width: 139"] Alaska
[/TD]
[TD="width: 139"] Arizona
[/TD]
[TD="width: 139"] Arkansas
[/TD]
[TD="width: 139"] California
[/TD]

[TD="width: 139"] Colorado
[/TD]
[TD="width: 139"] Connecticut
[/TD]
[TD="width: 139"] Delaware
[/TD]
[TD="width: 139"] District of Columbia
[/TD]
[TD="width: 139"] Florida
[/TD]

[TD="width: 139"] Georgia
[/TD]
[TD="width: 139"] Hawaii
[/TD]
[TD="width: 139"] Idaho
[/TD]
[TD="width: 139"] Illinois
[/TD]
[TD="width: 139"] Indiana
[/TD]

[TD="width: 139"] Iowa
[/TD]
[TD="width: 139"] Kansas
[/TD]
[TD="width: 139"] Kentucky
[/TD]
[TD="width: 139"] Louisiana
[/TD]
[TD="width: 139"] Maine
[/TD]

[TD="width: 139"] Maryland
[/TD]
[TD="width: 139"] Massachusetts
[/TD]
[TD="width: 139"] Michigan
[/TD]
[TD="width: 139"] Minnesota
[/TD]
[TD="width: 139"] Mississippi
[/TD]

[TD="width: 139"] Missouri
[/TD]
[TD="width: 139"] Montana
[/TD]
[TD="width: 139"] Nebraska
[/TD]
[TD="width: 139"] Nevada
[/TD]
[TD="width: 139"] New Hampshire
[/TD]

[TD="width: 139"] New Jersey
[/TD]
[TD="width: 139"] New Mexico
[/TD]
[TD="width: 139"] New York
[/TD]
[TD="width: 139"] North Carolina
[/TD]
[TD="width: 139"] North Dakota
[/TD]

[TD="width: 139"] Ohio
[/TD]
[TD="width: 139"] Oklahoma
[/TD]
[TD="width: 139"] Oregon
[/TD]
[TD="width: 139"] Pennsylvania
[/TD]
[TD="width: 139"] Rhode Island
[/TD]

[TD="width: 139"] South Carolina
[/TD]
[TD="width: 139"] South Dakota
[/TD]
[TD="width: 139"] Tennessee
[/TD]
[TD="width: 139"] Texas
[/TD]
[TD="width: 139"] Utah
[/TD]

[TD="width: 139"] Vermont
[/TD]
[TD="width: 139"] Virginia
[/TD]
[TD="width: 139"] Washington
[/TD]
[TD="width: 139"] West Virginia
[/TD]
[TD="width: 139"] Wisconsin
[/TD]

[TD="width: 139"] Wyoming
[/TD]
[TD="width: 139"] New York City
[/TD]
[TD="width: 139"] Puerto Rico
[/TD]
[TD="width: 139"] Virgin Islands
[/TD]
[TD="width: 139"] [/TD]

[FONT=&quot]World Health Organization: Additional influenza surveillance information from participating WHO member nations is available through FluNet and the Global Epidemiology Reports.[/FONT]
[FONT=&quot]WHO Collaborating Centers for Influenza located in Australia, China, Japan, the United Kingdom, and the United States (CDC in Atlanta, Georgia).[/FONT]
[FONT=&quot]Europe: For the most recent influenza surveillance information from Europe, please see WHO/Europe and the European Centre for Disease Prevention and Control at http://www.flunewseurope.org/.[/FONT]
[FONT=&quot]Public Health Agency of Canada: The most up-to-date influenza information from Canada is available at http://www.phac-aspc.gc.ca/fluwatch/[/FONT]
[FONT=&quot]Public Health England: The most up-to-date influenza information from the United Kingdom is available at https://www.gov.uk/government/statistics/weekly-national-flu-reports[/FONT]
[FONT=&quot] [/FONT]

[FONT=&quot] [/FONT]
Any links provided to non-Federal organizations are provided solely as a service to our users. These links do not constitute an endorsement of these organizations or their programs by CDC or the Federal Government, and none should be inferred. CDC is not responsible for the content of the individual organization web pages found at these links. [FONT=&quot] [/FONT]
[FONT=&quot]An overview of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component, is available at: http://www.cdc.gov/flu/weekly/overview.htm.

https://www.cdc.gov/flu/weekly/weeklyarchives2016-2017/Week48.htm
[/FONT]
 
[h=3]2016-2017 Influenza Season Week 49 ending December 10, 2016[/h] [FONT=&quot]All data are preliminary and may change as more reports are received.[/FONT]
[h=3]Synopsis:[/h] [FONT=&quot]During week 49 (December 4-10, 2016), influenza activity increased slightly in the United States.[/FONT]
  • Viral Surveillance:The most frequently identified influenza virus subtype reported by public health laboratories during week 49 was influenza A (H3). The percentage of respiratory specimens testing positive for influenza in clinical laboratories increased slightly.
  • Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was below the system-specific epidemic threshold in the National Center for Health Statistics (NCHS) Mortality Surveillance System.
  • Influenza-associated Pediatric Deaths: No influenza-associated pediatric deaths were reported.
  • Influenza-associated Hospitalizations: A cumulative rate for the season of 1.7 laboratory-confirmed influenza-associated hospitalizations per 100,000 population was reported.
  • Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 1.9%, which is below the national baseline of 2.2%. Two regions reported ILI at or above their region-specific baseline levels. Puerto Rico experienced high ILI activity, one state experienced moderate ILI activity, New York City and four states experienced low ILI activity, 45 states experienced minimal ILI activity, and the District of Columbia had insufficient data.
  • Geographic Spread of Influenza:The geographic spread of influenza in Puerto Rico was reported as widespread; Guam, the U.S. Virgin Islands, and seven states were reported as regional; the District of Columbia and 22 states reported local activity; 20 states reported sporadic activity; and one state reported no activity.
[h=3]National and Regional Summary of Select Surveillance Components[/h]
[FONT=&quot] [TABLE="class: table table-bordered opt-in"]
[TR]
[/TR]
[TR]
HHS Surveillance Regions* Data for current week Data cumulative since October 2, 2016 (week 40) [/TR]
[TR]
Out-patient ILI[SUP]?[/SUP] Number of jurisdictions reporting regional or widespread activity[SUP]?[/SUP] % respiratory specimens positive for flu in clinical laboratories[SUP]?[/SUP] A(H1N1)pdm09 A (H3) A (Subtyping not Performed) B Victoria lineage B Yamagata lineage B lineage not performed Pediatric Deaths [/TR]
[TR]
Influenza test results from public health laboratories only [/TR]
[TR]
Nation [TD]Normal[/TD]
[TD]10 of 54[/TD]
[TD]4.8%[/TD]
[TD]85[/TD]
[TD]1,201[/TD]
[TD]110[/TD]
[TD]47[/TD]
[TD]29[/TD]
[TD]61[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 1 [TD]Normal[/TD]
[TD]2 of 6[/TD]
[TD]2.0%[/TD]
[TD]0[/TD]
[TD]57[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 2 [TD]Elevated[/TD]
[TD]3 of 4[/TD]
[TD]2.9%[/TD]
[TD]0[/TD]
[TD]79[/TD]
[TD]2[/TD]
[TD]16[/TD]
[TD]4[/TD]
[TD]3[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 3 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]1.4%[/TD]
[TD]10[/TD]
[TD]113[/TD]
[TD]20[/TD]
[TD]2[/TD]
[TD]5[/TD]
[TD]8[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 4 [TD]Elevated[/TD]
[TD]1 of 8[/TD]
[TD]7.0%[/TD]
[TD]7[/TD]
[TD]120[/TD]
[TD]11[/TD]
[TD]4[/TD]
[TD]4[/TD]
[TD]36[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 5 [TD]Normal[/TD]
[TD]1 of 6[/TD]
[TD]1.7%[/TD]
[TD]3[/TD]
[TD]79[/TD]
[TD]60[/TD]
[TD]14[/TD]
[TD]4[/TD]
[TD]5[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 6 [TD]Normal[/TD]
[TD]1 of 5[/TD]
[TD]2.3%[/TD]
[TD]12[/TD]
[TD]33[/TD]
[TD]0[/TD]
[TD]5[/TD]
[TD]5[/TD]
[TD]1[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 7 [TD]Normal[/TD]
[TD]0 of 4[/TD]
[TD]2.0%[/TD]
[TD]0[/TD]
[TD]32[/TD]
[TD]1[/TD]
[TD]2[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 8 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]3.8%[/TD]
[TD]29[/TD]
[TD]150[/TD]
[TD]3[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 9 [TD]Normal[/TD]
[TD]1 of 5[/TD]
[TD]4.6%[/TD]
[TD]22[/TD]
[TD]321[/TD]
[TD]10[/TD]
[TD]2[/TD]
[TD]6[/TD]
[TD]4[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 10 [TD]Normal[/TD]
[TD]1 of 4[/TD]
[TD]8.6%[/TD]
[TD]2[/TD]
[TD]217[/TD]
[TD]3[/TD]
[TD]2[/TD]
[TD]0[/TD]
[TD]4[/TD]
[TD]0[/TD]
[/TR]
[/TABLE]
[/FONT]
[FONT=&quot]*HHS regions (Region 1 CT, ME, MA, NH, RI, VT; Region 2: NJ, NY, Puerto Rico, US Virgin Islands; Region 3: DE, DC, MD, PA, VA, WV; Region 4: AL, FL, GA, KY, MS, NC, SC, TN; Region 5: IL, IN, MI, MN, OH, WI; Region 6: AR, LA, NM, OK, TX; Region 7: IA, KS, MO, NE; Region 8: CO, MT, ND, SD, UT, WY; Region 9: AZ, CA, Guam, HI, NV; and Region 10: AK, ID, OR, WA).
? Elevated means the % of visits for ILI is at or above the national or region-specific baseline
? Includes all 50 states, the District of Columbia, Guam, Puerto Rico, and U.S. Virgin Islands
? National data are for current week; regional data are for the most recent three weeks

[/FONT]

[h=2]U.S. Virologic Surveillance:[/h] [FONT=&quot]WHO and NREVSS collaborating laboratories, which include both public health and clinical laboratories located in all 50 states, Puerto Rico, and the District of Columbia, report to CDC the total number of respiratory specimens tested for influenza and the number positive for influenza by virus type. In addition, public health laboratories also report the influenza A subtype (H1 or H3) and influenza B lineage information for the viruses they test and the age or age group of the persons from whom the specimens were collected.[/FONT]
[FONT=&quot]Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html and http://gis.cdc.gov/grasp/fluview/flu_by_age_virus.html.[/FONT]
[FONT=&quot]The results of tests performed by clinical laboratories during the current week are summarized below.[/FONT]
[TABLE="class: table table-bordered table-condensed opt-in"]
[TR]
[TD="width: 200"] [/TD]
Week 49 Data Cumulative since
October 2, 2016 (Week 40) [/TR]
[TR]
No. of specimens tested [TD]15,117[/TD]
[TD]157,423[/TD]
[/TR]
[TR]
No. of positive specimens (%) [TD]728 (4.8%)[/TD]
[TD]3,928 (2.5%)[/TD]
[/TR]
[TR]
Positive specimens by type [TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
Influenza A [TD]575 (79.0%)[/TD]
[TD]2,720 (69.2%)[/TD]
[/TR]
[TR]
Influenza B [TD]153 (21.0%)[/TD]
[TD]1,208 (30.8%)[/TD]
[/TR]
[/TABLE]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation
[FONT=&quot]The results of tests performed by public health laboratories, as well as the age group distribution of influenza positive tests, during the current week are summarized below.[/FONT]
[TABLE="class: table table-bordered table-condensed opt-in"]
[TR]
[TD] [/TD]
Week 49 Data Cumulative since
October 2, 2016 (Week 40) [/TR]
[TR]
No. of specimens tested [TD]928[/TD]
[TD]10,585[/TD]
[/TR]
[TR]
No. of positive specimens* [TD]206[/TD]
[TD]1,533[/TD]
[/TR]
[TR]
Positive specimens by type/subtype [TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
Influenza A [TD]198 (96.1%)[/TD]
[TD]1,396 (91.1%)[/TD]
[/TR]
[TR]
A(H1N1)pmd09 [TD]6 (3.0%)[/TD]
[TD]85 (6.1%)[/TD]
[/TR]
[TR]
H3 [TD]158 (79.8%)[/TD]
[TD]1,201 (86.0%)[/TD]
[/TR]
[TR]
Subtyping not performed [TD]34 (17.2%)[/TD]
[TD]110 (7.9%)[/TD]
[/TR]
[TR]
Influenza B [TD]8 (3.9%)[/TD]
[TD]137 (8.9%)[/TD]
[/TR]
[TR]
Yamagata lineage [TD]2 (25.0%)[/TD]
[TD]29 (21.2%)[/TD]
[/TR]
[TR]
Victoria lineage [TD]3 (37.5%)[/TD]
[TD]47 (34.3%)[/TD]
[/TR]
[TR]
Lineage not performed [TD]3 (37.5%)[/TD]
[TD]61 (44.5%)[/TD]
[/TR]
[/TABLE]
[FONT=&quot]*The percent of specimens testing positive for influenza is not reported because public health laboratories often receive samples that have already tested positive for influenza at a clinical laboratory and therefore percent positive would not be a valid indicator of influenza activity. Additional information is available at http://www.cdc.gov/flu/weekly/overview.htm.
[/FONT]


View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation


View Interactive Application | View Full Screen

[h=2]Influenza Virus Characterization:[/h] [FONT=&quot]CDC characterizes influenza viruses through one or more tests including genomic sequencing, hemagglutination inhibition (HI) and/or neutralization assays. These data are used to compare how similar currently circulating influenza viruses are to the reference viruses used for developing influenza vaccines, and to monitor for changes in circulating influenza viruses. Historically, HI data have been used most commonly to assess the similarity between reference viruses and circulating viruses to suggest how well the vaccine may work until such a time as vaccine effectiveness estimates are available.[/FONT]
[FONT=&quot]For nearly all virus positive surveillance samples received at CDC, next-generation sequencing is performed to ascertain genomic data of circulating influenza viruses. Viruses can be classified into genetic groups/clades based on analysis of their HA gene segments using phylogenetics and key amino acid changes (Klimov Vaccine 2012).[/FONT]
[FONT=&quot]A proportion of influenza A (H3N2) viruses don?t yield sufficient hemagglutination titers for antigenic characterization using the hemagglutination inhibition test. Therefore, CDC selects a subset of influenza A (H3N2) viruses to test using a focus reduction assay for supplementary antigenic characterization.[/FONT]
[h=2]Genetic Characterization[/h] [FONT=&quot]During the 2016-2017 season, 1,533 influenza positive specimens have been collected and reported by public health laboratories in the United States (figure, left). CDC genetically characterized 181 influenza viruses [22 influenza A (H1N1)pdm09, 130 influenza A (H3N2), and 29 influenza B viruses] collected by U.S. laboratories. The HA gene segment of all influenza A (H1N1)pdm09 viruses analyzed belonged to genetic group 6B.1. Influenza A (H3N2) virus HA gene segments analyzed belonged to genetic groups 3C.2a or 3C.3a. Genetic group 3C.2a includes a newly emerging subgroup known as 3C.2a1. The HA of influenza B/Victoria-lineage viruses all belonged to genetic group V1A. The HA of influenza B/Yamagata-lineage viruses analyzed all belonged to genetic group Y3.[/FONT]
[FONT=&quot]The majority of U.S. viruses submitted for characterization come from state and local public health laboratories. Due to Right Size Roadmap considerations, specimen submission guidance issued to the laboratories request that, if available, 2 influenza A (H1N1), 2 A influenza (H3N2), and 2 influenza B viruses be submitted every other week. Because of this, the number of each virus type/subtype characterized should be approximately equal. In the figure below, the results of tests performed by public health labs are presented on the left and sequence results by genetic group of specimens submitted to CDC are presented on the right.[/FONT]
Genetic49_small.gif

View Chart Data | View Full Screen | View PowerPoint Presentation
[h=2]Antigenic Characterization[/h] [FONT=&quot]CDC has antigenically characterized 64 influenza viruses [24 influenza A (H1N1)pdm09, 26 influenza A (H3N2), and 14 influenza B viruses] collected by U.S. laboratories since October 1, 2016.[/FONT]
[FONT=&quot]Influenza A Virus [50][/FONT]
  • A (H1N1)pdm09 [24]: All 24 (100%) influenza A (H1N1)pdm09 viruses were antigenically characterized using ferret post-infection antisera as A/California/7/2009-like, the influenza A (H1N1) component of the 2016-2017 Northern Hemisphere vaccine.
  • A (H3N2) [26]: All 26 (100%) influenza A (H3N2) viruses were antigenically characterized as A/Hong Kong/4801/2014-like, a virus that belongs in genetic group 3C.2a and is the influenza A (H3N2) component of the 2016-2017 Northern Hemisphere vaccine, by HI testing or neutralization testing.
[FONT=&quot]Influenza B Virus [14][/FONT]
  • Victoria Lineage [6]: 5 of 6 (83%) B/Victoria-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Brisbane/60/2008-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere trivalent and quadrivalent influenza vaccines.
  • Yamagata Lineage [8]: All 8 (100%) B/Yamagata-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Phuket/3073/2013-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere quadrivalent influenza vaccines.
[FONT=&quot]
[/FONT]

[h=2]Antiviral Resistance:[/h] [FONT=&quot]Testing of influenza A (H1N1)pdm09, influenza A (H3N2), and influenza B virus isolates for resistance to neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) is performed at CDC using a functional assay. Additional influenza A (H1N1)pdm09 and influenza A (H3N2) clinical samples are tested for mutations of the virus known to confer oseltamivir resistance. The data summarized below combine the results of both testing methods. These samples are routinely obtained for surveillance purposes rather than for diagnostic testing of patients suspected to be infected with antiviral-resistant virus.[/FONT]
[FONT=&quot]High levels of resistance to the adamantanes (amantadine and rimantadine) persist among influenza A (H1N1)pdm09 and influenza A (H3N2) viruses (the adamantanes are not effective against influenza B viruses). Therefore, data from adamantane resistance testing are not presented below.[/FONT]
[TABLE="class: table, align: center, border: 0, cellpadding: 3, cellspacing: 0"]
[h=3]Neuraminidase Inhibitor Resistance Testing Results on Samples Collected Since October 1, 2016[/h] [/TABLE]
[TABLE="class: table table-bordered opt-in"]
[TR]
[TD] [/TD]
Oseltamivir
Zanamivir
Peramivir
[/TR]
[TR]
[TD] [/TD]
Virus Samples tested (n)
Resistant Viruses, Number (%)
Virus Samples tested (n)
Resistant Viruses, Number (%)
Virus Samples tested (n)
Resistant Viruses, Number (%)
[/TR]
[TR]
Influenza A (H1N1)pdm09
[TD] 28
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 28
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 28
[/TD]
[TD] 0 (0.0)
[/TD]
[/TR]
[TR]
Influenza A (H3N2)
[TD] 119
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 119
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 95
[/TD]
[TD] 0 (0.0)
[/TD]
[/TR]
[TR]
Influenza B
[TD] 31
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 31
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 31
[/TD]
[TD] 0 (0.0)
[/TD]
[/TR]
[/TABLE]
[FONT=&quot]The majority of recently circulating influenza viruses are susceptible to the neuraminidase inhibitor antiviral medications, oseltamivir, zanamivir, and peramivir; however, rare sporadic instances of oseltamivir-resistant and peramivir-resistant influenza A (H1N1)pdm09 viruses and oseltamivir-resistant influenza A (H3N2) viruses have been detected worldwide. Antiviral treatment as early as possible is recommended for patients with confirmed or suspected influenza who have severe, complicated, or progressive illness; who require hospitalization; or who are at high risk for serious influenza-related complications. Additional information on recommendations for treatment and chemoprophylaxis of influenza virus infection with antiviral agents is available athttp://www.cdc.gov/flu/antivirals/index.htm.[/FONT]


[h=2]Pneumonia and Influenza (P&I) Mortality Surveillance:[/h] [FONT=&quot]Based on National Center for Health Statistics (NCHS) mortality surveillance data available on December 14, 2016, 5.6% of the deaths occurring during the week ending November 26, 2016 (week 47) were due to P&I. This percentage is below the epidemic threshold of 6.8% for week 47.[/FONT]
[FONT=&quot]Background: Weekly mortality surveillance data includes a combination of machine coded and manually coded causes of death collected from death certificates. There is a backlog of data requiring manual coding within NCHS mortality surveillance data. The percentages of deaths due to P&I are higher among manually coded records than more rapidly available machine coded records and may result in initially reported P&I percentages that are lower than percentages calculated from final data. Efforts continue to reduce and monitor the number of records awaiting manual coding.[/FONT]
[FONT=&quot]Beginning in the week ending October 8, 2016 (week 40), CDC retired the 122 Cities Mortality Reporting System and uses only the NCHS Mortality Surveillance System.[/FONT]
[FONT=&quot]Region and state-specific data are available at http://gis.cdc.gov/grasp/fluview/mortality.html.[/FONT]
NCHS49_small.gif

View Regional and State Level Data | View Chart Data | View Full Screen | View PowerPoint Presentation

[h=2]Influenza-Associated Pediatric Mortality:[/h] [FONT=&quot]No influenza-associated pediatric deaths were reported to CDC during week 49.[/FONT]
[FONT=&quot]Additional data can be found at: [/FONT]http://gis.cdc.gov/GRASP/Fluview/PedFluDeath.html[FONT=&quot].[/FONT] [FONT=&quot] [/FONT]

View Interactive Application | View Full Screen | View PowerPoint Presentation


[h=2]Influenza-Associated Hospitalizations:[/h] [FONT=&quot]The Influenza Hospitalization Surveillance Network (FluSurv-NET) conducts population-based surveillance for laboratory-confirmed influenza-related hospitalizations in children younger than 18 years of age (since the 2003-2004 influenza season) and adults (since the 2005-2006 influenza season).[/FONT]
[FONT=&quot]The FluSurv-NET covers more than 70 counties in the 10 Emerging Infections Program (EIP) states (CA, CO, CT, GA, MD, MN, NM, NY, OR, and TN) and additional Influenza Hospitalization Surveillance Project (IHSP) states. The IHSP began during the 2009-2010 season to enhance surveillance during the 2009 H1N1 pandemic. IHSP sites included IA, ID, MI, OK and SD during the 2009-2010 season; ID, MI, OH, OK, RI, and UT during the 2010-2011 season; MI, OH, RI, and UT during the 2011-2012 season; IA, MI, OH, RI, and UT during the 2012-2013 season; and MI, OH, and UT during the 2013-2014, 2014-15, 2015-16, and 2016-17 seasons.[/FONT]
[FONT=&quot]Data gathered are used to estimate age-specific hospitalization rates on a weekly basis, and describe characteristics of persons hospitalized with severe influenza illness. The rates provided are likely to be an underestimate as influenza-related hospitalizations can be missed, either because testing is not performed, or because cases may be attributed to other causes of pneumonia or other common influenza-related complications.[/FONT]
[FONT=&quot]Between October 1, 2016 and December 10, 2016, 487 laboratory-confirmed influenza-associated hospitalizations were reported. The overall hospitalization rate was 1.7 per 100,000 population. The highest rate of hospitalization was among adults aged ≥65 years (7.2 per 100,000 population), followed by adults aged 50-64 (1.8 per 100,000 population) and children aged 0-4 years (1.4 per 100,000 population). Among 487 hospitalizations, 392 (80.5%) were associated with influenza A virus, 76 (15.6%) with influenza B virus, 6 (1.2%) with influenza A virus and influenza B virus co-infection, and 13 (2.7%) with influenza virus for which the type was not determined. Among those with influenza A subtype information, 123 (99.2%) were A(H3N2) and 1 (0.8%) was A(H1N1)pdm09 virus.[/FONT]
[FONT=&quot]Clinical findings are preliminary and based on 121 (24.8%) cases with complete medical chart abstraction. Among 111 hospitalized adults with complete medical chart abstraction, 104 (93.7%) had at least one reported underlying medical condition; the most commonly reported were obesity, cardiovascular disease, metabolic disorders and chronic lung disease. Among 10 hospitalized children with complete medical chart abstraction, 5 (50.0%) had at least one underlying medical condition; the most commonly reported was asthma. Among the 10 hospitalized women of childbearing age (15-44 years), 0 (0%) were pregnant.[/FONT]
[FONT=&quot]Additional FluSurv-NET data can be found at: [/FONT]http://gis.cdc.gov/GRASP/Fluview/FluHospRates.html[FONT=&quot] and [/FONT]http://gis.cdc.gov/grasp/fluview/FluHospChars.html[FONT=&quot].[/FONT] [FONT=&quot] [/FONT]

[SIZE=1.5]Data from the Influenza Hospitalization Surveillance Network (FluSurv-NET), a population-based surveillance for influenza related hospitalizations in children and adults in 13 U.S. states. Cumulative incidence rates are calculated using the National Center for Health Statistics? (NCHS) population estimates for the counties included in the surveillance catchment area.[/SIZE]
View Interactive Application | View Full Screen | View PowerPoint Presentation
[SIZE=1.5]FluSurv-NET data are preliminary and displayed as they become available. Therefore, figures are based on varying denominators as some variables represent information that may require more time to be collected. Data are refreshed and updated weekly. Asthma includes a medical diagnosis of asthma or reactive airway disease; Cardiovascular diseases include conditions such as coronary heart disease, cardiac valve disorders, congestive heart failure, and pulmonary hypertension; does not include isolated hypertension; Chronic lung diseases include conditions such as chronic obstructive pulmonary disease, bronchiolitis obliterans, chronic aspiration pneumonia, and interstitial lung disease; Immune suppression includes conditions such as immunoglobulin deficiency, leukemia, lymphoma, HIV/AIDS, and individuals taking immunosuppressive medications; Metabolic disorders include conditions such as diabetes mellitus; Neurologic diseases include conditions such as seizure disorders, cerebral palsy, and cognitive dysfunction; Neuromuscular diseases include conditions such as multiple sclerosis and muscular dystrophy; Obesity was assigned if indicated in patient's medical chart or if body mass index (BMI) >30 kg/m2; Pregnancy percentage calculated using number of female cases aged between 15 and 44 years of age as the denominator; Renal diseases include conditions such as acute or chronic renal failure, nephrotic syndrome, glomerulonephritis, and impaired creatinine clearance; No known condition indicates that the case did not have any known high risk medical condition indicated in medical chart at the time of hospitalization.[/SIZE]
View Interactive Application | View Full Screen | View PowerPoint Presentation



[h=2]Outpatient Illness Surveillance:[/h] [FONT=&quot]Nationwide during week 49, 1.9% of patient visits reported through the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) were due to influenza-like illness (ILI). This percentage is below the national baseline of 2.2%.[/FONT]
[FONT=&quot](ILI is defined as fever (temperature of 100?F [37.8?C] or greater) and cough and/or sore throat.)[/FONT]
[FONT=&quot]Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html.[/FONT]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation
[FONT=&quot]On a regional level, the percentage of outpatient visits for ILI ranged from 0.7% to 3.6% during week 49. Two regions (regions 2 and 4) reported a proportion of outpatient visits for ILI at or above their region-specific baseline levels.[/FONT]
[FONT=&quot]

[/FONT]

[h=2]ILINet State Activity Indicator Map:[/h] [FONT=&quot]Data collected in ILINet are used to produce a measure of ILI activity* by state. Activity levels are based on the percent of outpatient visits in a state due to ILI and are compared to the average percent of ILI visits that occur during weeks with little or no influenza virus circulation. Activity levels range from minimal, which would correspond to ILI activity from outpatient clinics being below, or only slightly above, the average, to high, which would correspond to ILI activity from outpatient clinics being much higher than average.[/FONT]
[FONT=&quot]During week 49, the following ILI activity levels were experienced:[/FONT]
  • Puerto Rico experienced high ILI activity.
  • One state (Georgia) experienced moderate ILI activity.
  • New York City and four states (Arizona, Louisiana, Nevada, and Oklahoma) experienced low ILI activity.
  • 45 states (Alabama, Alaska, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Hawaii, Idaho, Illinois, Indiana, Iowa, Kanas, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, and Wyoming ) experienced minimal ILI activity.
  • Data were insufficient to calculate an ILI activity level from the District of Columbia.
[FONT=&quot][/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]Click on map to launch interactive tool[/FONT]
[FONT=&quot]*This map uses the proportion of outpatient visits to health care providers for ILI to measure the ILI activity level within a state. It does not, however, measure the extent of geographic spread of flu within a state. Therefore, outbreaks occurring in a single city could cause the state to display high activity levels.
Data collected in ILINet may disproportionally represent certain populations within a state, and therefore, may not accurately depict the full picture of influenza activity for the whole state.
Data displayed in this map are based on data collected in ILINet, whereas the State and Territorial flu activity map is based on reports from state and territorial epidemiologists. The data presented in this map is preliminary and may change as more data are received.
Differences in the data presented here by CDC and independently by some state health departments likely represent differing levels of data completeness with data presented by the state likely being the more complete.[/FONT]



[h=2]Geographic Spread of Influenza as Assessed by State and Territorial Epidemiologists[/h] [FONT=&quot]The influenza activity reported by state and territorial epidemiologists indicates geographic spread of influenza viruses, but does not measure the severity of influenza activity.[/FONT]
[FONT=&quot]During week 49, the following influenza activity was reported:[/FONT]
  • Widespread influenza activity was reported by Puerto Rico.
  • Regional influenza activity was reported by Guam, the U.S. Virgin Islands, and seven states (Indiana, Massachusetts, New Hampshire, New York, North Carolina, Oklahoma, and Washington).
  • Local influenza activity was reported by the District of Columbia and 22 states (Alabama, Arizona, Colorado, Connecticut, Delaware, Hawaii, Kentucky, Louisiana, Michigan, Minnesota, Mississippi, Nebraska, Nevada, Ohio, Oregon, Pennsylvania, South Carolina, Tennessee, Texas, Utah, Virginia, and Wyoming).
  • Sporadic influenza activity was reported by 20 states (Alaska, Arkansas, California, Florida, Georgia, Idaho, Illinois, Iowa, Kansas, Maine, Maryland, Missouri, Montana, New Jersey, New Mexico, North Dakota, South Dakota, Vermont, West Virginia, and Wisconsin).
  • No activity was reported by one state (Rhode Island).
[FONT=&quot][/FONT]


[FONT=&quot] [/FONT]
[h=2]Additional National and International Influenza Surveillance Information[/h] [FONT=&quot]FluView Interactive: FluView includes enhanced web-based interactive applications that can provide dynamic visuals of the influenza data collected and analyzed by CDC. These FluView Interactive applications allow people to create customized, visual interpretations of influenza data, as well as make comparisons across flu seasons, regions, age groups and a variety of other demographics. To access these tools, visit http://www.cdc.gov/flu/weekly/fluviewinteractive.htm.[/FONT]
[FONT=&quot]U.S. State and local influenza surveillance: Click on a jurisdiction below to access the latest local influenza information.[/FONT]
[FONT=&quot] [/FONT]

[TD="width: 139"] Alabama
[/TD]
[TD="width: 139"] Alaska
[/TD]
[TD="width: 139"] Arizona
[/TD]
[TD="width: 139"] Arkansas
[/TD]
[TD="width: 139"] California
[/TD]

[TD="width: 139"] Colorado
[/TD]
[TD="width: 139"] Connecticut
[/TD]
[TD="width: 139"] Delaware
[/TD]
[TD="width: 139"] District of Columbia
[/TD]
[TD="width: 139"] Florida
[/TD]

[TD="width: 139"] Georgia
[/TD]
[TD="width: 139"] Hawaii
[/TD]
[TD="width: 139"] Idaho
[/TD]
[TD="width: 139"] Illinois
[/TD]
[TD="width: 139"] Indiana
[/TD]

[TD="width: 139"] Iowa
[/TD]
[TD="width: 139"] Kansas
[/TD]
[TD="width: 139"] Kentucky
[/TD]
[TD="width: 139"] Louisiana
[/TD]
[TD="width: 139"] Maine
[/TD]

[TD="width: 139"] Maryland
[/TD]
[TD="width: 139"] Massachusetts
[/TD]
[TD="width: 139"] Michigan
[/TD]
[TD="width: 139"] Minnesota
[/TD]
[TD="width: 139"] Mississippi
[/TD]

[TD="width: 139"] Missouri
[/TD]
[TD="width: 139"] Montana
[/TD]
[TD="width: 139"] Nebraska
[/TD]
[TD="width: 139"] Nevada
[/TD]
[TD="width: 139"] New Hampshire
[/TD]

[TD="width: 139"] New Jersey
[/TD]
[TD="width: 139"] New Mexico
[/TD]
[TD="width: 139"] New York
[/TD]
[TD="width: 139"] North Carolina
[/TD]
[TD="width: 139"] North Dakota
[/TD]

[TD="width: 139"] Ohio
[/TD]
[TD="width: 139"] Oklahoma
[/TD]
[TD="width: 139"] Oregon
[/TD]
[TD="width: 139"] Pennsylvania
[/TD]
[TD="width: 139"] Rhode Island
[/TD]

[TD="width: 139"] South Carolina
[/TD]
[TD="width: 139"] South Dakota
[/TD]
[TD="width: 139"] Tennessee
[/TD]
[TD="width: 139"] Texas
[/TD]
[TD="width: 139"] Utah
[/TD]

[TD="width: 139"] Vermont
[/TD]
[TD="width: 139"] Virginia
[/TD]
[TD="width: 139"] Washington
[/TD]
[TD="width: 139"] West Virginia
[/TD]
[TD="width: 139"] Wisconsin
[/TD]

[TD="width: 139"] Wyoming
[/TD]
[TD="width: 139"] New York City
[/TD]
[TD="width: 139"] Puerto Rico
[/TD]
[TD="width: 139"] Virgin Islands
[/TD]
[TD="width: 139"] [/TD]

[FONT=&quot]World Health Organization: Additional influenza surveillance information from participating WHO member nations is available through FluNet and the Global Epidemiology Reports.[/FONT]
[FONT=&quot]WHO Collaborating Centers for Influenza located in Australia, China, Japan, the United Kingdom, and the United States (CDC in Atlanta, Georgia).[/FONT]
[FONT=&quot]Europe: For the most recent influenza surveillance information from Europe, please see WHO/Europe and the European Centre for Disease Prevention and Control at http://www.flunewseurope.org/.[/FONT]
[FONT=&quot]Public Health Agency of Canada: The most up-to-date influenza information from Canada is available at http://www.phac-aspc.gc.ca/fluwatch/[/FONT]
[FONT=&quot]Public Health England: The most up-to-date influenza information from the United Kingdom is available at https://www.gov.uk/government/statistics/weekly-national-flu-reports[/FONT]
[FONT=&quot] [/FONT]

[FONT=&quot] [/FONT]
Any links provided to non-Federal organizations are provided solely as a service to our users. These links do not constitute an endorsement of these organizations or their programs by CDC or the Federal Government, and none should be inferred. CDC is not responsible for the content of the individual organization web pages found at these links. [FONT=&quot] [/FONT]
[FONT=&quot]An overview of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component, is available at: http://www.cdc.gov/flu/weekly/overview.htm.[/FONT]


https://www.cdc.gov/flu/weekly/weeklyarchives2016-2017/Week49.htm
 
[h=3]2016-2017 Influenza Season Week 50 ending December 17, 2016[/h] [FONT=&quot]All data are preliminary and may change as more reports are received.[/FONT]
[h=3]Synopsis:[/h] [FONT=&quot]During week 50 (December 11-17, 2016), influenza activity increased slightly in the United States.[/FONT]
  • Viral Surveillance:The most frequently identified influenza virus subtype reported by public health laboratories during week 50 was influenza A (H3). The percentage of respiratory specimens testing positive for influenza in clinical laboratories increased.
  • Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was below the system-specific epidemic threshold in the National Center for Health Statistics (NCHS) Mortality Surveillance System.
  • Influenza-associated Pediatric Deaths: Two influenza-associated pediatric deaths were reported that occurred during the 2015-2016 season.
  • Influenza-associated Hospitalizations: A cumulative rate for the season of 2.4 laboratory-confirmed influenza-associated hospitalizations per 100,000 population was reported.
  • Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 2.3%, which is above the national baseline of 2.2%. Five regions reported ILI at or above their region-specific baseline levels. One state and Puerto Rico experienced high ILI activity, two states and New York City experienced moderate ILI activity, ten states experienced low ILI activity, 37 states experienced minimal ILI activity, and the District of Columbia had insufficient data.
  • Geographic Spread of Influenza:The geographic spread of influenza in Puerto Rico was reported as widespread; Guam, the U.S. Virgin Islands and 13 states reported as regional; the District of Columbia and 26 states reported local activity; and 11 states reported sporadic activity.
[h=3]National and Regional Summary of Select Surveillance Components[/h]
[FONT=&quot] [TABLE="class: table table-bordered opt-in"]
[TR]
[/TR]
[TR]
HHS Surveillance Regions* Data for current week Data cumulative since October 2, 2016 (week 40) [/TR]
[TR]
Out-patient ILI[SUP]?[/SUP] Number of jurisdictions reporting regional or widespread activity[SUP]?[/SUP] % respiratory specimens positive for flu in clinical laboratories[SUP]?[/SUP] A(H1N1)pdm09 A (H3) A (Subtyping not Performed) B Victoria lineage B Yamagata lineage B lineage not performed Pediatric Deaths [/TR]
[TR]
Influenza test results from public health laboratories only [/TR]
[TR]
Nation [TD]Elevated[/TD]
[TD]16 of 54[/TD]
[TD]7.1%[/TD]
[TD]95[/TD]
[TD]1,729[/TD]
[TD]106[/TD]
[TD]58[/TD]
[TD]39[/TD]
[TD]76[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 1 [TD]Normal[/TD]
[TD]3 of 6[/TD]
[TD]2.6%[/TD]
[TD]0[/TD]
[TD]75[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 2 [TD]Elevated[/TD]
[TD]3 of 4[/TD]
[TD]4.3%[/TD]
[TD]0[/TD]
[TD]125[/TD]
[TD]3[/TD]
[TD]16[/TD]
[TD]4[/TD]
[TD]11[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 3 [TD]Normal[/TD]
[TD]2 of 6[/TD]
[TD]2.0%[/TD]
[TD]11[/TD]
[TD]211[/TD]
[TD]9[/TD]
[TD]3[/TD]
[TD]7[/TD]
[TD]8[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 4 [TD]Elevated[/TD]
[TD]3 of 8[/TD]
[TD]8.5%[/TD]
[TD]7[/TD]
[TD]148[/TD]
[TD]10[/TD]
[TD]6[/TD]
[TD]5[/TD]
[TD]41[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 5 [TD]Normal[/TD]
[TD]0 of 6[/TD]
[TD]2.1%[/TD]
[TD]6[/TD]
[TD]163[/TD]
[TD]62[/TD]
[TD]20[/TD]
[TD]6[/TD]
[TD]4[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 6 [TD]Normal[/TD]
[TD]1 of 5[/TD]
[TD]3.1%[/TD]
[TD]12[/TD]
[TD]44[/TD]
[TD]0[/TD]
[TD]5[/TD]
[TD]5[/TD]
[TD]3[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 7 [TD]Normal[/TD]
[TD]0 of 4[/TD]
[TD]2.3%[/TD]
[TD]2[/TD]
[TD]46[/TD]
[TD]5[/TD]
[TD]4[/TD]
[TD]2[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 8 [TD]Elevated[/TD]
[TD]0 of 6[/TD]
[TD]4.5%[/TD]
[TD]30[/TD]
[TD]219[/TD]
[TD]4[/TD]
[TD]0[/TD]
[TD]1[/TD]
[TD]1[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 9 [TD]Elevated[/TD]
[TD]1 of 5[/TD]
[TD]4.4%[/TD]
[TD]25[/TD]
[TD]447[/TD]
[TD]10[/TD]
[TD]2[/TD]
[TD]8[/TD]
[TD]4[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 10 [TD]Elevated[/TD]
[TD]3 of 4[/TD]
[TD]11.6%[/TD]
[TD]2[/TD]
[TD]251[/TD]
[TD]3[/TD]
[TD]2[/TD]
[TD]0[/TD]
[TD]4[/TD]
[TD]0[/TD]
[/TR]
[/TABLE]
[/FONT]
[FONT=&quot]*HHS regions (Region 1 CT, ME, MA, NH, RI, VT; Region 2: NJ, NY, Puerto Rico, US Virgin Islands; Region 3: DE, DC, MD, PA, VA, WV; Region 4: AL, FL, GA, KY, MS, NC, SC, TN; Region 5: IL, IN, MI, MN, OH, WI; Region 6: AR, LA, NM, OK, TX; Region 7: IA, KS, MO, NE; Region 8: CO, MT, ND, SD, UT, WY; Region 9: AZ, CA, Guam, HI, NV; and Region 10: AK, ID, OR, WA).
? Elevated means the % of visits for ILI is at or above the national or region-specific baseline
? Includes all 50 states, the District of Columbia, Guam, Puerto Rico, and U.S. Virgin Islands
? National data are for current week; regional data are for the most recent three weeks

[/FONT]

[h=2]U.S. Virologic Surveillance:[/h] [FONT=&quot]WHO and NREVSS collaborating laboratories, which include both public health and clinical laboratories located in all 50 states, Puerto Rico, and the District of Columbia, report to CDC the total number of respiratory specimens tested for influenza and the number positive for influenza by virus type. In addition, public health laboratories also report the influenza A subtype (H1 or H3) and influenza B lineage information for the viruses they test and the age or age group of the persons from whom the specimens were collected.[/FONT]
[FONT=&quot]Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html and http://gis.cdc.gov/grasp/fluview/flu_by_age_virus.html.[/FONT]
[FONT=&quot]The results of tests performed by clinical laboratories during the current week are summarized below.[/FONT]
[TABLE="class: table table-bordered table-condensed opt-in"]
[TR]
[TD="width: 200"] [/TD]
Week 50 Data Cumulative since
October 2, 2016 (Week 40) [/TR]
[TR]
No. of specimens tested [TD]16,010[/TD]
[TD]177,867[/TD]
[/TR]
[TR]
No. of positive specimens (%) [TD]1,130 (7.1%)[/TD]
[TD]5,157 (2.9%)[/TD]
[/TR]
[TR]
Positive specimens by type [TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
Influenza A [TD]986 (87.3%)[/TD]
[TD]3,786 (73.4%)[/TD]
[/TR]
[TR]
Influenza B [TD]144 (12.7%)[/TD]
[TD]1,371 (26.6%)[/TD]
[/TR]
[/TABLE]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation
[FONT=&quot]The results of tests performed by public health laboratories, as well as the age group distribution of influenza positive tests, during the current week are summarized below.[/FONT]
[TABLE="class: table table-bordered table-condensed opt-in"]
[TR]
[TD] [/TD]
Week 50 Data Cumulative since
October 2, 2016 (Week 40) [/TR]
[TR]
No. of specimens tested [TD]1,094[/TD]
[TD]12,496[/TD]
[/TR]
[TR]
No. of positive specimens* [TD]337[/TD]
[TD]2,103[/TD]
[/TR]
[TR]
Positive specimens by type/subtype [TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
Influenza A [TD]319 (94.7%)[/TD]
[TD]1,930 (91.8%)[/TD]
[/TR]
[TR]
A(H1N1)pmd09 [TD]5 (1.6%)[/TD]
[TD]95 (4.9%)[/TD]
[/TR]
[TR]
H3 [TD]291 (91.2%)[/TD]
[TD]1,729 (89.6%)[/TD]
[/TR]
[TR]
Subtyping not performed [TD]23 (7.2%)[/TD]
[TD]106 (5.5%)[/TD]
[/TR]
[TR]
Influenza B [TD]18 (5.3%)[/TD]
[TD]173 (8.2%)[/TD]
[/TR]
[TR]
Yamagata lineage [TD]6 (33.3%)[/TD]
[TD]39 (22.5%)[/TD]
[/TR]
[TR]
Victoria lineage [TD]4 (22.2%)[/TD]
[TD]58 (33.5%)[/TD]
[/TR]
[TR]
Lineage not performed [TD]8 (44.4%)[/TD]
[TD]76 (43.9%)[/TD]
[/TR]
[/TABLE]
[FONT=&quot]*The percent of specimens testing positive for influenza is not reported because public health laboratories often receive samples that have already tested positive for influenza at a clinical laboratory and therefore percent positive would not be a valid indicator of influenza activity. Additional information is available at http://www.cdc.gov/flu/weekly/overview.htm.
[/FONT]


View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation


View Interactive Application | View Full Screen

[h=2]Influenza Virus Characterization:[/h] [FONT=&quot]CDC characterizes influenza viruses through one or more tests including genomic sequencing, hemagglutination inhibition (HI) and/or neutralization assays. These data are used to compare how similar currently circulating influenza viruses are to the reference viruses used for developing influenza vaccines, and to monitor for changes in circulating influenza viruses. Historically, HI data have been used most commonly to assess the similarity between reference viruses and circulating viruses to suggest how well the vaccine may work until such a time as vaccine effectiveness estimates are available.[/FONT]
[FONT=&quot]For nearly all virus positive surveillance samples received at CDC, next-generation sequencing is performed to ascertain genomic data of circulating influenza viruses. Viruses can be classified into genetic groups/clades based on analysis of their HA gene segments using phylogenetics and key amino acid changes (Klimov Vaccine 2012).[/FONT]
[FONT=&quot]A proportion of influenza A (H3N2) viruses don?t yield sufficient hemagglutination titers for antigenic characterization using the hemagglutination inhibition test. Therefore, CDC selects a subset of influenza A (H3N2) viruses to test using a focus reduction assay for supplementary antigenic characterization.[/FONT]
[h=2]Genetic Characterization[/h] [FONT=&quot]During the 2016-2017 season, 2,103 influenza positive specimens have been collected and reported by public health laboratories in the United States (figure, left). CDC genetically characterized 293 influenza viruses [31 influenza A (H1N1)pdm09, 215 influenza A (H3N2), and 47 influenza B viruses] collected by U.S. laboratories. The HA gene segment of all influenza A (H1N1)pdm09 viruses analyzed belonged to genetic group 6B.1. Influenza A (H3N2) virus HA gene segments analyzed belonged to genetic groups 3C.2a or 3C.3a. Genetic group 3C.2a includes a newly emerging subgroup known as 3C.2a1. The HA of influenza B/Victoria-lineage viruses all belonged to genetic group V1A. The HA of influenza B/Yamagata-lineage viruses analyzed all belonged to genetic group Y3.[/FONT]
[FONT=&quot]The majority of U.S. viruses submitted for characterization come from state and local public health laboratories. Due to Right Size Roadmap considerations, specimen submission guidance issued to the laboratories request that, if available, 2 influenza A (H1N1), 2 A influenza (H3N2), and 2 influenza B viruses be submitted every other week. Because of this, the number of each virus type/subtype characterized should be approximately equal. In the figure below, the results of tests performed by public health labs are presented on the left and sequence results by genetic group of specimens submitted to CDC are presented on the right.[/FONT]
Genetic50_small.gif

View Chart Data | View Full Screen | View PowerPoint Presentation
[h=2]Antigenic Characterization[/h] [FONT=&quot]CDC has antigenically characterized 89 influenza viruses [26 influenza A (H1N1)pdm09, 42 influenza A (H3N2), and 21 influenza B viruses] collected by U.S. laboratories since October 1, 2016.[/FONT]
[FONT=&quot]Influenza A Virus [68][/FONT]
  • A (H1N1)pdm09 [26]: All 26 (100%) influenza A (H1N1)pdm09 viruses were antigenically characterized using ferret post-infection antisera as A/California/7/2009-like, the influenza A (H1N1) component of the 2016-2017 Northern Hemisphere vaccine.
  • A (H3N2) [42]: 39 of 42 (92.9%) influenza A (H3N2) viruses were antigenically characterized as A/Hong Kong/4801/2014-like, a virus that belongs in genetic group 3C.2a and is the influenza A (H3N2) component of the 2016-2017 Northern Hemisphere vaccine, by HI testing or neutralization testing. Among the viruses which reacted poorly with ferret antisera raised against A/Hong Kong/4801/2014-like viruses, all 3 (100%) are more closely related to A/Switzerland/9715293/2013, a virus belonging to genetic group 3C.3a.
[FONT=&quot]Influenza B Virus [21][/FONT]
  • Victoria Lineage [7]: 6 of 7 (85.7%) B/Victoria-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Brisbane/60/2008-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere trivalent and quadrivalent influenza vaccines.
  • Yamagata Lineage [14]: All 14 (100%) B/Yamagata-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Phuket/3073/2013-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere quadrivalent influenza vaccines.
[FONT=&quot]
[/FONT]

[h=2]Antiviral Resistance:[/h] [FONT=&quot]Testing of influenza A (H1N1)pdm09, influenza A (H3N2), and influenza B virus isolates for resistance to neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) is performed at CDC using a functional assay. Additional influenza A (H1N1)pdm09 and influenza A (H3N2) clinical samples are tested for mutations of the virus known to confer oseltamivir resistance. The data summarized below combine the results of both testing methods. These samples are routinely obtained for surveillance purposes rather than for diagnostic testing of patients suspected to be infected with antiviral-resistant virus.[/FONT]
[FONT=&quot]High levels of resistance to the adamantanes (amantadine and rimantadine) persist among influenza A (H1N1)pdm09 and influenza A (H3N2) viruses (the adamantanes are not effective against influenza B viruses). Therefore, data from adamantane resistance testing are not presented below.[/FONT]
[TABLE="class: table, align: center, border: 0, cellpadding: 3, cellspacing: 0"]
[h=3]Neuraminidase Inhibitor Resistance Testing Results on Samples Collected Since October 1, 2016[/h] [/TABLE]
[TABLE="class: table table-bordered opt-in"]
[TR]
[TD] [/TD]
Oseltamivir
Zanamivir
Peramivir
[/TR]
[TR]
[TD] [/TD]
Virus Samples tested (n)
Resistant Viruses, Number (%)
Virus Samples tested (n)
Resistant Viruses, Number (%)
Virus Samples tested (n)
Resistant Viruses, Number (%)
[/TR]
[TR]
Influenza A (H1N1)pdm09
[TD] 35
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 35
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 35
[/TD]
[TD] 0 (0.0)
[/TD]
[/TR]
[TR]
Influenza A (H3N2)
[TD] 154
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 154
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 123
[/TD]
[TD] 0 (0.0)
[/TD]
[/TR]
[TR]
Influenza B
[TD] 47
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 47
[/TD]
[TD] 0 (0.0)
[/TD]
[TD] 47
[/TD]
[TD] 0 (0.0)
[/TD]
[/TR]
[/TABLE]
[FONT=&quot]The majority of recently circulating influenza viruses are susceptible to the neuraminidase inhibitor antiviral medications, oseltamivir, zanamivir, and peramivir; however, rare sporadic instances of oseltamivir-resistant and peramivir-resistant influenza A (H1N1)pdm09 viruses and oseltamivir-resistant influenza A (H3N2) viruses have been detected worldwide. Antiviral treatment as early as possible is recommended for patients with confirmed or suspected influenza who have severe, complicated, or progressive illness; who require hospitalization; or who are at high risk for serious influenza-related complications. Additional information on recommendations for treatment and chemoprophylaxis of influenza virus infection with antiviral agents is available athttp://www.cdc.gov/flu/antivirals/index.htm.[/FONT]


[h=2]Pneumonia and Influenza (P&I) Mortality Surveillance:[/h] [FONT=&quot]Based on National Center for Health Statistics (NCHS) mortality surveillance data available on December 21, 2016, 5.9% of the deaths occurring during the week ending December 3, 2016 (week 48) were due to P&I. This percentage is below the epidemic threshold of 6.9% for week 48.[/FONT]
[FONT=&quot]Background: Weekly mortality surveillance data includes a combination of machine coded and manually coded causes of death collected from death certificates. There is a backlog of data requiring manual coding within NCHS mortality surveillance data. The percentages of deaths due to P&I are higher among manually coded records than more rapidly available machine coded records and may result in initially reported P&I percentages that are lower than percentages calculated from final data. Efforts continue to reduce and monitor the number of records awaiting manual coding.[/FONT]
[FONT=&quot]Beginning in the week ending October 8, 2016 (week 40), CDC retired the 122 Cities Mortality Reporting System and uses only the NCHS Mortality Surveillance System.[/FONT]
[FONT=&quot]Region and state-specific data are available at http://gis.cdc.gov/grasp/fluview/mortality.html.[/FONT]
NCHS50_small.gif

View Regional and State Level Data | View Chart Data | View Full Screen | View PowerPoint Presentation

[h=2]Influenza-Associated Pediatric Mortality:[/h] [FONT=&quot]Two influenza-associated pediatric deaths that occurred during the 2015-2016 season were reported to CDC during week 50. One death was associated with an influenza A (H3) virus and one was associated with an influenza B virus. These deaths bring the total number of reported influenza-associated pediatric deaths occurring during that season to 89.[/FONT]
[FONT=&quot]No influenza-associated pediatric deaths for the 2016-2017 season have been reported to CDC.[/FONT]
[FONT=&quot]Additional data can be found at: [/FONT]http://gis.cdc.gov/GRASP/Fluview/PedFluDeath.html[FONT=&quot].[/FONT] [FONT=&quot] [/FONT]

View Interactive Application | View Full Screen | View PowerPoint Presentation


[h=2]Influenza-Associated Hospitalizations:[/h] [FONT=&quot]The Influenza Hospitalization Surveillance Network (FluSurv-NET) conducts population-based surveillance for laboratory-confirmed influenza-related hospitalizations in children younger than 18 years of age (since the 2003-2004 influenza season) and adults (since the 2005-2006 influenza season).[/FONT]
[FONT=&quot]The FluSurv-NET covers more than 70 counties in the 10 Emerging Infections Program (EIP) states (CA, CO, CT, GA, MD, MN, NM, NY, OR, and TN) and additional Influenza Hospitalization Surveillance Project (IHSP) states. The IHSP began during the 2009-2010 season to enhance surveillance during the 2009 H1N1 pandemic. IHSP sites included IA, ID, MI, OK and SD during the 2009-2010 season; ID, MI, OH, OK, RI, and UT during the 2010-2011 season; MI, OH, RI, and UT during the 2011-2012 season; IA, MI, OH, RI, and UT during the 2012-2013 season; and MI, OH, and UT during the 2013-2014, 2014-15, 2015-16, and 2016-17 seasons.[/FONT]
[FONT=&quot]Data gathered are used to estimate age-specific hospitalization rates on a weekly basis, and describe characteristics of persons hospitalized with severe influenza illness. The rates provided are likely to be an underestimate as influenza-related hospitalizations can be missed, either because testing is not performed, or because cases may be attributed to other causes of pneumonia or other common influenza-related complications.[/FONT]
[FONT=&quot]Between October 1, 2016 and December 17, 2016, 676 laboratory-confirmed influenza-associated hospitalizations were reported. The overall hospitalization rate was 2.4 per 100,000 population. The highest rate of hospitalization was among adults aged ≥65 years (9.8 per 100,000 population), followed by adults aged 50-64 (2.8 per 100,000 population) and children aged 0-4 years (1.7 per 100,000 population). Among 676 hospitalizations, 566 (83.7%) were associated with influenza A virus, 92 (13.6%) with influenza B virus, 6 (0.9%) with influenza A virus and influenza B virus co-infection, and 12 (1.8%) with influenza virus for which the type was not determined. Among those with influenza A subtype information, 179 (98.9%) were A(H3N2) and 2 (1.1%) were A(H1N1)pdm09 virus.[/FONT]
[FONT=&quot]Clinical findings are preliminary and based on 175 (25.9%) cases with complete medical chart abstraction. Among 164 hospitalized adults with complete medical chart abstraction, 154 (93.9%) had at least one reported underlying medical condition; the most commonly reported were obesity, cardiovascular disease, metabolic disorders and chronic lung disease. Among 11 hospitalized children with complete medical chart abstraction, 6 (54.6%) had at least one underlying medical condition; the most commonly reported were asthma and neurologic disorder. Among the 13 hospitalized women of childbearing age (15-44 years), 0 (0%) were pregnant.[/FONT]
[FONT=&quot]Additional FluSurv-NET data can be found at: [/FONT]http://gis.cdc.gov/GRASP/Fluview/FluHospRates.html[FONT=&quot] and [/FONT]http://gis.cdc.gov/grasp/fluview/FluHospChars.html[FONT=&quot].[/FONT] [FONT=&quot] [/FONT]

[SIZE=1.5]Data from the Influenza Hospitalization Surveillance Network (FluSurv-NET), a population-based surveillance for influenza related hospitalizations in children and adults in 13 U.S. states. Cumulative incidence rates are calculated using the National Center for Health Statistics? (NCHS) population estimates for the counties included in the surveillance catchment area.[/SIZE]
View Interactive Application | View Full Screen | View PowerPoint Presentation
[SIZE=1.5]FluSurv-NET data are preliminary and displayed as they become available. Therefore, figures are based on varying denominators as some variables represent information that may require more time to be collected. Data are refreshed and updated weekly. Asthma includes a medical diagnosis of asthma or reactive airway disease; Cardiovascular diseases include conditions such as coronary heart disease, cardiac valve disorders, congestive heart failure, and pulmonary hypertension; does not include isolated hypertension; Chronic lung diseases include conditions such as chronic obstructive pulmonary disease, bronchiolitis obliterans, chronic aspiration pneumonia, and interstitial lung disease; Immune suppression includes conditions such as immunoglobulin deficiency, leukemia, lymphoma, HIV/AIDS, and individuals taking immunosuppressive medications; Metabolic disorders include conditions such as diabetes mellitus; Neurologic diseases include conditions such as seizure disorders, cerebral palsy, and cognitive dysfunction; Neuromuscular diseases include conditions such as multiple sclerosis and muscular dystrophy; Obesity was assigned if indicated in patient's medical chart or if body mass index (BMI) >30 kg/m2; Pregnancy percentage calculated using number of female cases aged between 15 and 44 years of age as the denominator; Renal diseases include conditions such as acute or chronic renal failure, nephrotic syndrome, glomerulonephritis, and impaired creatinine clearance; No known condition indicates that the case did not have any known high risk medical condition indicated in medical chart at the time of hospitalization.[/SIZE]
View Interactive Application | View Full Screen | View PowerPoint Presentation



[h=2]Outpatient Illness Surveillance:[/h] [FONT=&quot]Nationwide during week 50, 2.3% of patient visits reported through the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) were due to influenza-like illness (ILI). This percentage is above the national baseline of 2.2%.[/FONT]
[FONT=&quot](ILI is defined as fever (temperature of 100?F [37.8?C] or greater) and cough and/or sore throat.)[/FONT]
[FONT=&quot]Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html.[/FONT]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation
[FONT=&quot]On a regional level, the percentage of outpatient visits for ILI ranged from 1.1% to 3.5% during week 50. Five regions (regions 2, 4, 8, 9 and 10) reported a proportion of outpatient visits for ILI at or above their region-specific baseline levels.[/FONT]
[FONT=&quot]

[/FONT]

[h=2]ILINet State Activity Indicator Map:[/h] [FONT=&quot]Data collected in ILINet are used to produce a measure of ILI activity* by state. Activity levels are based on the percent of outpatient visits in a state due to ILI and are compared to the average percent of ILI visits that occur during weeks with little or no influenza virus circulation. Activity levels range from minimal, which would correspond to ILI activity from outpatient clinics being below, or only slightly above, the average, to high, which would correspond to ILI activity from outpatient clinics being much higher than average.[/FONT]
[FONT=&quot]During week 50, the following ILI activity levels were experienced:[/FONT]
  • One state (Oklahoma) and Puerto Rico experienced high ILI activity.
  • Two states (Arizona and Georgia) and New York City experienced moderate ILI activity.
  • Ten states (Alabama, Colorado, Hawaii, Louisiana, Mississippi, Nevada, New Jersey, North Carolina, South Carolina and Virginia) experienced low ILI activity.
  • 37 states (Alaska, Arkansas, California, Connecticut, Delaware, Florida, Idaho, Illinois, Indiana, Iowa, Kanas, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nebraska, New Hampshire, New Mexico, New York, North Dakota, Ohio, Oregon, Pennsylvania, Rhode Island, South Dakota, Tennessee, Texas, Utah, Vermont, Washington, West Virginia, Wisconsin, and Wyoming ) experienced minimal ILI activity.
  • Data were insufficient to calculate an ILI activity level from the District of Columbia.
[FONT=&quot][/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]Click on map to launch interactive tool[/FONT]
[FONT=&quot]*This map uses the proportion of outpatient visits to health care providers for ILI to measure the ILI activity level within a state. It does not, however, measure the extent of geographic spread of flu within a state. Therefore, outbreaks occurring in a single city could cause the state to display high activity levels.
Data collected in ILINet may disproportionally represent certain populations within a state, and therefore, may not accurately depict the full picture of influenza activity for the whole state.
Data displayed in this map are based on data collected in ILINet, whereas the State and Territorial flu activity map is based on reports from state and territorial epidemiologists. The data presented in this map is preliminary and may change as more data are received.
Differences in the data presented here by CDC and independently by some state health departments likely represent differing levels of data completeness with data presented by the state likely being the more complete.[/FONT]



[h=2]Geographic Spread of Influenza as Assessed by State and Territorial Epidemiologists[/h] [FONT=&quot]The influenza activity reported by state and territorial epidemiologists indicates geographic spread of influenza viruses, but does not measure the severity of influenza activity.[/FONT]
[FONT=&quot]During week 50, the following influenza activity was reported:[/FONT]
  • Widespread influenza activity was reported by Puerto Rico.
  • Regional influenza activity was reported by Guam, the U.S. Virgin Islands, and 13 states (Alabama, Alaska, Connecticut, Massachusetts, New Hampshire, New York, North Carolina, Oklahoma, Oregon, Pennsylvania, South Carolina, Virginia, and Washington).
  • Local influenza activity was reported by the District of Columbia and 26 states (Arizona, Arkansas, Colorado, Delaware, Florida, Georgia, Hawaii, Idaho, Indiana, Kentucky, Louisiana, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nebraska, Nevada, New Jersey, North Dakota, Ohio, Tennessee, Texas, Utah, and Wyoming).
  • Sporadic influenza activity was reported by 11 states (California, Illinois, Iowa, Kansas, Montana, New Mexico, Rhode Island, South Dakota, Vermont, West Virginia, and Wisconsin).
[FONT=&quot][/FONT]


[FONT=&quot] [/FONT]
[h=2]Additional National and International Influenza Surveillance Information[/h] [FONT=&quot]FluView Interactive: FluView includes enhanced web-based interactive applications that can provide dynamic visuals of the influenza data collected and analyzed by CDC. These FluView Interactive applications allow people to create customized, visual interpretations of influenza data, as well as make comparisons across flu seasons, regions, age groups and a variety of other demographics. To access these tools, visit http://www.cdc.gov/flu/weekly/fluviewinteractive.htm.[/FONT]
[FONT=&quot]U.S. State and local influenza surveillance: Click on a jurisdiction below to access the latest local influenza information.[/FONT]
[FONT=&quot] [/FONT]

[TD="width: 139"] Alabama
[/TD]
[TD="width: 139"] Alaska
[/TD]
[TD="width: 139"] Arizona
[/TD]
[TD="width: 139"] Arkansas
[/TD]
[TD="width: 139"] California
[/TD]

[TD="width: 139"] Colorado
[/TD]
[TD="width: 139"] Connecticut
[/TD]
[TD="width: 139"] Delaware
[/TD]
[TD="width: 139"] District of Columbia
[/TD]
[TD="width: 139"] Florida
[/TD]

[TD="width: 139"] Georgia
[/TD]
[TD="width: 139"] Hawaii
[/TD]
[TD="width: 139"] Idaho
[/TD]
[TD="width: 139"] Illinois
[/TD]
[TD="width: 139"] Indiana
[/TD]

[TD="width: 139"] Iowa
[/TD]
[TD="width: 139"] Kansas
[/TD]
[TD="width: 139"] Kentucky
[/TD]
[TD="width: 139"] Louisiana
[/TD]
[TD="width: 139"] Maine
[/TD]

[TD="width: 139"] Maryland
[/TD]
[TD="width: 139"] Massachusetts
[/TD]
[TD="width: 139"] Michigan
[/TD]
[TD="width: 139"] Minnesota
[/TD]
[TD="width: 139"] Mississippi
[/TD]

[TD="width: 139"] Missouri
[/TD]
[TD="width: 139"] Montana
[/TD]
[TD="width: 139"] Nebraska
[/TD]
[TD="width: 139"] Nevada
[/TD]
[TD="width: 139"] New Hampshire
[/TD]

[TD="width: 139"] New Jersey
[/TD]
[TD="width: 139"] New Mexico
[/TD]
[TD="width: 139"] New York
[/TD]
[TD="width: 139"] North Carolina
[/TD]
[TD="width: 139"] North Dakota
[/TD]

[TD="width: 139"] Ohio
[/TD]
[TD="width: 139"] Oklahoma
[/TD]
[TD="width: 139"] Oregon
[/TD]
[TD="width: 139"] Pennsylvania
[/TD]
[TD="width: 139"] Rhode Island
[/TD]

[TD="width: 139"] South Carolina
[/TD]
[TD="width: 139"] South Dakota
[/TD]
[TD="width: 139"] Tennessee
[/TD]
[TD="width: 139"] Texas
[/TD]
[TD="width: 139"] Utah
[/TD]

[TD="width: 139"] Vermont
[/TD]
[TD="width: 139"] Virginia
[/TD]
[TD="width: 139"] Washington
[/TD]
[TD="width: 139"] West Virginia
[/TD]
[TD="width: 139"] Wisconsin
[/TD]

[TD="width: 139"] Wyoming
[/TD]
[TD="width: 139"] New York City
[/TD]
[TD="width: 139"] Puerto Rico
[/TD]
[TD="width: 139"] Virgin Islands
[/TD]
[TD="width: 139"] [/TD]

[FONT=&quot]World Health Organization: Additional influenza surveillance information from participating WHO member nations is available through FluNet and the Global Epidemiology Reports.[/FONT]
[FONT=&quot]WHO Collaborating Centers for Influenza located in Australia, China, Japan, the United Kingdom, and the United States (CDC in Atlanta, Georgia).[/FONT]
[FONT=&quot]Europe: For the most recent influenza surveillance information from Europe, please see WHO/Europe and the European Centre for Disease Prevention and Control at http://www.flunewseurope.org/.[/FONT]
[FONT=&quot]Public Health Agency of Canada: The most up-to-date influenza information from Canada is available at http://www.phac-aspc.gc.ca/fluwatch/[/FONT]
[FONT=&quot]Public Health England: The most up-to-date influenza information from the United Kingdom is available at https://www.gov.uk/government/statistics/weekly-national-flu-reports[/FONT]
[FONT=&quot] [/FONT]

[FONT=&quot] [/FONT]
Any links provided to non-Federal organizations are provided solely as a service to our users. These links do not constitute an endorsement of these organizations or their programs by CDC or the Federal Government, and none should be inferred. CDC is not responsible for the content of the individual organization web pages found at these links. [FONT=&quot] [/FONT]
[FONT=&quot]An overview of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component, is available at: http://www.cdc.gov/flu/weekly/overview.htm.[/FONT]

https://www.cdc.gov/flu/weekly/weeklyarchives2016-2017/Week50.htm
 
[h=3]2016-2017 Influenza Season Week 52 ending December 31, 2016[/h] All data are preliminary and may change as more reports are received.
[h=3]Synopsis:[/h] During week 52 (December 25-31, 2016), influenza activity increased in the United States.
  • Viral Surveillance: The most frequently identified influenza virus subtype reported by public health laboratories during week 52 was influenza A (H3). The percentage of respiratory specimens testing positive for influenza in clinical laboratories increased.
  • Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was below the system-specific epidemic threshold in the National Center for Health Statistics (NCHS) Mortality Surveillance System.
  • Influenza-associated Pediatric Deaths: No influenza-associated pediatric deaths were reported.
  • Influenza-associated Hospitalizations: A cumulative rate for the season of 4.9 laboratory-confirmed influenza-associated hospitalizations per 100,000 population was reported.
  • Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 3.4%, which is above the national baseline of 2.2%. Nine regions reported ILI at or above their region-specific baseline levels. New York City, Puerto Rico, and 10 states experienced high ILI activity; 10 states experienced moderate ILI activity; five states experienced low ILI activity; 25 states experienced minimal ILI activity, and the District of Columbia had insufficient data.
  • Geographic Spread of Influenza: The geographic spread of influenza in 12 states was reported as widespread; Guam and 28 states reported regional activity; the District of Columbia and 10 states reported local activity; the U.S. Virgin Islands reported sporadic activity; and Puerto Rico did not report.
[h=3]National and Regional Summary of Select Surveillance Components[/h]
[TABLE="class: table table-bordered opt-in, width: 100%"]
[TR]
[/TR]
[TR]
HHS Surveillance Regions* Data for current week Data cumulative since October 2, 2016 (week 40) [/TR]
[TR]
Out-patient ILI? Number of jurisdictions reporting regional or widespread activity? % respiratory specimens positive for flu in clinical laboratories? A(H1N1)pdm09 A (H3) A (Subtyping not Performed) B Victoria lineage B Yamagata lineage B lineage not performed Pediatric Deaths [/TR]
[TR]
Influenza test results from public health laboratories only [/TR]
[TR]
Nation [TD]Elevated[/TD]
[TD]41 of 54[/TD]
[TD]13.7%[/TD]
[TD]127[/TD]
[TD]3,193[/TD]
[TD]159[/TD]
[TD]107[/TD]
[TD]78[/TD]
[TD]129[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 1 [TD]Elevated[/TD]
[TD]5 of 6[/TD]
[TD]7.3%[/TD]
[TD]6[/TD]
[TD]163[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]2[/TD]
[TD]3[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 2 [TD]Elevated[/TD]
[TD]2 of 4[/TD]
[TD]12.6%[/TD]
[TD]1[/TD]
[TD]207[/TD]
[TD]4[/TD]
[TD]16[/TD]
[TD]6[/TD]
[TD]20[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 3 [TD]Elevated[/TD]
[TD]3 of 6[/TD]
[TD]8.9%[/TD]
[TD]13[/TD]
[TD]348[/TD]
[TD]32[/TD]
[TD]4[/TD]
[TD]7[/TD]
[TD]15[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 4 [TD]Elevated[/TD]
[TD]7 of 8[/TD]
[TD]12.2%[/TD]
[TD]9[/TD]
[TD]235[/TD]
[TD]19[/TD]
[TD]12[/TD]
[TD]11[/TD]
[TD]55[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 5 [TD]Elevated[/TD]
[TD]5 of 6[/TD]
[TD]6.1%[/TD]
[TD]10[/TD]
[TD]424[/TD]
[TD]15[/TD]
[TD]39[/TD]
[TD]12[/TD]
[TD]20[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 6 [TD]Elevated[/TD]
[TD]4 of 5[/TD]
[TD]6.5%[/TD]
[TD]15[/TD]
[TD]91[/TD]
[TD]1[/TD]
[TD]10[/TD]
[TD]8[/TD]
[TD]4[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 7 [TD]Elevated[/TD]
[TD]1 of 4[/TD]
[TD]5.5%[/TD]
[TD]4[/TD]
[TD]118[/TD]
[TD]24[/TD]
[TD]7[/TD]
[TD]9[/TD]
[TD]2[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 8 [TD]Elevated[/TD]
[TD]5 of 6[/TD]
[TD]15.2%[/TD]
[TD]31[/TD]
[TD]382[/TD]
[TD]5[/TD]
[TD]4[/TD]
[TD]6[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 9 [TD]Normal[/TD]
[TD]5 of 5[/TD]
[TD]7.5%[/TD]
[TD]36[/TD]
[TD]804[/TD]
[TD]51[/TD]
[TD]10[/TD]
[TD]17[/TD]
[TD]5[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 10 [TD]Elevated[/TD]
[TD]4 of 4[/TD]
[TD]27.4%[/TD]
[TD]2[/TD]
[TD]421[/TD]
[TD]8[/TD]
[TD]5[/TD]
[TD]0[/TD]
[TD]5[/TD]
[TD]0[/TD]
[/TR]
[/TABLE]
*HHS regions (Region 1 CT, ME, MA, NH, RI, VT; Region 2: NJ, NY, Puerto Rico, US Virgin Islands; Region 3: DE, DC, MD, PA, VA, WV; Region 4: AL, FL, GA, KY, MS, NC, SC, TN; Region 5: IL, IN, MI, MN, OH, WI; Region 6: AR, LA, NM, OK, TX; Region 7: IA, KS, MO, NE; Region 8: CO, MT, ND, SD, UT, WY; Region 9: AZ, CA, Guam, HI, NV; and Region 10: AK, ID, OR, WA).
? Elevated means the % of visits for ILI is at or above the national or region-specific baseline
? Includes all 50 states, the District of Columbia, Guam, Puerto Rico, and U.S. Virgin Islands
? National data are for current week; regional data are for the most recent three weeks


[h=2]U.S. Virologic Surveillance:[/h] WHO and NREVSS collaborating laboratories, which include both public health and clinical laboratories located in all 50 states, Puerto Rico, and the District of Columbia, report to CDC the total number of respiratory specimens tested for influenza and the number positive for influenza by virus type. In addition, public health laboratories also report the influenza A subtype (H1 or H3) and influenza B lineage information for the viruses they test and the age or age group of the persons from whom the specimens were collected.
Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html and http://gis.cdc.gov/grasp/fluview/flu_by_age_virus.html.
The results of tests performed by clinical laboratories during the current week are summarized below.
[TABLE="class: table table-bordered table-condensed opt-in, width: 100%"]
[TR]
[TD="width: 200"] [/TD]
Week 52 Data Cumulative since
October 2, 2016 (Week 40) [/TR]
[TR]
No. of specimens tested [TD]21,564[/TD]
[TD]228,434[/TD]
[/TR]
[TR]
No. of positive specimens (%) [TD]2,955 (13.7%)[/TD]
[TD]10,920 (4.8%)[/TD]
[/TR]
[TR]
Positive specimens by type [TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
Influenza A [TD]2,702 (91.4%)[/TD]
[TD]8,948 (81.9%)[/TD]
[/TR]
[TR]
Influenza B [TD]253 (8.6%)[/TD]
[TD]1,972 (18.1%)[/TD]
[/TR]
[/TABLE]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation The results of tests performed by public health laboratories, as well as the age group distribution of influenza positive tests, during the current week are summarized below.
[TABLE="class: table table-bordered table-condensed opt-in, width: 100%"]
[TR]
[TD] [/TD]
Week 52 Data Cumulative since
October 2, 2016 (Week 40) [/TR]
[TR]
No. of specimens tested [TD]952[/TD]
[TD]16,972[/TD]
[/TR]
[TR]
No. of positive specimens* [TD]433[/TD]
[TD]3,793[/TD]
[/TR]
[TR]
Positive specimens by type/subtype [TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
Influenza A [TD]405 (93.5%)[/TD]
[TD]3,479 (91.7%)[/TD]
[/TR]
[TR]
A(H1N1)pmd09 [TD]4 (1.0%)[/TD]
[TD]127 (3.7%)[/TD]
[/TR]
[TR]
H3 [TD]333 (82.2%)[/TD]
[TD]3,193 (91.8%)[/TD]
[/TR]
[TR]
Subtyping not performed [TD]68 (16.8%)[/TD]
[TD]159 (4.6%)[/TD]
[/TR]
[TR]
Influenza B [TD]28 (6.5%)[/TD]
[TD]314 (8.3%)[/TD]
[/TR]
[TR]
Yamagata lineage [TD]7 (25.0%)[/TD]
[TD]78 (24.8%)[/TD]
[/TR]
[TR]
Victoria lineage [TD]11 (39.3%)[/TD]
[TD]107 (34.1%)[/TD]
[/TR]
[TR]
Lineage not performed [TD]10 (35.7%)[/TD]
[TD]129 (41.1%)[/TD]
[/TR]
[/TABLE]
*The percent of specimens testing positive for influenza is not reported because public health laboratories often receive samples that have already tested positive for influenza at a clinical laboratory and therefore percent positive would not be a valid indicator of influenza activity. Additional information is available at http://www.cdc.gov/flu/weekly/overview.htm.


View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation
View Interactive Application | View Full Screen

[h=2]Influenza Virus Characterization:[/h] CDC characterizes influenza viruses through one or more tests including genomic sequencing, hemagglutination inhibition (HI) and/or neutralization assays. These data are used to compare how similar currently circulating influenza viruses are to the reference viruses used for developing influenza vaccines, and to monitor for changes in circulating influenza viruses. Historically, HI data have been used most commonly to assess the similarity between reference viruses and circulating viruses to suggest how well the vaccine may work until such a time as vaccine effectiveness estimates are available.
For nearly all virus positive surveillance samples received at CDC, next-generation sequencing is performed to ascertain genomic data of circulating influenza viruses. Viruses can be classified into genetic groups/clades based on analysis of their HA gene segments using phylogenetics and key amino acid changes (Klimov Vaccine 2012).
A proportion of influenza A (H3N2) viruses don?t yield sufficient hemagglutination titers for antigenic characterization using the hemagglutination inhibition test. Therefore, CDC selects a subset of influenza A (H3N2) viruses to test using a focus reduction assay for supplementary antigenic characterization.
[h=2]Genetic Characterization[/h] During the 2016-2017 season, 3,793 influenza positive specimens have been collected and reported by public health laboratories in the United States (figure, left). CDC genetically characterized 350 influenza viruses [38 influenza A (H1N1)pdm09, 259 influenza A (H3N2), and 53 influenza B viruses] collected by U.S. laboratories. The HA gene segment of all influenza A (H1N1)pdm09 viruses analyzed belonged to genetic group 6B.1. Influenza A (H3N2) virus HA gene segments analyzed belonged to genetic groups 3C.2a or 3C.3a. Genetic group 3C.2a includes a newly emerging subgroup known as 3C.2a1. The HA of influenza B/Victoria-lineage viruses all belonged to genetic group V1A. The HA of influenza B/Yamagata-lineage viruses analyzed all belonged to genetic group Y3.
The majority of U.S. viruses submitted for characterization come from state and local public health laboratories. Due to Right Size Roadmap considerations, specimen submission guidance issued to the laboratories request that, if available, 2 influenza A (H1N1), 2 A influenza (H3N2), and 2 influenza B viruses be submitted every other week. Because of this, the number of each virus type/subtype characterized should be approximately equal. In the figure below, the results of tests performed by public health labs are presented on the left and sequence results by genetic group of specimens submitted to CDC are presented on the right.
Genetic52_small.gif

View Chart Data | View Full Screen | View PowerPoint Presentation [h=2]Antigenic Characterization[/h] CDC has antigenically characterized 173 influenza viruses [37 influenza A (H1N1)pdm09, 93 influenza A (H3N2), and 43 influenza B viruses] collected by U.S. laboratories since October 1, 2016.
Influenza A Virus [130]
  • A (H1N1)pdm09 [37]: All 37 (100%) influenza A (H1N1)pdm09 viruses were antigenically characterized using ferret post-infection antisera as A/California/7/2009-like, the influenza A (H1N1) component of the 2016-2017 Northern Hemisphere vaccine.
  • A (H3N2) [93]: 90 of 93 (96.8%) influenza A (H3N2) viruses were antigenically characterized as A/Hong Kong/4801/2014-like, a virus that belongs in genetic group 3C.2a and is the influenza A (H3N2) component of the 2016-2017 Northern Hemisphere vaccine, by HI testing or neutralization testing. Among the viruses which reacted poorly with ferret antisera raised against A/Hong Kong/4801/2014-like viruses, all 3 (100%) are more closely related to A/Switzerland/9715293/2013, a virus belonging to genetic group 3C.3a.
Influenza B Virus [43]
  • Victoria Lineage [28]: 27 of 28 (96.4%) B/Victoria-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Brisbane/60/2008-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere trivalent and quadrivalent influenza vaccines.
  • Yamagata Lineage [15]: All 15 (100%) B/Yamagata-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Phuket/3073/2013-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere quadrivalent influenza vaccines.

[h=2]Antiviral Resistance:[/h] Testing of influenza A (H1N1)pdm09, influenza A (H3N2), and influenza B virus isolates for resistance to neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) is performed at CDC using a functional assay. Additional influenza A (H1N1)pdm09 and influenza A (H3N2) clinical samples are tested for mutations of the virus known to confer oseltamivir resistance. The data summarized below combine the results of both testing methods. These samples are routinely obtained for surveillance purposes rather than for diagnostic testing of patients suspected to be infected with antiviral-resistant virus.
High levels of resistance to the adamantanes (amantadine and rimantadine) persist among influenza A (H1N1)pdm09 and influenza A (H3N2) viruses (the adamantanes are not effective against influenza B viruses). Therefore, data from adamantane resistance testing are not presented below.
[TABLE="class: table, align: center, border: 0, cellpadding: 3, cellspacing: 0, width: 100%"]
[h=3]Neuraminidase Inhibitor Resistance Testing Results on Samples Collected Since October 1, 2016[/h] [/TABLE]
[TABLE="class: table table-bordered opt-in, width: 100%"]
[TR]
[TD] [/TD]
Oseltamivir​
Zanamivir​
Peramivir​
[/TR]
[TR]
[TD] [/TD]
Virus Samples tested (n)
Resistant Viruses, Number (%)​
Virus Samples tested (n)
Resistant Viruses, Number (%)​
Virus Samples tested (n)
Resistant Viruses, Number (%)​
[/TR]
[TR]
Influenza A (H1N1)pdm09
[TD]
43​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
43​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
43​
[/TD]
[TD]
0 (0.0)​
[/TD]
[/TR]
[TR]
Influenza A (H3N2)
[TD]
176​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
176​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
145​
[/TD]
[TD]
0 (0.0)​
[/TD]
[/TR]
[TR]
Influenza B
[TD]
66​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
66​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
66​
[/TD]
[TD]
0 (0.0)​
[/TD]
[/TR]
[/TABLE]
The majority of recently circulating influenza viruses are susceptible to the neuraminidase inhibitor antiviral medications, oseltamivir, zanamivir, and peramivir; however, rare sporadic instances of oseltamivir-resistant and peramivir-resistant influenza A (H1N1)pdm09 viruses and oseltamivir-resistant influenza A (H3N2) viruses have been detected worldwide. Antiviral treatment as early as possible is recommended for patients with confirmed or suspected influenza who have severe, complicated, or progressive illness; who require hospitalization; or who are at high risk for serious influenza-related complications. Additional information on recommendations for treatment and chemoprophylaxis of influenza virus infection with antiviral agents is available at http://www.cdc.gov/flu/antivirals/index.htm.


[h=2]Pneumonia and Influenza (P&I) Mortality Surveillance:[/h] Based on National Center for Health Statistics (NCHS) mortality surveillance data available on January 4, 2017, 6.3% of the deaths occurring during the week ending December 17, 2016 (week 50) were due to P&I. This percentage is below the epidemic threshold of 7.1% for week 50.
Background: Weekly mortality surveillance data includes a combination of machine coded and manually coded causes of death collected from death certificates. There is a backlog of data requiring manual coding within NCHS mortality surveillance data. The percentages of deaths due to P&I are higher among manually coded records than more rapidly available machine coded records and may result in initially reported P&I percentages that are lower than percentages calculated from final data. Efforts continue to reduce and monitor the number of records awaiting manual coding.
Beginning in the week ending October 8, 2016 (week 40), CDC retired the 122 Cities Mortality Reporting System and uses only the NCHS Mortality Surveillance System.
Region and state-specific data are available at http://gis.cdc.gov/grasp/fluview/mortality.html.
NCHS52_small.gif

View Regional and State Level Data | View Chart Data | View Full Screen | View PowerPoint Presentation

[h=2]Influenza-Associated Pediatric Mortality:[/h] No influenza-associated pediatric deaths were reported to CDC during week 52.
Additional data can be found at: http://gis.cdc.gov/GRASP/Fluview/PedFluDeath.html.

View Interactive Application | View Full Screen | View PowerPoint Presentation


[h=2]Influenza-Associated Hospitalizations:[/h] The Influenza Hospitalization Surveillance Network (FluSurv-NET) conducts population-based surveillance for laboratory-confirmed influenza-related hospitalizations in children younger than 18 years of age (since the 2003-2004 influenza season) and adults (since the 2005-2006 influenza season).
The FluSurv-NET covers more than 70 counties in the 10 Emerging Infections Program (EIP) states (CA, CO, CT, GA, MD, MN, NM, NY, OR, and TN) and additional Influenza Hospitalization Surveillance Project (IHSP) states. The IHSP began during the 2009-2010 season to enhance surveillance during the 2009 H1N1 pandemic. IHSP sites included IA, ID, MI, OK and SD during the 2009-2010 season; ID, MI, OH, OK, RI, and UT during the 2010-2011 season; MI, OH, RI, and UT during the 2011-2012 season; IA, MI, OH, RI, and UT during the 2012-2013 season; and MI, OH, and UT during the 2013-2014, 2014-2015, 2015-2016, and 2016-2017 seasons.
Data gathered are used to estimate age-specific hospitalization rates on a weekly basis, and describe characteristics of persons hospitalized with severe influenza illness. The rates provided are likely to be an underestimate as influenza-related hospitalizations can be missed, either because testing is not performed, or because cases may be attributed to other causes of pneumonia or other common influenza-related complications.
Between October 1, 2016 and December 31, 2016, 1,376 laboratory-confirmed influenza-associated hospitalizations were reported. The overall hospitalization rate was 4.9 per 100,000 population. The highest rate of hospitalization was among adults aged ≥65 years (21.1 per 100,000 population), followed by adults aged 50-64 (5.0 per 100,000 population) and children aged 0-4 years (4.2 per 100,000 population). Among 1,376 hospitalizations, 1,207 (87.7%) were associated with influenza A virus, 142 (10.3%) with influenza B virus, 8 (0.6%) with influenza A virus and influenza B virus co-infection, and 19 (1.4%) with influenza virus for which the type was not determined. Among those with influenza A subtype information, 366 (98.1%) were A(H3N2) and 7 (1.9%) were A(H1N1)pdm09 virus.
Clinical findings are preliminary and based on 274 (19.9%) cases with complete medical chart abstraction. Among 251 hospitalized adults with complete medical chart abstraction, 232 (92.4%) had at least one reported underlying medical condition; the most commonly reported were cardiovascular disease, obesity, metabolic disorders and chronic lung disease. Among 23 hospitalized children with complete medical chart abstraction, 13 (56.5%) had at least one underlying medical condition; the most commonly reported were asthma and chronic lung disease. Among the 19 hospitalized women of childbearing age (15-44 years), 3 (15.8%) were pregnant.
Additional FluSurv-NET data can be found at: http://gis.cdc.gov/GRASP/Fluview/FluHospRates.html and http://gis.cdc.gov/grasp/fluview/FluHospChars.html.

[SIZE=1.5]Data from the Influenza Hospitalization Surveillance Network (FluSurv-NET), a population-based surveillance for influenza related hospitalizations in children and adults in 13 U.S. states. Cumulative incidence rates are calculated using the National Center for Health Statistics? (NCHS) population estimates for the counties included in the surveillance catchment area.

View Interactive Application | View Full Screen | View PowerPoint Presentation
[SIZE=1.5]FluSurv-NET data are preliminary and displayed as they become available. Therefore, figures are based on varying denominators as some variables represent information that may require more time to be collected. Data are refreshed and updated weekly. Asthma includes a medical diagnosis of asthma or reactive airway disease; Cardiovascular diseases include conditions such as coronary heart disease, cardiac valve disorders, congestive heart failure, and pulmonary hypertension; does not include isolated hypertension; Chronic lung diseases include conditions such as chronic obstructive pulmonary disease, bronchiolitis obliterans, chronic aspiration pneumonia, and interstitial lung disease; Immune suppression includes conditions such as immunoglobulin deficiency, leukemia, lymphoma, HIV/AIDS, and individuals taking immunosuppressive medications;Metabolic disorders include conditions such as diabetes mellitus; Neurologic diseases include conditions such as seizure disorders, cerebral palsy, and cognitive dysfunction; Neuromuscular diseases include conditions such as multiple sclerosis and muscular dystrophy; Obesity was assigned if indicated in patient's medical chart or if body mass index (BMI) >30 kg/m2; Pregnancy percentage calculated using number of female cases aged between 15 and 44 years of age as the denominator; Renal diseases include conditions such as acute or chronic renal failure, nephrotic syndrome, glomerulonephritis, and impaired creatinine clearance; No known condition indicates that the case did not have any known high risk medical condition indicated in medical chart at the time of hospitalization.[/SIZE]
View Interactive Application | View Full Screen | View PowerPoint Presentation



[h=2]Outpatient Illness Surveillance:[/h] Nationwide during week 52, 3.4% of patient visits reported through the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) were due to influenza-like illness (ILI). This percentage is above the national baseline of 2.2%.
(ILI is defined as fever (temperature of 100?F [37.8?C] or greater) and cough and/or sore throat.)
The increase in the percentage of patient visits for ILI may be influenced in part by a reduction in routine healthcare visits during the holidays, as has occurred in previous seasons.

Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html.

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation On a regional level, the percentage of outpatient visits for ILI ranged from 1.4% to 5.8% during week 52. Nine regions (regions 1, 2, 3, 4, 5, 6, 7, 8, and 10) reported a proportion of outpatient visits for ILI at or above their region-specific baseline levels.



[h=2]ILINet State Activity Indicator Map:[/h] Data collected in ILINet are used to produce a measure of ILI activity* by state. Activity levels are based on the percent of outpatient visits in a state due to ILI and are compared to the average percent of ILI visits that occur during weeks with little or no influenza virus circulation. Activity levels range from minimal, which would correspond to ILI activity from outpatient clinics being below, or only slightly above, the average, to high, which would correspond to ILI activity from outpatient clinics being much higher than average.
During week 52, the following ILI activity levels were experienced:
  • New York City, Puerto Rico, and 10 states (Alabama, Georgia, Louisiana, Missouri, New Jersey, New York, Oklahoma, Oregon, South Carolina, and Utah) experienced high ILI activity.
  • 10 states (Arizona, Illinois, Indiana, Kentucky, Minnesota, Mississippi, Nevada, North Carolina, Pennsylvania, and Virginia) experienced moderate ILI activity.
  • Five states (Arkansas, California, Michigan, Tennessee, and Washington) experienced low ILI activity.
  • 25 states (Alaska, Colorado, Connecticut, Delaware, Florida, Hawaii, Idaho, Iowa, Kansas, Maine, Maryland, Massachusetts, Montana, Nebraska, New Hampshire, New Mexico, North Dakota, Ohio, Rhode Island, South Dakota, Texas, Vermont, West Virginia, Wisconsin, and Wyoming) experienced minimal ILI activity.
  • Data were insufficient to calculate an ILI activity level from the District of Columbia.
Click on map to launch interactive tool
*This map uses the proportion of outpatient visits to health care providers for ILI to measure the ILI activity level within a state. It does not, however, measure the extent of geographic spread of flu within a state. Therefore, outbreaks occurring in a single city could cause the state to display high activity levels.
Data collected in ILINet may disproportionally represent certain populations within a state, and therefore, may not accurately depict the full picture of influenza activity for the whole state.
Data displayed in this map are based on data collected in ILINet, whereas the State and Territorial flu activity map is based on reports from state and territorial epidemiologists. The data presented in this map is preliminary and may change as more data are received.
Differences in the data presented here by CDC and independently by some state health departments likely represent differing levels of data completeness with data presented by the state likely being the more complete.


[h=2]Geographic Spread of Influenza as Assessed by State and Territorial Epidemiologists[/h] The influenza activity reported by state and territorial epidemiologists indicates geographic spread of influenza viruses, but does not measure the severity of influenza activity.
During week 52, the following influenza activity was reported:
  • Widespread influenza activity was reported by 12 states (California, Connecticut, Idaho, Massachusetts, New Hampshire, New York, North Carolina, Oklahoma, Oregon, Pennsylvania, Virginia, and Washington).
  • Regional influenza activity was reported by Guam and 28 states (Alabama, Alaska, Arizona, Arkansas, Colorado, Florida, Georgia, Hawaii, Indiana, Kentucky, Louisiana, Maine, Maryland, Michigan, Minnesota, Mississippi, Montana, Nebraska, Nevada, New Jersey, North Dakota, Ohio, Rhode Island, South Carolina, Texas, Utah, Wisconsin, and Wyoming).
  • Local influenza activity was reported by the District of Columbia and 10 states (Delaware, Illinois, Iowa, Kansas, Missouri, New Mexico, South Dakota, Tennessee, Vermont, and West Virginia).
  • Sporadic influenza activity was reported by the U.S. Virgin Islands. .
  • Puerto Rico did not report.



[h=2]Additional National and International Influenza Surveillance Information[/h] FluView Interactive: FluView includes enhanced web-based interactive applications that can provide dynamic visuals of the influenza data collected and analyzed by CDC. These FluView Interactive applications allow people to create customized, visual interpretations of influenza data, as well as make comparisons across flu seasons, regions, age groups and a variety of other demographics. To access these tools, visithttp://www.cdc.gov/flu/weekly/fluviewinteractive.htm.
U.S. State and local influenza surveillance: Click on a jurisdiction below to access the latest local influenza information.

[TABLE="width: 100%"]
[TR]
[TD="width: 139"] Alabama
[/TD]
[TD="width: 139"] Alaska
[/TD]
[TD="width: 139"] Arizona
[/TD]
[TD="width: 139"] Arkansas
[/TD]
[TD="width: 139"] California
[/TD]
[/TR]
[TR]
[TD="width: 139"] Colorado
[/TD]
[TD="width: 139"] Connecticut
[/TD]
[TD="width: 139"] Delaware
[/TD]
[TD="width: 139"] District of Columbia
[/TD]
[TD="width: 139"] Florida
[/TD]
[/TR]
[TR]
[TD="width: 139"] Georgia
[/TD]
[TD="width: 139"] Hawaii
[/TD]
[TD="width: 139"] Idaho
[/TD]
[TD="width: 139"] Illinois
[/TD]
[TD="width: 139"] Indiana
[/TD]
[/TR]
[TR]
[TD="width: 139"] Iowa
[/TD]
[TD="width: 139"] Kansas
[/TD]
[TD="width: 139"] Kentucky
[/TD]
[TD="width: 139"] Louisiana
[/TD]
[TD="width: 139"] Maine
[/TD]
[/TR]
[TR]
[TD="width: 139"] Maryland
[/TD]
[TD="width: 139"] Massachusetts
[/TD]
[TD="width: 139"] Michigan
[/TD]
[TD="width: 139"] Minnesota
[/TD]
[TD="width: 139"] Mississippi
[/TD]
[/TR]
[TR]
[TD="width: 139"] Missouri
[/TD]
[TD="width: 139"] Montana
[/TD]
[TD="width: 139"] Nebraska
[/TD]
[TD="width: 139"] Nevada
[/TD]
[TD="width: 139"] New Hampshire
[/TD]
[/TR]
[TR]
[TD="width: 139"] New Jersey
[/TD]
[TD="width: 139"] New Mexico
[/TD]
[TD="width: 139"] New York
[/TD]
[TD="width: 139"] North Carolina
[/TD]
[TD="width: 139"] North Dakota
[/TD]
[/TR]
[TR]
[TD="width: 139"] Ohio
[/TD]
[TD="width: 139"] Oklahoma
[/TD]
[TD="width: 139"] Oregon
[/TD]
[TD="width: 139"] Pennsylvania
[/TD]
[TD="width: 139"] Rhode Island
[/TD]
[/TR]
[TR]
[TD="width: 139"] South Carolina
[/TD]
[TD="width: 139"] South Dakota
[/TD]
[TD="width: 139"] Tennessee
[/TD]
[TD="width: 139"] Texas
[/TD]
[TD="width: 139"] Utah
[/TD]
[/TR]
[TR]
[TD="width: 139"] Vermont
[/TD]
[TD="width: 139"] Virginia
[/TD]
[TD="width: 139"] Washington
[/TD]
[TD="width: 139"] West Virginia
[/TD]
[TD="width: 139"] Wisconsin
[/TD]
[/TR]
[TR]
[TD="width: 139"] Wyoming
[/TD]
[TD="width: 139"] New York City
[/TD]
[TD="width: 139"] Puerto Rico
[/TD]
[TD="width: 139"] Virgin Islands
[/TD]
[TD="width: 139"] [/TD]
[/TR]
[/TABLE]
World Health Organization: Additional influenza surveillance information from participating WHO member nations is available through FluNet and the Global Epidemiology Reports.
WHO Collaborating Centers for Influenza located in Australia, China, Japan, the United Kingdom, and the United States (CDC in Atlanta, Georgia).
Europe: For the most recent influenza surveillance information from Europe, please see WHO/Europe and the European Centre for Disease Prevention and Control at http://www.flunewseurope.org/.
Public Health Agency of Canada: The most up-to-date influenza information from Canada is available at http://www.phac-aspc.gc.ca/fluwatch/
Public Health England: The most up-to-date influenza information from the United Kingdom is available athttps://www.gov.uk/government/statistics/weekly-national-flu-reports


Any links provided to non-Federal organizations are provided solely as a service to our users. These links do not constitute an endorsement of these organizations or their programs by CDC or the Federal Government, and none should be inferred. CDC is not responsible for the content of the individual organization web pages found at these links.
An overview of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component, is available at: http://www.cdc.gov/flu/weekly/overview.htm.
--------------------------------------------------------------------------------







[/SIZE]


[h=5]File Formats Help:[/h] How do I view different file formats (PDF, DOC, PPT, MPEG) on this site?

[/COLOR]


https://www.cdc.gov/flu/weekly/
 
[h=3]2016-2017 Influenza Season Week 1 ending January 7, 2017[/h] All data are preliminary and may change as more reports are received.
[h=3]Synopsis:[/h] During week 1 (January 1-7, 2017), influenza activity increased in the United States.
  • Viral Surveillance: The most frequently identified influenza virus subtype reported by public health laboratories during week 1 was influenza A (H3). The percentage of respiratory specimens testing positive for influenza in clinical laboratories increased.
  • Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was below the system-specific epidemic threshold in the National Center for Health Statistics (NCHS) Mortality Surveillance System.
  • Influenza-associated Pediatric Deaths: Three influenza-associated pediatric deaths were reported.
  • Influenza-associated Hospitalizations: A cumulative rate for the season of 7.1 laboratory-confirmed influenza-associated hospitalizations per 100,000 population was reported.
  • Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 3.2%, which is above the national baseline of 2.2%. All 10 regions reported ILI at or above their region-specific baseline levels. New York City, Puerto Rico, and eight states experienced high ILI activity; six states experienced moderate ILI activity; seven states experienced low ILI activity; 28 states experienced minimal ILI activity, and the District of Columbia and one state had insufficient data.
  • Geographic Spread of Influenza: The geographic spread of influenza in Puerto Rico and 21 states was reported as widespread; Guam and 21 states reported regional activity; the District of Columbia and eight states reported local activity; and the U.S. Virgin Islands reported no activity.
[h=3]National and Regional Summary of Select Surveillance Components[/h]
[TABLE="class: table table-bordered opt-in, width: 100%"]
[TR]
[/TR]
[TR]
HHS Surveillance Regions* Data for current week Data cumulative since October 2, 2016 (week 40) [/TR]
[TR]
Out-patient ILI? Number of jurisdictions reporting regional or widespread activity? % respiratory specimens positive for flu in clinical laboratories? A(H1N1)pdm09 A (H3) A (Subtyping not Performed) B Victoria lineage B Yamagata lineage B lineage not performed Pediatric Deaths [/TR]
[TR]
Influenza test results from public health laboratories only [/TR]
[TR]
Nation [TD]Elevated[/TD]
[TD]44 of 54[/TD]
[TD]13.9%[/TD]
[TD]177[/TD]
[TD]5,261[/TD]
[TD]134[/TD]
[TD]174[/TD]
[TD]123[/TD]
[TD]147[/TD]
[TD]3[/TD]
[/TR]
[TR]
Region 1 [TD]Elevated[/TD]
[TD]5 of 6[/TD]
[TD]11.6%[/TD]
[TD]15[/TD]
[TD]266[/TD]
[TD]0[/TD]
[TD]0[/TD]
[TD]3[/TD]
[TD]5[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 2 [TD]Elevated[/TD]
[TD]3 of 4[/TD]
[TD]15.5%[/TD]
[TD]1[/TD]
[TD]285[/TD]
[TD]8[/TD]
[TD]16[/TD]
[TD]8[/TD]
[TD]20[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 3 [TD]Elevated[/TD]
[TD]4 of 6[/TD]
[TD]9.6%[/TD]
[TD]17[/TD]
[TD]651[/TD]
[TD]10[/TD]
[TD]21[/TD]
[TD]25[/TD]
[TD]14[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 4 [TD]Elevated[/TD]
[TD]6 of 8[/TD]
[TD]12.1%[/TD]
[TD]15[/TD]
[TD]355[/TD]
[TD]16[/TD]
[TD]17[/TD]
[TD]12[/TD]
[TD]66[/TD]
[TD]1[/TD]
[/TR]
[TR]
Region 5 [TD]Elevated[/TD]
[TD]5 of 6[/TD]
[TD]7.2%[/TD]
[TD]17[/TD]
[TD]659[/TD]
[TD]13[/TD]
[TD]60[/TD]
[TD]23[/TD]
[TD]15[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 6 [TD]Elevated[/TD]
[TD]4 of 5[/TD]
[TD]8.0%[/TD]
[TD]21[/TD]
[TD]124[/TD]
[TD]0[/TD]
[TD]11[/TD]
[TD]8[/TD]
[TD]8[/TD]
[TD]1[/TD]
[/TR]
[TR]
Region 7 [TD]Elevated[/TD]
[TD]2 of 4[/TD]
[TD]7.9%[/TD]
[TD]5[/TD]
[TD]204[/TD]
[TD]10[/TD]
[TD]12[/TD]
[TD]13[/TD]
[TD]4[/TD]
[TD]1[/TD]
[/TR]
[TR]
Region 8 [TD]Elevated[/TD]
[TD]6 of 6[/TD]
[TD]16.8%[/TD]
[TD]32[/TD]
[TD]608[/TD]
[TD]8[/TD]
[TD]9[/TD]
[TD]11[/TD]
[TD]0[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 9 [TD]Elevated[/TD]
[TD]5 of 5[/TD]
[TD]10.4%[/TD]
[TD]52[/TD]
[TD]1,522[/TD]
[TD]64[/TD]
[TD]21[/TD]
[TD]20[/TD]
[TD]8[/TD]
[TD]0[/TD]
[/TR]
[TR]
Region 10 [TD]Elevated[/TD]
[TD]4 of 4[/TD]
[TD]29.8%[/TD]
[TD]2[/TD]
[TD]587[/TD]
[TD]5[/TD]
[TD]7[/TD]
[TD]0[/TD]
[TD]7[/TD]
[TD]0[/TD]
[/TR]
[/TABLE]
*HHS regions (Region 1 CT, ME, MA, NH, RI, VT; Region 2: NJ, NY, Puerto Rico, US Virgin Islands; Region 3: DE, DC, MD, PA, VA, WV; Region 4: AL, FL, GA, KY, MS, NC, SC, TN; Region 5: IL, IN, MI, MN, OH, WI; Region 6: AR, LA, NM, OK, TX; Region 7: IA, KS, MO, NE; Region 8: CO, MT, ND, SD, UT, WY; Region 9: AZ, CA, Guam, HI, NV; and Region 10: AK, ID, OR, WA).
? Elevated means the % of visits for ILI is at or above the national or region-specific baseline
? Includes all 50 states, the District of Columbia, Guam, Puerto Rico, and U.S. Virgin Islands
? National data are for current week; regional data are for the most recent three weeks


[h=2]U.S. Virologic Surveillance:[/h] WHO and NREVSS collaborating laboratories, which include both public health and clinical laboratories located in all 50 states, Puerto Rico, and the District of Columbia, report to CDC the total number of respiratory specimens tested for influenza and the number positive for influenza by virus type. In addition, public health laboratories also report the influenza A subtype (H1 or H3) and influenza B lineage information for the viruses they test and the age or age group of the persons from whom the specimens were collected.
Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html and http://gis.cdc.gov/grasp/fluview/flu_by_age_virus.html.
The results of tests performed by clinical laboratories during the current week are summarized below.
[TABLE="class: table table-bordered table-condensed opt-in, width: 100%"]
[TR]
[TD="width: 200"] [/TD]
Week 1 Data Cumulative since
October 2, 2016 (Week 40) [/TR]
[TR]
No. of specimens tested [TD]25,797[/TD]
[TD]259,647[/TD]
[/TR]
[TR]
No. of positive specimens (%) [TD]3,580 (13.9%)[/TD]
[TD]15,026 (5.8%)[/TD]
[/TR]
[TR]
Positive specimens by type [TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
Influenza A [TD]3,287 (91.8%)[/TD]
[TD]12,709 (84.6%)[/TD]
[/TR]
[TR]
Influenza B [TD]293 (8.2%)[/TD]
[TD]2,317 (15.4%)[/TD]
[/TR]
[/TABLE]

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation The results of tests performed by public health laboratories, as well as the age group distribution of influenza positive tests, during the current week are summarized below.
[TABLE="class: table table-bordered table-condensed opt-in, width: 100%"]
[TR]
[TD] [/TD]
Week 1 Data Cumulative since
October 2, 2016 (Week 40) [/TR]
[TR]
No. of specimens tested [TD]1,973[/TD]
[TD]21,365[/TD]
[/TR]
[TR]
No. of positive specimens* [TD]928[/TD]
[TD]6,016[/TD]
[/TR]
[TR]
Positive specimens by type/subtype [TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
Influenza A [TD]885 (95.4%)[/TD]
[TD]5,572 (92.6%)[/TD]
[/TR]
[TR]
A(H1N1)pmd09 [TD]21 (2.4%)[/TD]
[TD]177 (3.2%)[/TD]
[/TR]
[TR]
H3 [TD]833 (94.1%)[/TD]
[TD]5,261 (94.4%)[/TD]
[/TR]
[TR]
Subtyping not performed [TD]31 (3.5%)[/TD]
[TD]134 (2.4%)[/TD]
[/TR]
[TR]
Influenza B [TD]43 (4.6%)[/TD]
[TD]444 (7.4%)[/TD]
[/TR]
[TR]
Yamagata lineage [TD]15 (34.9%)[/TD]
[TD]123 (27.7%)[/TD]
[/TR]
[TR]
Victoria lineage [TD]12 (27.9%)[/TD]
[TD]174 (39.2%)[/TD]
[/TR]
[TR]
Lineage not performed [TD]16 (37.2%)[/TD]
[TD]147 (33.1%)[/TD]
[/TR]
[/TABLE]
*The percent of specimens testing positive for influenza is not reported because public health laboratories often receive samples that have already tested positive for influenza at a clinical laboratory and therefore percent positive would not be a valid indicator of influenza activity. Additional information is available at http://www.cdc.gov/flu/weekly/overview.htm.


View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation
View Interactive Application | View Full Screen

[h=2]Influenza Virus Characterization:[/h] CDC characterizes influenza viruses through one or more tests including genomic sequencing, hemagglutination inhibition (HI) and/or neutralization assays. These data are used to compare how similar currently circulating influenza viruses are to the reference viruses used for developing influenza vaccines, and to monitor for changes in circulating influenza viruses. Historically, HI data have been used most commonly to assess the similarity between reference viruses and circulating viruses to suggest how well the vaccine may work until such a time as vaccine effectiveness estimates are available.
For nearly all virus positive surveillance samples received at CDC, next-generation sequencing is performed to ascertain genomic data of circulating influenza viruses. Viruses can be classified into genetic groups/clades based on analysis of their HA gene segments using phylogenetics and key amino acid changes (Klimov Vaccine 2012).
A proportion of influenza A (H3N2) viruses don?t yield sufficient hemagglutination titers for antigenic characterization using the hemagglutination inhibition test. Therefore, CDC selects a subset of influenza A (H3N2) viruses to test using a focus reduction assay for supplementary antigenic characterization.
[h=2]Genetic Characterization[/h] During the 2016-2017 season, 6,016 influenza positive specimens have been collected and reported by public health laboratories in the United States (figure, left). CDC genetically characterized 412 influenza viruses [44 influenza A (H1N1)pdm09, 299 influenza A (H3N2), and 69 influenza B viruses] collected by U.S. laboratories. The HA gene segment of all influenza A (H1N1)pdm09 viruses analyzed belonged to genetic group 6B.1. Influenza A (H3N2) virus HA gene segments analyzed belonged to genetic groups 3C.2a or 3C.3a. Genetic group 3C.2a includes a newly emerging subgroup known as 3C.2a1. The HA of influenza B/Victoria-lineage viruses all belonged to genetic group V1A. The HA of influenza B/Yamagata-lineage viruses analyzed all belonged to genetic group Y3.
The majority of U.S. viruses submitted for characterization come from state and local public health laboratories. Due to Right Size Roadmap considerations, specimen submission guidance issued to the laboratories request that, if available, 2 influenza A (H1N1), 2 A influenza (H3N2), and 2 influenza B viruses be submitted every other week. Because of this, the number of each virus type/subtype characterized should be approximately equal. In the figure below, the results of tests performed by public health labs are presented on the left and sequence results by genetic group of specimens submitted to CDC are presented on the right.
Genetic01_small.gif

View Chart Data | View Full Screen | View PowerPoint Presentation [h=2]Antigenic Characterization[/h] CDC has antigenically characterized 235 influenza viruses [37 influenza A (H1N1)pdm09, 139 influenza A (H3N2), and 59 influenza B viruses] collected by U.S. laboratories since October 1, 2016.
Influenza A Virus [176]
  • A (H1N1)pdm09 [37]: All 37 (100%) influenza A (H1N1)pdm09 viruses were antigenically characterized using ferret post-infection antisera as A/California/7/2009-like, the influenza A (H1N1) component of the 2016-2017 Northern Hemisphere vaccine.
  • A (H3N2) [139]: 132 of 139 (95.0%) influenza A (H3N2) viruses were antigenically characterized as A/Hong Kong/4801/2014-like, a virus that belongs in genetic group 3C.2a and is the influenza A (H3N2) component of the 2016-2017 Northern Hemisphere vaccine, by HI testing or neutralization testing. Among the viruses which reacted poorly with ferret antisera raised against A/Hong Kong/4801/2014-like viruses, 6 out of 7 (85.7%) are more closely related to A/Switzerland/9715293/2013, a virus belonging to genetic group 3C.3a.
Influenza B Virus [59]
  • Victoria Lineage [31]: 28 of 31 (90.3%) B/Victoria-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Brisbane/60/2008-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere trivalent and quadrivalent influenza vaccines.
  • Yamagata Lineage [28]: All 28 (100%) B/Yamagata-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Phuket/3073/2013-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere quadrivalent influenza vaccines.

[h=2]Antiviral Resistance:[/h] Testing of influenza A (H1N1)pdm09, influenza A (H3N2), and influenza B virus isolates for resistance to neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) is performed at CDC using a functional assay. Additional influenza A (H1N1)pdm09 and influenza A (H3N2) clinical samples are tested for mutations of the virus known to confer oseltamivir resistance. The data summarized below combine the results of both testing methods. These samples are routinely obtained for surveillance purposes rather than for diagnostic testing of patients suspected to be infected with antiviral-resistant virus.
High levels of resistance to the adamantanes (amantadine and rimantadine) persist among influenza A (H1N1)pdm09 and influenza A (H3N2) viruses (the adamantanes are not effective against influenza B viruses). Therefore, data from adamantane resistance testing are not presented below.
[TABLE="class: table, align: center, border: 0, cellpadding: 3, cellspacing: 0, width: 100%"]
[h=3]Neuraminidase Inhibitor Resistance Testing Results on Samples Collected Since October 1, 2016[/h] [/TABLE]
[TABLE="class: table table-bordered opt-in, width: 100%"]
[TR]
[TD] [/TD]
Oseltamivir​
Zanamivir​
Peramivir​
[/TR]
[TR]
[TD] [/TD]
Virus Samples tested (n)
Resistant Viruses, Number (%)​
Virus Samples tested (n)
Resistant Viruses, Number (%)​
Virus Samples tested (n)
Resistant Viruses, Number (%)​
[/TR]
[TR]
Influenza A (H1N1)pdm09
[TD]
51​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
51​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
51​
[/TD]
[TD]
0 (0.0)​
[/TD]
[/TR]
[TR]
Influenza A (H3N2)
[TD]
317​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
317​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
251​
[/TD]
[TD]
0 (0.0)​
[/TD]
[/TR]
[TR]
Influenza B
[TD]
81​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
81​
[/TD]
[TD]
0 (0.0)​
[/TD]
[TD]
81​
[/TD]
[TD]
0 (0.0)​
[/TD]
[/TR]
[/TABLE]
The majority of recently circulating influenza viruses are susceptible to the neuraminidase inhibitor antiviral medications, oseltamivir, zanamivir, and peramivir; however, rare sporadic instances of oseltamivir-resistant and peramivir-resistant influenza A (H1N1)pdm09 viruses and oseltamivir-resistant influenza A (H3N2) viruses have been detected worldwide. Antiviral treatment as early as possible is recommended for patients with confirmed or suspected influenza who have severe, complicated, or progressive illness; who require hospitalization; or who are at high risk for serious influenza-related complications. Additional information on recommendations for treatment and chemoprophylaxis of influenza virus infection with antiviral agents is available at http://www.cdc.gov/flu/antivirals/index.htm.


[h=2]Pneumonia and Influenza (P&I) Mortality Surveillance:[/h] Based on National Center for Health Statistics (NCHS) mortality surveillance data available on January 12, 2017, 6.2% of the deaths occurring during the week ending December 24, 2016 (week 51) were due to P&I. This percentage is below the epidemic threshold of 7.2% for week 51.
Background: Weekly mortality surveillance data includes a combination of machine coded and manually coded causes of death collected from death certificates. There is a backlog of data requiring manual coding within NCHS mortality surveillance data. The percentages of deaths due to P&I are higher among manually coded records than more rapidly available machine coded records and may result in initially reported P&I percentages that are lower than percentages calculated from final data. Efforts continue to reduce and monitor the number of records awaiting manual coding.
Beginning in the week ending October 8, 2016 (week 40), CDC retired the 122 Cities Mortality Reporting System and uses only the NCHS Mortality Surveillance System.
Region and state-specific data are available at http://gis.cdc.gov/grasp/fluview/mortality.html.
NCHS01_small.gif

View Regional and State Level Data | View Chart Data | View Full Screen | View PowerPoint Presentation

[h=2]Influenza-Associated Pediatric Mortality:[/h] Three influenza-associated pediatric deaths were reported to CDC during week 1. One death was associated with an influenza A (H3) virus and occurred during week 51 (the week ending December 24, 2016). One death was associated with an influenza A virus for which no subtyping was performed and occurred during week 52 (the week ending December 31, 2016). One death was associated with an influenza B virus and occurred during week 51.
A total of three influenza-associated pediatric deaths have been reported for the 2016-2017 season.
Additional data can be found at: http://gis.cdc.gov/GRASP/Fluview/PedFluDeath.html.

View Interactive Application | View Full Screen | View PowerPoint Presentation


[h=2]Influenza-Associated Hospitalizations:[/h] The Influenza Hospitalization Surveillance Network (FluSurv-NET) conducts population-based surveillance for laboratory-confirmed influenza-related hospitalizations in children younger than 18 years of age (since the 2003-2004 influenza season) and adults (since the 2005-2006 influenza season).
The FluSurv-NET covers more than 70 counties in the 10 Emerging Infections Program (EIP) states (CA, CO, CT, GA, MD, MN, NM, NY, OR, and TN) and additional Influenza Hospitalization Surveillance Project (IHSP) states. The IHSP began during the 2009-2010 season to enhance surveillance during the 2009 H1N1 pandemic. IHSP sites included IA, ID, MI, OK and SD during the 2009-2010 season; ID, MI, OH, OK, RI, and UT during the 2010-2011 season; MI, OH, RI, and UT during the 2011-2012 season; IA, MI, OH, RI, and UT during the 2012-2013 season; and MI, OH, and UT during the 2013-2014, 2014-2015, 2015-2016, and 2016-2017 seasons.
Data gathered are used to estimate age-specific hospitalization rates on a weekly basis, and describe characteristics of persons hospitalized with severe influenza illness. The rates provided are likely to be an underestimate as influenza-related hospitalizations can be missed, either because testing is not performed, or because cases may be attributed to other causes of pneumonia or other common influenza-related complications.
Between October 1, 2016 and January 7, 2017, 1,992 laboratory-confirmed influenza-associated hospitalizations were reported. The overall hospitalization rate was 7.1 per 100,000 population. The highest rate of hospitalization was among adults aged ≥65 years (32.4 per 100,000 population), followed by adults aged 50-64 (7.1 per 100,000 population) and children aged 0-4 years (4.8 per 100,000 population). Among 1,992 hospitalizations, 1,774 (89.1%) were associated with influenza A virus, 184 (9.2%) with influenza B virus, 11 (0.6%) with influenza A virus and influenza B virus co-infection, and 23 (1.2%) with influenza virus for which the type was not determined. Among those with influenza A subtype information, 493 (98.4%) were A(H3N2) and 8 (1.6%) were A(H1N1)pdm09 virus.
Clinical findings are preliminary and based on 336 (16.7%) cases with complete medical chart abstraction. Among 307 hospitalized adults with complete medical chart abstraction, 289 (94.1%) had at least one reported underlying medical condition; the most commonly reported were cardiovascular disease, obesity, and metabolic disorders. Among 29 hospitalized children with complete medical chart abstraction, 16 (55.2%) had at least one underlying medical condition; the most commonly reported were asthma and chronic lung disease. Among the 24 hospitalized women of childbearing age (15-44 years), 5 (15.8%) were pregnant.
Additional FluSurv-NET data can be found at: http://gis.cdc.gov/GRASP/Fluview/FluHospRates.html and http://gis.cdc.gov/grasp/fluview/FluHospChars.html.

[SIZE=1.5]Data from the Influenza Hospitalization Surveillance Network (FluSurv-NET), a population-based surveillance for influenza related hospitalizations in children and adults in 13 U.S. states. Cumulative incidence rates are calculated using the National Center for Health Statistics? (NCHS) population estimates for the counties included in the surveillance catchment area.

View Interactive Application | View Full Screen | View PowerPoint Presentation
[SIZE=1.5]FluSurv-NET data are preliminary and displayed as they become available. Therefore, figures are based on varying denominators as some variables represent information that may require more time to be collected. Data are refreshed and updated weekly. Asthma includes a medical diagnosis of asthma or reactive airway disease; Cardiovascular diseases include conditions such as coronary heart disease, cardiac valve disorders, congestive heart failure, and pulmonary hypertension; does not include isolated hypertension; Chronic lung diseases include conditions such as chronic obstructive pulmonary disease, bronchiolitis obliterans, chronic aspiration pneumonia, and interstitial lung disease; Immune suppression includes conditions such as immunoglobulin deficiency, leukemia, lymphoma, HIV/AIDS, and individuals taking immunosuppressive medications;Metabolic disorders include conditions such as diabetes mellitus; Neurologic diseases include conditions such as seizure disorders, cerebral palsy, and cognitive dysfunction; Neuromuscular diseases include conditions such as multiple sclerosis and muscular dystrophy; Obesity was assigned if indicated in patient's medical chart or if body mass index (BMI) >30 kg/m2; Pregnancy percentage calculated using number of female cases aged between 15 and 44 years of age as the denominator; Renal diseases include conditions such as acute or chronic renal failure, nephrotic syndrome, glomerulonephritis, and impaired creatinine clearance; No known condition indicates that the case did not have any known high risk medical condition indicated in medical chart at the time of hospitalization.[/SIZE]
View Interactive Application | View Full Screen | View PowerPoint Presentation



[h=2]Outpatient Illness Surveillance:[/h] Nationwide during week 1, 3.2% of patient visits reported through the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) were due to influenza-like illness (ILI). This percentage is above the national baseline of 2.2%.
(ILI is defined as fever (temperature of 100?F [37.8?C] or greater) and cough and/or sore throat.)
The increase in the percentage of patient visits for ILI may be influenced in part by a reduction in routine healthcare visits during the holidays, as has occurred in previous seasons.

Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html.

View National and Regional Level Graphs and Data | View Chart Data | View Full Screen | View PowerPoint Presentation On a regional level, the percentage of outpatient visits for ILI ranged from 1.7% to 5.9% during week 1. All ten regions reported a proportion of outpatient visits for ILI at or above their region-specific baseline levels.



[h=2]ILINet State Activity Indicator Map:[/h] Data collected in ILINet are used to produce a measure of ILI activity* by state. Activity levels are based on the percent of outpatient visits in a state due to ILI and are compared to the average percent of ILI visits that occur during weeks with little or no influenza virus circulation. Activity levels range from minimal, which would correspond to ILI activity from outpatient clinics being below, or only slightly above, the average, to high, which would correspond to ILI activity from outpatient clinics being much higher than average.
During week 1, the following ILI activity levels were experienced:
  • New York City, Puerto Rico, and eight states (Arizona, Georgia, Missouri, New Jersey, New York, Oklahoma, Oregon, and South Carolina) experienced high ILI activity.
  • Six states (Alabama, California, Louisiana, Nevada, Pennsylvania, and Virginia) experienced moderate ILI activity.
  • Seven states (Colorado, Hawaii, Illinois, Kansas, Michigan, Mississippi, and Tennessee) experienced low ILI activity.
  • 28 states (Alaska, Arkansas, Connecticut, Delaware, Florida, Idaho, Indiana, Iowa, Kentucky, Maine, Maryland, Massachusetts, Minnesota, Montana, Nebraska, New Hampshire, New Mexico, North Carolina, North Dakota, Ohio, Rhode Island, South Dakota, Texas, Vermont, Washington, West Virginia, Wisconsin, and Wyoming) experienced minimal ILI activity.
  • Data were insufficient to calculate an ILI activity level from the District of Columbia and one state (Utah).
Click on map to launch interactive tool
*This map uses the proportion of outpatient visits to health care providers for ILI to measure the ILI activity level within a state. It does not, however, measure the extent of geographic spread of flu within a state. Therefore, outbreaks occurring in a single city could cause the state to display high activity levels.
Data collected in ILINet may disproportionally represent certain populations within a state, and therefore, may not accurately depict the full picture of influenza activity for the whole state.
Data displayed in this map are based on data collected in ILINet, whereas the State and Territorial flu activity map is based on reports from state and territorial epidemiologists. The data presented in this map is preliminary and may change as more data are received.
Differences in the data presented here by CDC and independently by some state health departments likely represent differing levels of data completeness with data presented by the state likely being the more complete.


[h=2]Geographic Spread of Influenza as Assessed by State and Territorial Epidemiologists[/h] The influenza activity reported by state and territorial epidemiologists indicates geographic spread of influenza viruses, but does not measure the severity of influenza activity.
During week 1, the following influenza activity was reported:



[h=2]Additional National and International Influenza Surveillance Information[/h] FluView Interactive: FluView includes enhanced web-based interactive applications that can provide dynamic visuals of the influenza data collected and analyzed by CDC. These FluView Interactive applications allow people to create customized, visual interpretations of influenza data, as well as make comparisons across flu seasons, regions, age groups and a variety of other demographics. To access these tools, visithttp://www.cdc.gov/flu/weekly/fluviewinteractive.htm.
U.S. State and local influenza surveillance: Click on a jurisdiction below to access the latest local influenza information.

[TABLE="width: 100%"]
[TR]
[TD="width: 139"] Alabama
[/TD]
[TD="width: 139"] Alaska
[/TD]
[TD="width: 139"] Arizona
[/TD]
[TD="width: 139"] Arkansas
[/TD]
[TD="width: 139"] California
[/TD]
[/TR]
[TR]
[TD="width: 139"] Colorado
[/TD]
[TD="width: 139"] Connecticut
[/TD]
[TD="width: 139"] Delaware
[/TD]
[TD="width: 139"] District of Columbia
[/TD]
[TD="width: 139"] Florida
[/TD]
[/TR]
[TR]
[TD="width: 139"] Georgia
[/TD]
[TD="width: 139"] Hawaii
[/TD]
[TD="width: 139"] Idaho
[/TD]
[TD="width: 139"] Illinois
[/TD]
[TD="width: 139"] Indiana
[/TD]
[/TR]
[TR]
[TD="width: 139"] Iowa
[/TD]
[TD="width: 139"] Kansas
[/TD]
[TD="width: 139"] Kentucky
[/TD]
[TD="width: 139"] Louisiana
[/TD]
[TD="width: 139"] Maine
[/TD]
[/TR]
[TR]
[TD="width: 139"] Maryland
[/TD]
[TD="width: 139"] Massachusetts
[/TD]
[TD="width: 139"] Michigan
[/TD]
[TD="width: 139"] Minnesota
[/TD]
[TD="width: 139"] Mississippi
[/TD]
[/TR]
[TR]
[TD="width: 139"] Missouri
[/TD]
[TD="width: 139"] Montana
[/TD]
[TD="width: 139"] Nebraska
[/TD]
[TD="width: 139"] Nevada
[/TD]
[TD="width: 139"] New Hampshire
[/TD]
[/TR]
[TR]
[TD="width: 139"] New Jersey
[/TD]
[TD="width: 139"] New Mexico
[/TD]
[TD="width: 139"] New York
[/TD]
[TD="width: 139"] North Carolina
[/TD]
[TD="width: 139"] North Dakota
[/TD]
[/TR]
[TR]
[TD="width: 139"] Ohio
[/TD]
[TD="width: 139"] Oklahoma
[/TD]
[TD="width: 139"] Oregon
[/TD]
[TD="width: 139"] Pennsylvania
[/TD]
[TD="width: 139"] Rhode Island
[/TD]
[/TR]
[TR]
[TD="width: 139"] South Carolina
[/TD]
[TD="width: 139"] South Dakota
[/TD]
[TD="width: 139"] Tennessee
[/TD]
[TD="width: 139"] Texas
[/TD]
[TD="width: 139"] Utah
[/TD]
[/TR]
[TR]
[TD="width: 139"] Vermont
[/TD]
[TD="width: 139"] Virginia
[/TD]
[TD="width: 139"] Washington
[/TD]
[TD="width: 139"] West Virginia
[/TD]
[TD="width: 139"] Wisconsin
[/TD]
[/TR]
[TR]
[TD="width: 139"] Wyoming
[/TD]
[TD="width: 139"] New York City
[/TD]
[TD="width: 139"] Puerto Rico
[/TD]
[TD="width: 139"] Virgin Islands
[/TD]
[TD="width: 139"] [/TD]
[/TR]
[/TABLE]
World Health Organization: Additional influenza surveillance information from participating WHO member nations is available through FluNet and the Global Epidemiology Reports.
WHO Collaborating Centers for Influenza located in Australia, China, Japan, the United Kingdom, and the United States (CDC in Atlanta, Georgia).
Europe: For the most recent influenza surveillance information from Europe, please see WHO/Europe and the European Centre for Disease Prevention and Control at http://www.flunewseurope.org/.
Public Health Agency of Canada: The most up-to-date influenza information from Canada is available at http://www.phac-aspc.gc.ca/fluwatch/
Public Health England: The most up-to-date influenza information from the United Kingdom is available athttps://www.gov.uk/government/statistics/weekly-national-flu-reports
  • Widespread influenza activity was reported by Puerto Rico and 21 states (Alaska, California, Connecticut, Delaware, Idaho, Kentucky, Maryland, Massachusetts, Montana, Nebraska, New Hampshire, New Jersey, New York, North Carolina, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, Virginia, and Washington).
  • Regional influenza activity was reported by Guam and 21 states (Alabama, Arizona, Arkansas, Colorado, Florida, Hawaii, Indiana, Louisiana, Maine, Michigan, Minnesota, Mississippi, Missouri, Nevada, North Dakota, South Carolina, South Dakota, Texas, Utah, Wisconsin, and Wyoming).
  • Local influenza activity was reported by the District of Columbia and eight states (Georgia, Illinois, Iowa, Kansas, New Mexico, Tennessee, Vermont, and West Virginia).
  • No influenza activity was reported by the U.S. Virgin Islands.
  • Any links provided to non-Federal organizations are provided solely as a service to our users. These links do not constitute an endorsement of these organizations or their programs by CDC or the Federal Government, and none should be inferred. CDC is not responsible for the content of the individual organization web pages found at these links.
    An overview of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component, is available at: http://www.cdc.gov/flu/weekly/overview.htm.
    --------------------------------------------------------------------------------







[/SIZE]


[h=5]File Formats Help:[/h] How do I view different file formats (PDF, DOC, PPT, MPEG) on this site?

[/COLOR]


https://www.cdc.gov/flu/weekly/
 
Back
Top