Announcement

**Commonground** · January 9, 2026, 02:39 PM

Epidemic Trends
CDC uses data from emergency department visits to model epidemic trends. This model helps tell whether the number of new respiratory infections is growing or declining in your state. While this model tells us the trend, it does not tell us the actual number of current infections with SARS-CoV-2 (the virus that causes COVID-19), influenza virus, or RSV. Refer to data notesfor more details.

Severe Viral Respiratory Illness
JAN. 9, 2026
ABOUT
Provides an update on how respiratory viruses are contributing to serious health outcomes, like hospitalizations and deaths.

This Week’s Illness Severity Update:

Reported on Friday, January 9, 2026

Influenza hospitalizations are elevated.
Hospitalizations for RSV are elevated.
COVID-19 hospitalizations are low.
Deaths associated with COVID-19 (0.3%) and influenza (0.2%) are low. Deaths associated with RSV are very low. However, these respiratory death data are current as of the week ending December 6, 2025, and will be updated as soon as new data are available.

https://www.cdc.gov/respiratory-viru...ty-levels.html

**sharon sanders** · January 9, 2026, 09:19 PM

Weekly US Influenza Surveillance Report: Key Updates for Week 53, ending January 3, 2026

For Everyone
Jan. 9, 2026

Weekly US Influenza Surveillance Report: Key Updates for Week 53, ending January 3, 2026

https://www.cdc.gov/fluview/surveillance/2025-week-53.html

Seasonal influenza activity remains elevated across the country.

**Commonground** · January 16, 2026, 01:06 PM

Weekly US Influenza Surveillance Report: Key Updates for Week 1, ending January 10, 2026

For Everyone
JAN. 15, 2026

Seasonal influenza activity remains elevated nationally, but influenza activity has decreased or remained stable for two consecutive weeks. CDC will continue to monitor for a second period of increased influenza activity that often occurs after the winter holidays.

Summary

Viruses

Illness

Key Points

Seasonal influenza activity remains elevated nationally, but influenza activity has decreased or remained stable for two consecutive weeks. CDC will continue to monitor for a second period of increased influenza activity that often occurs after the winter holidays.

Influenza A(H3N2) viruses are the most frequently reported influenza viruses so far this season.
- Among 547 influenza A(H3N2) viruses collected since September 28, 2025, that underwent additional genetic characterization at CDC, 90.9% belonged to subclade K.

The weekly influenza-associated hospitalization rate overall in FluSurv-Net peaked during Week 52 at 12.6 per 100,000 population. This is the second highest peak weekly rate overall since the 2010-2011 season. Notably, children younger than 18 years have the highest peak weekly hospitalization rate observed since the 2010-2011 season.

Fifteen influenza-associated pediatric deaths occurring in the 2025-2026 season were reported to CDC this week, bringing the season total to 32 reported influenza-related pediatric deaths.
- Among children who were eligible for influenza vaccination and with known vaccine status, 90% of reported pediatric deaths this season have occurred in children who were not fully vaccinated against influenza.

CDC's in-season severity assessment framework classified the season as moderate across all ages. CDC also assesses severity by three age groups: pediatric (0-17 years), adult (18-64 years), and older adults (≥65 years). At this point in the season, the pediatric age group is classified as having high severity, while both the adult and older adult age groups are classified as having moderate severity. These assessments are conducted each week during the season, and the season's severity assessment can change if activity should increase again.

CDC estimates that there have been at least 18,000,000 illnesses, 230,000 hospitalizations, and 9,300 deaths from flu so far this season.

Influenza (flu) vaccination has been shown to reduce the risk of flu and its potentially serious complications. There is still time to get vaccinated against flu this season. Approximately 130 million doses of influenza vaccine have been distributed in the United States this season.
There are prescription flu antiviral drugs that can treat flu illness; those should be started as early as possible and are especially important for patients at higher risk for flu-related complications.¹
Influenza viruses are among several viruses contributing to respiratory disease activity. CDC provides updated, integrated information about COVID-19, flu, and respiratory syncytial virus (RSV) activity on a weekly basis.
No new avian influenza A(H5) infections were reported to CDC this week. To date, person-to-person transmission of influenza A(H5) viruses has not been identified in the United States.

U.S. virologic surveillance

Nationally and in all ten HHS regions the percentage of respiratory specimens testing positive for influenza virus in clinical laboratories decreased (change of at least 0.5 percentage points) in Week 1 compared to Week 53. Region 2 had the highest percent positivity (22.9%) and Region 9 had the lowest (11.5%). Influenza A(H3N2) viruses were the most frequently reported influenza viruses this week; however, the distribution of circulating viruses varies by region. For regional and state level data and age group distribution, please visit FluView Interactive. Viruses known to be associated with recent receipt of live attenuated influenza vaccine (LAIV) or found upon further testing to be a vaccine virus are not included, as they are not circulating influenza viruses.

Continued: https://www.cdc.gov/fluview/surveill...6-week-01.html

**Commonground** · January 17, 2026, 09:14 AM

Respiratory Virus Activity Levels
JAN. 16, 2026

This Week’s Activity Update:

Reported on Friday, January 16, 2026

The amount of acute respiratory illness causing people to seek health care is moderate.
Seasonal influenza activity remains elevated across the country.
RSV activity is elevated in many areas of the country.
Nationally, COVID-19 activity is increasing from low levels.
Nationally, wastewater activity level for COVID-19 and influenza is moderate and RSV is low.

Level of Respiratory Illness Activity
Respiratory illness activity is monitored using the acute respiratory illness (ARI) metric. ARI captures a broad range of diagnoses from emergency department visits for respiratory illnesses, from the common cold to severe infections like influenza, RSV and COVID-19. It captures illnesses that may not present with fever, offering a more complete picture than the previous influenza-like illness (ILI) metric. Refer to data notes for more details.

Epidemic Trends

Influenza:

COVID-19

Data last updated on January 14, 2026 and presented through January 13, 2026. View this dataset on data.cdc.gov.

Respiratory Virus Activity Levels

https://www.cdc.gov/respiratory-viruses/data/activity-levels.html#cdc_data_surveillance_section_3-emergency-department-visits-for-viral-respiratory-illness

Updates on how COVID-19, Flu, and RSV may be spreading nationally and in your state

**sharon sanders** · February 9, 2026, 03:23 PM

Weekly US Influenza Surveillance Report: Key Updates for Week 3, ending January 24, 2026

For Everyone
Jan. 30, 2026

Key points

Seasonal influenza activity remains elevated nationally and increased this week after three weeks of decreasing trends.
Summary

Viruses

Clinical Lab 18.0% (Trend )
positive for influenza
this week. Public Health Lab The most frequently reported
influenza viruses this week were influenza A(H3N2).

Illness

Outpatient Respiratory Illness 4.7% (Trend )
of visits to a health care provider this week were for respiratory illness
(above baseline). Activity Map 10 moderate jurisdictions 29 high or very high jurisdictions FluSurv-NET 59.5 per 100,000
cumulative hospitalization rate
per 100,000 population NHSN LTCF Respiratory
Data 26.4 per 100,000 (Trend ) weekly hospitalization rate
per 100,000 residents NHSN Hospital Respiratory Data 15,080 (Trend )
patients admitted to hospitals
with influenza this week. NCHS Mortality 1.5% (Trend ) of deaths attributed to influenza this week. Pediatric Deaths 8 influenza-associated deaths were reported this week for a total of 52 deaths this season.
All data are preliminary and may change as more reports are received.

Directional arrows indicate changes between the current week and the previous week. Additional information on the arrows can be found at the bottom of this page.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component is available on the surveillance methods page.¹

Additional information on the current and previous influenza seasons for each surveillance component are available on FluView Interactive. Key Points

Seasonal influenza activity remains elevated nationally and increased during Week 3 after three weeks of decreasing trends. Influenza A activity has remained stable while influenza B activity is increasing nationally; however, trends vary by region.

Influenza A(H3N2) viruses are the most frequently reported influenza viruses so far this season.
- Among 692 influenza A(H3N2) viruses collected since September 28, 2025, that underwent additional genetic characterization at CDC, 90.5% belonged to subclade K.

The weekly influenza-associated hospitalization rate overall in FluSurv-Net peaked during Week 52 at 12.8 per 100,000 population. This is the second highest peak weekly rate overall since the 2010-2011 season. Notably, children younger than 18 years have the highest peak weekly hospitalization rate observed since the 2010-2011 season.

Eight influenza-associated pediatric deaths occurring in the 2025-2026 season were reported to CDC this week, bringing the season total to 52 reported influenza-related pediatric deaths.
- Among children who were eligible for influenza vaccination and with known vaccine status, approximately 90% of reported pediatric deaths this season have occurred in children who were not fully vaccinated against influenza.

CDC's in-season severity assessment framework classified the season as moderate across all ages. CDC also assesses severity by three age groups: pediatric (0-17 years), adult (18-64 years), and older adults (≥65 years). At this point in the season, the pediatric age group is classified as having high severity, while both the adult and older adult age groups are classified as having moderate severity. These assessments are conducted each week during the season, and the season's severity assessment can change if activity should increase again.

CDC estimates that there have been at least 20,000,000 illnesses, 270,000 hospitalizations, and 11,000 deaths from flu so far this season.
Influenza (flu) vaccination has been shown to reduce the risk of flu and its potentially serious complications. There is still time to get vaccinated against flu this season. Approximately 130 million doses of influenza vaccine have been distributed in the United States this season.
There are prescription flu antiviral drugs that can treat flu illness; those should be started as early as possible and are especially important for patients at higher risk for flu-related complications.¹
Influenza viruses are among several viruses contributing to respiratory disease activity. CDC provides updated, integrated information about COVID-19, flu, and respiratory syncytial virus (RSV) activity on a weekly basis.
No new avian influenza A(H5) infections were reported to CDC this week. To date, person-to-person transmission of influenza A(H5) viruses has not been identified in the United States.

U.S. virologic surveillance

Nationally, the percentage of respiratory specimens testing positive for the influenza virus in clinical laboratories increased (change of at least 0.5 percentage points), with influenza A percent positivity remaining stable and influenza B percent positivity slightly increasing. Influenza A(H3N2) viruses were the most frequently reported influenza viruses this week nationally and in all HHS regions. Trends in percent positivity and the distribution of circulating viruses varies by HHS region. For regional and state level data and age group distribution, please visit FluView Interactive. Viruses known to be associated with recent receipt of live attenuated influenza vaccine (LAIV) or found upon further testing to be a vaccine virus are not included, as they are not circulating influenza viruses.

Clinical Laboratories

The results of tests performed by clinical laboratories nationwide are summarized below. Data from clinical laboratories (the percentage of specimens tested that are positive for influenza virus) are used to monitor whether influenza activity is increasing or decreasing.

No. of specimens tested	69,595	1,291,988
No. of positive specimens (%)	12,556 (18.0%)	173,991 (13.5%)
*Positive specimens by type*
Influenza A	10,931 (87.1%)	162,592 (93.4%)
Influenza B	1,625 (12.9%)	11,399 (6.6%)

View Larger Download Influenza Positive Tests Reported to CDC by Clinical Laboratories, National Summary, 2025-26 Season, week ending Jan. 24, 2026
View Chart Data Public Health Laboratories

The results of tests performed by public health laboratories nationwide are summarized below. Data from public health laboratories are used to monitor the proportion of circulating influenza viruses that belong to each influenza subtype/lineage.

No. of specimens tested	1,394	45,227
No. of positive specimens	951	29,749
*Positive specimens by type/subtype*
Influenza A	889 (93.5%)	28,697 (96.5%)
Subtyping Performed	665 (74.8%)	24,478 (85.3%)
(H1N1)pdm09	77 (11.6%)	2,839 (11.6%)
H3N2	588 (88.4%)	21,637 (88.4%)
H3N2v	0	0
H5	0	2 (<0.1%)
Subtyping not performed	224 (25.2%)	4,219 (14.7%)
Influenza B	62 (6.5%)	1,052 (3.5%)
Lineage testing performed	16 (25.8%)	303 (28.8%)
Yamagata lineage	0	0
Victoria lineage	16 (100%)	303 (100%)
Lineage not performed	46 (74.2%)	749 (71.2%)

_{*These data reflect specimens tested, and the number determined to be positive for influenza viruses at the public health labs (specimens tested is not the same as cases). The data do not reflect specimens tested only at CDC and could include more than one specimen tested per person. For more information on the number of people infected with A/H5 viruses, please visit the "How CDC is monitoring influenza data among people to better understand the current avian influenza A (H5N1) situation"}

_{^†When an influenza virus that normally circulates in swine (but not people) is detected in a person, it is called a "variant" influenza virus. Most human infections with variant influenza viruses occur following exposure to swine, but human-to-human transmission can occur. It is important to note that in most cases, variant influenza viruses have not shown the ability to spread easily and sustainably from human-to-human.} View Larger Download This graph reflects the number of specimens tested and the number determined to be positive for influenza viruses at the public health lab (specimens tested is not the same as cases). It does not reflect specimens tested only at CDC and could include... Show More
_{*This graph reflects the number of specimens determined to be positive for influenza viruses at the public health lab (specimens tested is not the same as cases). It does not reflect specimens tested only at CDC and could include more than one specimen tested per person. Specimens tested as part of routine influenza surveillance as well as those tested as part of targeted testing for people exposed to avian influenza A(H5) are included.}

View Chart Data

Additional virologic surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive: National, Regional, and State Data or Age Data

Novel Influenza A Virus Infections

No new confirmed human infections with avian influenza A(H5) virus were reported to CDC this week. To date, person-to-person transmission of avian influenza A(H5) virus (H5 bird flu) has not been identified in the United States.

The CSTE position statement, which includes updated case definitions for confirmed, probable, and suspected cases is available at http://www.cste.org/resource/resmgr/...nfluenza_A.pdf.

An up-to-date human case summary during the current outbreak by state and exposure source is available at www.cdc.gov/bird-flu/situation-summary/index.html.

Information about avian influenza is available at https://www.cdc.gov/flu/avianflu/index.htm. A(H5N1) virus interim recommendations for Prevention, Monitoring, and Public Health Investigations are available at https://www.cdc.gov/bird-flu/prevent...endations.html.

Additional information regarding human infections with novel influenza A viruses:

Surveillance Methods | FluView Interactive

Influenza Virus Characterization

CDC performs genetic and antigenic characterization of U.S. viruses submitted from state and local public health laboratories according to the Right Size Roadmap submission guidance. These data are used to compare how similar the currently circulating influenza viruses are relative to the reference viruses representing the current influenza vaccines. The data are also used to monitor evolutionary changes that continually occur in influenza viruses circulating in humans. CDC also tests susceptibility of circulating influenza viruses to antiviral medications including the neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) and the polymerase acidic protein (PA) endonuclease inhibitor baloxavir. The HA clade and subclades were assigned using Nextclade (https://clades.nextstrain.org).

CDC has genetically characterized 1,072 influenza viruses collected since September 28, 2025.

A/H1	279
		5a.2a	2 (0.7%)	C.1.9.3	2 (0.7%)
5a.2a.1	277 (99.3%)	D.3.1	130 (46.6%)
D.3.1.1	147 (52.7%)
A/H3	692
		2a.3a.1	692 (100%)	J.2	4 (0.6%)
J.2.2	5 (0.7%)
J.2.3	27 (3.9%)
J.2.4	30 (4.3%)
K	626 (90.5%)
B/Victoria	101
		3a.2	101 (100%)	C.3.1	59 (58.4%)
C.5.1	11 (10.9%)
C.5.6	10 (9.9%)
C.5.6.1	9 (8.9%)
C.5.7	12 (11.9%)
B/Yamagata	0
		Y3	0	Y3	0

CDC antigenically characterizes influenza viruses by hemagglutination inhibition (HI) assay (H1N1pdm09, H3N2, and B/Victoria viruses) or neutralization-based HINT (H3N2 viruses) using antisera from ferrets infected with reference viruses representing the recommended cell-based or recombinant influenza vaccines for the 2025-2026 Northern Hemisphere season. Antigenic differences between viruses are determined by comparing how well the antibodies raised against the vaccine reference viruses recognize the circulating viruses, which were grown in cell culture. Ferret antisera are useful because antibodies raised against a particular virus can often recognize small changes in the surface proteins of other viruses. In HI assays, viruses are deemed antigenically similar when their HI titer differences are less than or equal to 4-fold. In HINT, viruses with similar antigenic properties have antibody neutralization titer differences of less than 8-fold. Circulating viruses with antigenic testing results that show titer differences greater than 4-fold by HI or equal to or greater than 8-fold by HINT) are considered "low reactors" or antigenically drifted compared to the vaccine virus. From the recent genetically characterized viruses, a subset is selected for antigenic characterization based on identified genetic changes in their surface proteins. The subset tested may not be proportional to the number of such viruses circulating in the United States.

Influenza A Viruses

A(H1N1)pdm09: 68 A(H1N1)pdm09 viruses collected since September 28, 2025, were antigenically characterized by HI, and 67 (98.5%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer) by ferret antisera to cell-grown A/Wisconsin/67/2022-like reference viruses representing the A(H1N1)pdm09 component for the cell- and recombinant-based influenza vaccines.
A(H3N2): 77 A(H3N2) viruses collected since September 28, 2025, were antigenically characterized by HI or HINT, and 3 (3.9%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer in HI or reacting at titers that were less than 8-fold of the homologous virus in HINT) by ferret antisera to cell-grown A/District Of Columbia/27/2023-like reference viruses representing the A(H3N2) component for the cell- and recombinant-based influenza vaccines.

Influenza B Viruses

B/Victoria: 31 influenza B/Victoria-lineage viruses collected since September 28, 2025, were antigenically characterized by HI, and 16 (51.6%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer) by ferret antisera to cell-grown B/Austria/1359417/2021-like reference viruses representing the B/Victoria component for the cell- and recombinant-based influenza vaccines.
B/Yamagata: No influenza B/Yamagata-lineage viruses were available for antigenic characterization.

Assessment of Virus Susceptibility to Antiviral Medications

CDC assesses susceptibility of influenza viruses to the antiviral medications including the neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) and the PA endonuclease inhibitor baloxavir using next generation sequence analysis supplemented by laboratory assays. Information about antiviral susceptibility test methods can be found at U.S. Influenza Surveillance: Purpose and Methods | CDC.

Viruses collected in the U.S. since September 28, 2025, were tested for antiviral susceptibility as follows:

Neuraminidase Inhibitors	Oseltamivir	Viruses Tested	1061	281	681	99
Reduced Inhibition	2 (0.2%)	2 (0.7%)	0	0
Highly Reduced Inhibition	2 (0.2%)	2 (0.7%)	0	0
Peramivir	Viruses Tested	1061	281	681	99
Reduced Inhibition	1 (<0.1%)	0	0	1 (1.0%)
Highly Reduced Inhibition	2 (0.2%)	2 (0.7%)	0	0
Zanamivir	Viruses Tested	1061	281	681	99
Reduced Inhibition	0	0	0	0
Highly Reduced Inhibition	0	0	0	0
PA Cap-Dependent Endonuclease Inhibitor	Baloxavir	Viruses Tested	1033	267	670	96
Decreased Susceptibility	0	0	0	0

Two A(H1N1)pdm09 viruses had NA-H275Y amino acid substitution conferring highly reduced inhibition by oseltamivir and peramivir. Two A(H1N1)pdm09 viruses had amino acid substitutions NA-I223V and NA-S247N and showed reduced inhibition by oseltamivir. One B virus had amino acid substitution NA- M464T and showed reduced inhibition by peramivir.

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, use of these antivirals for treatment and prevention of influenza A virus infection is not recommended and data from adamantane resistance testing are not presented.

Outpatient and Emergency Department Illness Surveillance

Outpatient Respiratory Illness Visits

The U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) monitors outpatient visits for respiratory illness referred to as influenza-like illness [ILI (fever plus cough or sore throat)], not laboratory-confirmed influenza, and will therefore capture respiratory illness visits due to infection with any pathogen that can present with similar symptoms, including influenza virus, SARS-CoV-2, and RSV. It is important to evaluate syndromic surveillance data, including that from ILINet, in the context of other sources of surveillance data to obtain a complete and accurate picture of influenza, SARS-CoV-2, and other respiratory virus activity.

Nationally, during Week 3, 4.7% of patient visits reported through ILINet were due to respiratory illness that included fever plus a cough or sore throat, also referred to as ILI. This week's national percentage increased (change of > 0.1 percentage points) and remains above the national baseline for the eighth consecutive week. ILI activity increased (change of > 0.1 percentage points) in HHS regions 4, 6, 7, 9, and 10, decreased (change of > 0.1 percentage points) in regions 1, 2, 3, and 5, and remained stable (change of ≤ 0.1 percentage points) in Region 8 this week compared to Week 2. Region 2 is below its regional baseline while all other regions (1, 3, 4, 5, 6, 7, 8, 9, and 10) remain above their respective baselines. Multiple respiratory viruses are co-circulating, and the relative contribution of influenza virus infection to ILI varies by location. View Larger Download Percentage of Outpatient Visits for Respiratory Illness Reported by. The U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet)
View Chart Data

Outpatient Respiratory Illness Visits by Age Group

About 70% of ILINet participants provide both the number of patient visits for respiratory illness and the total number of patient visits for the week broken out by age group. Based on these data, the percentage of visits for respiratory illness increased (change of > 0.1 percentage points) in the 5-17 years age group, remained stable (change of ≤ 0.1 percentage points) in the 0-4 years and 25-49 years age groups, and decreased (change of > 0.1 percentage points) in the 50-64 years and 65 years and older age groups this week compared to Week 2. View Larger Download Percent of Outpatient Visits for Respiratory Illness by Age Group. Reported by the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet)
View Chart Data

Outpatient Respiratory Illness Activity Map

Data collected in ILINet are used to produce a measure of ILI activity* by state/jurisdiction and Core Based Statistical Areas (CBSA).

Week 3 (Week ending Jan. 24, 2026)	Week 2 (Week ending Jan. 17, 2026)	Week 3 (Week ending Jan. 24, 2026)	Week 2 (Week ending Jan. 17, 2026)
Very High	6	6	22	17
High	23	25	124	135
Moderate	10	9	157	153
Low	8	10	215	217
Minimal	8	4	183	190
Insufficient Data	0	1	228	217

_{*Data collected in ILINet may disproportionally represent certain populations within a jurisdiction or CBSA, and therefore, may not accurately depict the full picture of influenza activity for the entire jurisdiction or CBSA. Differences in the data presented here by CDC and independently by some health departments likely represent differing levels of data completeness with data presented by the health department likely being the more complete.}

Additional information about medically attended visits for ILI for current and past seasons:

Surveillance Methods | FluView Interactive: National, Regional, and State Data or ILI Activity Map

National Syndromic Surveillance System (NSSP)

The national percentage of emergency department (ED) visits with a discharge diagnosis (DD) of influenza reported in NSSP was 3.4% during Week 3 and increased (change of > 0.1 percentage point) compared to the previous week. Nationally, the percentage of ED visits with a DD of influenza increased among the 5-17 years age group, remained stable among the 18-64 years age group, and decreased among the 0-4 years and 65 years and older age groups. The percentage of ED visits with a DD of influenza increased this week compared to the previous week in HHS regions 4, 6, 7, 9, and 10, remained stable in region 5, and decreased in regions 1, 2, 3, and 8. The age group trends varied by region. View Larger Download NSSP week 3 Additional information about emergency department visits for flu for current and past seasons:‎‎‎

Surveillance Methods | Emergency Department Visits for COVID-19, flu, and RSV

Hospitalization surveillance

FluSurv-Net

Influenza-Associated Hospitalizations: The Influenza Hospitalization Surveillance Network (FluSurv-NET) conducts population-based surveillance for laboratory-confirmed influenza-related hospitalizations in select counties in 14 states and represents approximately 10% of the U.S. population. FluSurv-NET hospitalization data are preliminary. As data are received each week, prior case counts and rates are updated accordingly.

A total of 20,736 laboratory-confirmed influenza-associated hospitalizations were reported by FluSurv-NET sites between October 1, 2025, and January 24, 2026. The weekly hospitalization rate observed during Week 3 was 2.4 per 100,000 population, which decreased from last week. After accounting for reporting delays, the estimated rate during Week 3 likely ranges from 3.1 to 4.4. The cumulative hospitalization rate observed in Week 3 was 59.5 per 100,000 population and is the highest cumulative rate this week since the 2010-11 season.

Among all hospitalizations, 20,078 (96.8%) were associated with influenza A virus, 531 (2.6%) with influenza B virus, 24 (0.1%) with influenza A virus and influenza B virus co-infection, and 103 (0.5%) with influenza virus for which the type was not determined. Among those with influenza A subtype information, 4,586 (90.9%) were A(H3N2), and 460 (9.1%) were A(H1N1)pdm09.

When examining rates by age, the highest rate of hospitalization per 100,000 population was among adults aged 65 and older (199.0), followed by children aged 0-4 years (62.9), adults aged 50-64 years (52.6), children aged 5-17 years (23.1), and adults aged 18-49 years (22.9).

Among children, the peak weekly rate is the highest going back to the 2010-11 season in Week 52 (7.2). The cumulative rate for pediatric cases is the second highest since 2010-11 (33.3). Among children, rates are highest among infants aged less than 1 year (99.3), followed by children aged 1-4 years (54.0). For all pediatric age groups, this is the second highest cumulative rate at this time of the season since the 2010-11 season.

When examining age-adjusted rates by race and ethnicity, the highest rate of hospitalization per 100,000 population was among non-Hispanic Black persons (108.1), followed by American Indian or Alaska Native persons (58.4), Hispanic persons (53.7), non-Hispanic White persons (50.2), and Asian and/or Pacific Islander persons (25.1).

Among 1,613 hospitalized adults with information on underlying medical conditions, 96.2% had at least one reported underlying medical condition; the most commonly reported were hypertension, cardiovascular disease, chronic metabolic disease, and chronic lung disease. Among 2,357 hospitalized women of childbearing age (15-49 years) with information on pregnancy status, 31.0% were pregnant. Among 618 hospitalized children with information on underlying medical conditions, 59.4% had at least one reported underlying medical condition; the most commonly reported was asthma, followed by neurologic disorder, and obesity.

Additional FluSurv-NET data are available on FluView Interactive including hospitalization rates for the current and past seasons by age, sex, and race/ethnicity (http://gis.cdc.gov/GRASP/Fluview/FluHospRates.html) as well as data on patient characteristics at: (http://gis.cdc.gov/grasp/fluview/FluHospChars.html.)

FluSurv-NET data are used to generate national estimates of the total numbers of influenza cases, medical visits, hospitalizations and deaths. This season, CDC is reporting preliminary cumulative in-season estimates, which are available at https://www.cdc.gov/flu-burden/php/data-vis/index.html. View Larger Download **In this figure, weekly rates for all seasons prior to the 2024-2025 season reflect end-of-season rates. For the 2024-2025 season, rates for recent hospital admissions are subject to reporting delays and are shown as a dashed line for the current se... Show More
_{**In this figure, weekly rates for all seasons prior to the 2025-26 season reflect end-of-season rates. For the 2025-26 season, rates for recent hospital admissions are subject to reporting delays and are shown as a dashed line for the current season. As hospitalization data are received each week, prior case counts and rates are updated accordingly.} Additional FluSurv-NET hospitalization surveillance information for current and past seasons and additional age groups:

Surveillance Methods | FluView Interactive: Rates by Age, Sex, and Race/Ethnicity or Data on Patient Characteristics | RESP-NET Interactive

National Healthcare Safety Network (NHSN) Hospital Respiratory Data

Hospitals report to NHSN the weekly number of patients with laboratory-confirmed influenza who were admitted to the hospital. Nationally, during Week 3, 15,080 laboratory-confirmed influenza-associated hospitalizations were reported. This week's influenza-associated hospital admission rate (4.5 per 100,000 population) decreased (difference of < 0.2) compared to Week 2.

Laboratory confirmed, influenza-associated hospital admission rates per 100,000 population decreased in HHS Regions 1, 2, 3, 4, 5, 8, and 10, increased in Region 6, and remained stable in Regions 7 and 9. Regional admission rates ranged from 3.4 (Region 9) to 6.6 (Region 3) during Week 3.

When examining rates by age for Week 3, all age groups decreased, except for the 5-17 year age group, which remained stable. The highest hospital admission rate per 100,000 population was among those 65 years and older (14.1), followed by the 0-4 years age group (5.0), and the 50-64 years age group (3.6). View Larger Download NHSN week 3 Additional NHSN Hospital Respiratory Data information:

Surveillance Methods | Additional Data | FluView Interactive

National Healthcare Safety Network (NHSN) Long-Term Care Respiratory Pathogens & Vaccination Module

Long-term care facilities (LTCFs [e.g., Nursing homes/skilled nursing facilities]) report respiratory pathogen (e.g., COVID-19, influenza and RSV) data, including vaccination, cases, and hospitalizations among residents, to the NHSN Long-Term Care Respiratory Pathogens & Vaccination Module.

Nationally, during Week 3, the hospitalization rate for residents with a positive influenza test in the prior 10 days was 26.4 per 100,000 residents. The national rate and rates in HHS Regions 1, 2, 3, 4, 7, and 8 are trending downward. Rates remain stable in Region 6 and continue to increase in Region 10. In HHS regions 5 and 9, the rate does not show a consistent trend. View Larger Download National Healthcare Safety Network (NHSN) Long-Term Care Respiratory Pathogens & Vaccination Module

Mortality surveillance

National Center for Health Statistics (NCHS) Mortality Surveillance

Based on NCHS mortality surveillance data available on January 29, 2026, 1.5% of the deaths that occurred during the week ending January 24, 2026 (Week 3), were due to influenza. This percentage decreased (≥ 0.1 percentage point change) compared to Week 2. The data presented are preliminary and may change as more data are received and processed. View Larger Download Influenza Mortality from the National Center for Health Statistics Mortality Surveillance System
View Chart Data

Additional pneumonia, influenza and COVID-19 mortality surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive

Influenza-Associated Pediatric Mortality

Eight influenza-associated pediatric deaths occurring during the 2025-2026 season were reported to CDC during Week 3. The deaths occurred during weeks 52, 53, 1, and 2 (the weeks ending December 27, 2025, January 3, 2026, January 10, 2026, and January 17, 2026). Seven deaths were associated with influenza A viruses. Four of the influenza A viruses had subtyping performed; one was an A(H1N1) virus and three were A(H3N2) viruses. One death was associated with an influenza B virus with no lineage determined.

A total of 52 influenza-associated pediatric deaths occurring during the 2025–2026 season have been reported to CDC. Among children who were eligible for influenza vaccination and with known vaccine status, approximately 90% of reported pediatric deaths this season have occurred in children who were not fully vaccinated against influenza. View Larger Download Influenza-Associated Pediatric Deaths by Week of Death, 2022-23 season to 2025-26 season Additional pediatric mortality surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive
All data in this report are preliminary and may change as more reports are received.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component, is available on the surveillance methods page.¹

Additional information on the current and previous influenza seasons for each surveillance component are available on FluView Interactive.
Additional National and International Influenza Surveillance Information

Indicators Status by System

Increasing:
Decreasing:
Stable:

Clinical Labs: Up or down arrows indicate a change of greater than or equal to 0.5 percentage points in the percent of specimens positive for influenza compared to the previous week.
Outpatient Respiratory Illness (ILINet): Up or down arrows indicate a change of greater than 0.1 percentage points in the percent of visits due to respiratory illness (ILI) compared to the previous week.
NHSN Hospitalizations: Up or down arrows indicate change of greater than or equal to 0.2 in the rate of hospital admissions or greater than or equal to 691 patients admitted with laboratory-confirmed influenza compared to the previous week.
NHSN Long- Term Care (LTC): Up or down arrows indicate change of greater than or equal to 5% in hospitalization rates for residents in LTC facilities who were hospitalized with laboratory-confirmed influenza compared to the previous week.
NCHS Mortality: Up or down arrows indicate change of greater than 0.1 percentage points of the percent of deaths due to influenza compared to the previous week.

Additional surveillance information

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.

National Institute for Occupational Safety and Health: Monthly surveillance data on the prevalence of health-related workplace absenteeism among full-time workers in the United States are available from NIOSH.

U.S. State and local influenza surveillance: Select a jurisdiction below to access the latest local influenza information.

Alabama	Alaska	Arizona	Arkansas	California
Colorado	Connecticut	Delaware	District of Columbia	Florida
Georgia	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	Oklahoma	Oregon	Pennsylvania	Rhode Island
South Carolina	South Dakota	Tennessee	Texas	Utah
Vermont	Virginia	Washington	West Virginia	Wisconsin
Wyoming	New York City	Puerto Rico	Virgin Islands

Public Health Agency of Canada:
The most up-to-date influenza information from Canada is available in Canada's weekly FluWatch report.

Public Health England:
The most up-to-date influenza information from the United Kingdom is available from Public Health England.

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.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component is available on the surveillance methods page.

Weekly US Influenza Surveillance Report: Key Updates for Week 3, ending January 24, 2026

https://www.cdc.gov/fluview/surveillance/2026-week-03.html

Seasonal influenza activity is low.

**sharon sanders** · February 9, 2026, 03:27 PM

Weekly US Influenza Surveillance Report: Key Updates for Week 4, ending January 31, 2026

For Everyone
Feb. 6, 2026

Key points

Seasonal influenza activity remains elevated nationally.
Summary

Viruses

Clinical Lab 18.0% (Trend )
positive for influenza
this week. Public Health Lab The most frequently reported
influenza viruses this week were influenza A(H3N2).

Illness

Outpatient Respiratory Illness 4.4% (Trend )
of visits to a health care provider this week were for respiratory illness
(above baseline). Activity Map 7 moderate jurisdictions 27 high or very high jurisdictions FluSurv-NET 63.2
cumulative hospitalization rate
per 100,000 population NHSN LTCF Respiratory
Data 27.5 (Trend ) weekly hospitalization rate
per 100,000 residents NHSN Hospital Respiratory Data 14,548 (Trend )
patients admitted to hospitals
with influenza this week. NCHS Mortality 1.2% (Trend ) of deaths attributed to influenza this week. Pediatric Deaths 8 influenza-associated deaths were reported this week for a total of 60 deaths this season.
All data are preliminary and may change as more reports are received.

Directional arrows indicate changes between the current week and the previous week. Additional information on the arrows can be found at the bottom of this page.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component is available on the surveillance methods page.¹

Additional information on the current and previous influenza seasons for each surveillance component are available on FluView Interactive.

Key Points

Seasonal influenza activity remains elevated nationally. Most areas of the country are reporting stable or decreasing trends in activity; however, activity continues to increase in HHS Region 10 (Pacific Northwest).
- Influenza A activity is decreasing while influenza B activity is increasing nationally and in most areas of the country; however, trends vary by region.

Influenza A(H3N2) viruses are the most frequently reported influenza viruses so far this season.
- Among 822 influenza A(H3N2) viruses collected since September 28, 2025, that underwent additional genetic characterization at CDC, 91.5% belonged to subclade K.

The weekly influenza-associated hospitalization rate overall in FluSurv-Net peaked during Week 52 at 12.8 per 100,000 population. This is the second highest peak weekly rate overall since the 2010-2011 season. Notably, children younger than 18 years have the highest peak weekly hospitalization rate observed since the 2010-2011 season.

Eight influenza-associated pediatric deaths occurring in the 2025-2026 season were reported to CDC this week, bringing the season total to 60 reported influenza-associated pediatric deaths.
- Among children who were eligible for influenza vaccination and with known vaccination status, approximately 90% of reported pediatric deaths this season have occurred in children who were not fully vaccinated against influenza.

CDC's in-season severity assessment framework classified the season as moderate across all ages. CDC also assesses severity by three age groups: pediatric (0-17 years), adult (18-64 years), and older adults (≥65 years). At this point in the season, the pediatric age group is classified as having high severity, while both the adult and older adult age groups are classified as having moderate severity. These assessments are conducted each week during the season, and the season's severity assessment can change if activity should increase again.
CDC estimates that there have been at least 22,000,000 illnesses, 280,000 hospitalizations, and 12,000 deaths from flu so far this season.
Influenza (flu) vaccination has been shown to reduce the risk of flu and its potentially serious complications. There is still time to get vaccinated against flu this season. Approximately 134 million doses of influenza vaccine have been distributed in the United States this season.

There are prescription flu antiviral drugs that can treat flu illness; those should be started as early as possible and are especially important for patients at higher risk for flu-related complications.¹
Influenza viruses are among several viruses contributing to respiratory disease activity. CDC provides updated, integrated information about COVID-19, flu, and respiratory syncytial virus (RSV) activity on a weekly basis.
No new avian influenza A(H5) infections were reported to CDC this week. To date, person-to-person transmission of influenza A(H5) viruses has not been identified in the United States.

U.S. virologic surveillance

Nationally, the percentage of respiratory specimens testing positive for the influenza virus in clinical laboratories remained stable (change < 0.5 percentage points). The percent positivity for influenza A decreased, while the percent positivity for influenza B has increased for two consecutive weeks. Influenza A(H3N2) viruses were the most frequently reported influenza viruses this week nationally and in all HHS regions. Trends in percent positivity and the distribution of circulating viruses varies by HHS region. For regional and state level data and age group distribution, please visit FluView Interactive. Viruses known to be associated with recent receipt of live attenuated influenza vaccine (LAIV) or found upon further testing to be a vaccine virus are not included, as they are not circulating influenza viruses.

Clinical Laboratories

The results of tests performed by clinical laboratories nationwide are summarized below. Data from clinical laboratories (the percentage of specimens tested that are positive for influenza virus) are used to monitor whether influenza activity is increasing or decreasing.

No. of specimens tested	71,514	1,385,003
No. of positive specimens (%)	12,869 (18.0%)	190,020 (13.7%)
*Positive specimens by type*
Influenza A	9,893 (76.9%)	174,848 (92.0%)
Influenza B	2,976 (23.1%)	15,172 (8.0%)

Public Health Laboratories

The results of tests performed by public health laboratories nationwide are summarized below. Data from public health laboratories are used to monitor the proportion of circulating influenza viruses that belong to each influenza subtype/lineage.

No. of specimens tested	1,527	50,378
No. of positive specimens	1,102	33,908
*Positive specimens by type/subtype*
Influenza A	1,023 (92.8%)	32,669 (96.3%)
Subtyping Performed	775 (75.8%)	27,314 (83.6%)
(H1N1)pdm09	111 (14.3%)	3,163 (11.6%)
H3N2	664 (85.7%)	24,149 (88.4%)
H3N2v^†	0	0
H5*	0	2 (<0.1%)
Subtyping not performed	248 (24.2%)	5,355 (16.4%)
Influenza B	79 (7.2%)	1,239 (3.7%)
Lineage testing performed	28 (35.4%)	376 (30.3%)
Yamagata lineage	0	0
Victoria lineage	28 (100%)	376 (100%)
Lineage not performed	51 (64.6%)	863 (69.7%)

_{*These data reflect specimens tested, and the number determined to be positive for influenza viruses at the public health labs (specimens tested is not the same as cases). The data do not reflect specimens tested only at CDC and could include more than one specimen tested per person. For more information on the number of people infected with A/H5 viruses, please visit the "How CDC is monitoring influenza data among people to better understand the current avian influenza A (H5N1) situation"}

_{^†When an influenza virus that normally circulates in swine (but not people) is detected in a person, it is called a "variant" influenza virus. Most human infections with variant influenza viruses occur following exposure to swine, but human-to-human transmission can occur. It is important to note that in most cases, variant influenza viruses have not shown the ability to spread easily and sustainably from human-to-human.}

_{*This graph reflects the number of specimens determined to be positive for influenza viruses at the public health lab (specimens tested is not the same as cases). It does not reflect specimens tested only at CDC and could include more than one specimen tested per person. Specimens tested as part of routine influenza surveillance as well as those tested as part of targeted testing for people exposed to avian influenza A(H5) are included.}

Additional virologic surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive: National, Regional, and State Data or Age Data

Novel Influenza A Virus Infections

No new confirmed human infections with avian influenza A(H5) virus were reported to CDC this week. To date, person-to-person transmission of avian influenza A(H5) virus (H5 bird flu) has not been identified in the United States.

The CSTE position statement, which includes updated case definitions for confirmed, probable, and suspected cases is available at http://www.cste.org/resource/resmgr/...nfluenza_A.pdf.

An up-to-date human case summary during the current outbreak by state and exposure source is available at www.cdc.gov/bird-flu/situation-summary/index.html.

Information about avian influenza is available at https://www.cdc.gov/flu/avianflu/index.htm. A(H5N1) virus interim recommendations for Prevention, Monitoring, and Public Health Investigations are available at https://www.cdc.gov/bird-flu/prevent...endations.html.

Additional information regarding human infections with novel influenza A viruses:

Surveillance Methods | FluView Interactive
Influenza Virus Characterization

CDC performs genetic and antigenic characterization of U.S. viruses submitted from state and local public health laboratories according to the Right Size Roadmap submission guidance. These data are used to compare how similar the currently circulating influenza viruses are relative to the reference viruses representing the current influenza vaccines. The data are also used to monitor evolutionary changes that continually occur in influenza viruses circulating in humans. CDC also tests susceptibility of circulating influenza viruses to antiviral medications including the neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) and the polymerase acidic protein (PA) endonuclease inhibitor baloxavir. The HA clade and subclades were assigned using Nextclade (https://clades.nextstrain.org).

CDC has genetically characterized 1,303 influenza viruses collected since September 28, 2025.

A/H1	349
		5a.2a	2 (0.6%)	C.1.9.3	2 (0.6%)
5a.2a.1	347 (99.4%)	D.3.1	155 (44.4%)
D.3.1.1	192 (55.0%)
A/H3	822
		2a.3a.1	822 (100%)	J.2	4 (0.5%)
J.2.2	5 (0.6%)
J.2.3	28 (3.4%)
J.2.4	33 (4.0%)
K	752 (91.5%)
B/Victoria	132
		3a.2	132 (100%)	C.3	3 (2.3%)
C.3.1	80 (60.6%)
C.5.1	15 (11.4%)
C.5.6	10 (7.6%)
C.5.6.1	11 (8.3%)
C.5.7	13 (9.8%)
B/Yamagata	0
		Y3	0	Y3	0

CDC antigenically characterizes influenza viruses by hemagglutination inhibition (HI) assay (H1N1pdm09, H3N2, and B/Victoria viruses) or neutralization-based HINT (H3N2 viruses) using antisera from ferrets infected with reference viruses representing the recommended cell-based or recombinant influenza vaccines for the 2025-2026 Northern Hemisphere season. Antigenic differences between viruses are determined by comparing how well the antibodies raised against the vaccine reference viruses recognize the circulating viruses, which were grown in cell culture. Ferret antisera are useful because antibodies raised against a particular virus can often recognize small changes in the surface proteins of other viruses. In HI assays, viruses are deemed antigenically similar when their HI titer differences are less than or equal to 4-fold. In HINT, viruses with similar antigenic properties have antibody neutralization titer differences of less than 8-fold. Circulating viruses with antigenic testing results that show titer differences greater than 4-fold by HI or equal to or greater than 8-fold by HINT) are considered “low reactors” or antigenically drifted compared to the vaccine virus. From the recent genetically characterized viruses, a subset is selected for antigenic characterization based on identified genetic changes in their surface proteins. The subset tested may not be proportional to the number of such viruses circulating in the United States.

Influenza A Viruses

A(H1N1)pdm09: 95 A(H1N1)pdm09 viruses collected since September 28, 2025, were antigenically characterized by HI, and 93 (97.9%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer) by ferret antisera to cell-grown A/Wisconsin/67/2022-like reference viruses representing the A(H1N1)pdm09 component for the cell- and recombinant-based influenza vaccines.
A(H3N2): 99 A(H3N2) viruses collected since September 28, 2025, were antigenically characterized by HI or HINT, and 4 (4.0%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer in HI or reacting at titers that were less than 8-fold of the homologous virus in HINT) by ferret antisera to cell-grown A/District Of Columbia/27/2023-like reference viruses representing the A(H3N2) component for the cell- and recombinant-based influenza vaccines.

Influenza B Viruses

B/Victoria: 31 influenza B/Victoria-lineage viruses collected since September 28, 2025, since were antigenically characterized by HI, and 16 (51.6%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer) by ferret antisera to cell-grown B/Austria/1359417/2021-like reference viruses representing the B/Victoria component for the cell- and recombinant-based influenza vaccines.
B/Yamagata: No influenza B/Yamagata-lineage viruses were available for antigenic characterization.

Assessment of Virus Susceptibility to Antiviral Medications

CDC assesses susceptibility of influenza viruses to the antiviral medications including the neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) and the PA endonuclease inhibitor baloxavir using next generation sequence analysis supplemented by laboratory assays. Information about antiviral susceptibility test methods can be found at U.S. Influenza Surveillance: Purpose and Methods | CDC.

Viruses collected in the U.S. since September 28, 2025, were tested for antiviral susceptibility as follows:

Neuraminidase Inhibitors	Oseltamivir	Viruses Tested	1,291	351	811	129
Reduced Inhibition	4 (0.3%)	4 (1.1%)	0	0
Highly Reduced Inhibition	2 (0.2%)	2 (0.6%)	0	0
Peramivir	Viruses Tested	1,291	351	811	129
Reduced Inhibition	1 (0.1%)	0	0	1 (0.8%)
Highly Reduced Inhibition	2 (0.2%)	2 (0.6%)	0	0
Zanamivir	Viruses Tested	1,291	351	811	129
Reduced Inhibition	0	0	0	0
Highly Reduced Inhibition	0	0	0	0
PA Cap-Dependent Endonuclease Inhibitor	Baloxavir	Viruses Tested	1,249	328	794	127
Decreased Susceptibility	0	0	0	0

Two A(H1N1)pdm09 viruses had NA-H275Y amino acid substitution conferring highly reduced inhibition by oseltamivir and peramivir. Four A(H1N1)pdm09 viruses had amino acid substitutions NA-I223V and NA-S247N and showed reduced inhibition by oseltamivir. One B virus had amino acid substitution NA- M464T and showed reduced inhibition by peramivir.

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, use of these antivirals for treatment and prevention of influenza A virus infection is not recommended and data from adamantane resistance testing are not presented.

Outpatient and Emergency Department Illness Surveillance

Outpatient Respiratory Illness Visits

The U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) monitors outpatient visits for respiratory illness referred to as influenza-like illness [ILI (fever plus cough or sore throat)], not laboratory-confirmed influenza, and will therefore capture respiratory illness visits due to infection with any pathogen that can present with similar symptoms, including influenza virus, SARS-CoV-2, and RSV. It is important to evaluate syndromic surveillance data, including that from ILINet, in the context of other sources of surveillance data to obtain a complete and accurate picture of influenza, SARS-CoV-2, and other respiratory virus activity.

Nationally, during Week 4, 4.4% of patient visits reported through ILINet were due to respiratory illness that included fever plus a cough or sore throat, also referred to as ILI. This week’s national percentage decreased (change of > 0.1 percentage points) slightly but remains above the national baseline for the ninth consecutive week. ILI activity increased (change of > 0.1 percentage points) in HHS Region 10, decreased (change of > 0.1 percentage points) in regions 1, 2, 3, 5, and 6, and remained stable (change of ≤ 0.1 percentage points) in regions 4, 7, 8, and 9 this week compared to Week 3. Region 2 is below its regional baseline for the second consecutive week while all other regions (1, 3, 4, 5, 6, 7, 8, 9, and 10) remain above their respective baselines. Multiple respiratory viruses are co-circulating, and the relative contribution of influenza virus infection to ILI varies by location.

_{*Some calendar years do not include an epidemiologic Week 53. In those years, the Week 53 value shown is the average between Week 52 and Week 1.}

_{**Effective October 3, 2021 (Week 40), the respiratory illness definition (fever plus cough or sore throat) no longer includes "without a known cause other than influenza."}

Outpatient Respiratory Illness Visits by Age Group

About 70% of ILINet participants provide both the number of patient visits for respiratory illness and the total number of patient visits for the week broken out by age group. Based on these data, the percentage of visits for respiratory illness decreased (change of > 0.1 percentage points) in the 0-4 years age group and remained stable (change of ≤ 0.1 percentage points) in all other age groups (5-24 years, 25-49 years, 50-64 years, and 65 years and older) this week compared to Week 3.

Outpatient Respiratory Illness Activity Map

Data collected in ILINet are used to produce a measure of ILI activity* by state/jurisdiction and Core Based Statistical Areas (CBSA).

Week 4 (Week ending Jan. 31, 2026)	Week 3 (Week ending Jan. 24, 2026)	Week 4 (Week ending Jan. 31, 2026)	Week 3 (Week ending Jan. 24, 2026)
Very High	7	6	26	23
High	20	24	122	125
Moderate	7	10	150	158
Low	12	8	208	217
Minimal	9	7	201	183
Insufficient Data	0	0	222	223

_{*Data collected in ILINet may disproportionally represent certain populations within a jurisdiction or CBSA, and therefore, may not accurately depict the full picture of influenza activity for the entire jurisdiction or CBSA. Differences in the data presented here by CDC and independently by some health departments likely represent differing levels of data completeness with data presented by the health department likely being the more complete.}

Additional information about medically attended visits for ILI for current and past seasons:

Surveillance Methods | FluView Interactive: National, Regional, and State Data or ILI Activity Map

National Syndromic Surveillance System (NSSP)

The national percentage of emergency department (ED) visits with a discharge diagnosis (DD) of influenza reported in NSSP was 3.3% during Week 4 which is stable (change of ≤ 0.1 percentage point) compared to the previous week. Nationally, the percentage of ED visits with a DD of influenza remained stable among the 18-64 years age group and decreased (change of > 0.1 percentage points) among all other age groups (0-4 years, 5-17 years, and 65 years and older). The percentage of ED visits with a DD of influenza increased this week compared to the previous week in HHS Region 10, remained stable in regions 4 and 9, and decreased in all other regions (1, 2, 3, 5, 6, 7, and 8). Age group trends varied by region. RegionNationalRegion 1Region 2Region 3Region 4Region 5Region 6Region 7Region 8Region 9Region 10
Season
2025-2026x
2024-2025x

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2.0%4.0%6.0%8.0%10.0%12.0%14.0%16.0%18.0%20.0%Perc ent of Emergency Department Visits for InfluenzaWeek 41 of 2024Week 45 of 2024Week 49 of 2024Week 1 of 2025Week 5 of 2025Week 9 of 2025Week 13 of 2025Week 17 of 2025Week 21 of 2025Week 25 of 2025Week 29 of 2025Week 33 of 2025Week 37 of 2025Week 41 of 2025Week 45 of 2025Week 49 of 2025Week 53 of 2025Week 4 of 2026

Age Group

Skip Data Table
Data Table Download Data (CSV)
Skipped data table.

Additional information about emergency department visits for flu for current and past seasons:‎‎‎

Surveillance Methods | Emergency Department Visits for COVID-19, flu, and RSV
Hospitalization surveillance

FluSurv-Net

Influenza-Associated Hospitalizations: The Influenza Hospitalization Surveillance Network (FluSurv-NET) conducts population-based surveillance for laboratory-confirmed influenza-related hospitalizations in select counties in 14 states and represents approximately 10% of the U.S. population. FluSurv-NET hospitalization data are preliminary. As data are received each week, prior case counts and rates are updated accordingly.

A total of 22,045 laboratory-confirmed influenza-associated hospitalizations were reported by FluSurv-NET sites between October 1, 2025, and January 31, 2026. The weekly hospitalization rate observed during Week 4 was 2.2 per 100,000 population, which decreased from last week. After accounting for reporting delays, the estimated rate during Week 4 likely ranges from 2.9 to 3.8. The cumulative hospitalization rate observed in Week 4 was 63.2 per 100,000 population and is the highest cumulative rate this week since the 2010-11 season.

Among all hospitalizations, 21,286 (96.6%) were associated with influenza A virus, 627 (2.8%) with influenza B virus, 25 (0.1%) with influenza A virus and influenza B virus co-infection, and 107 (0.5%) with influenza virus for which the type was not determined. Among those with influenza A subtype information, 4,976 (90.9%) were A(H3N2), and 498 (9.1%) were A(H1N1)pdm09.

When examining rates by age, the highest rate of hospitalization per 100,000 population was among adults aged 65 and older (211.9), followed by children aged 0-4 years (66.1), adults aged 50-64 years (55.8), adults aged 18-49 years (24.4), and children aged 5-17 years (24.3).

Among children, the peak weekly rate is the highest going back to the 2010-11 season in Week 52 (7.1). The cumulative rate for pediatric cases is the second highest since 2010-11 (35.0). Among children, rates are highest among infants aged less than 1 year (105.6), followed by children aged 1-4 years (56.4). For all pediatric age groups, this is the second highest cumulative rate at this time of the season since the 2010-11 season.

When examining age-adjusted rates by race and ethnicity, the highest rate of hospitalization per 100,000 population was among non-Hispanic Black persons (113.7), followed by American Indian or Alaska Native persons (61.8), Hispanic persons (57.3), non-Hispanic White persons (54.2), and Asian and/or Pacific Islander persons (27.3).

Among 1,840 hospitalized adults with information on underlying medical conditions, 96.8% had at least one reported underlying medical condition; the most commonly reported were hypertension, cardiovascular disease, chronic metabolic disease, and chronic lung disease. Among 2,508 hospitalized women of childbearing age (15-49 years) with information on pregnancy status, 31.9% were pregnant. Among 752 hospitalized children with information on underlying medical conditions, 72.8% had at least one reported underlying medical condition; the most commonly reported was asthma, followed by neurologic disorder, and obesity.

Additional FluSurv-NET data are available on FluView Interactive including hospitalization rates for the current and past seasons by age, sex, and race/ethnicity (http://gis.cdc.gov/GRASP/Fluview/FluHospRates.html) as well as data on patient characteristics at: (http://gis.cdc.gov/grasp/fluview/FluHospChars.html.)

FluSurv-NET data are used to generate national estimates of the total numbers of influenza cases, medical visits, hospitalizations and deaths. This season, CDC is reporting preliminary cumulative in-season estimates, which are available at https://www.cdc.gov/flu-burden/php/data-vis/index.html. View Larger Download

_{**In this figure, weekly rates for all seasons prior to the 2025-26 season reflect end-of-season rates. For the 2025-26 season, rates for recent hospital admissions are subject to reporting delays and are shown as a dashed line for the current season. As hospitalization data are received each week, prior case counts and rates are updated accordingly.} Additional FluSurv-NET hospitalization surveillance information for current and past seasons and additional age groups:

Surveillance Methods | FluView Interactive: Rates by Age, Sex, and Race/Ethnicity or Data on Patient Characteristics | RESP-NET Interactive

National Healthcare Safety Network (NHSN) Hospital Respiratory Data

Hospitals report to NHSN the weekly number of patients with laboratory-confirmed influenza who were admitted to the hospital. Nationally, during Week 4, 14,548 laboratory-confirmed influenza-associated hospitalizations were reported. This week's influenza-associated hospital admission rate (4.3 per 100,000 population) decreased (difference of < 0.2) compared to Week 3.

Laboratory confirmed influenza-associated hospital admission rates per 100,000 population decreased in HHS regions 1, 2, 3, 5, 6, 7, and 8, increased in Region 10, and remained stable in regions 4 and 9. Region admission rates ranged from 2.7 (Region 2) to 6.4 (Region 7) during Week 4.

When examining rates by age for Week 4, all age groups decreased. The highest hospital admission rate per 100,000 population was among those 65 years and older (13.7), followed by the 0-4 years age group (4.5), and the 50-64 years age group (3.6).

Additional NHSN Hospital Respiratory Data information:

Surveillance Methods | Additional Data | FluView Interactive

National Healthcare Safety Network (NHSN) Long-Term Care Respiratory Pathogens & Vaccination Module

Long-term care facilities (LTCFs [e.g., Nursing homes/skilled nursing facilities]) report respiratory pathogen (e.g., COVID-19, influenza and RSV) data, including vaccination, cases, and hospitalizations among residents, to the NHSN Long-Term Care Respiratory Pathogens & Vaccination Module.

Nationally, during Week 4, the hospitalization rate for residents with a positive influenza test in the prior 10 days was 27.5 per 100,000 residents. The national rate and rates in HHS regions 1, 2, 3, 4, 5, 7, and 8 are trending downward. Rates continue to increase in Region 10. The rates do not show a consistent trend in regions 6 and 9. View Larger Download National Healthcare Safety Network (NHSN) Long-Term Care Respiratory Pathogens & Vaccination Module
Mortality surveillance

National Center for Health Statistics (NCHS) Mortality Surveillance

Based on NCHS mortality surveillance data available on February 5, 2026, 1.2% of the deaths that occurred during the week ending January 31, 2026 (Week 4), were due to influenza. This percentage decreased (≥ 0.1 percentage point change) compared to Week 3. The data presented are preliminary and may change as more data are received and processed.

Additional pneumonia, influenza and COVID-19 mortality surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive

Influenza-Associated Pediatric Mortality

Eight influenza-associated pediatric deaths occurring during the 2025-2026 season were reported to CDC during Week 4. The deaths occurred during weeks 51, 52, 1 and 3 (the weeks ending December 20, 2025, December 27, 2025, January 10, 2026, and January 24, 2026). All eight deaths were associated with influenza A viruses. Six of the influenza A viruses had subtyping performed and all were A(H3N2) viruses.

A total of 60 influenza-associated pediatric deaths occurring during the 2025–2026 season have been reported to CDC. Among children who were eligible for influenza vaccination and with known vaccination status, approximately 90% of reported pediatric deaths this season have occurred in children who were not fully vaccinated against influenza.

Additional pediatric mortality surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive
All data in this report are preliminary and may change as more reports are received.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component, is available on the surveillance methods page.¹

Additional information on the current and previous influenza seasons for each surveillance component are available on FluView Interactive.

Additional National and International Influenza Surveillance Information

Indicators Status by System

Increasing:
Decreasing:
Stable:

Clinical Labs: Up or down arrows indicate a change of greater than or equal to 0.5 percentage points in the percent of specimens positive for influenza compared to the previous week.
Outpatient Respiratory Illness (ILINet): Up or down arrows indicate a change of greater than 0.1 percentage points in the percent of visits due to respiratory illness (ILI) compared to the previous week.
NHSN Hospitalizations: Up or down arrows indicate change of greater than or equal to 0.2 in the rate of hospital admissions or greater than or equal to 691 patients admitted with laboratory-confirmed influenza compared to the previous week.
NHSN Long- Term Care (LTC): Up or down arrows indicate change of greater than or equal to 5% in hospitalization rates for residents in LTC facilities who were hospitalized with laboratory-confirmed influenza compared to the previous week.
NCHS Mortality: Up or down arrows indicate change of greater than 0.1 percentage points of the percent of deaths due to influenza compared to the previous week.

Additional surveillance information

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.

National Institute for Occupational Safety and Health: Monthly surveillance data on the prevalence of health-related workplace absenteeism among full-time workers in the United States are available from NIOSH.

U.S. State and local influenza surveillance: Select a jurisdiction below to access the latest local influenza information.

Alabama	Alaska	Arizona	Arkansas	California
Colorado	Connecticut	Delaware	District of Columbia	Florida
Georgia	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	Oklahoma	Oregon	Pennsylvania	Rhode Island
South Carolina	South Dakota	Tennessee	Texas	Utah
Vermont	Virginia	Washington	West Virginia	Wisconsin
Wyoming	New York City	Puerto Rico	Virgin Islands

Public Health Agency of Canada:
The most up-to-date influenza information from Canada is available in Canada's weekly FluWatch report.

Public Health England:
The most up-to-date influenza information from the United Kingdom is available from Public Health England.

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.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component is available on the surveillance methods page.

Weekly US Influenza Surveillance Report: Key Updates for Week 4, ending January 31, 2026

https://www.cdc.gov/fluview/surveillance/2026-week-04.html

Seasonal influenza activity remains elevated nationally.

**Commonground** · February 13, 2026, 01:01 PM

Respiratory Virus Activity Levels

For Everyone
FEB. 13, 2026

This Week’s Activity Update:

Reported on Friday, February 13, 2026

The amount of acute respiratory illness causing people to seek health care is moderate.
Seasonal influenza activity remains elevated nationally. Influenza A activity is decreasing while influenza B activity is increasing nationally and in most areas of the country; however, trends vary by region.
RSV activity is elevated in many areas of the country.
COVID-19 activity is elevated in some areas of the country.
Nationally, wastewater activity levels for COVID-19 and RSV are moderate and influenza is low.

Level of Respiratory Illness Activity

Respiratory illness activity is monitored using the acute respiratory illness (ARI) metric. ARI captures a broad range of diagnoses from emergency department visits for respiratory illnesses, from the common cold to severe infections like influenza, RSV and COVID-19. It captures illnesses that may not present with fever, offering a more complete picture than the previous influenza-like illness (ILI) metric. Refer to data notes for more details.

[map]

-snip-
Epidemic Trends

CDC uses data from emergency department visits to model epidemic trends. This model helps tell whether the number of new respiratory infections is growing or declining in your state. While this model tells us the trend, it does not tell us the actual number of current infections with SARS-CoV-2 (the virus that causes COVID-19), influenza virus, or RSV. Refer to data notesfor more details.

Continued: https://www.cdc.gov/respiratory-viru...ty-levels.html

**Commonground** · February 13, 2026, 01:05 PM

Epidemic trends

We estimate the time-varying reproductive number, R_t, a measure of transmission based on data from incident emergency department (ED) visits. The method for determining epidemic status estimates the probability that R_t is greater than 1 (map below). Estimated R_t values above 1 indicate epidemic growth.

The second figure below shows the estimated R_t and uncertainty interval from December 17, 2025 through February 10, 2026 for the U.S. and for each reported state. (Click on the map to view the data for a specific state). While R_t tells us if the number of infections is likely growing or declining, it does not reflect the burden of disease.

R_tshould be used alongside other surveillance metrics (such as the percentage of ED visits, which are displayed in the callout boxes in the map) for a more complete picture. View a summary of key data for COVID-19, influenza, and RSV.

Epidemic trend summary

COVID-19InfluenzaRSV

As of February 10, 2026, we estimate that Influenza infections are growing or likely growing in 18 states, declining or likely declining in 10 states, and not changing in 19 states. Previous estimates can be found on data.cdc.gov
.
continued: https://www.cdc.gov/cfa-modeling-and...dex.html?tab=1

**sharon sanders** · February 13, 2026, 05:16 PM

Weekly US Influenza Surveillance Report: Key Updates for Week 5, ending February 7, 2026

For Everyone
Feb. 13, 2026

Key points

Seasonal influenza activity remains elevated nationally.
Summary

Viruses

Clinical Lab 18.6% (Trend )
positive for influenza
this week. Public Health Lab The most frequently reported
influenza viruses this week were influenza A(H3N2).

Illness

Outpatient Respiratory Illness 4.6% (Trend )
of visits to a health care provider this week were for respiratory illness
(above baseline). Activity Map 8 moderate jurisdictions 24 high or very high jurisdictions FluSurv-NET 67.0 per 100,000
cumulative hospitalization rate
per 100,000 population NHSN LTCF Respiratory
Data 27.8 per 100,000 (Trend ) weekly hospitalization rate
per 100,000 residents NHSN Hospital Respiratory Data 14,656 (Trend )
patients admitted to hospitals
with influenza this week. NCHS Mortality 1.0% (Trend ) of deaths attributed to influenza this week. Pediatric Deaths 6 influenza-associated deaths were reported this week for a total of 66 deaths this season.
All data are preliminary and may change as more reports are received.

Directional arrows indicate changes between the current week and the previous week. Additional information on the arrows can be found at the bottom of this page.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component is available on the surveillance methods page.¹

Additional information on the current and previous influenza seasons for each surveillance component are available on FluView Interactive.

Key Points

Seasonal influenza activity remains elevated nationally. Influenza A activity is decreasing while influenza B activity is increasing nationally and in most areas of the country; however, trends vary by region.

Influenza A(H3N2) viruses are the most frequently reported influenza viruses so far this season.
- Among 1,126 influenza A(H3N2) viruses collected since September 28, 2025, that underwent additional genetic characterization at CDC, 92% belonged to subclade K.

The weekly influenza-associated hospitalization rate overall in FluSurv-Net peaked during Week 52 at 12.8 per 100,000 population. This is the second highest peak weekly rate overall since the 2010-2011 season. Notably, children younger than 18 years have the highest peak weekly hospitalization rate observed since the 2010-2011 season.

Six influenza-associated pediatric deaths occurring in the 2025-2026 season were reported to CDC this week, bringing the season total to 66 reported influenza-associated pediatric deaths.
- Among children who were eligible for influenza vaccination and with known vaccination status, approximately 90% of reported pediatric deaths this season have occurred in children who were not fully vaccinated against influenza.

CDC's in-season severity assessment framework classified the season as moderate across all ages. CDC also assesses severity by three age groups: pediatric (0-17 years), adult (18-64 years), and older adults (≥65 years). At this point in the season, the pediatric age group is classified as having high severity, while both the adult and older adult age groups are classified as having moderate severity. These assessments are conducted each week during the season, and the season's severity assessment can change if activity should increase again.
CDC estimates that there have been at least 23,000,000 illnesses, 300,000 hospitalizations, and 19,000 deaths from flu so far this season.
Influenza (flu) vaccination has been shown to reduce the risk of flu and its potentially serious complications. There is still time to get vaccinated against flu this season. Approximately 134 million doses of influenza vaccine have been distributed in the United States this season.

There are prescription flu antiviral drugs that can treat flu illness; those should be started as early as possible and are especially important for patients at higher risk for flu-related complications.¹
Influenza viruses are among several viruses contributing to respiratory disease activity. CDC provides updated, integrated information about COVID-19, flu, and respiratory syncytial virus (RSV) activity on a weekly basis.
No new avian influenza A(H5) infections were reported to CDC this week. To date, person-to-person transmission of influenza A(H5) viruses has not been identified in the United States.

U.S. virologic surveillance

Nationally, the percentage of respiratory specimens testing positive for the influenza virus in clinical laboratories increased (change > 0.5 percentage points). The percent positivity for influenza A decreased, while the percent positivity for influenza B has increased for three consecutive weeks. Influenza A(H3N2) viruses were the most frequently reported influenza viruses this week nationally and in all HHS regions. Trends in percent positivity and the distribution of circulating viruses varies by HHS region. For regional and state level data and age group distribution, please visit FluView Interactive. Viruses known to be associated with recent receipt of live attenuated influenza vaccine (LAIV) or found upon further testing to be a vaccine virus are not included, as they are not circulating influenza viruses.

Clinical Laboratories

The results of tests performed by clinical laboratories nationwide are summarized below. Data from clinical laboratories (the percentage of specimens tested that are positive for influenza virus) are used to monitor whether influenza activity is increasing or decreasing.

No. of specimens tested	76,625	1,476,444
No. of positive specimens (%)	14,223 (18.6%)	206,370 (14.0%)
*Positive specimens by type*
Influenza A	9,561 (67.2%)	186,288 (90.3%)
Influenza B	4,662 (32.8%)	20,082 (9.7%)

Public Health Laboratories

The results of tests performed by public health laboratories nationwide are summarized below. Data from public health laboratories are used to monitor the proportion of circulating influenza viruses that belong to each influenza subtype/lineage.

No. of specimens tested	1,697	54,951
No. of positive specimens	1,145	37,325
*Positive specimens by type/subtype*
Influenza A	1,000 (87.3%)	35,757 (95.8%)
Subtyping Performed	802 (80.2%)	30,097 (84.2%)
(H1N1)pdm09	117 (14.6%)	3,475 (11.5%)
H3N2	685 (85.4%)	26,620 (88.4%)
H3N2v	0	0
H5	0	2 (<0.1%)
Subtyping not performed	198 (19.8%)	5,660 (15.8%)
Influenza B	145 (12.7%)	1,568 (4.2%)
Lineage testing performed	47 (32.4%)	479 (30.5%)
Yamagata lineage	0	0
Victoria lineage	47 (100%)	479 (100%)
Lineage not performed	98 (67.6%)	1,089 (69.5%)

_{*These data reflect specimens tested, and the number determined to be positive for influenza viruses at the public health labs (specimens tested is not the same as cases). The data do not reflect specimens tested only at CDC and could include more than one specimen tested per person. For more information on the number of people infected with A/H5 viruses, please visit the "How CDC is monitoring influenza data among people to better understand the current avian influenza A (H5N1) situation"}

_{^†When an influenza virus that normally circulates in swine (but not people) is detected in a person, it is called a "variant" influenza virus. Most human infections with variant influenza viruses occur following exposure to swine, but human-to-human transmission can occur. It is important to note that in most cases, variant influenza viruses have not shown the ability to spread easily and sustainably from human-to-human.}

_{*This graph reflects the number of specimens determined to be positive for influenza viruses at the public health lab (specimens tested is not the same as cases). It does not reflect specimens tested only at CDC and could include more than one specimen tested per person. Specimens tested as part of routine influenza surveillance as well as those tested as part of targeted testing for people exposed to avian influenza A(H5) are included.}

Additional virologic surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive: National, Regional, and State Data or Age Data

Novel Influenza A Virus Infections

No new confirmed human infections with avian influenza A(H5) virus were reported to CDC this week. To date, person-to-person transmission of avian influenza A(H5) virus (H5 bird flu) has not been identified in the United States.

The CSTE position statement, which includes updated case definitions for confirmed, probable, and suspected cases is available at http://www.cste.org/resource/resmgr/...nfluenza_A.pdf.

An up-to-date human case summary during the current outbreak by state and exposure source is available at www.cdc.gov/bird-flu/situation-summary/index.html.

Information about avian influenza is available at https://www.cdc.gov/bird-flu/.

Information about avian influenza is available at https://www.cdc.gov/flu/avianflu/index.htm. A(H5N1) virus interim recommendations for Prevention, Monitoring, and Public Health Investigations are available at https://www.cdc.gov/bird-flu/prevent...endations.html.

Additional information regarding human infections with novel influenza A viruses:

Surveillance Methods | FluView Interactive

Influenza Virus Characterization

CDC performs genetic and antigenic characterization of U.S. viruses submitted from state and local public health laboratories according to the Right Size Roadmap submission guidance. These data are used to compare how similar the currently circulating influenza viruses are relative to the reference viruses representing the current influenza vaccines. The data are also used to monitor evolutionary changes that continually occur in influenza viruses circulating in humans. CDC also tests susceptibility of circulating influenza viruses to antiviral medications including the neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) and the polymerase acidic protein (PA) endonuclease inhibitor baloxavir. The HA clade and subclades were assigned using Nextclade (https://clades.nextstrain.org).

CDC has genetically characterized 1,766 influenza viruses collected since September 28, 2025.

A/H1	430
		5a.2a	2 (0.5%)	C.1.9.3	2 (0.5%)
5a.2a.1	428 (99.5%)	D.3.1	182 (42.3%)
D.3.1.1	246 (57.2%)
A/H3	1,126
		2a.3a.1	1,126 (100%)	J.2	4 (0.4%)
J.2.2	5 (0.4%)
J.2.3	41 (3.6%)
J.2.4	40 (3.6%)
K	1,036 (92.0%)
B/Victoria	210
		3a.2	210 (100%)	C.3	4 (1.9%)
C.3.1	133 (63.3%)
C.5.1	18 (8.6%)
C.5.6	11 (5.2%)
C.5.6.1	27 (12.9%)
C.5.7	17 (8.1%)
B/Yamagata	0
		Y3	0	Y3	0

CDC antigenically characterizes influenza viruses by hemagglutination inhibition (HI) assay (H1N1pdm09, H3N2, and B/Victoria viruses) or neutralization-based HINT (H3N2 viruses) using antisera from ferrets infected with reference viruses representing the recommended cell-based or recombinant influenza vaccines for the 2025-2026 Northern Hemisphere season. Antigenic differences between viruses are determined by comparing how well the antibodies raised against the vaccine reference viruses recognize the circulating viruses, which were grown in cell culture. Ferret antisera are useful because antibodies raised against a particular virus can often recognize small changes in the surface proteins of other viruses. In HI assays, viruses are deemed antigenically similar when their HI titer differences are less than or equal to 4-fold. In HINT, viruses with similar antigenic properties have antibody neutralization titer differences of less than 8-fold. Circulating viruses with antigenic testing results that show titer differences greater than 4-fold by HI or equal to or greater than 8-fold by HINT) are considered "low reactors" or antigenically drifted compared to the vaccine virus. From the recent genetically characterized viruses, a subset is selected for antigenic characterization based on identified genetic changes in their surface proteins. The subset tested may not be proportional to the number of such viruses circulating in the United States.

Influenza A Viruses

A(H1N1)pdm09: 95 A(H1N1)pdm09 viruses collected since September 28, 2025, were antigenically characterized by HI, and 93 (97.9%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer) by ferret antisera to cell-grown A/Wisconsin/67/2022-like reference viruses representing the A(H1N1)pdm09 component for the cell- and recombinant-based influenza vaccines.
A(H3N2): 130 A(H3N2) viruses collected since September 28, 2025, were antigenically characterized by HI or HINT, and 4 (3.1%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer in HI or reacting at titers that were less than 8-fold of the homologous virus in HINT) by ferret antisera to cell-grown A/District Of Columbia/27/2023-like reference viruses representing the A(H3N2) component for the cell- and recombinant-based influenza vaccines.

Influenza B Viruses

B/Victoria: 31 influenza B/Victoria-lineage viruses collected since September 28, 2025, since were antigenically characterized by HI, and 16 (51.6%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer) by ferret antisera to cell-grown B/Austria/1359417/2021-like reference viruses representing the B/Victoria component for the cell- and recombinant-based influenza vaccines.
B/Yamagata: No influenza B/Yamagata-lineage viruses were available for antigenic characterization.

Assessment of Virus Susceptibility to Antiviral Medications

CDC assesses susceptibility of influenza viruses to the antiviral medications including the neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) and the PA endonuclease inhibitor baloxavir using next generation sequence analysis supplemented by laboratory assays. Information about antiviral susceptibility test methods can be found at U.S. Influenza Surveillance: Purpose and Methods | CDC.

Viruses collected in the U.S. since September 28, 2025, were tested for antiviral susceptibility as follows:

Neuraminidase Inhibitors	Oseltamivir	Viruses Tested	1701	426	1086	189
Reduced Inhibition	7 (0.4%)	7 (1.6%)	0	0
Highly Reduced Inhibition	3 (0.2%)	3 (0.7%)	0	0
Peramivir	Viruses Tested	1701	426	1086	189
Reduced Inhibition	2 (0.1%)	0	0	2 (1.1%)
Highly Reduced Inhibition	3 (0.2%)	3 (0.7%)	0	0
Zanamivir	Viruses Tested	1701	426	1086	189
Reduced Inhibition	0	0	0	0
Highly Reduced Inhibition	0	0	0	0
PA Cap-Dependent Endonuclease Inhibitor	Baloxavir	Viruses Tested	1672	408	1071	193
Decreased Susceptibility	0	0	0	0

Three A(H1N1)pdm09 viruses had NA-H275Y amino acid substitution conferring highly reduced inhibition by oseltamivir and peramivir. Seven A(H1N1)pdm09 viruses had amino acid substitutions NA-I223V and NA-S247N and showed reduced inhibition by oseltamivir. Two B viruses had amino acid substitution NA- M464T and showed reduced inhibition by peramivir.

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, use of these antivirals for treatment and prevention of influenza A virus infection is not recommended and data from adamantane resistance testing are not presented.

Outpatient and Emergency Department Illness Surveillance

Outpatient Respiratory Illness Visits

The U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) monitors outpatient visits for respiratory illness referred to as influenza-like illness [ILI (fever plus cough or sore throat)], not laboratory-confirmed influenza, and will therefore capture respiratory illness visits due to infection with any pathogen that can present with similar symptoms, including influenza virus, SARS-CoV-2, and RSV. It is important to evaluate syndromic surveillance data, including that from ILINet, in the context of other sources of surveillance data to obtain a complete and accurate picture of influenza, SARS-CoV-2, and other respiratory virus activity.

Nationally, during Week 5, 4.6% of patient visits reported through ILINet were due to respiratory illness that included fever plus a cough or sore throat, also referred to as ILI. This week's national percentage increased (change of > 0.1 percentage points) slightly and remains above the national baseline for the tenth consecutive week. ILI activity increased (change of > 0.1 percentage points) in HHS Regions 6, 8, 9, and 10, decreased (change of > 0.1 percentage points) in regions 2, 3, and 5, and remained stable (change of ≤ 0.1 percentage points) in regions 1, 4, and 7 this week compared to Week 4. Regions 2 and 3 are below their respective regional baselines while all other regions (1, 4, 5, 6, 7, 8, 9, and 10) remain above their respective baselines. Multiple respiratory viruses are co-circulating, and the relative contribution of influenza virus infection to ILI varies by location.

Outpatient Respiratory Illness Visits by Age Group

About 70% of ILINet participants provide both the number of patient visits for respiratory illness and the total number of patient visits for the week broken out by age group. Based on these data, the percentage of visits for respiratory illness decreased (change of > 0.1 percentage points) in the 0-4 years age group and remained stable (change of ≤ 0.1 percentage points) in all other age groups (5-24 years, 25-49 years, 50-64 years, and 65 years and older) this week compared to Week 4.

Outpatient Respiratory Illness Activity Map

Data collected in ILINet are used to produce a measure of ILI activity* by state/jurisdiction and Core Based Statistical Areas (CBSA).

Week 5 (Week ending Feb. 7, 2026)	Week 4 (Week ending Jan. 31, 2026)	Week 5 (Week ending Feb. 7, 2026)	Week 4 (Week ending Jan. 31, 2026)
Very High	11	6	26	27
High	13	21	134	122
Moderate	8	8	115	154
Low	15	11	195	205
Minimal	8	9	235	202
Insufficient Data	0	0	224	219

_{*Data collected in ILINet may disproportionally represent certain populations within a jurisdiction or CBSA, and therefore, may not accurately depict the full picture of influenza activity for the entire jurisdiction or CBSA. Differences in the data presented here by CDC and independently by some health departments likely represent differing levels of data completeness with data presented by the health department likely being the more complete.} Additional information about medically attended visits for ILI for current and past seasons:

Surveillance Methods | FluView Interactive: National, Regional, and State Data or ILI Activity Map

National Syndromic Surveillance System (NSSP)

The national percentage of emergency department (ED) visits with a discharge diagnosis (DD) of influenza reported in NSSP was 3.2% during Week 5 which is stable (change of ≤ 0.1 percentage point) compared to the previous week. Nationally, the percentage of ED visits with a DD of influenza remained stable among the 65 years and older and 18-64 years age groups and decreased (change of > 0.1 percentage points) among the 0-4 years and 5-17 years age groups. The percentage of ED visits with a DD of influenza increased (change of > 0.1 percentage points) this week compared to the previous week in HHS Regions 4 and 9, remained stable in regions 2, 8 and 10, and decreased in all other regions (1, 3, 5, 6, and 7). Age group trends varied by region. RegionNationalRegion 1Region 2Region 3Region 4Region 5Region 6Region 7Region 8Region 9Region 10
Season
2025-2026x
2024-2025x

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2.0%4.0%6.0%8.0%10.0%12.0%14.0%16.0%18.0%20.0%Perc ent of Emergency Department Visits for InfluenzaWeek 42 of 2024Week 46 of 2024Week 50 of 2024Week 2 of 2025Week 6 of 2025Week 10 of 2025Week 14 of 2025Week 18 of 2025Week 22 of 2025Week 26 of 2025Week 30 of 2025Week 34 of 2025Week 38 of 2025Week 42 of 2025Week 46 of 2025Week 50 of 2025Week 1 of 2026Week 5 of 2026

Age Group

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Data Table Download Data (CSV)
Skipped data table.

Additional information about emergency department visits for flu for current and past seasons:‎‎‎

Surveillance Methods | Emergency Department Visits for COVID-19, flu, and RSV
Hospitalization surveillance

FluSurv-Net

Influenza-Associated Hospitalizations: The Influenza Hospitalization Surveillance Network (FluSurv-NET) conducts population-based surveillance for laboratory-confirmed influenza-related hospitalizations in select counties in 14 states and represents approximately 10% of the U.S. population. FluSurv-NET hospitalization data are preliminary. As data are received each week, prior case counts and rates are updated accordingly.

A total of 23,370 laboratory-confirmed influenza-associated hospitalizations were reported by FluSurv-NET sites between October 1, 2025, and February 7, 2026. The weekly hospitalization rate observed during Week 5 was 2.3 per 100,000 population, which decreased from last week. After accounting for reporting delays, the estimated rate during Week 5 likely ranges from 3.0 to 4.0. The cumulative hospitalization rate observed in Week 5 was 67.0 per 100,000 population, which is the second highest cumulative rate at this point in the season since the 2010-11 season.

Among all hospitalizations, 22,489 (96.2%) were associated with influenza A virus, 743 (3.2%) with influenza B virus, 32 (0.1%) with influenza A virus and influenza B virus co-infection, and 106 (0.5%) with influenza virus for which the type was not determined. Among those with influenza A subtype information, 5542 (90.8%) were A(H3N2), and 564 (9.2%) were A(H1N1)pdm09.

When examining rates by age, the highest rate of hospitalization per 100,000 population was among adults aged 65 and older (225.1), followed by children aged 0-4 years (68.9), adults aged 50-64 years (59.5), adults aged 18-49 years (25.8), and children aged 5-17 years (25.5).

Among children, the peak weekly rate is the highest going back to the 2010-11 season in Week 52 (7.0). The cumulative rate for pediatric cases is the second highest since 2010-11 (36.6). Among children, rates are highest among infants aged less than 1 year (108.6), followed by children aged 1-4 years (59.2). For all pediatric age groups, this is the second highest cumulative rate at this time of the season since the 2010-11 season.

When examining age-adjusted rates by race and ethnicity, the highest rate of hospitalization per 100,000 population was among non-Hispanic Black persons (119.3), followed by American Indian or Alaska Native persons (68.8), Hispanic persons (61.6), non-Hispanic White persons (57.4), and Asian and/or Pacific Islander persons (29.9).

Among 2,066 hospitalized adults with information on underlying medical conditions, 96.0% had at least one reported underlying medical condition; the most commonly reported were hypertension, cardiovascular disease, chronic metabolic disease, and chronic lung disease. Among 2,631 hospitalized women of childbearing age (15-49 years) with information on pregnancy status, 30.9% were pregnant. Among 863 hospitalized children with information on underlying medical conditions, 58.2% had at least one reported underlying medical condition; the most commonly reported was asthma, followed by neurologic disorder, and obesity.

Additional FluSurv-NET data are available on FluView Interactive including hospitalization rates for the current and past seasons by age, sex, and race/ethnicity (http://gis.cdc.gov/GRASP/Fluview/FluHospRates.html) as well as data on patient characteristics at: (http://gis.cdc.gov/grasp/fluview/FluHospChars.html.)

FluSurv-NET data are used to generate national estimates of the total numbers of influenza cases, medical visits, hospitalizations and deaths. This season, CDC is reporting preliminary cumulative in-season estimates, which are available at Estimated US Flu Disease Burden | Flu Burden | CDC.

^{^{**In this figure, weekly rates for all seasons prior to the 2025-26 season reflect end-of-season rates. For the 2025-26 season, rates for recent hospital admissions are subject to reporting delays and are shown as a dashed line for the current season. As hospitalization data are received each week, prior case counts and rates are updated accordingly.}}

Additional FluSurv-NET hospitalization surveillance information for current and past seasons and additional age groups:

Surveillance Methods | FluView Interactive: Rates by Age, Sex, and Race/Ethnicity or Data on Patient Characteristics | RESP-NET Interactive

National Healthcare Safety Network (NHSN) Hospital Respiratory Data

Hospitals report to NHSN the weekly number of patients with laboratory-confirmed influenza who were admitted to the hospital. Nationally, during Week 5, 14,656 laboratory-confirmed influenza-associated hospitalizations were reported. This week's influenza-associated hospital admission rate (4.3 per 100,000 population) decreased (difference of > 0.2) compared to Week 4.

Laboratory confirmed, influenza-associated hospital admission rates per 100,000 population decreased in HHS regions 1, 2, 3, 5, 7, and 8; increased in regions 4, 9, and 10; and remained stable in region 6. Region admission rates ranged from 2.0 (Region 2) to 5.9 (Region 7) during Week 5.

When examining rates by age for Week 5, all age groups decreased, except for the 5 - 17 years and 18 - 49 years age groups, which remained stable. The highest hospital admission rate per 100,000 population was among those 65 years and older (13.6), followed by the 0-4 years age group (4.2), and the 50-64 years age group (3.6).

Additional NHSN Hospital Respiratory Data information:

Surveillance Methods | Additional Data | FluView Interactive

National Healthcare Safety Network (NHSN) Long-Term Care Respiratory Pathogens & Vaccination Module

Long-term care facilities (LTCFs [e.g., Nursing homes/skilled nursing facilities]) report respiratory pathogen (e.g., COVID-19, influenza and RSV) data, including vaccination, cases, and hospitalizations among residents, to the NHSN Long-Term Care Respiratory Pathogens & Vaccination Module.

Nationally, during Week 5, the hospitalization rate for residents with a positive influenza test in the prior 10 days was 27.8 per 100,000 residents. The national rate and rates in HHS Regions 1, 2, 3, 4, 5, and 7 are trending downwards. Rates are trending upwards in region 9 and remain stable in region 8. In HHS Regions 6 and 10, the rate does not show a consistent trend. View Larger Download National Healthcare Safety Network (NHSN) Long-Term Care Respiratory Pathogens & Vaccination Module
Mortality surveillance

National Center for Health Statistics (NCHS) Mortality Surveillance

Based on NCHS mortality surveillance data available on February 12, 2026, 1.0% of the deaths that occurred during the week ending February 7, 2026 (Week 5), were due to influenza. This percentage decreased (≥ 0.1 percentage point change) compared to Week 4. The data presented are preliminary and may change as more data are received and processed.

Additional pneumonia, influenza and COVID-19 mortality surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive

Influenza-Associated Pediatric Mortality

Six influenza-associated pediatric deaths occurring during the 2025-2026 season were reported to CDC during Week 5. The deaths occurred between week 51 of 2025 and week 5 of 2026 (the weeks ending December 20, 2025, through February 7, 2026). Four deaths were associated with influenza A viruses. Two of the influenza A viruses had subtyping performed and both were A(H3N2) viruses. Two deaths were associated with influenza B viruses with no lineage determined.

A total of 66 influenza-associated pediatric deaths occurring during the 2025–2026 season have been reported to CDC. Among children who were eligible for influenza vaccination and with known vaccination status, approximately 90% of reported pediatric deaths this season have occurred in children who were not fully vaccinated against influenza.

Additional pediatric mortality surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive
All data in this report are preliminary and may change as more reports are received.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component, is available on the surveillance methods page.¹

Additional information on the current and previous influenza seasons for each surveillance component are available on FluView Interactive.

Additional National and International Influenza Surveillance Information

Indicators Status by System

Increasing:
Decreasing:
Stable:

Clinical Labs: Up or down arrows indicate a change of greater than or equal to 0.5 percentage points in the percent of specimens positive for influenza compared to the previous week.
Outpatient Respiratory Illness (ILINet): Up or down arrows indicate a change of greater than 0.1 percentage points in the percent of visits due to respiratory illness (ILI) compared to the previous week.
NHSN Hospitalizations: Up or down arrows indicate change of greater than or equal to 0.2 in the rate of hospital admissions or greater than or equal to 691 patients admitted with laboratory-confirmed influenza compared to the previous week.
NHSN Long- Term Care (LTC): Up or down arrows indicate change of greater than or equal to 5% in hospitalization rates for residents in LTC facilities who were hospitalized with laboratory-confirmed influenza compared to the previous week.
NCHS Mortality: Up or down arrows indicate change of greater than 0.1 percentage points of the percent of deaths due to influenza compared to the previous week.

Additional surveillance information

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.

National Institute for Occupational Safety and Health: Monthly surveillance data on the prevalence of health-related workplace absenteeism among full-time workers in the United States are available from NIOSH.

U.S. State and local influenza surveillance: Select a jurisdiction below to access the latest local influenza information.

Alabama	Alaska	Arizona	Arkansas	California
Colorado	Connecticut	Delaware	District of Columbia	Florida
Georgia	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	Oklahoma	Oregon	Pennsylvania	Rhode Island
South Carolina	South Dakota	Tennessee	Texas	Utah
Vermont	Virginia	Washington	West Virginia	Wisconsin
Wyoming	New York City	Puerto Rico	Virgin Islands

Public Health Agency of Canada:
The most up-to-date influenza information from Canada is available in Canada's weekly FluWatch report.

Public Health England:
The most up-to-date influenza information from the United Kingdom is available from Public Health England.

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.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component is available on the surveillance methods page.

Weekly US Influenza Surveillance Report: Key Updates for Week 5, ending February 7, 2026

https://www.cdc.gov/fluview/surveillance/2026-week-05.html

Seasonal influenza activity is low.

**sharon sanders** · February 27, 2026, 05:34 PM

Weekly US Influenza Surveillance Report: Key Updates for Week 6, ending February 14, 2026

For Everyone
Feb. 20, 2026

Key points

Seasonal influenza activity remains elevated nationally.
Summary

Viruses

Clinical Lab 19.8% (Trend )
positive for influenza
this week. Public Health Lab The most frequently reported
influenza viruses this week were influenza A(H3N2). Illness

Outpatient Respiratory Illness 4.5% (Trend )
of visits to a health care provider this week were for respiratory illness
(above baseline). Activity Map 9 moderate jurisdictions 26 high or very high jurisdictions FluSurv-NET 70.2
cumulative hospitalization rate
per 100,000 population NHSN LTCF Respiratory
Data 27.5 (Trend ) weekly hospitalization rate
per 100,000 residents NHSN Hospital Respiratory Data 14,940 (Trend )
patients admitted to hospitals
with influenza this week. NCHS Mortality 0.9% (Trend ) of deaths attributed to influenza this week. Pediatric Deaths 5 influenza-associated deaths were reported this week for a total of 71 deaths this season.
All data are preliminary and may change as more reports are received.

Directional arrows indicate changes between the current week and the previous week. Additional information on the arrows can be found at the bottom of this page.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component is available on the surveillance methods page.¹

Additional information on the current and previous influenza seasons for each surveillance component are available on FluView Interactive.

Key Points

Seasonal influenza activity remains elevated nationally. Influenza A activity is decreasing while influenza B activity is increasing nationally and in most areas of the country; however, trends vary by region.

Influenza A(H3N2) viruses are the most frequently reported influenza viruses so far this season.
- Among 1,193 influenza A(H3N2) viruses collected since September 28, 2025, that underwent additional genetic characterization at CDC, 92.1% belonged to subclade K.

The weekly influenza-associated hospitalization rate overall in FluSurv-Net peaked during Week 52. This is the second highest peak weekly rate overall since the 2010-2011 season. Notably, children younger than 18 years have the highest peak weekly hospitalization rate observed since the 2010-2011 season.

Five influenza-associated pediatric deaths occurring in the 2025-2026 season were reported to CDC this week, bringing the season total to 71 reported influenza-associated pediatric deaths.
- Among children who were eligible for influenza vaccination and with known vaccination status, approximately 90% of reported pediatric deaths this season have occurred in children who were not fully vaccinated against influenza.

CDC's in-season severity assessment framework classified the season as moderate across all ages. CDC also assesses severity by three age groups: pediatric (0-17 years), adult (18-64 years), and older adults (≥65 years). At this point in the season, the pediatric age group is classified as having high severity, while both the adult and older adult age groups are classified as having moderate severity. These assessments are conducted each week during the season, and the season's severity assessment can change if activity should increase again.
CDC estimates that there have been at least 24,000,000 illnesses, 310,000 hospitalizations, and 20,000 deaths from flu so far this season.
Influenza (flu) vaccination has been shown to reduce the risk of flu and its potentially serious complications. There is still time to get vaccinated against flu this season. Approximately 134 million doses of influenza vaccine have been distributed in the United States this season.

There are prescription flu antiviral drugs that can treat flu illness; those should be started as early as possible and are especially important for patients at higher risk for flu-related complications.¹
Influenza viruses are among several viruses contributing to respiratory disease activity. CDC provides updated, integrated information about COVID-19, flu, and respiratory syncytial virus (RSV) activity on a weekly basis.
No new avian influenza A(H5) infections were reported to CDC this week. To date, person-to-person transmission of influenza A(H5) viruses has not been identified in the United States.

U.S. virologic surveillance

Nationally, the percentage of respiratory specimens testing positive for the influenza virus in clinical laboratories increased (change > 0.5 percentage points) this week. The percent positivity for influenza A viruses decreased, while the percent positivity for influenza B viruses continues to increase. Across HHS Regions, activity increased in regions 2, 4, 5, 6, 7, and 8; decreased in regions 1, 9 and 10; and remained stable in region 3. Influenza A(H3N2) viruses were the most frequently reported influenza viruses this week nationally and in all HHS regions. Trends in percent positivity and the distribution of circulating viruses varies by HHS region. For regional and state level data and age group distribution, please visit FluView Interactive. Viruses known to be associated with recent receipt of live attenuated influenza vaccine (LAIV) or found upon further testing to be a vaccine virus are not included, as they are not circulating influenza viruses.

Clinical Laboratories

The results of tests performed by clinical laboratories nationwide are summarized below. Data from clinical laboratories (the percentage of specimens tested that are positive for influenza virus) are used to monitor whether influenza activity is increasing or decreasing.

No. of specimens tested	79,524	1,569,361
No. of positive specimens (%)	15,715 (19.8%)	224,378 (14.3%)
*Positive specimens by type*
Influenza A	8,577 (54.6%)	196,853 (87.7%)
Influenza B	7,138 (45.4%)	27,525 (12.3%)

View Larger Download Influenza Positive Tests Reported to CDC by Clinical Laboratories, National Summary, 2025-26 Season, week ending Feb. 14, 2026
View Chart Data Public Health Laboratories

The results of tests performed by public health laboratories nationwide are summarized below. Data from public health laboratories are used to monitor the proportion of circulating influenza viruses that belong to each influenza subtype/lineage.

No. of specimens tested	1,585	59,855
No. of positive specimens	943	40,380
*Positive specimens by type/subtype*
Influenza A	769 (81.5%)	38,414 (95.1%)
Subtyping Performed	638 (83.0%)	32,294 (84.1%)
(H1N1)pdm09	106 (16.6%)	3,753 (11.6%)
H3N2	532 (83.4%)	28,539 (88.4%)
H3N2v	0	0
H5*	0	2 (<0.1%)
Subtyping not performed	131 (17.0%)	6,120 (15.9%)
Influenza B	174 (18.5%)	1,966 (4.9%)
Lineage testing performed	67 (38.5%)	647 (32.9%)
Yamagata lineage	0	0
Victoria lineage	67 (100%)	647 (100%)
Lineage not performed	107 (61.5%)	1,319 (67.1%)

_{*These data reflect specimens tested, and the number determined to be positive for influenza viruses at the public health labs (specimens tested is not the same as cases). The data do not reflect specimens tested only at CDC and could include more than one specimen tested per person. For more information on the number of people infected with A/H5 viruses, please visit the "How CDC is monitoring influenza data among people to better understand the current avian influenza A (H5N1) situation"}

_{^†When an influenza virus that normally circulates in swine (but not people) is detected in a person, it is called a "variant" influenza virus. Most human infections with variant influenza viruses occur following exposure to swine, but human-to-human transmission can occur. It is important to note that in most cases, variant influenza viruses have not shown the ability to spread easily and sustainably from human-to-human.} View Larger Download This graph reflects the number of specimens tested and the number determined to be positive for influenza viruses at the public health lab (specimens tested is not the same as cases). It does not reflect specimens tested only at CDC and could include... Show More
_{*This graph reflects the number of specimens determined to be positive for influenza viruses at the public health lab (specimens tested is not the same as cases). It does not reflect specimens tested only at CDC and could include more than one specimen tested per person. Specimens tested as part of routine influenza surveillance as well as those tested as part of targeted testing for people exposed to avian influenza A(H5) are included.}

View Chart Data Additional virologic surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive: National, Regional, and State Data or Age Data Novel Influenza A Virus Infections

No new confirmed human infections with avian influenza A(H5) virus were reported to CDC this week. To date, person-to-person transmission of avian influenza A(H5) virus (H5 bird flu) has not been identified in the United States.

The CSTE position statement, which includes updated case definitions for confirmed, probable, and suspected cases is available at http://www.cste.org/resource/resmgr/...nfluenza_A.pdf.

An up-to-date human case summary during the current outbreak by state and exposure source is available at www.cdc.gov/bird-flu/situation-summary/index.html.

Information about avian influenza is available at https://www.cdc.gov/flu/avianflu/index.htm. A(H5N1) virus interim recommendations for Prevention, Monitoring, and Public Health Investigations are available at https://www.cdc.gov/bird-flu/prevent...endations.html.

Additional information regarding human infections with novel influenza A viruses:

Surveillance Methods | FluView Interactive

Influenza Virus Characterization

CDC performs genetic and antigenic characterization of U.S. viruses submitted from state and local public health laboratories according to the Right Size Roadmap submission guidance. These data are used to compare how similar the currently circulating influenza viruses are relative to the reference viruses representing the current influenza vaccines. The data are also used to monitor evolutionary changes that continually occur in influenza viruses circulating in humans. CDC also tests susceptibility of circulating influenza viruses to antiviral medications including the neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) and the polymerase acidic protein (PA) endonuclease inhibitor baloxavir. The HA clade and subclades were assigned using Nextclade (https://clades.nextstrain.org).

CDC has genetically characterized 1,887 influenza viruses collected since September 28, 2025.

A/H1	459
		5a.2a	2 (0.4%)	C.1.9.3	2 (0.4%)
5a.2a.1	457 (99.6%)	D.3.1	189 (41.4%)
D.3.1.1	268 (58.4%)
A/H3	1,193
		2a.3a.1	1,193 (100%)	J.2	4 (0.3%)
J.2.2	5 (0.4%)
J.2.3	41 (3.4%)
J.2.4	44 (3.7%)
K	1,099 (92.1%)
B/Victoria	235
		3a.2	235 (100%)	C.3	6 (2.6%)
C.3.1	147 (62.6%)
C.5.1	19 (8.1%)
C.5.6	12 (5.1%)
C.5.6.1	33 (14.0%)
C.5.7	18 (7.7%)
B/Yamagata	0
		Y3	0	Y3	0

CDC antigenically characterizes influenza viruses by hemagglutination inhibition (HI) assay (H1N1pdm09, H3N2, and B/Victoria viruses) or neutralization-based HINT (H3N2 viruses) using antisera from ferrets infected with reference viruses representing the recommended cell-based or recombinant influenza vaccines for the 2025-2026 Northern Hemisphere season. Antigenic differences between viruses are determined by comparing how well the antibodies raised against the vaccine reference viruses recognize the circulating viruses, which were grown in cell culture. Ferret antisera are useful because antibodies raised against a particular virus can often recognize small changes in the surface proteins of other viruses. In HI assays, viruses are deemed antigenically similar when their HI titer differences are less than or equal to 4-fold. In HINT, viruses with similar antigenic properties have antibody neutralization titer differences of less than 8-fold. Circulating viruses with antigenic testing results that show titer differences greater than 4-fold by HI or equal to or greater than 8-fold by HINT are considered "low reactors" or antigenically drifted compared to the vaccine virus. From the recent genetically characterized viruses, a subset is selected for antigenic characterization based on identified genetic changes in their surface proteins. The subset tested may not be proportional to the number of such viruses circulating in the United States.

Influenza A Viruses

A(H1N1)pdm09: 95 A(H1N1)pdm09 viruses collected since September 28, 2025 were antigenically characterized by HI, and 93 (97.9%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer) by ferret antisera to cell-grown A/Wisconsin/67/2022-like reference viruses representing the A(H1N1)pdm09 component for the cell- and recombinant-based influenza vaccines.
A(H3N2): 151 A(H3N2) viruses collected since September 28, 2025 were antigenically characterized by HI or HINT, and 4 (2.6%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer in HI or reacting at titers that were less than 8-fold of the homologous virus in HINT) by ferret antisera to cell-grown A/District Of Columbia/27/2023-like reference viruses representing the A(H3N2) component for the cell- and recombinant-based influenza vaccines.

Influenza B Viruses

B/Victoria: 55 influenza B/Victoria-lineage viruses collected since September 28, 2025 since were antigenically characterized by HI, and 22 (40.0%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer) by ferret antisera to cell-grown B/Austria/1359417/2021-like reference viruses representing the B/Victoria component for the cell- and recombinant-based influenza vaccines.
B/Yamagata: No influenza B/Yamagata-lineage viruses were available for antigenic characterization.

Assessment of Virus Susceptibility to Antiviral Medications

CDC assesses susceptibility of influenza viruses to the antiviral medications including the neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) and the PA endonuclease inhibitor baloxavir using next generation sequence analysis supplemented by laboratory assays. Information about antiviral susceptibility test methods can be found at U.S. Influenza Surveillance: Purpose and Methods | CDC.

Viruses collected in the U.S. since September 28, 2025, were tested for antiviral susceptibility as follows:

Neuraminidase Inhibitors	Oseltamivir	Viruses Tested	1830	442	1164	224
Reduced Inhibition	7 (0.4%)	7 (1.6%)	0	0
Highly Reduced Inhibition	3 (0.2%)	3 (0.7%)	0	0
Peramivir	Viruses Tested	1830	442	1164	224
Reduced Inhibition	2 (0.1%)	0	0	2 (0.9%)
Highly Reduced Inhibition	3 (0.2%)	3 (0.7%)	0	0
Zanamivir	Viruses Tested	1830	442	1164	224
Reduced Inhibition	0	0	0	0
Highly Reduced Inhibition	0	0	0	0
PA Cap-Dependent Endonuclease Inhibitor	Baloxavir	Viruses Tested	1793	424	1148	221
Decreased Susceptibility	0	0	0	0

Three A(H1N1)pdm09 viruses had NA-H275Y amino acid substitution conferring highly reduced inhibition by oseltamivir and peramivir. Seven A(H1N1)pdm09 viruses had amino acid substitutions NA-I223V and NA-S247N and showed reduced inhibition by oseltamivir. Two B viruses had amino acid substitution NA- M464T and showed reduced inhibition by peramivir.

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, use of these antivirals for treatment and prevention of influenza A virus infection is not recommended and data from adamantane resistance testing are not presented.

Outpatient and Emergency Department Illness Surveillance

Outpatient Respiratory Illness Visits

The U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) monitors outpatient visits for respiratory illness referred to as influenza-like illness [ILI (fever plus cough or sore throat)], not laboratory-confirmed influenza, and will therefore capture respiratory illness visits due to infection with any pathogen that can present with similar symptoms, including influenza virus, SARS-CoV-2, and RSV. It is important to evaluate syndromic surveillance data, including that from ILINet, in the context of other sources of surveillance data to obtain a complete and accurate picture of influenza, SARS-CoV-2, and other respiratory virus activity.

Nationally, during Week 6, 4.5% of patient visits reported through ILINet were due to respiratory illness that included fever plus a cough or sore throat, also referred to as ILI. This week's national percentage remained stable (change of ≤ 0.1 percentage points) and remains above the national baseline for the eleventh consecutive week. ILI activity increased (change of > 0.1 percentage points) in HHS regions 2, 4, 5, and 7; decreased (change of > 0.1 percentage points) in regions 6, 9, and 10; and remained stable in regions 1, 3, and 8 this week compared to Week 5. Regions 2 and 3 are below their respective regional baselines while all other regions (1, 4, 5, 6, 7, 8, 9, and 10) remain above their respective baselines. Multiple respiratory viruses are co-circulating, and the relative contribution of influenza virus infection to ILI varies by location. View Larger Download Percentage of Outpatient Visits for Respiratory Illness Reported by. The U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet)
_{*Some calendar years do not include an epidemiologic Week 53. In those years, the Week 53 value shown is the average between Week 52 and Week 1.}

_{**Effective October 3, 2021 (Week 40), the respiratory illness definition (fever plus cough or sore throat) no longer includes "without a known cause other than influenza."}

View Chart Data

Outpatient Respiratory Illness Visits by Age Group

About 70% of ILINet participants provide both the number of patient visits for respiratory illness and the total number of patient visits for the week broken out by age group. Based on these data, the percentage of visits for respiratory remained stable (change of ≤ 0.1 percentage points) in the 0-4 years, 25-49 years, 50-64 years, and 65 years and older age groups and increased (change of > 0.1 percentage points) in the 5-24 years age group this week compared to Week 5. View Larger Download Percent of Outpatient Visits for Respiratory Illness by Age Group. Reported by the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet)
View Chart Data

Outpatient Respiratory Illness Activity Map

Data collected in ILINet are used to produce a measure of ILI activity* by state/jurisdiction and Core Based Statistical Areas (CBSA).

Week 6 (Week ending Feb. 14, 2026)	Week 5 (Week ending Feb. 7, 2026)	Week 6 (Week ending Feb. 14, 2026)	Week 5 (Week ending Feb. 7, 2026)
Very High	10	10	36	26
High	16	14	126	134
Moderate	9	8	128	117
Low	10	15	186	193
Minimal	10	8	232	236
Insufficient Data	0	0	221	223

_{*Data collected in ILINet may disproportionally represent certain populations within a jurisdiction or CBSA, and therefore, may not accurately depict the full picture of influenza activity for the entire jurisdiction or CBSA. Differences in the data presented here by CDC and independently by some health departments likely represent differing levels of data completeness with data presented by the health department likely being the more complete.} Additional information about medically attended visits for ILI for current and past seasons:

Surveillance Methods | FluView Interactive: National, Regional, and State Data or ILI Activity Map

National Syndromic Surveillance System (NSSP)

The national percentage of emergency department (ED) visits with a discharge diagnosis (DD) of influenza reported in NSSP was 3.5% during Week 6, which increased (change of ≤ 0.1 percentage point) compared to the previous week. Nationally, the percentage of ED visits with a DD of influenza remained stable among the 0-4 years, 18-64 years, and the 65 years and older age groups and increased (change of > 0.1 percentage points) among the 5-17 years age group. The percentage of ED visits with a DD of influenza increased (change of > 0.1 percentage points) this week compared to the previous week in HHS Regions 2, 4, 5, and 6; remained stable in regions 1, 3, 7, and 8; and decreased in regions 9 and 10. Age group trends varied by region. View Larger Download NSSP week 6 Additional information about emergency department visits for flu for current and past seasons:‎‎‎

Surveillance Methods | Emergency Department Visits for COVID-19, flu, and RSV
Hospitalization surveillance

FluSurv-Net

Influenza-Associated Hospitalizations: The Influenza Hospitalization Surveillance Network (FluSurv-NET) conducts population-based surveillance for laboratory-confirmed influenza-related hospitalizations in select counties in 14 states and represents approximately 10% of the U.S. population. FluSurv-NET hospitalization data are preliminary. As data are received each week, prior case counts and rates are updated accordingly.

A total of 24,469 laboratory-confirmed influenza-associated hospitalizations were reported by FluSurv-NET sites between October 1, 2025, and February 14, 2026. The weekly hospitalization rate observed during Week 6 was 2.0 per 100,000 population, which decreased from a rate of 3.2 per 100,000 population last week. After accounting for reporting delays, the estimated rate during Week 6 likely ranges from 2.6 to 3.5. The cumulative hospitalization rate observed in Week 6 was 70.2 per 100,000 population, which is the third highest cumulative rate at this point in the season since the 2010-11 season.

Among all hospitalizations, 23,418 (95.7%) were associated with influenza A virus, 889 (3.6%) with influenza B virus, 53 (0.2%) with influenza A virus and influenza B virus co-infection, and 109 (0.4%) with influenza virus for which the type was not determined. Among those with influenza A subtype information, 5,894 (90.2%) were A(H3N2), and 638 (9.8%) were A(H1N1)pdm09.

When examining rates by age, the highest rate of hospitalization per 100,000 population was among adults aged 65 and older (231.4), followed by children aged 0-4 years (71.6), adults aged 50-64 years (61.7), children aged 5-17 years (26.9), and adults aged 18-49 years (26.8).

Among children, the peak weekly rate is the highest going back to the 2010-11 season in Week 52 (7.1). The cumulative rate for pediatric cases is the second highest since 2010-11 (38.8). Among children, rates are highest among infants aged younger than 1 year (115.9), followed by children aged 1-4 years (61.8). For all pediatric age groups, this is the second highest cumulative rate at this time of the season since the 2010-11 season.

When examining age-adjusted rates by race and ethnicity, the highest rate of hospitalization per 100,000 population was among non-Hispanic Black persons (123.8), followed by American Indian or Alaska Native persons (74.2), Hispanic persons (64.5), non-Hispanic White persons (60.2), and Asian and/or Pacific Islander persons (31.6).

Among 2,309 hospitalized adults with information on underlying medical conditions, 95.8% had at least one reported underlying medical condition; the most commonly reported were hypertension, cardiovascular disease, chronic metabolic disease, and chronic lung disease. Among 2,767 hospitalized women of childbearing age (15-49 years) with information on pregnancy status, 30.5% were pregnant. Among 939 hospitalized children with information on underlying medical conditions, 58.0% had at least one reported underlying medical condition; the most commonly reported was asthma, followed by neurologic disorder, and obesity.

Additional FluSurv-NET data are available on FluView Interactive including hospitalization rates for the current and past seasons by age, sex, and race/ethnicity (http://gis.cdc.gov/GRASP/Fluview/FluHospRates.html) as well as data on patient characteristics at: (http://gis.cdc.gov/grasp/fluview/FluHospChars.html.)

FluSurv-NET data are used to generate national estimates of the total numbers of influenza cases, medical visits, hospitalizations, and deaths. This season, CDC is reporting preliminary cumulative in-season estimates, which are available at Estimated US Flu Disease Burden | Flu Burden | CDC. View Larger Download **In this figure, weekly rates for all seasons prior to the 2025-2026 season reflect end-of-season rates. For the 2025-2026 season, rates for recent hospital admissions are subject to reporting delays and are shown as a dashed line for the current se... Show More
_{**In this figure, weekly rates for all seasons prior to the 2025-26 season reflect end-of-season rates. For the 2025-26 season, rates for recent hospital admissions are subject to reporting delays and are shown as a dashed line for the current season. As hospitalization data are received each week, prior case counts and rates are updated accordingly.}

Additional FluSurv-NET hospitalization surveillance information for current and past seasons and additional age groups:

Surveillance Methods | FluView Interactive: Rates by Age, Sex, and Race/Ethnicity or Data on Patient Characteristics | RESP-NET Interactive

National Healthcare Safety Network (NHSN) Hospital Respiratory Data

Hospitals report to NHSN the weekly number of patients with laboratory-confirmed influenza who were admitted to the hospital. Nationally, during Week 6, 14,940 laboratory-confirmed influenza-associated hospitalizations were reported. This week's influenza-associated hospital admission rate (4.4 per 100,000 population) remained stable (difference of < 0.2) compared to Week 5.

Laboratory-confirmed influenza-associated hospital admission rates per 100,000 population decreased in HHS regions 1, 2, 3, 5, 8, 9, and 10; increased in regions 4 and 7; and remained stable in region 6. Region admission rates ranged from 1.6 (Region 1) to 6.9 (Region 7) during Week 6.

When examining rates by age for Week 6, the 5-17 years age group increased, the 0-4 and 18-49 years age groups remained stable, and the 50-64 and 65 years and older age groups decreased this week compared to Week 5. The highest hospital admission rate per 100,000 population was among those 65 years and older (13.7), followed by the 0-4 years age group (4.3), and the 50-64 years age group (3.7). View Larger Download NHSN week 6

Additional NHSN Hospital Respiratory Data information:

Surveillance Methods | Additional Data | FluView Interactive

National Healthcare Safety Network (NHSN) Long-Term Care Respiratory Pathogens & Vaccination Module

Long-term care facilities (LTCFs [e.g., Nursing homes/skilled nursing facilities]) report respiratory pathogen (e.g., COVID-19, influenza, and RSV) data, including vaccination, cases, and hospitalizations among residents, to the NHSN Long-Term Care Respiratory Pathogens & Vaccination Module.

Nationally, during Week 6, the hospitalization rate for residents with a positive influenza test in the prior 10 days was 27.5 per 100,000 residents. The national rate and rates in HHS regions 1, 2, 4, 8 and 10 are trending downward. Rates are trending upward in regions 7 and 9. In regions 3, 5, and 6, the rate does not show a consistent trend. View Larger Download National Healthcare Safety Network (NHSN) Long-Term Care Respiratory Pathogens & Vaccination Module Mortality surveillance

National Center for Health Statistics (NCHS) Mortality Surveillance

Based on NCHS mortality surveillance data available on February 19, 2026, 0.9% of the deaths that occurred during the week ending February 14, 2026 (Week 6) were due to influenza. This percentage decreased (≥ 0.1 percentage point change) compared to Week 5. The data presented are preliminary and may change as more data are received and processed. View Larger Download Influenza Mortality from the National Center for Health Statistics Mortality Surveillance System
View Chart Data

Additional pneumonia, influenza and COVID-19 mortality surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive

Influenza-Associated Pediatric Mortality

Six influenza-associated pediatric deaths were reported to CDC during Week 6.

Five deaths occurred during the 2025-2026 season, bringing the total number of pediatric deaths for this season to 71. The deaths occurred during weeks 2, 4 and 5 (the weeks ending January 17, 2026, January 31, 2026, and February 7, 2026). Four deaths were associated with influenza A viruses. Three of the influenza A viruses had subtyping performed and all were A(H3N2) viruses. One death was associated with an influenza B virus with no lineage determined. Among children who were eligible for influenza vaccination and with known vaccination status, approximately 90% of reported pediatric deaths this season have occurred in children who were not fully vaccinated against influenza.

One death occurring during the 2024–2025 season was also reported, bringing the total number of pediatric deaths for last season to 290. This death was associated with an influenza A(H1N1) virus and occurred during Week 34 of 2025 (the week ending August 23, 2025). View Larger Download Influenza-Associated Pediatric Deaths by Week of Death, 2022-23 season to 2025-26 season Additional pediatric mortality surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive
All data in this report are preliminary and may change as more reports are received.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component, is available on the surveillance methods page.¹

Additional information on the current and previous influenza seasons for each surveillance component are available on FluView Interactive.
Additional National and International Influenza Surveillance Information

Indicators Status by System

Increasing:
Decreasing:
Stable:

Clinical Labs: Up or down arrows indicate a change of greater than or equal to 0.5 percentage points in the percent of specimens positive for influenza compared to the previous week.
Outpatient Respiratory Illness (ILINet): Up or down arrows indicate a change of greater than 0.1 percentage points in the percent of visits due to respiratory illness (ILI) compared to the previous week.
NHSN Hospitalizations: Up or down arrows indicate change of greater than or equal to 0.2 in the rate of hospital admissions or greater than or equal to 691 patients admitted with laboratory-confirmed influenza compared to the previous week.
NHSN Long- Term Care (LTC): Up or down arrows indicate change of greater than or equal to 5% in hospitalization rates for residents in LTC facilities who were hospitalized with laboratory-confirmed influenza compared to the previous week.
NCHS Mortality: Up or down arrows indicate change of greater than 0.1 percentage points of the percent of deaths due to influenza compared to the previous week.

Additional surveillance information

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.

National Institute for Occupational Safety and Health: Monthly surveillance data on the prevalence of health-related workplace absenteeism among full-time workers in the United States are available from NIOSH.

U.S. State and local influenza surveillance: Select a jurisdiction below to access the latest local influenza information.

Alabama	Alaska	Arizona	Arkansas	California
Colorado	Connecticut	Delaware	District of Columbia	Florida
Georgia	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	Oklahoma	Oregon	Pennsylvania	Rhode Island
South Carolina	South Dakota	Tennessee	Texas	Utah
Vermont	Virginia	Washington	West Virginia	Wisconsin
Wyoming	New York City	Puerto Rico	Virgin Islands

Public Health Agency of Canada:
The most up-to-date influenza information from Canada is available in Canada's weekly FluWatch report.

Public Health England:
The most up-to-date influenza information from the United Kingdom is available from Public Health England.

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.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component is available on the surveillance methods page.

On This Page

Related Pages

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Key Updates for Week 7, ending February 21, 2026
Sources

Weekly US Influenza Surveillance Report: Key Updates for Week 6, ending February 14, 2026

https://www.cdc.gov/fluview/surveillance/2026-week-06.html

Seasonal influenza activity is low.

**sharon sanders** · February 27, 2026, 05:35 PM

Weekly US Influenza Surveillance Report: Key Updates for Week 7, ending February 21, 2026

For Everyone
Feb. 27, 2026

Key points

Seasonal influenza activity remains elevated nationally.
Summary

Viruses

Clinical Lab 17.9% (Trend )
positive for influenza
this week. Public Health Lab The most frequently reported
influenza viruses this week were influenza A(H3N2).

Illness

Outpatient Respiratory Illness 4.4% (Trend )
of visits to a health care provider this week were for respiratory illness
(above baseline). Activity Map 11 moderate jurisdictions 25 high or very high jurisdictions FluSurv-NET 73.3
cumulative hospitalization rate
per 100,000 population NHSN LTCF Respiratory
Data 21.6 (Trend ) weekly hospitalization rate
per 100,000 residents NHSN Hospital Respiratory Data 13,785 (Trend )
patients admitted to hospitals
with influenza this week. NCHS Mortality 0.9% (Trend ) of deaths attributed to influenza this week. Pediatric Deaths 8 influenza-associated deaths
occurring during the 2025-2026 season
were reported this week for
a total of 79 deaths this season.
All data are preliminary and may change as more reports are received.

Directional arrows indicate changes between the current week and the previous week. Additional information on the arrows can be found at the bottom of this page.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component is available on the surveillance methods page.¹

Additional information on the current and previous influenza seasons for each surveillance component are available on FluView Interactive.

Key Points

Seasonal influenza activity remains elevated nationally. Influenza A activity is decreasing while influenza B activity is increasing nationally and in most areas of the country.

Influenza A(H3N2) viruses are the most frequently reported influenza viruses so far this season.
- Among 1,354 influenza A(H3N2) viruses collected since September 28, 2025, that underwent additional genetic characterization at CDC, 92.4% belonged to subclade K.

The cumulative influenza-associated hospitalization rate overall in FluSurv-NET is the third highest since the 2010-2011 season. Children younger than 18 years have the second highest cumulative hospitalization rate for that age group since the 2010-2011 season.

Eight influenza-associated pediatric deaths occurring during the 2025-2026 season were reported to CDC this week, bringing the season total to 79 reported influenza-associated pediatric deaths.
- Among children who were eligible for influenza vaccination and with known vaccination status, approximately 90% of reported pediatric deaths this season have occurred in children who were not fully vaccinated against influenza.

CDC's in-season severity assessment framework classified the season as moderate across all ages. CDC also assesses severity by three age groups: pediatric (0-17 years), adult (18-64 years), and older adults (≥65 years). At this point in the season, the pediatric age group is classified as having high severity, while both the adult and older adult age groups are classified as having moderate severity. These assessments are conducted each week during the season, and the season's severity assessment can change if activity should increase again.
CDC estimates that there have been at least 25,000,000 illnesses, 330,000 hospitalizations, and 20,000 deaths from flu so far this season.
Influenza (flu) vaccination has been shown to reduce the risk of flu and its potentially serious complications.There is still time to get vaccinated against flu this season. Approximately 135 million doses of influenza vaccine have been distributed in the United States this season.

There are prescription flu antiviral drugs that can treat flu illness; those should be started as early as possible and are especially important for patients at higher risk for flu-related complications.¹
Influenza viruses are among several viruses contributing to respiratory disease activity. CDC provides updated, integrated information about COVID-19, flu, and respiratory syncytial virus (RSV) activity on a weekly basis.
No new avian influenza A(H5) infections were reported to CDC this week. To date, person-to-person transmission of influenza A(H5) viruses has not been identified in the United States.

U.S. virologic surveillance

Nationally, the percentage of respiratory specimens testing positive for the influenza virus in clinical laboratories decreased (change > 0.5 percentage points) slightly this week. The percent positivity for influenza A viruses decreased, while the percent positivity for influenza B viruses continues to increase in most areas of the country. Across HHS Regions, the overall percent of specimens testing positive for influenza increased in regions 1, 2, 3, 4, and 8; decreased in regions 6, 7, 9, and 10; and remained stable in region 5. Influenza A(H3N2) viruses were the most frequently reported influenza viruses this week nationally, though trends in percent positivity and the distribution of circulating viruses varies by HHS region. For regional and state level data and age group distribution, please visit FluView Interactive. Viruses known to be associated with recent receipt of live attenuated influenza vaccine (LAIV) or found upon further testing to be a vaccine virus are not included, as they are not circulating influenza viruses.

Clinical Laboratories

The results of tests performed by clinical laboratories nationwide are summarized below. Data from clinical laboratories (the percentage of specimens tested that are positive for influenza virus) are used to monitor whether influenza activity is increasing or decreasing.

No. of specimens tested	85,506	1,682,057
No. of positive specimens (%)	15,316 (17.9%)	243,440 (14.5%)
*Positive specimens by type*
Influenza A	6,874 (44.9%)	206,754 (84.9%)
Influenza B	8,442 (55.1%)	36,686 (15.1%)

Public Health Laboratories

The results of tests performed by public health laboratories nationwide are summarized below. Data from public health laboratories are used to monitor the proportion of circulating influenza viruses that belong to each influenza subtype/lineage.

No. of specimens tested	1,494	64,716
No. of positive specimens	1,019	43,816
*Positive specimens by type/subtype*
Influenza A	725 (71.1%)	41,217 (94.1%)
Subtyping Performed	569 (78.5%)	34,482 (83.7%)
(H1N1)pdm09	96 (16.9%)	4,092 (11.9%)
H3N2	473 (83.1%)	30,388 (88.1%)
H3N2v^†	0	0
H5*	0	2 (<0.01%)
Subtyping not performed	156 (21.5%)	6,735 (16.3%)
Influenza B	294 (28.9%)	2,599 (5.9%)
Lineage testing performed	102 (34.7%)	904 (34.8%)
Yamagata lineage	0	0
Victoria lineage	102 (100%)	904 (100%)
Lineage not performed	192 (65.3%)	1,695 (65.2%)

_{*These data reflect specimens tested, and the number determined to be positive for influenza viruses at the public health labs (specimens tested is not the same as cases). The data do not reflect specimens tested only at CDC and could include more than one specimen tested per person. For more information on the number of people infected with A/H5 viruses, please visit the "How CDC is monitoring influenza data among people to better understand the current avian influenza A (H5N1) situation"}

_{^†When an influenza virus that normally circulates in swine (but not people) is detected in a person, it is called a "variant" influenza virus. Most human infections with variant influenza viruses occur following exposure to swine, but human-to-human transmission can occur. It is important to note that in most cases, variant influenza viruses have not shown the ability to spread easily and sustainably from human-to-human.}

_{*This graph reflects the number of specimens determined to be positive for influenza viruses at the public health lab (specimens tested is not the same as cases). It does not reflect specimens tested only at CDC and could include more than one specimen tested per person. Specimens tested as part of routine influenza surveillance as well as those tested as part of targeted testing for people exposed to avian influenza A(H5) are included.}

Additional virologic surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive: National, Regional, and State Data or Age Data

Novel Influenza A Virus Infections

No new confirmed human infections with avian influenza A(H5) virus were reported to CDC this week. To date, person-to-person transmission of avian influenza A(H5) virus (H5 bird flu) has not been identified in the United States.

The CSTE position statement, which includes updated case definitions for confirmed, probable, and suspected cases is available at http://www.cste.org/resource/resmgr/...nfluenza_A.pdf.

An up-to-date human case summary during the current outbreak by state and exposure source is available at www.cdc.gov/bird-flu/situation-summary/index.html.

Information about avian influenza is available at https://www.cdc.gov/flu/avianflu/index.htm. A(H5N1) virus interim recommendations for Prevention, Monitoring, and Public Health Investigations are available at https://www.cdc.gov/bird-flu/prevent...endations.html.

Additional information regarding human infections with novel influenza A viruses:

Surveillance Methods | FluView Interactive

Influenza Virus Characterization

CDC performs genetic and antigenic characterization of U.S. viruses submitted from state and local public health laboratories according to the Right Size Roadmap submission guidance. These data are used to compare how similar the currently circulating influenza viruses are relative to the reference viruses representing the current influenza vaccines. The data are also used to monitor evolutionary changes that continually occur in influenza viruses circulating in humans. CDC also tests susceptibility of circulating influenza viruses to antiviral medications including the neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) and the polymerase acidic protein (PA) endonuclease inhibitor baloxavir. The HA clade and subclades were assigned using Nextclade (https://clades.nextstrain.org).

CDC has genetically characterized 2,186 influenza viruses collected since September 28, 2025.

A/H1	520
		5a.2a	3 (0.6%)	C.1.9.3	3 (0.6%)
5a.2a.1	517 (99.4%)	D.3.1	206 (39.6%)
D.3.1.1	311 (59.8%)
A/H3	1,354
		2a.3a.1	1,354 (100%)	J.2	4 (0.3%)
J.2.2	5 (0.4%)
J.2.3	42 (3.1%)
J.2.4	52 (3.8%)
K	1,251 (92.4%)
B/Victoria	312
		3a.2	312 (100%)	C.3	12 (3.8%)
C.3.1	193 (61.9%)
C.5.1	24 (7.7%)
C.5.6	13 (4.2%)
C.5.6.1	47 (15.1%)
C.5.7	23 (7.4%)
B/Yamagata	0
		Y3	0	Y3	0

CDC antigenically characterizes influenza viruses by hemagglutination inhibition (HI) assay (H1N1pdm09, H3N2, and B/Victoria viruses) or neutralization-based HINT (H3N2 viruses) using antisera from ferrets infected with reference viruses representing the recommended cell-based or recombinant influenza vaccines for the 2025-2026 Northern Hemisphere season. Antigenic differences between viruses are determined by comparing how well the antibodies raised against the vaccine reference viruses recognize the circulating viruses, which were grown in cell culture. Ferret antisera are useful because antibodies raised against a particular virus can often recognize small changes in the surface proteins of other viruses. In HI assays, viruses are deemed antigenically similar when their HI titer differences are less than or equal to 4-fold. In HINT, viruses with similar antigenic properties have antibody neutralization titer differences of less than 8-fold. Circulating viruses with antigenic testing results that show titer differences greater than 4-fold by HI or equal to or greater than 8-fold by HINT) are considered “low reactors” or antigenically drifted compared to the vaccine virus. From the recent genetically characterized viruses, a subset is selected for antigenic characterization based on identified genetic changes in their surface proteins. The subset tested may not be proportional to the number of such viruses circulating in the United States.

Influenza A Viruses

A(H1N1)pdm09: 123 A(H1N1)pdm09 viruses collected since September 28, 2025, were antigenically characterized by HI, and 120 (97.6%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer) by ferret antisera to cell-grown A/Wisconsin/67/2022-like reference viruses representing the A(H1N1)pdm09 component for the cell- and recombinant-based influenza vaccines.
A(H3N2): 151 A(H3N2) viruses collected since September 28, 2025, were antigenically characterized by HI or HINT, and 4 (2.6%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer in HI or reacting at titers that were less than 8-fold of the homologous virus in HINT) by ferret antisera to cell-grown A/District Of Columbia/27/2023-like reference viruses representing the A(H3N2) component for the cell- and recombinant-based influenza vaccines.

Influenza B Viruses

B/Victoria: 77 influenza B/Victoria-lineage viruses collected since September 28, 2025, since were antigenically characterized by HI, and 26 (33.8%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer) by ferret antisera to cell-grown B/Austria/1359417/2021-like reference viruses representing the B/Victoria component for the cell- and recombinant-based influenza vaccines.
B/Yamagata: No influenza B/Yamagata-lineage viruses were available for antigenic characterization.

Assessment of Virus Susceptibility to Antiviral Medications

CDC assesses susceptibility of influenza viruses to the antiviral medications including the neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) and the PA endonuclease inhibitor baloxavir using next generation sequence analysis supplemented by laboratory assays. Information about antiviral susceptibility test methods can be found at U.S. Influenza Surveillance: Purpose and Methods | CDC.

Viruses collected in the U.S. since September 28, 2025, were tested for antiviral susceptibility as follows:

Neuraminidase Inhibitors	Oseltamivir	Viruses Tested	2,163	517	1,338	308
Reduced Inhibition	10 (0.5%)	10 (1.9%)	0	0
Highly Reduced Inhibition	4 (0.2%)	4 (0.8%)	0	0
Peramivir	Viruses Tested	2,163	517	1,338	308
Reduced Inhibition	2 (<0.1%)	0	0	2 (0.6%)
Highly Reduced Inhibition	4 (0.2%)	4 (0.8%)	0	0
Zanamivir	Viruses Tested	2,163	517	1,338	308
Reduced Inhibition	0	0	0	0
Highly Reduced Inhibition	0	0	0	0
PA Cap-Dependent Endonuclease Inhibitor	Baloxavir	Viruses Tested	2,112	494	1,314	304
Decreased Susceptibility	0	0	0	0

Four A(H1N1)pdm09 viruses had NA-H275Y amino acid substitution conferring highly reduced inhibition by oseltamivir and peramivir. Ten A(H1N1)pdm09 viruses had amino acid substitutions NA-I223V and NA-S247N and showed reduced inhibition by oseltamivir. Two B viruses had amino acid substitution NA- M464T and showed reduced inhibition by peramivir.

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, use of these antivirals for treatment and prevention of influenza A virus infection is not recommended and data from adamantane resistance testing are not presented.

Outpatient and Emergency Department Illness Surveillance

Outpatient Respiratory Illness Visits

The U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) monitors outpatient visits for respiratory illness referred to as influenza-like illness [ILI (fever plus cough or sore throat)], not laboratory-confirmed influenza, and will therefore capture respiratory illness visits due to infection with any pathogen that can present with similar symptoms, including influenza virus, SARS-CoV-2, and RSV. It is important to evaluate syndromic surveillance data, including that from ILINet, in the context of other sources of surveillance data to obtain a complete and accurate picture of influenza, SARS-CoV-2, and other respiratory virus activity.

Nationally, during Week 7, 4.4% of patient visits reported through ILINet were due to respiratory illness that included fever plus a cough or sore throat, also referred to as ILI. This week’s national percentage remained stable (change of ≤ 0.1 percentage points) compared to Week 6 and remains above the national baseline for the twelfth consecutive week. ILI activity increased (change of > 0.1 percentage points) in HHS regions 1, 3, 5, and 8; decreased (change of > 0.1 percentage points) in regions 4, 6, 7, 9, and 10; and remained stable in Region 2 this week compared to Week 6. Region 2 is below its regional baseline while all other regions (1, 3, 4, 5, 6, 7, 8, 9, and 10) are above their respective baselines. Multiple respiratory viruses are co-circulating, and the relative contribution of influenza virus infection to ILI varies by location.

_{*Some calendar years do not include an epidemiologic Week 53. In those years, the Week 53 value shown is the average between Week 52 and Week 1.}

_{**Effective October 3, 2021 (Week 40), the respiratory illness definition (fever plus cough or sore throat) no longer includes "without a known cause other than influenza."}

Outpatient Respiratory Illness Visits by Age Group

About 70% of ILINet participants provide both the number of patient visits for respiratory illness and the total number of patient visits for the week broken out by age group. Based on these data, the percentage of visits for respiratory illness remained stable (change of ≤ 0.1 percentage points) in the 0-4 years, 25-49 years, 50-64 years, and 65 years and older age groups and decreased (change of > 0.1 percentage points) slightly in the 5-24 years age group this week compared to Week 6.

Outpatient Respiratory Illness Activity Map

Data collected in ILINet are used to produce a measure of ILI activity* by state/jurisdiction and Core Based Statistical Areas (CBSA).

Week 7 (Week ending Feb. 21, 2026)	Week 6 (Week ending Feb. 14, 2026)	Week 7 (Week ending Feb. 21, 2026)	Week 6 (Week ending Feb. 14, 2026)
Very High	8	10	24	35
High	17	15	141	127
Moderate	11	10	142	128
Low	8	10	191	190
Minimal	11	10	212	236
Insufficient Data	0	0	219	213

_{*Data collected in ILINet may disproportionally represent certain populations within a jurisdiction or CBSA, and therefore, may not accurately depict the full picture of influenza activity for the entire jurisdiction or CBSA. Differences in the data presented here by CDC and independently by some health departments likely represent differing levels of data completeness with data presented by the health department likely being the more complete.} Additional information about medically attended visits for ILI for current and past seasons:

Surveillance Methods | FluView Interactive: National, Regional, and State Data or ILI Activity Map

National Syndromic Surveillance System (NSSP)

The national percentage of emergency department (ED) visits with a discharge diagnosis (DD) of influenza reported in NSSP was 3.2% during Week 7, which decreased (change of > 0.1 percentage points) slightly compared to the previous week. Nationally, the percentage of ED visits with a DD of influenza decreased among all age groups (0-4 years, 5-17 years, 18-64 years, and 65 years and older). The percentage of ED visits with a DD of influenza increased (change of > 0.1 percentage points) this week compared to the previous week in HHS Regions 1, 2, 3, and 5, remained stable (change of ≤ 0.1 percentage points) in region 8, and decreased in all other regions (4, 6, 7, 9, and 10). Age group trends varied by region. RegionNationalRegion 1Region 2Region 3Region 4Region 5Region 6Region 7Region 8Region 9Region 10
Season
2025-2026x
2024-2025x

Skip Over Chart Container
2.0%4.0%6.0%8.0%10.0%12.0%14.0%16.0%18.0%20.0%Perc ent of Emergency Department Visits for InfluenzaWeek 40 of 2024Week 44 of 2024Week 48 of 2024Week 52 of 2024Week 4 of 2025Week 8 of 2025Week 12 of 2025Week 16 of 2025Week 20 of 2025Week 24 of 2025Week 28 of 2025Week 32 of 2025Week 36 of 2025Week 40 of 2025Week 44 of 2025Week 48 of 2025Week 52 of 2025Week 3 of 2026Week 7 of 2026 Age Group

Skip Data Table
Data Table Download Data (CSV)
Skipped data table.

Additional information about emergency department visits for flu for current and past seasons:‎‎‎

Surveillance Methods | Emergency Department Visits for COVID-19, flu, and RSV
Hospitalization surveillance

FluSurv-Net

Influenza-Associated Hospitalizations: The Influenza Hospitalization Surveillance Network (FluSurv-NET) conducts population-based surveillance for laboratory-confirmed influenza-related hospitalizations in select counties in 14 states and represents approximately 10% of the U.S. population. FluSurv-NET hospitalization data are preliminary. As data are received each week, prior case counts and rates are updated accordingly.

A total of 25,558 laboratory-confirmed influenza-associated hospitalizations were reported by FluSurv-NET sites between October 1, 2025, and February 21, 2026. The weekly hospitalization rate observed during Week 7 was 2.0 per 100,000 population, which decreased from last week. After accounting for reporting delays, the estimated rate during Week 7 is likely to range from 2.7 to 3.7. The cumulative hospitalization rate observed in Week 7 was 73.3 per 100,000 population. This is the third highest cumulative rate since the 2010-11 season.

Among all hospitalizations, 24,241 (94.8%) were associated with influenza A virus, 1,133 (4.4%) with influenza B virus, 76 (0.3%) with influenza A virus and influenza B virus co-infection, and 108 (0.4%) with influenza virus for which the type was not determined. Among those with influenza A subtype information, 6,139 (89.4%) were A(H3N2), and 724 (10.5%) were A(H1N1)pdm09.

When examining rates by age, the highest rate of hospitalization per 100,000 population was among adults aged 65 and older (243.7), followed by children aged 0-4 years (75.7), adults aged 50-64 years (65.2), children aged 5-17 years (29.1), and adults aged 18-49 years (28.6).

Among children, the peak weekly rate is the highest going back to the 2010-2011 season in Week 52 (7.0). The cumulative rate for pediatric cases is the second highest since 2010-2011 (41.0). Among children, rates are highest among infants aged less than 1 year (120.3), followed by children aged 1-4 years (64.8).

When examining age-adjusted rates by race and ethnicity, the highest rate of hospitalization per 100,000 population was among non-Hispanic Black persons (127.9), followed by American Indian or Alaska Native persons (76.7), Hispanic persons (66.9), non-Hispanic White persons (63.1), and Asian and/or Pacific Islander persons (33.1).

Among 2,581 hospitalized adults with information on underlying medical conditions, 95.9% had at least one reported underlying medical condition; the most commonly reported were hypertension, cardiovascular disease, chronic metabolic disease, and chronic lung disease. Among 2,898 hospitalized women of childbearing age (15-49 years) with information on pregnancy status, 30.3% were pregnant. Among 1,049 hospitalized children with information on underlying medical conditions, 58.2% had at least one reported underlying medical condition; the most commonly reported was asthma, followed by neurologic disorder, and obesity.

Additional FluSurv-NET data are available on FluView Interactive including hospitalization rates for the current and past seasons by age, sex, and race/ethnicity (http://gis.cdc.gov/GRASP/Fluview/FluHospRates.html) as well as data on patient characteristics at: (http://gis.cdc.gov/grasp/fluview/FluHospChars.html.)

FluSurv-NET data are used to generate national estimates of the total numbers of influenza cases, medical visits, hospitalizations and deaths. This season, CDC is reporting preliminary cumulative in-season estimates, which are available at https://www.cdc.gov/flu-burden/php/data-vis/index.html.

_{**In this figure, weekly rates for all seasons prior to the 2025-26 season reflect end-of-season rates. For the 2025-26 season, rates for recent hospital admissions are subject to reporting delays and are shown as a dashed line for the current season. As hospitalization data are received each week, prior case counts and rates are updated accordingly.}

Additional FluSurv-NET hospitalization surveillance information for current and past seasons and additional age groups:

Surveillance Methods | FluView Interactive: Rates by Age, Sex, and Race/Ethnicity or Data on Patient Characteristics | RESP-NET Interactive

National Healthcare Safety Network (NHSN) Hospital Respiratory Data

Hospitals report to NHSN the weekly number of patients with laboratory-confirmed influenza who were admitted to the hospital. Nationally, during Week 7, 13,785 laboratory-confirmed influenza-associated hospitalizations were reported. This week's influenza-associated hospital admission rate (4.1 per 100,000 population) decreased (difference of > 0.2) compared to Week 6.

Laboratory-confirmed influenza-associated hospital admission rates per 100,000 population decreased in HHS regions 4, 6, 7, 8, 9, and 10; increased in regions 2 and 5; and remained stable in regions 1 and 3. Region admission rates ranged from 1.7 (Region 1) to 5.8 (Region 7) during Week 7.

When examining rates by age for Week 7, the 5-17 years age group remained stable and all other age groups decreased this week compared to Week 6. The highest hospital admission rate per 100,000 population was among those 65 years and older (12.2), followed by the 0-4 years age group (4.3), and the 50-64 years age group (3.3).

Additional NHSN Hospital Respiratory Data information:

Surveillance Methods | Additional Data | FluView Interactive

National Healthcare Safety Network (NHSN) Long-Term Care Respiratory Pathogens & Vaccination Module

Long-term care facilities (LTCFs [e.g., Nursing homes/skilled nursing facilities]) report respiratory pathogen (e.g., COVID-19, influenza, and RSV) data, including vaccination, cases, and hospitalizations among residents, to the NHSN Long-Term Care Respiratory Pathogens & Vaccination Module.

Nationally, during Week 7, the hospitalization rate for residents with a positive influenza test in the prior 10 days was 21.6 per 100,000 residents. The national rate and rates in HHS Regions 1, 2, 4, 5, and 10 are trending downward. Rates are trending upwards in regions 7 and 9. In regions 3, 6, and 8, the rate does not show a consistent trend. View Larger Download National Healthcare Safety Network (NHSN) Long-Term Care Respiratory Pathogens & Vaccination Module
Mortality surveillance

National Center for Health Statistics (NCHS) Mortality Surveillance

Based on NCHS mortality surveillance data available on February 26, 2026, 0.9% of the deaths that occurred during the week ending February 21, 2026 (Week 7) were due to influenza. This percentage increased (≥ 0.1 percentage point change) slightly compared to Week 6. The data presented are preliminary and may change as more data are received and processed.

Additional pneumonia, influenza and COVID-19 mortality surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive

Influenza-Associated Pediatric Mortality

Eleven influenza-associated pediatric deaths were reported to CDC during Week 7.

Eight deaths occurred during the 2025-2026 season, bringing the total number of pediatric deaths for this season to 79. The deaths occurred between week 50 and week 7 (the weeks ending December 13, 2025, and February 14, 2026). Seven of the deaths were associated with influenza A viruses. Five of the influenza A viruses had subtyping performed and all were A(H3N2) viruses. One death was associated with an influenza B/Victoria virus. Among children who were eligible for influenza vaccination and with known vaccination status, approximately 90% of reported pediatric deaths this season have occurred in children who were not fully vaccinated against influenza.

Three deaths occurring during the 2024–2025 season were also reported, bringing the total number of pediatric deaths for last season to 293. The deaths occurred during weeks 7, 9 and 15 of 2025 (the weeks ending February 15, 2025, March 1, 2025, and April 12, 2025). Two deaths were associated with influenza A viruses. One of the influenza A viruses had subtyping performed and it was an A(H1N1) virus. One death was associated with an influenza B virus with no lineage determined.

Additional pediatric mortality surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive
All data in this report are preliminary and may change as more reports are received.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component, is available on the surveillance methods page.¹

Additional information on the current and previous influenza seasons for each surveillance component are available on FluView Interactive.

Additional National and International Influenza Surveillance Information

Indicators Status by System

Increasing:
Decreasing:
Stable:

Clinical Labs: Up or down arrows indicate a change of greater than or equal to 0.5 percentage points in the percent of specimens positive for influenza compared to the previous week.
Outpatient Respiratory Illness (ILINet): Up or down arrows indicate a change of greater than 0.1 percentage points in the percent of visits due to respiratory illness (ILI) compared to the previous week.
NHSN Hospitalizations: Up or down arrows indicate change of greater than or equal to 0.2 in the rate of hospital admissions or greater than or equal to 691 patients admitted with laboratory-confirmed influenza compared to the previous week.
NHSN Long- Term Care (LTC): Up or down arrows indicate change of greater than or equal to 5% in hospitalization rates for residents in LTC facilities who were hospitalized with laboratory-confirmed influenza compared to the previous week.
NCHS Mortality: Up or down arrows indicate change of greater than 0.1 percentage points of the percent of deaths due to influenza compared to the previous week.

Additional surveillance information

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.

National Institute for Occupational Safety and Health: Monthly surveillance data on the prevalence of health-related workplace absenteeism among full-time workers in the United States are available from NIOSH.

U.S. State and local influenza surveillance: Select a jurisdiction below to access the latest local influenza information.

Alabama	Alaska	Arizona	Arkansas	California
Colorado	Connecticut	Delaware	District of Columbia	Florida
Georgia	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	Oklahoma	Oregon	Pennsylvania	Rhode Island
South Carolina	South Dakota	Tennessee	Texas	Utah
Vermont	Virginia	Washington	West Virginia	Wisconsin
Wyoming	New York City	Puerto Rico	Virgin Islands

Public Health Agency of Canada:
The most up-to-date influenza information from Canada is available in Canada's weekly FluWatch report.

Public Health England:
The most up-to-date influenza information from the United Kingdom is available from Public Health England.

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.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component is available on the surveillance methods page.

Weekly US Influenza Surveillance Report: Key Updates for Week 7, ending February 21, 2026

https://www.cdc.gov/fluview/surveillance/2026-week-07.html

Seasonal influenza activity remains elevated nationally.

**sharon sanders** · March 6, 2026, 06:11 PM

Weekly US Influenza Surveillance Report: Key Updates for Week 8, ending February 28, 2026

Mar. 6, 2026
For Everyone

Key points

Seasonal influenza activity remains elevated nationally.
Summary

Viruses

Clinical Lab 15.8% (Trend )
positive for influenza
this week. Public Health Lab The most frequently reported
influenza viruses this week were influenza A(H3N2).

Illness

Outpatient Respiratory Illness 3.9% (Trend )
of visits to a health care provider this week were for respiratory illness
(above baseline). Activity Map 13 moderate jurisdictions 18 high or very high jurisdictions FluSurv-NET 76.0
cumulative hospitalization rate
per 100,000 population NHSN LTCF Respiratory
Data 15.9 (Trend ) weekly hospitalization rate
per 100,000 residents NHSN Hospital Respiratory Data 10,673 (Trend )
patients admitted to hospitals
with influenza this week. NCHS Mortality 0.7% (Trend ) of deaths attributed to influenza this week. Pediatric Deaths 11 influenza-associated deaths were
reported this week for a total of
90 deaths this season.
All data are preliminary and may change as more reports are received.

Directional arrows indicate changes between the current week and the previous week. Additional information on the arrows can be found at the bottom of this page.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component is available on the surveillance methods page.

Additional information on the current and previous influenza seasons for each surveillance component are available on FluView Interactive.

Key Points

Seasonal influenza activity remains elevated nationally. Influenza A activity is decreasing in most areas of the country while trends in influenza B activity vary by region.

Influenza A(H3N2) viruses are the most frequently reported influenza viruses so far this season.
- Among 1,507 influenza A(H3N2) viruses collected since September 28, 2025, that underwent additional genetic characterization at CDC, 92.6% belonged to subclade K.

The cumulative influenza-associated hospitalization rate overall in FluSurv-NET is the third highest since the 2010-2011 season. Children younger than 18 years have the second highest cumulative hospitalization rate for that age group since the 2010-2011 season.

Eleven influenza-associated pediatric deaths occurring during the 2025-2026 season were reported to CDC this week, bringing the season total to 90 reported influenza-associated pediatric deaths.
- Among children who were eligible for influenza vaccination and with known vaccination status, approximately 85% of reported pediatric deaths this season have occurred in children who were not fully vaccinated against influenza.

CDC's in-season severity assessment framework classified the season as moderate across all ages. CDC also assesses severity by three age groups: pediatric (0-17 years), adult (18-64 years), and older adults (≥65 years). At this point in the season, the pediatric age group is classified as having high severity, while both the adult and older adult age groups are classified as having moderate severity. These assessments are conducted each week during the season, and the season's severity assessment can change if activity should increase again.
CDC estimates that there have been at least 26,000,000 illnesses, 340,000 hospitalizations, and 21,000 deaths from flu so far this season.
Influenza (flu) vaccination has been shown to reduce the risk of flu and its potentially serious complications. There is still time to get vaccinated against flu this season. Approximately 135 million doses of influenza vaccine have been distributed in the United States this season.

There are prescription flu antiviral drugs that can treat flu illness; those should be started as early as possible and are especially important for patients at higher risk for flu-related complications.¹
Influenza viruses are among several viruses contributing to respiratory disease activity. CDC provides updated, integrated information about COVID-19, flu, and respiratory syncytial virus (RSV) activity on a weekly basis.
No new avian influenza A(H5) infections were reported to CDC this week. To date, person-to-person transmission of influenza A(H5) viruses has not been identified in the United States.

U.S. virologic surveillance

Nationally, the percentage of respiratory specimens testing positive for the influenza virus in clinical laboratories decreased (change > 0.5 percentage points) this week. The percent positivity for influenza A viruses decreased nationally and in most areas of the country. Nationally, the percent positivity for influenza B viruses remained stable, but trends vary by region. Across HHS regions, the overall percent of specimens testing positive for influenza increased in regions 3 and 8 and decreased in regions 1, 2, 4, 5, 6, 7, 9, and 10. Influenza A(H3N2) viruses were the most frequently reported influenza viruses by public health labs this week nationally, though trends in percent positivity and the distribution of circulating viruses varies by HHS region. For regional and state level data and age group distribution, please visit FluView Interactive. Viruses known to be associated with recent receipt of live attenuated influenza vaccine (LAIV) or found upon further testing to be a vaccine virus are not included, as they are not circulating influenza viruses.

Clinical Laboratories

The results of tests performed by clinical laboratories nationwide are summarized below. Data from clinical laboratories (the percentage of specimens tested that are positive for influenza virus) are used to monitor whether influenza activity is increasing or decreasing.

No. of specimens tested	78,361	1,769,647
No. of positive specimens (%)	12,374 (15.8%)	257,325 (14.5%)
*Positive specimens by type*
Influenza A	4,477 (36.2%)	211,650 (82.3%)
Influenza B	7,897 (63.8%)	45,675 (17.7%)

Public Health Laboratories

The results of tests performed by public health laboratories nationwide are summarized below. Data from public health laboratories are used to monitor the proportion of circulating influenza viruses that belong to each influenza subtype/lineage.

No. of specimens tested	1,259	69,433
No. of positive specimens	732	47,123
*Positive specimens by type/subtype*
Influenza A	510 (69.7%)	43,920 (93.2%)
Subtyping Performed	360 (70.6%)	36,108 (82.2%)
(H1N1)pdm09	73 (20.3%)	4,345 (12.0%)
H3N2	287 (79.7%)	31,761 (88.0%)
H3N2v^†	0	0
H5*	0	2 (<0.01%)
Subtyping not performed	150 (29.4%)	7,812 (17.8%)
Influenza B	222 (30.3%)	3,203 (6.8%)
Lineage testing performed	76 (34.2%)	1,089 (34.0%)
Yamagata lineage	0	0
Victoria lineage	76 (100%)	1,089 (100%)
Lineage not performed	146 (65.8%)	2,114 (66.0%)

_{*These data reflect specimens tested, and the number determined to be positive for influenza viruses at the public health labs (specimens tested is not the same as cases). The data do not reflect specimens tested only at CDC and could include more than one specimen tested per person. For more information on the number of people infected with A/H5 viruses, please visit the "How CDC is monitoring influenza data among people to better understand the current avian influenza A (H5N1) situation"}

_{^†When an influenza virus that normally circulates in swine (but not people) is detected in a person, it is called a "variant" influenza virus. Most human infections with variant influenza viruses occur following exposure to swine, but human-to-human transmission can occur. It is important to note that in most cases, variant influenza viruses have not shown the ability to spread easily and sustainably from human-to-human.}

_{*This graph reflects the number of specimens determined to be positive for influenza viruses at the public health lab (specimens tested is not the same as cases). It does not reflect specimens tested only at CDC and could include more than one specimen tested per person. Specimens tested as part of routine influenza surveillance as well as those tested as part of targeted testing for people exposed to avian influenza A(H5) are included.}

Additional virologic surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive: National, Regional, and State Data or Age Data

Novel Influenza A Virus Infections

No new confirmed human infections with avian influenza A(H5) virus were reported to CDC this week. To date, person-to-person transmission of avian influenza A(H5) virus (H5 bird flu) has not been identified in the United States.

The CSTE position statement, which includes updated case definitions for confirmed, probable, and suspected cases is available at http://www.cste.org/resource/resmgr/...nfluenza_A.pdf.

An up-to-date human case summary during the current outbreak by state and exposure source is available at www.cdc.gov/bird-flu/situation-summary/index.html.

Information about avian influenza is available at https://www.cdc.gov/flu/avianflu/index.htm. A(H5N1) virus interim recommendations for Prevention, Monitoring, and Public Health Investigations are available at https://www.cdc.gov/bird-flu/prevent...endations.html.

Additional information regarding human infections with novel influenza A viruses:

Surveillance Methods | FluView Interactive

Influenza Virus Characterization

CDC performs genetic and antigenic characterization of U.S. viruses submitted from state and local public health laboratories according to the Right Size Roadmap submission guidance. These data are used to compare how similar the currently circulating influenza viruses are relative to the reference viruses representing the current influenza vaccines. The data are also used to monitor evolutionary changes that continually occur in influenza viruses circulating in humans. CDC also tests susceptibility of circulating influenza viruses to antiviral medications including the neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) and the polymerase acidic protein (PA) endonuclease inhibitor baloxavir. The HA clade and subclades were assigned using Nextclade (https://clades.nextstrain.org).

CDC has genetically characterized 2,401 influenza viruses collected since September 28, 2025.

A/H1	547
		5a.2a	3 (0.5%)	C.1.9.3	3 (0.5%)
5a.2a.1	544 (99.5%)	D.1	211 (38.6%)
D.3.1.1	333 (60.9%)
A/H3	1,507
		2a.3a.1	1,507 (100%)	J.2	4 (0.3%)
J.2.2	5 (0.3%)
J.2.3	49 (3.3%)
J.2.4	53 (3.5%)
K	1,396 (92.6%)
B/Victoria	347
		3a.2	347 (100%)	C.3	12 (3.5%)
C.3.1	221 (63.7%)
C.5.1	26 (7.5%)
C.5.6	15 (4.3%)
C.5.6.1	50 (14.4%)
C.5.7	23 (6.6%)
B/Yamagata	0
		Y3	0	Y3	0

CDC antigenically characterizes influenza viruses by hemagglutination inhibition (HI) assay (H1N1pdm09, H3N2, and B/Victoria viruses) or neutralization-based HINT (H3N2 viruses) using antisera from ferrets infected with reference viruses representing the recommended cell-based or recombinant influenza vaccines for the 2025-2026 Northern Hemisphere season. Antigenic differences between viruses are determined by comparing how well the antibodies raised against the vaccine reference viruses recognize the circulating viruses, which were grown in cell culture. Ferret antisera are useful because antibodies raised against a particular virus can often recognize small changes in the surface proteins of other viruses. In HI assays, viruses are deemed antigenically similar when their HI titer differences are less than or equal to 4-fold. In HINT, viruses with similar antigenic properties have antibody neutralization titer differences of less than 8-fold. Circulating viruses with antigenic testing results that show titer differences greater than 4-fold by HI or equal to or greater than 8-fold by HINT) are considered “low reactors” or antigenically drifted compared to the vaccine virus. From the recent genetically characterized viruses, a subset is selected for antigenic characterization based on identified genetic changes in their surface proteins. The subset tested may not be proportional to the number of such viruses circulating in the United States.

Influenza A Viruses

A(H1N1)pdm09: 123 A(H1N1)pdm09 viruses collected since September 28, 2025, were antigenically characterized by HI, and 120 (97.6%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer) by ferret antisera to cell-grown A/Wisconsin/67/2022-like reference viruses representing the A(H1N1)pdm09 component for the cell- and recombinant-based influenza vaccines.
A(H3N2): 180 A(H3N2) viruses collected since September 28, 2025, were antigenically characterized by HI or HINT, and 4 (2.2%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer in HI or reacting at titers that were less than 8-fold of the homologous virus in HINT) by ferret antisera to cell-grown A/District Of Columbia/27/2023-like reference viruses representing the A(H3N2) component for the cell- and recombinant-based influenza vaccines.

Influenza B Viruses

B/Victoria: 77 influenza B/Victoria-lineage viruses collected since September 28, 2025, since were antigenically characterized by HI, and 26 (33.8%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer) by ferret antisera to cell-grown B/Austria/1359417/2021-like reference viruses representing the B/Victoria component for the cell- and recombinant-based influenza vaccines.
B/Yamagata: No influenza B/Yamagata-lineage viruses were available for antigenic characterization.

Assessment of Virus Susceptibility to Antiviral Medications

CDC assesses susceptibility of influenza viruses to the antiviral medications including the neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) and the PA endonuclease inhibitor baloxavir using next generation sequence analysis supplemented by laboratory assays. Information about antiviral susceptibility test methods can be found at U.S. Influenza Surveillance: Purpose and Methods | CDC.

Viruses collected in the U.S. since September 28, 2025, were tested for antiviral susceptibility as follows:

Neuraminidase Inhibitors	Oseltamivir	Viruses Tested	2,374	543	1,489	342
Reduced Inhibition	11 (0.5%)	11 (2.0%)	0	0
Highly Reduced Inhibition	4 (0.2%)	4 (0.7%)	0	0
Peramivir	Viruses Tested	2,374	543	1,489	342
Reduced Inhibition	2 (<0.1%)	0	0	2 (0.6%)
Highly Reduced Inhibition	4 (0.2%)	4 (0.7%)	0	0
Zanamivir	Viruses Tested	2,374	543	1,489	342
Reduced Inhibition	0	0	0	0
Highly Reduced Inhibition	0	0	0	0
PA Cap-Dependent Endonuclease Inhibitor	Baloxavir	Viruses Tested	2,321	522	1,460	339
Decreased Susceptibility	0	0	0	0

Four A(H1N1)pdm09 viruses had NA-H275Y amino acid substitution conferring highly reduced inhibition by oseltamivir and peramivir. Eleven A(H1N1)pdm09 viruses had amino acid substitutions NA-I223V and NA-S247N and showed reduced inhibition by oseltamivir. Two B viruses had amino acid substitution NA- M464T and showed reduced inhibition by peramivir.

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, use of these antivirals for treatment and prevention of influenza A virus infection is not recommended and data from adamantane resistance testing are not presented.

Outpatient and Emergency Department Illness Surveillance

Outpatient Respiratory Illness Visits

The U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) monitors outpatient visits for respiratory illness referred to as influenza-like illness [ILI (fever plus cough or sore throat)], not laboratory-confirmed influenza, and will therefore capture respiratory illness visits due to infection with any pathogen that can present with similar symptoms, including influenza virus, SARS-CoV-2, and RSV. It is important to evaluate syndromic surveillance data, including that from ILINet, in the context of other sources of surveillance data to obtain a complete and accurate picture of influenza, SARS-CoV-2, and other respiratory virus activity.

Nationally, during Week 8, 3.9% of patient visits reported through ILINet were due to respiratory illness that included fever plus a cough or sore throat, also referred to as ILI. This week's national percentage decreased (change of > 0.1 percentage points) compared to Week 7 but remains above the national baseline for the thirteenth consecutive week. ILI activity decreased in all ten HHS regions this week compared to Week 7. Regions 2 and 6 are below their respective baselines while all other regions (1, 3, 4, 5, 7, 8, 9, and 10) remain above their respective baselines. Multiple respiratory viruses are co-circulating, and the relative contribution of influenza virus infection to ILI varies by location.

_{*Some calendar years do not include an epidemiologic Week 53. In those years, the Week 53 value shown is the average between Week 52 and Week 1.}

_{**Effective October 3, 2021 (Week 40), the respiratory illness definition (fever plus cough or sore throat) no longer includes "without a known cause other than influenza."}

Outpatient Respiratory Illness Visits by Age Group

About 70% of ILINet participants provide both the number of patient visits for respiratory illness and the total number of patient visits for the week broken out by age group. Based on these data, the percentage of visits for respiratory illness decreased (change of > 0.1 percentage points) in all age groups (0-4 years, 5-24 years, 25-49 years, 50-64 years, and 65 years and older) this week compared to Week 7.

Outpatient Respiratory Illness Activity Map

Data collected in ILINet are used to produce a measure of ILI activity* by state/jurisdiction and Core Based Statistical Areas (CBSA).

Week 8 (Week ending Feb. 28, 2025)	Week 7 (Week ending Feb. 21, 2025)	Week 8 (Week ending Feb. 28, 2025)	Week 7 (Week ending Feb. 21, 2025)
Very High	4	8	11	26
High	14	16	91	140
Moderate	13	14	137	142
Low	12	7	211	195
Minimal	12	10	263	212
Insufficient Data	0	0	216	214

_{*Data collected in ILINet may disproportionally represent certain populations within a jurisdiction or CBSA, and therefore, may not accurately depict the full picture of influenza activity for the entire jurisdiction or CBSA. Differences in the data presented here by CDC and independently by some health departments likely represent differing levels of data completeness with data presented by the health department likely being the more complete.}

Additional information about medically attended visits for ILI for current and past seasons:

Surveillance Methods | FluView Interactive: National, Regional, and State Data or ILI Activity Map

National Syndromic Surveillance System (NSSP)

The national percentage of emergency department (ED) visits with a discharge diagnosis (DD) of influenza reported in NSSP was 2.5% during Week 8, which decreased (change of > 0.1 percentage points) slightly compared to the previous week. Nationally, the percentage of ED visits with a DD of influenza decreased among all age groups (0-4 years, 5-17 years, 18-64 years, and 65 years and older). The percentage of ED visits with a DD of influenza remained stable in HHS Region 3 and decreased (change of > 0.1 percentage points) this week compared to the previous week in all other HHS regions (1, 2, 4, 5, 6, 7, 8, 9, and 10). Age group trends varied by region. RegionNationalRegion 1Region 2Region 3Region 4Region 5Region 6Region 7Region 8Region 9Region 10
Season
2025-2026x
2024-2025x

Skip Over Chart Container
2.0%4.0%6.0%8.0%10.0%12.0%14.0%16.0%18.0%20.0%Perc ent of Emergency Department Visits for InfluenzaWeek 41 of 2024Week 45 of 2024Week 49 of 2024Week 1 of 2025Week 5 of 2025Week 9 of 2025Week 13 of 2025Week 17 of 2025Week 21 of 2025Week 25 of 2025Week 29 of 2025Week 33 of 2025Week 37 of 2025Week 41 of 2025Week 45 of 2025Week 49 of 2025Week 53 of 2025Week 4 of 2026Week 8 of 2026

Age Group

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Data Table Download Data (CSV)
Skipped data table.

Additional information about emergency department visits for flu for current and past seasons:‎‎‎

Surveillance Methods | Emergency Department Visits for COVID-19, flu, and RSV
Hospitalization surveillance

FluSurv-Net

Influenza-Associated Hospitalizations: The Influenza Hospitalization Surveillance Network (FluSurv-NET) conducts population-based surveillance for laboratory-confirmed influenza-related hospitalizations in select counties in 14 states and represents approximately 10% of the U.S. population. FluSurv-NET hospitalization data are preliminary. As data are received each week, prior case counts and rates are updated accordingly.

A total of 26,474 laboratory-confirmed influenza-associated hospitalizations were reported by FluSurv-NET sites between October 1, 2025, and February 28, 2026. The weekly hospitalization rate observed during Week 8 was 1.7 per 100,000 population, which decreased from last week. After accounting for reporting delays, the estimated rate during Week 8 likely ranges from 2.2 to 2.9. The cumulative hospitalization rate observed in Week 8 was 76.0 per 100,000 population, which is the third highest rate at this point in the season going back to the 2010-2011 season.

Among all hospitalizations, 24,909 (94.1%) were associated with influenza A virus, 1,412 (5.3%) with influenza B virus, 37 (0.1%) with influenza A virus and influenza B virus co-infection, and 116 (0.4%) with influenza virus for which the type was not determined. Among those with influenza A subtype information, 6,286 (89.2%) were A(H3N2), and 761 (10.8%) were A(H1N1)pdm09.

When examining rates by age, the highest rate of hospitalization per 100,000 population was among adults aged 65 and older (251.3), followed by children aged 0-4 years (79.1), adults aged 50-64 years (67.2), children aged 5-17 years (31.1), and adults aged 18-49 years (29.8). Among children, the peak weekly rate was the highest going back to the 2010-11 season in Week 52 (7.0). The cumulative rate for pediatric cases was the second highest since 2010-2011 (43.4). Among children, rates were highest among infants aged less than 1 year (125.5), followed by children aged 1-4 years (67.7).

When examining age-adjusted rates by race and ethnicity, the highest rate of hospitalization per 100,000 population was among non-Hispanic Black persons (130.9), followed by American Indian or Alaska Native persons (80.6), Hispanic persons (69.7), non-Hispanic White persons (65.5), and Asian and/or Pacific Islander persons (34.9).

Among 2,786 hospitalized adults with information on underlying medical conditions, 95.7% had at least one reported underlying medical condition; the most commonly reported were hypertension, cardiovascular disease, chronic metabolic disease, and chronic lung disease. Among 3,027 hospitalized women of childbearing age (15-49 years) with information on pregnancy status, 30.2% were pregnant. Among 1,099 hospitalized children with information on underlying medical conditions, 57.8% had at least one reported underlying medical condition; the most commonly reported was asthma, followed by neurologic disorder, and obesity.

Additional FluSurv-NET data are available on FluView Interactive including hospitalization rates for the current and past seasons by age, sex, and race/ethnicity (http://gis.cdc.gov/GRASP/Fluview/FluHospRates.html) as well as data on patient characteristics at: (http://gis.cdc.gov/grasp/fluview/FluHospChars.html.)

FluSurv-NET data are used to generate national estimates of the total numbers of influenza cases, medical visits, hospitalizations and deaths. This season, CDC is reporting preliminary cumulative in-season estimates, which are available at https://www.cdc.gov/flu-burden/php/data-vis/index.html.

_{**In this figure, weekly rates for all seasons prior to the 2025-26 season reflect end-of-season rates. For the 2025-26 season, rates for recent hospital admissions are subject to reporting delays and are shown as a dashed line for the current season. As hospitalization data are received each week, prior case counts and rates are updated accordingly.}

Additional FluSurv-NET hospitalization surveillance information for current and past seasons and additional age groups:

Surveillance Methods | FluView Interactive: Rates by Age, Sex, and Race/Ethnicity or Data on Patient Characteristics | RESP-NET Interactive

National Healthcare Safety Network (NHSN) Hospital Respiratory Data

Hospitals report to NHSN the weekly number of patients with laboratory-confirmed influenza who were admitted to the hospital. Nationally, during Week 8, 10,673 laboratory-confirmed influenza-associated hospitalizations were reported. This week's influenza-associated hospital admission rate (3.2 per 100,000 population) decreased (difference of > 0.2) compared to Week 7.

Laboratory-confirmed influenza-associated hospital admission rates per 100,000 population decreased in all HHS Regions (1-10). Region admission rates ranged from 1.4 (Region 1) to 4.3 (Region 7) during Week 8.

When examining rates by age for Week 8, all age groups decreased this week compared to Week 7. The highest hospital admission rate per 100,000 population was among those 65 years and older (8.9), followed by the 0-4 years age group (3.7), and the 50-64 years age group (2.5).

Additional NHSN Hospital Respiratory Data information:

Surveillance Methods | Additional Data | FluView Interactive

National Healthcare Safety Network (NHSN) Long-Term Care Respiratory Pathogens & Vaccination Module

Long-term care facilities (LTCFs [e.g., Nursing homes/skilled nursing facilities]) report respiratory pathogen (e.g., COVID-19, influenza, and RSV) data, including vaccination, cases, and hospitalizations among residents, to the NHSN Long-Term Care Respiratory Pathogens & Vaccination Module.

Nationally, during Week 8, the hospitalization rate for residents with a positive influenza test in the prior 10 days was 15.9 per 100,000 residents. The national rate and rates in HHS regions 1, 2, 4, 5 and 9 are trending downward. The rate is trending upward in Region 7. In HHS Regions 3, 6, 8 and 10, the rate does not show a consistent trend. View Larger Download National Healthcare Safety Network (NHSN) Long-Term Care Respiratory Pathogens & Vaccination Module
Mortality surveillance

National Center for Health Statistics (NCHS) Mortality Surveillance

Based on NCHS mortality surveillance data available on March 5, 2026, 0.7% of the deaths that occurred during the week ending February 28, 2026 (Week 8) were due to influenza. This percentage decreased (≥ 0.1 percentage point change) compared to Week 7. The data presented are preliminary and may change as more data are received and processed.

Additional pneumonia, influenza and COVID-19 mortality surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive Influenza-Associated Pediatric Mortality

Eleven influenza-associated pediatric deaths occurring during the 2025-2026 season were reported to CDC during Week 8. The deaths occurred between week 51 and week 8 (the weeks ending December 20, 2025, and February 28, 2026). Seven of the deaths were associated with influenza A viruses. Six of the influenza A viruses had subtyping performed and all were A(H3N2) viruses. Four deaths were associated with influenza B viruses. One of the influenza B viruses had lineage determined and it was a B/Victoria virus. Among children who were eligible for influenza vaccination and with known vaccination status, approximately 85% of reported pediatric deaths this season have occurred in children who were not fully vaccinated against influenza.

Additional pediatric mortality surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive
All data in this report are preliminary and may change as more reports are received.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component, is available on the surveillance methods page.

Additional information on the current and previous influenza seasons for each surveillance component are available on FluView Interactive.

Additional National and International Influenza Surveillance Information

Indicators Status by System

Increasing:
Decreasing:
Stable:

Clinical Labs: Up or down arrows indicate a change of greater than or equal to 0.5 percentage points in the percent of specimens positive for influenza compared to the previous week.
Outpatient Respiratory Illness (ILINet): Up or down arrows indicate a change of greater than 0.1 percentage points in the percent of visits due to respiratory illness (ILI) compared to the previous week.
NHSN Hospitalizations: Up or down arrows indicate change of greater than or equal to 0.2 in the rate of hospital admissions or greater than or equal to 691 patients admitted with laboratory-confirmed influenza compared to the previous week.
NHSN Long- Term Care (LTC): Up or down arrows indicate change of greater than or equal to 5% in hospitalization rates for residents in LTC facilities who were hospitalized with laboratory-confirmed influenza compared to the previous week.
NCHS Mortality: Up or down arrows indicate change of greater than 0.1 percentage points of the percent of deaths due to influenza compared to the previous week.

Additional surveillance information

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.

National Institute for Occupational Safety and Health: Monthly surveillance data on the prevalence of health-related workplace absenteeism among full-time workers in the United States are available from NIOSH.

U.S. State and local influenza surveillance: Select a jurisdiction below to access the latest local influenza information.

Alabama	Alaska	Arizona	Arkansas	California
Colorado	Connecticut	Delaware	District of Columbia	Florida
Georgia	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	Oklahoma	Oregon	Pennsylvania	Rhode Island
South Carolina	South Dakota	Tennessee	Texas	Utah
Vermont	Virginia	Washington	West Virginia	Wisconsin
Wyoming	New York City	Puerto Rico	Virgin Islands

Public Health Agency of Canada:
The most up-to-date influenza information from Canada is available in Canada's weekly FluWatch report.

Public Health England:
The most up-to-date influenza information from the United Kingdom is available from Public Health England.

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.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component is available on the surveillance methods page.

Weekly US Influenza Surveillance Report: Key Updates for Week 8, ending February 28, 2026

https://www.cdc.gov/fluview/surveillance/2026-week-08.html

Seasonal influenza activity remains elevated nationally.

**Commonground** · March 13, 2026, 03:11 PM

Weekly US Influenza Surveillance Report: Key Updates for Week 9, ending March 7, 2026
MAR. 13, 2026
KEY POINTS

Seasonal influenza activity remains elevated nationally.

Viruses
Clinical Lab 15.3% (Trend )
positive for influenza
this week. Public Health Lab The most frequently reported
influenza viruses this week were influenza A(H3N2) and influenza B. Illness

Outpatient Respiratory Illness 3.7% (Trend )
of visits to a health care provider this week were for respiratory illness
(above baseline). Activity Map 11 moderate jurisdictions 16 high or very high jurisdictions FluSurv-NET 78.2 per 100,000
cumulative hospitalization rate
per 100,000 population

NHSN LTCF Respiratory Data 13.6 (Trend )

weekly hospitalization rate per 100,000 residents

NHSN Hospital Respiratory Data 9,130 (Trend )
patients admitted to hospitals with influenza this week. NCHS Mortality 0.5% (Trend ) of deaths attributed to influenza this week. Pediatric Deaths 11 influenza-associated deaths were
reported this week for a total of
101 deaths this season.
All data are preliminary and may change as more reports are received.

Directional arrows indicate changes between the current week and the previous week. Additional information on the arrows can be found at the bottom of this page.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component is available on the surveillance methodspage.¹

Additional information on the current and previous influenza seasons for each surveillance component are available on FluView Interactive. Key

Points

Overall seasonal influenza activity remains elevated nationally but is decreasing in most areas of the country. Influenza A activity continues to decrease and trends in influenza B activity vary by HHS region.
Influenza A(H3N2) viruses are the most frequently reported influenza viruses overall this season.

- Among 1,667 influenza A(H3N2) viruses collected since September 28, 2025, that underwent additional genetic characterization at CDC, 92.6% belonged to subclade K.

The cumulative influenza-associated hospitalization rate overall in FluSurv-NET is the third highest since the 2010-2011 season. Children younger than 18 years have the second highest cumulative hospitalization rate for that age group since the 2010-2011 season.

Eleven influenza-associated pediatric deaths occurring during the 2025-2026 season were reported to CDC this week, bringing the season total to 101 reported influenza-associated pediatric deaths.
- Among children who were eligible for influenza vaccination and with known vaccination status, approximately 85% of reported pediatric deaths this season have occurred in children who were not fully vaccinated against influenza.

CDC's in-season severity assessment framework classified the season as moderate across all ages. CDC also assesses severity by three age groups: pediatric (0-17 years), adult (18-64 years), and older adults (≥65 years). At this point in the season, the pediatric age group is classified as having high severity, while both the adult and older adult age groups are classified as having moderate severity. These assessments are conducted each week during the season, and the season's severity assessment can change if activity should increase again.
CDC estimates that there have been at least 27,000,000 illnesses, 350,000 hospitalizations, and 22,000 deaths from flu so far this season.
Influenza (flu) vaccination has been shown to reduce the risk of flu and its potentially serious complications. There is still time to get vaccinated against flu this season. Approximately 135 million doses of influenza vaccine have been distributed in the United States this season.

There are prescription flu antiviral drugs that can treat flu illness; those should be started as early as possible and are especially important for patients at higher risk for flu-related complications.
Influenza viruses are among several viruses contributing to respiratory disease activity. CDC provides updated, integrated information about COVID-19, flu, and respiratory syncytial virus (RSV) activity on a weekly basis.
No new avian influenza A(H5) infections were reported to CDC this week. To date, person-to-person transmission of influenza A(H5) viruses has not been identified in the United States.

U.S. virologic surveillance
Nationally, the percentage of respiratory specimens testing positive for the influenza virus in clinical laboratories decreased (change > 0.5 percentage points) this week. The percentage of specimens testing positive for influenza increased in regions 4 and 7, primarily driven by increases in influenza B, decreased in regions 5, 6, 8, and 9, and remained stable in regions 1, 2, 3, and 10. The percent positivity for influenza A viruses decreased in most areas of the country, while influenza B percent positivity increased overall, with variation in trends regionally. Influenza A(H3N2) and influenza B viruses were the most frequently reported influenza viruses by public health labs this week nationally, with distribution of circulating viruses differing by HHS region. For regional and state level data and age group distribution, please visit FluView Interactive. Viruses known to be associated with recent receipt of live attenuated influenza vaccine (LAIV) or found upon further testing to be a vaccine virus are not included, as they are not circulating influenza viruses.

Continued: https://www.cdc.gov/fluview/surveill...6-week-09.html

**sharon sanders** · March 20, 2026, 07:15 AM

Weekly US Influenza Surveillance Report: Key Updates for Week 9, ending March 7, 2026

Mar. 13, 2026
For Everyone

Key points

Seasonal influenza activity remains elevated nationally.
Summary

Viruses

Clinical Lab 15.3% (Trend )
positive for influenza
this week. Public Health Lab The most frequently reported
influenza viruses this week were influenza A(H3N2) and influenza B.

Illness

Outpatient Respiratory Illness 3.7% (Trend )
of visits to a health care provider this week were for respiratory illness
(above baseline). Activity Map 11 moderate jurisdictions 16 high or very high jurisdictions FluSurv-NET 78.2 per 100,000
cumulative hospitalization rate
per 100,000 population NHSN LTCF Respiratory
Data 13.6 (Trend ) weekly hospitalization rate
per 100,000 residents NHSN Hospital Respiratory Data 9,130 (Trend )
patients admitted to hospitals
with influenza this week. NCHS Mortality 0.5% (Trend ) of deaths attributed to influenza this week. Pediatric Deaths 11 influenza-associated deaths were
reported this week for a total of
101 deaths this season.
All data are preliminary and may change as more reports are received.

Directional arrows indicate changes between the current week and the previous week. Additional information on the arrows can be found at the bottom of this page.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component is available on the surveillance methods page.¹

Additional information on the current and previous influenza seasons for each surveillance component are available on FluView Interactive.

Key Points

Overall seasonal influenza activity remains elevated nationally but is decreasing in most areas of the country. Influenza A activity continues to decrease and trends in influenza B activity vary by HHS region.
Influenza A(H3N2) viruses are the most frequently reported influenza viruses overall this season.

- Among 1,667 influenza A(H3N2) viruses collected since September 28, 2025, that underwent additional genetic characterization at CDC, 92.6% belonged to subclade K.

The cumulative influenza-associated hospitalization rate overall in FluSurv-NET is the third highest since the 2010-2011 season. Children younger than 18 years have the second highest cumulative hospitalization rate for that age group since the 2010-2011 season.

Eleven influenza-associated pediatric deaths occurring during the 2025-2026 season were reported to CDC this week, bringing the season total to 101 reported influenza-associated pediatric deaths.
- Among children who were eligible for influenza vaccination and with known vaccination status, approximately 85% of reported pediatric deaths this season have occurred in children who were not fully vaccinated against influenza.

CDC's in-season severity assessment framework classified the season as moderate across all ages. CDC also assesses severity by three age groups: pediatric (0-17 years), adult (18-64 years), and older adults (≥65 years). At this point in the season, the pediatric age group is classified as having high severity, while both the adult and older adult age groups are classified as having moderate severity. These assessments are conducted each week during the season, and the season's severity assessment can change if activity should increase again.
CDC estimates that there have been at least 27,000,000 illnesses, 350,000 hospitalizations, and 22,000 deaths from flu so far this season.
Influenza (flu) vaccination has been shown to reduce the risk of flu and its potentially serious complications. There is still time to get vaccinated against flu this season. Approximately 135 million doses of influenza vaccine have been distributed in the United States this season.

There are prescription flu antiviral drugs that can treat flu illness; those should be started as early as possible and are especially important for patients at higher risk for flu-related complications.
Influenza viruses are among several viruses contributing to respiratory disease activity. CDC provides updated, integrated information about COVID-19, flu, and respiratory syncytial virus (RSV) activity on a weekly basis.
No new avian influenza A(H5) infections were reported to CDC this week. To date, person-to-person transmission of influenza A(H5) viruses has not been identified in the United States.

U.S. virologic surveillance

Nationally, the percentage of respiratory specimens testing positive for the influenza virus in clinical laboratories decreased (change > 0.5 percentage points) this week. The percentage of specimens testing positive for influenza increased in regions 4 and 7, primarily driven by increases in influenza B, decreased in regions 5, 6, 8, and 9, and remained stable in regions 1, 2, 3, and 10. The percent positivity for influenza A viruses decreased in most areas of the country, while influenza B percent positivity increased overall, with variation in trends regionally. Influenza A(H3N2) and influenza B viruses were the most frequently reported influenza viruses by public health labs this week nationally, with distribution of circulating viruses differing by HHS region. For regional and state level data and age group distribution, please visit FluView Interactive. Viruses known to be associated with recent receipt of live attenuated influenza vaccine (LAIV) or found upon further testing to be a vaccine virus are not included, as they are not circulating influenza viruses.

Clinical Laboratories

The results of tests performed by clinical laboratories nationwide are summarized below. Data from clinical laboratories (the percentage of specimens tested that are positive for influenza virus) are used to monitor whether influenza activity is increasing or decreasing.

No. of specimens tested	73,380	1,865,885
No. of positive specimens (%)	11,252 (15.3%)	271,929 (14.6%)
*Positive specimens by type*
Influenza A	3,065 (27.2%)	216,316 (79.5%)
Influenza B	8,187 (72.8%)	55,613 (20.5%)

Public Health Laboratories

The results of tests performed by public health laboratories nationwide are summarized below. Data from public health laboratories are used to monitor the proportion of circulating influenza viruses that belong to each influenza subtype/lineage.

No. of specimens tested	1,319	75,728
No. of positive specimens	798	51,494
*Positive specimens by type/subtype*
Influenza A	478 (59.9%)	47,355 (92.0%)
Subtyping Performed	364 (76.2%)	38,725 (81.8%)
(H1N1)pdm09	71 (19.5%)	4,665 (12.0%)
H3N2	293 (80.5%)	34,058 (87.9%)
H3N2v	0	0
H5	0	2 (<0.1%)
Subtyping not performed	114 (23.8%)	8,630 (18.2%)
Influenza B	320 (40.1%)	4,139 (8.0%)
Lineage testing performed	77 (24.1%)	1,386 (33.5%)
Yamagata lineage	0	0
Victoria lineage	77 (100%)	1,386 (100%)
Lineage not performed	243 (75.9%)	2,753 (66.5%)

_{*These data reflect specimens tested, and the number determined to be positive for influenza viruses at the public health labs (specimens tested is not the same as cases). The data do not reflect specimens tested only at CDC and could include more than one specimen tested per person. For more information on the number of people infected with A/H5 viruses, please visit the "How CDC is monitoring influenza data among people to better understand the current avian influenza A (H5N1) situation"}

_{^†When an influenza virus that normally circulates in swine (but not people) is detected in a person, it is called a "variant" influenza virus. Most human infections with variant influenza viruses occur following exposure to swine, but human-to-human transmission can occur. It is important to note that in most cases, variant influenza viruses have not shown the ability to spread easily and sustainably from human-to-human.}

_{*This graph reflects the number of specimens determined to be positive for influenza viruses at the public health lab (specimens tested is not the same as cases). It does not reflect specimens tested only at CDC and could include more than one specimen tested per person. Specimens tested as part of routine influenza surveillance as well as those tested as part of targeted testing for people exposed to avian influenza A(H5) are included.}

Additional virologic surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive: National, Regional, and State Data or Age Data

Novel Influenza A Virus Infections

No new confirmed human infections with avian influenza A(H5) virus were reported to CDC this week. To date, person-to-person transmission of avian influenza A(H5) virus (H5 bird flu) has not been identified in the United States.

The CSTE position statement, which includes updated case definitions for confirmed, probable, and suspected cases is available at http://www.cste.org/resource/resmgr/...nfluenza_A.pdf.

An up-to-date human case summary during the current outbreak by state and exposure source is available at www.cdc.gov/bird-flu/situation-summary/index.html.

Information about avian influenza is available at https://www.cdc.gov/bird-flu/. A(H5N1) virus interim recommendations for Prevention, Monitoring, and Public Health Investigations are available at https://www.cdc.gov/bird-flu/prevent...endations.html.

Additional information regarding human infections with novel influenza A viruses:

Surveillance Methods | FluView Interactive

Influenza Virus Characterization

CDC performs genetic and antigenic characterization of U.S. viruses submitted from state and local public health laboratories according to the Right Size Roadmap submission guidance. These data are used to compare how similar the currently circulating influenza viruses are relative to the reference viruses representing the current influenza vaccines. The data are also used to monitor evolutionary changes that continually occur in influenza viruses circulating in humans. CDC also tests susceptibility of circulating influenza viruses to antiviral medications including the neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) and the polymerase acidic protein (PA) endonuclease inhibitor baloxavir. The HA clade and subclades were assigned using Nextclade (https://clades.nextstrain.org).

CDC has genetically characterized 2,696 influenza viruses collected since September 28, 2025.

A/H1	604
		5a.2a	3 (0.5%)	C.1.9.3	3 (0.5%)
5a.2a.1	601 (99.5%)	D.3.1	222 (36.8%)
D.3.1.1	379 (62.7%)
A/H3	1,667
		2a.3a.1	1,667 (100%)	J.2	4 (0.2%)
J.2.2	5 (0.3%)
J.2.3	56 (3.4%)
J.2.4	58 (3.5%)
K	1,544 (92.6%)
B/Victoria	425
		3a.2	425 (100%)	C.3	14 (3.3%)
C.3.1	269 (63.3%)
C.5.1	32 (7.5%)
C.5.6	16 (3.8%)
C.5.6.1	67 (15.8%)
C.5.7	27 (6.4%)
B/Yamagata	0
		Y3	0	Y3	0

CDC antigenically characterizes influenza viruses by hemagglutination inhibition (HI) assay (H1N1pdm09, H3N2, and B/Victoria viruses) or neutralization-based HINT (H3N2 viruses) using antisera from ferrets infected with reference viruses representing the recommended cell-based or recombinant influenza vaccines for the 2025-2026 Northern Hemisphere season. Antigenic differences between viruses are determined by comparing how well the antibodies raised against the vaccine reference viruses recognize the circulating viruses, which were grown in cell culture. Ferret antisera are useful because antibodies raised against a particular virus can often recognize small changes in the surface proteins of other viruses. In HI assays, viruses are deemed antigenically similar when their HI titer differences are less than or equal to 4-fold. In HINT, viruses with similar antigenic properties have antibody neutralization titer differences of less than 8-fold. Circulating viruses with antigenic testing results that show titer differences greater than 4-fold by HI or equal to or greater than 8-fold by HINT) are considered "low reactors" or antigenically drifted compared to the vaccine virus. From the recent genetically characterized viruses, a subset is selected for antigenic characterization based on identified genetic changes in their surface proteins. The subset tested may not be proportional to the number of such viruses circulating in the United States.

Influenza A Viruses

A(H1N1)pdm09: 150 A(H1N1)pdm09 viruses collected since September 28, 2025, were antigenically characterized by HI, and 147 (98.0%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer) by ferret antisera to cell-grown A/Wisconsin/67/2022-like reference viruses representing the A(H1N1)pdm09 component for the cell- and recombinant-based influenza vaccines.
A(H3N2): 180 A(H3N2) viruses collected since September 28, 2025, were antigenically characterized by HI or HINT, and 4 (2.2%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer in HI or reacting at titers that were less than 8-fold of the homologous virus in HINT) by ferret antisera to cell-grown A/District Of Columbia/27/2023-like reference viruses representing the A(H3N2) component for the cell- and recombinant-based influenza vaccines.

Influenza B Viruses

B/Victoria: 77 influenza B/Victoria-lineage viruses collected since September 28, 2025, since were antigenically characterized by HI, and 26 (33.8%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer) by ferret antisera to cell-grown B/Austria/1359417/2021-like reference viruses representing the B/Victoria component for the cell- and recombinant-based influenza vaccines.
B/Yamagata: No influenza B/Yamagata-lineage viruses were available for antigenic characterization.

Assessment of Virus Susceptibility to Antiviral Medications

CDC assesses susceptibility of influenza viruses to the antiviral medications including the neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) and the PA endonuclease inhibitor baloxavir using next generation sequence analysis supplemented by laboratory assays. Information about antiviral susceptibility test methods can be found at U.S. Influenza Surveillance: Purpose and Methods | CDC.

Viruses collected in the U.S. since September 28, 2025, were tested for antiviral susceptibility as follows:

Neuraminidase Inhibitors	Oseltamivir	Viruses Tested	2665	599	1646	420
Reduced Inhibition	12 (0.5%)	12 (2.0%)	0	0
Highly Reduced Inhibition	4 (0.2%)	4 (0.7%)	0	0
Peramivir	Viruses Tested	2665	599	1646	420
Reduced Inhibition	2 (0.1%)	0	0	2 (0.5%)
Highly Reduced Inhibition	4 (0.2%)	4 (0.7%)	0	0
Zanamivir	Viruses Tested	2665	599	1646	420
Reduced Inhibition	0	0	0	0
Highly Reduced Inhibition	0	0	0	0
PA Cap-Dependent Endonuclease Inhibitor	Baloxavir	Viruses Tested	2603	576	1612	415
Decreased Susceptibility	0	0	0	0

Four A(H1N1)pdm09 viruses had NA-H275Y amino acid substitution conferring highly reduced inhibition by oseltamivir and peramivir. Twelve A(H1N1)pdm09 viruses had amino acid substitutions NA-I223V and NA-S247N and showed reduced inhibition by oseltamivir. Two B viruses had amino acid substitution NA- M464T and showed reduced inhibition by peramivir.

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, use of these antivirals for treatment and prevention of influenza A virus infection is not recommended and data from adamantane resistance testing are not presented.

Outpatient and Emergency Department Illness Surveillance

Outpatient Respiratory Illness Visits

The U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) monitors outpatient visits for respiratory illness referred to as influenza-like illness [ILI (fever plus cough or sore throat)], not laboratory-confirmed influenza, and will therefore capture respiratory illness visits due to infection with any pathogen that can present with similar symptoms, including influenza virus, SARS-CoV-2, and RSV. It is important to evaluate syndromic surveillance data, including that from ILINet, in the context of other sources of surveillance data to obtain a complete and accurate picture of influenza, SARS-CoV-2, and other respiratory virus activity.

Nationally, during Week 9, 3.7% of patient visits reported through ILINet were due to respiratory illness that included fever plus a cough or sore throat, also referred to as ILI. This week's national percentage decreased slightly (change of > 0.1 percentage points) compared to Week 8 but remains above the national baseline for the fourteenth consecutive week. ILI activity decreased in HHS regions 1, 4, 6, 9, and 10 and remained stable in all other regions (2, 3, 5, 7, and 8) compared to Week 8. Regions 2 and 6 are below their respective baselines while all other regions (1, 3, 4, 5, 7, 8, 9, and 10) remain above their respective baselines. Multiple respiratory viruses are co-circulating, and the relative contribution of influenza virus infection to ILI varies by location.

Outpatient Respiratory Illness Visits by Age Group

About 70% of ILINet participants provide both the number of patient visits for respiratory illness and the total number of patient visits for the week broken out by age group. Based on these data, the percentage of visits for respiratory illness decreased (change of > 0.1 percentage points) in the 25-49 years, 50-64 years, and 65 years and older age groups and remained stable in the 0-4 years and 5-24 years age groups this week compared to Week 8.

Outpatient Respiratory Illness Activity Map

Data collected in ILINet are used to produce a measure of ILI activity* by state/jurisdiction and Core Based Statistical Areas (CBSA).

Week 9 (Week ending Mar. 7, 2025)	Week 8 (Week ending Feb. 28, 2025)	Week 9 (Week ending Mar. 7, 2025)	Week 8 (Week ending Feb. 28, 2025)
Very High	1	4	11	11
High	15	14	86	93
Moderate	11	13	127	136
Low	13	11	214	216
Minimal	15	13	266	259
Insufficient Data	0	0	225	214

_{*Data collected in ILINet may disproportionally represent certain populations within a jurisdiction or CBSA, and therefore, may not accurately depict the full picture of influenza activity for the entire jurisdiction or CBSA. Differences in the data presented here by CDC and independently by some health departments likely represent differing levels of data completeness with data presented by the health department likely being the more complete.}

Additional information about medically attended visits for ILI for current and past seasons:

Surveillance Methods | FluView Interactive: National, Regional, and State Data or ILI Activity Map

National Syndromic Surveillance System (NSSP)

The national percentage of emergency department (ED) visits with a discharge diagnosis (DD) of influenza reported in NSSP was 2.4% during Week 9, which decreased (change of > 0.1 percentage points) slightly compared to the previous week. Nationally, the percentage of ED visits with a DD of influenza decreased among the 0-4 years,18-64 years, and 65 years and older age groups; the 5-17 years age group remained stable compared to the previous week. The percentage of ED visits with a DD of influenza remained stable in HHS Regions 2, 3, 4, 5, and 8 and decreased (change of > 0.1 percentage points) this week compared to the previous week in all other HHS regions (1, 6, 7, 9, and 10). Age group trends varied by region. RegionNationalRegion 1Region 2Region 3Region 4Region 5Region 6Region 7Region 8Region 9Region 10
Season
2025-2026x
2024-2025x

Skip Over Chart Container
2.0%4.0%6.0%8.0%10.0%12.0%14.0%16.0%18.0%20.0%Perc ent of Emergency Department Visits for InfluenzaWeek 42 of 2024Week 46 of 2024Week 50 of 2024Week 2 of 2025Week 6 of 2025Week 10 of 2025Week 14 of 2025Week 18 of 2025Week 22 of 2025Week 26 of 2025Week 30 of 2025Week 34 of 2025Week 38 of 2025Week 42 of 2025Week 46 of 2025Week 50 of 2025Week 1 of 2026Week 5 of 2026Week 9 of 2026

Age Group

Skip Data Table
Data Table Download Data (CSV)
Skipped data table.

Additional information about emergency department visits for flu for current and past seasons:‎‎‎

Surveillance Methods | Emergency Department Visits for COVID-19, flu, and RSV
Hospitalization surveillance

FluSurv-Net

Influenza-Associated Hospitalizations: The Influenza Hospitalization Surveillance Network (FluSurv-NET) conducts population-based surveillance for laboratory-confirmed influenza-related hospitalizations in select counties in 14 states and represents approximately 10% of the U.S. population. FluSurv-NET hospitalization data are preliminary. As data are received each week, prior case counts and rates are updated accordingly.

A total of 27,242 laboratory-confirmed influenza-associated hospitalizations were reported by FluSurv-NET sites between October 1, 2025, and March 7, 2026. The weekly hospitalization rate observed during Week 9 was 1.7 per 100,000 population, which decreased from last week. After accounting for reporting delays, the estimated rate during Week 9 likely ranges from 1.9 to 2.5. The cumulative hospitalization rate observed in Week 9 was 78.2 per 100,000 population, which is the third highest cumulative rate thus far since the 2010-11 season.

Among all hospitalizations, 25,369 (93.1%) were associated with influenza A virus, 1722 (6.3%) with influenza B virus, 37 (0.1%) with influenza A virus and influenza B virus co-infection, and 114 (0.4%) with influenza virus for which the type was not determined. Among those with influenza A subtype information, 6,456 (88.9%) were A(H3N2), and 803 (11.1%) were A(H1N1)pdm09.

When examining rates by age, the highest rate of hospitalization per 100,000 population was among adults aged 65 and older (256.9), followed by children aged 0-4 years (82.4), adults aged 50-64 years (69.2), children aged 5-17 years (33), and adults aged 18-49 years (30.8).

Among children, the peak weekly rate was the highest going back to the 2010-2011 season in Week 52 (7.0). The cumulative rate for pediatric cases was the second highest since 2010-2011 (45.6). Among children, rates were highest among infants aged less than 1 year (129.3), followed by children aged 1-4 years (70.9).

When examining age-adjusted rates by race and ethnicity, the highest rate of hospitalization per 100,000 population was among non-Hispanic Black persons (133.8), followed by American Indian or Alaska Native persons (81.5), Hispanic persons (71.7), non-Hispanic White persons (67.7), and Asian and/or Pacific Islander persons (35.9).

Among 2,944 hospitalized adults with information on underlying medical conditions, 95.7% had at least one reported underlying medical condition; the most commonly reported were hypertension, cardiovascular disease, chronic metabolic disease, and chronic lung disease. Among 3,138 hospitalized women of childbearing age (15-49 years) with information on pregnancy status, 29.6% were pregnant. Among 1,186 hospitalized children with information on underlying medical conditions, 57.3% had at least one reported underlying medical condition; the most commonly reported was asthma, followed by neurologic disorder, and obesity.

Additional FluSurv-NET data are available on FluView Interactive including hospitalization rates for the current and past seasons by age, sex, and race/ethnicity (http://gis.cdc.gov/GRASP/Fluview/FluHospRates.html) as well as data on patient characteristics at: (http://gis.cdc.gov/grasp/fluview/FluHospChars.html.)

FluSurv-NET data are used to generate national estimates of the total numbers of influenza cases, medical visits, hospitalizations and deaths. This season, CDC is reporting preliminary cumulative in-season estimates, which are available at Estimated US Flu Disease Burden | Flu Burden | CDC

_{**In this figure, weekly rates for all seasons prior to the 2025-26 season reflect end-of-season rates. For the 2025-26 season, rates for recent hospital admissions are subject to reporting delays and are shown as a dashed line for the current season. As hospitalization data are received each week, prior case counts and rates are updated accordingly.}

Additional FluSurv-NET hospitalization surveillance information for current and past seasons and additional age groups:

Surveillance Methods | FluView Interactive: Rates by Age, Sex, and Race/Ethnicity or Data on Patient Characteristics | RESP-NET Interactive

National Healthcare Safety Network (NHSN) Hospital Respiratory Data

Hospitals report to NHSN the weekly number of patients with laboratory-confirmed influenza who were admitted to the hospital. Nationally, during Week 9, 9,130 laboratory-confirmed influenza-associated hospitalizations were reported. This week's influenza-associated hospital admission rate (2.7 per 100,000 population) decreased (difference of > 0.2) compared to Week 8.

Laboratory-confirmed influenza-associated hospital admission rates per 100,000 population decreased in HHS Regions 2, 4, 6, 7, 8, 9, and 10 and remained stable in HHS Regions 1, 3, and 5. Region admission rates ranged from 1.2 (Region 1) to 4.0 (Region 3) during Week 9.

When examining rates by age for Week 9, the 5-17 years age group remained stable compared to the previous week, while the remaining age groups (0-4 years, 18-49 years, 50-64 years, and 65 years and older) decreased. The highest hospital admission rate per 100,000 population was among those 65 years and older (7.2), followed by the 0-4 years age group (3.3), and the 50-64 years age group (2.2).

Additional NHSN Hospital Respiratory Data information:

Surveillance Methods | Additional Data | FluView Interactive

National Healthcare Safety Network (NHSN) Long-Term Care Respiratory Pathogens & Vaccination Module

Long-term care facilities (LTCFs [e.g., Nursing homes/skilled nursing facilities]) report respiratory pathogen (e.g., COVID-19, influenza, and RSV) data, including vaccination, cases, and hospitalizations among residents, to the NHSN Long-Term Care Respiratory Pathogens & Vaccination Module.

Nationally, during Week 9, the hospitalization rate for residents with a positive influenza test in the prior 10 days was 13.6 per 100,000 residents. The national rate and rates in HHS regions 1, 2, 4, 5, 6, and 8 are trending downward. In HHS Regions 3, 7, 9, and 10, the rate does not show a consistent trend. View Larger Download National Healthcare Safety Network (NHSN) Long-Term Care Respiratory Pathogens & Vaccination Module
Mortality surveillance

National Center for Health Statistics (NCHS) Mortality Surveillance

Based on NCHS mortality surveillance data available on March 12, 2026, 0.5% of the deaths that occurred during the week ending March 7, 2026 (Week 9) were due to influenza. This percentage decreased (≥ 0.1 percentage point change) compared to Week 8. The data presented are preliminary and may change as more data are received and processed.

Additional pneumonia, influenza and COVID-19 mortality surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive

Influenza-Associated Pediatric Mortality

Eleven influenza-associated pediatric deaths occurring during the 2025-2026 season were reported to CDC during Week 9. The deaths occurred between Week 52 and Week 9 (the weeks ending December 27, 2025, and March 7, 2026). Seven deaths were associated with influenza A viruses. Five of the influenza A viruses had subtyping performed; two were A(H1N1) viruses and three were A(H3N2) viruses. Four deaths were associated with influenza B viruses with no lineage determined. Among children who were eligible for influenza vaccination and with known vaccination status, approximately 85% of reported pediatric deaths this season have occurred in children who were not fully vaccinated against influenza.

Additional pediatric mortality surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive
All data in this report are preliminary and may change as more reports are received.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component, is available on the surveillance methods page.¹

Additional information on the current and previous influenza seasons for each surveillance component are available on FluView Interactive.

Additional National and International Influenza Surveillance Information

Indicators Status by System

Increasing:
Decreasing:
Stable:

Clinical Labs: Up or down arrows indicate a change of greater than or equal to 0.5 percentage points in the percent of specimens positive for influenza compared to the previous week.
Outpatient Respiratory Illness (ILINet): Up or down arrows indicate a change of greater than 0.1 percentage points in the percent of visits due to respiratory illness (ILI) compared to the previous week.
NHSN Hospitalizations: Up or down arrows indicate change of greater than or equal to 0.2 in the rate of hospital admissions or greater than or equal to 691 patients admitted with laboratory-confirmed influenza compared to the previous week.
NHSN Long- Term Care (LTC): Up or down arrows indicate change of greater than or equal to 5% in hospitalization rates for residents in LTC facilities who were hospitalized with laboratory-confirmed influenza compared to the previous week.
NCHS Mortality: Up or down arrows indicate change of greater than 0.1 percentage points of the percent of deaths due to influenza compared to the previous week.

Additional surveillance information

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.

National Institute for Occupational Safety and Health: Monthly surveillance data on the prevalence of health-related workplace absenteeism among full-time workers in the United States are available from NIOSH.

U.S. State and local influenza surveillance: Select a jurisdiction below to access the latest local influenza information.

Alabama	Alaska	Arizona	Arkansas	California
Colorado	Connecticut	Delaware	District of Columbia	Florida
Georgia	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	Oklahoma	Oregon	Pennsylvania	Rhode Island
South Carolina	South Dakota	Tennessee	Texas	Utah
Vermont	Virginia	Washington	West Virginia	Wisconsin
Wyoming	New York City	Puerto Rico	Virgin Islands

Public Health Agency of Canada:
The most up-to-date influenza information from Canada is available in Canada's weekly FluWatch report.

Public Health England:
The most up-to-date influenza information from the United Kingdom is available from Public Health England.

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.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component is available on the surveillance methods page.

Weekly US Influenza Surveillance Report: Key Updates for Week 9, ending March 7, 2026

https://www.cdc.gov/fluview/surveillance/2026-week-09.html

Seasonal influenza activity is low.

**sharon sanders** · March 21, 2026, 12:21 PM

Weekly US Influenza Surveillance Report: Key Updates for Week 10, ending March 14, 2026

Mar. 20, 2026
For Everyone

Key points

Seasonal influenza activity remains elevated nationally but is decreasing in most areas of the country.
Summary

Viruses

Clinical Lab 12.7% (Trend )
positive for influenza
this week. Public Health Lab The most frequently reported
influenza viruses this week were influenza A(H3N2) and influenza B.

Illness

Outpatient Respiratory Illness 3.3% (Trend )
of visits to a health care provider this week were for respiratory illness
(above baseline). Activity Map 10 moderate jurisdictions 10 high jurisdictions FluSurv-NET 80.0
cumulative hospitalization rate
per 100,000 population NHSN LTCF Respiratory
Data 8.6 (Trend ) weekly hospitalization rate
per 100,000 residents NHSN Hospital Respiratory Data 7,348 (Trend )
patients admitted to hospitals
with influenza this week. NCHS Mortality 0.5% (Trend ) of deaths attributed to influenza this week. Pediatric Deaths 14 influenza-associated deaths were
reported this week for a total of
115 deaths this season.
All data are preliminary and may change as more reports are received.

Directional arrows indicate changes between the current week and the previous week. Additional information on the arrows can be found at the bottom of this page.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component is available on the surveillance methods page.

Additional information on the current and previous influenza seasons for each surveillance component are available on FluView Interactive.

Key Points

Overall seasonal influenza activity remains elevated nationally but is decreasing in most areas of the country. Influenza A activity continues to decrease and trends in influenza B activity vary by HHS region.
Influenza A(H3N2) viruses are the most frequently reported influenza viruses overall this season.

- Among 1,754 influenza A(H3N2) viruses collected since September 28, 2025, that underwent additional genetic characterization at CDC, 92.7% belonged to subclade K.

The cumulative influenza-associated hospitalization rate overall in FluSurv-NET is the third highest since the 2010-2011 season. Children younger than 18 years have the second highest cumulative hospitalization rate for that age group since the 2010-2011 season.

Fourteen influenza-associated pediatric deaths occurring during the 2025-2026 season were reported to CDC this week, bringing the season total to 115 reported influenza-associated pediatric deaths.
- Among children who were eligible for influenza vaccination and with known vaccination status, approximately 85% of reported pediatric deaths this season have occurred in children who were not fully vaccinated against influenza.

CDC's in-season severity assessment framework classified the season as moderate across all ages. CDC also assesses severity by three age groups: pediatric (0-17 years), adult (18-64 years), and older adults (≥65 years). At this point in the season, the pediatric age group is classified as having high severity, while both the adult and older adult age groups are classified as having moderate severity. These assessments are conducted each week during the season, and the season's severity assessment can change if activity should increase again.
CDC estimates that there have been at least 28 million illnesses, 360,000 hospitalizations, and 22,000 deaths from flu so far this season
Influenza (flu) vaccination has been shown to reduce the risk of flu and its potentially serious complications.There is still time to get vaccinated against flu this season. Approximately 135 million doses of influenza vaccine have been distributed in the United States this season.

There are prescription flu antiviral drugs that can treat flu illness; those should be started as early as possible and are especially important for patients at higher risk for flu-related complications.¹
Influenza viruses are among several viruses contributing to respiratory disease activity. CDC provides updated, integrated information about COVID-19, flu, and respiratory syncytial virus (RSV) activity on a weekly basis.
No new avian influenza A(H5) infections were reported to CDC this week. To date, person-to-person transmission of influenza A(H5) viruses has not been identified in the United States.

U.S. virologic surveillance

Nationally, the percentage of respiratory specimens testing positive for the influenza virus in clinical laboratories decreased (change > 0.5 percentage points) this week. The percentage of specimens testing positive for influenza increased in regions 1, 3, and 8, primarily driven by increases in influenza B activity, decreased in regions 4, 5, 6, 7, 9, and 10, and remained stable in Region 2. The percent positivity for influenza A viruses decreased in most areas of the country, and influenza B percent positivity decreased overall with variation in trends regionally. Influenza A(H3N2) and influenza B viruses were the most frequently reported influenza viruses by public health labs this week nationally, with distribution of circulating viruses differing by HHS region. For regional and state level data and age group distribution, please visit FluView Interactive. Viruses known to be associated with recent receipt of live attenuated influenza vaccine (LAIV) or found upon further testing to be a vaccine virus are not included, as they are not circulating influenza viruses. Clinical Laboratories

The results of tests performed by clinical laboratories nationwide are summarized below. Data from clinical laboratories (the percentage of specimens tested that are positive for influenza virus) are used to monitor whether influenza activity is increasing or decreasing.

No. of specimens tested	60,262	1,939,806
No. of positive specimens (%)	7,637 (12.7%)	281,329 (14.5%)
*Positive specimens by type*
Influenza A	1,793 (23.5%)	218,833 (77.8%)
Influenza B	5,844 (76.5%)	62,496 (22.2%)

Public Health Laboratories

The results of tests performed by public health laboratories nationwide are summarized below. Data from public health laboratories are used to monitor the proportion of circulating influenza viruses that belong to each influenza subtype/lineage.

No. of specimens tested	1,054	80,834
No. of positive specimens	602	55,318
*Positive specimens by type/subtype*
Influenza A	318 (52.8%)	50,291 (90.9%)
Subtyping Performed	290 (91.2%)	40,779 (81.1%)
(H1N1)pdm09	67 (23.1%)	4,976 (12.2%)
H3N2	223 (76.9%)	35,801 (87.8%)
H3N2v	0	0
H5	0	2 (<0.01%)
Subtyping not performed	28 (8.8%)	9,512 (18.9%)
Influenza B	284 (47.2%)	5,027 (9.1%)
Lineage testing performed	87 (30.6%)	1,785 (35.5%)
Yamagata lineage	0	0
Victoria lineage	87 (100%)	1,785 (100%)
Lineage not performed	197 (69.4%)	3,242 (64.5%)

_{*These data reflect specimens tested, and the number determined to be positive for influenza viruses at the public health labs (specimens tested is not the same as cases). The data do not reflect specimens tested only at CDC and could include more than one specimen tested per person. For more information on the number of people infected with A/H5 viruses, please visit the "How CDC is monitoring influenza data among people to better understand the current avian influenza A (H5N1) situation"}

_{^†When an influenza virus that normally circulates in swine (but not people) is detected in a person, it is called a "variant" influenza virus. Most human infections with variant influenza viruses occur following exposure to swine, but human-to-human transmission can occur. It is important to note that in most cases, variant influenza viruses have not shown the ability to spread easily and sustainably from human-to-human.}

_{*This graph reflects the number of specimens determined to be positive for influenza viruses at the public health lab (specimens tested is not the same as cases). It does not reflect specimens tested only at CDC and could include more than one specimen tested per person. Specimens tested as part of routine influenza surveillance as well as those tested as part of targeted testing for people exposed to avian influenza A(H5) are included.}

Additional virologic surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive: National, Regional, and State Data or Age Data

Novel Influenza A Virus Infections

No new confirmed human infections with avian influenza A(H5) virus were reported to CDC this week. To date, person-to-person transmission of avian influenza A(H5) virus (H5 bird flu) has not been identified in the United States.

The CSTE position statement, which includes updated case definitions for confirmed, probable, and suspected cases is available at http://www.cste.org/resource/resmgr/...nfluenza_A.pdf.

An up-to-date human case summary during the current outbreak by state and exposure source is available at www.cdc.gov/bird-flu/situation-summary/index.html.

Information about avian influenza is available at https://www.cdc.gov/flu/avianflu/index.htm. A(H5N1) virus interim recommendations for Prevention, Monitoring, and Public Health Investigations are available at https://www.cdc.gov/bird-flu/prevent...endations.html.

Additional information regarding human infections with novel influenza A viruses:

Surveillance Methods | FluView Interactive
Influenza Virus Characterization

CDC performs genetic and antigenic characterization of U.S. viruses submitted from state and local public health laboratories according to the Right Size Roadmap submission guidance. These data are used to compare how similar the currently circulating influenza viruses are relative to the reference viruses representing the current influenza vaccines. The data are also used to monitor evolutionary changes that continually occur in influenza viruses circulating in humans. CDC also tests susceptibility of circulating influenza viruses to antiviral medications including the neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) and the polymerase acidic protein (PA) endonuclease inhibitor baloxavir. The HA clade and subclades were assigned using Nextclade (https://clades.nextstrain.org).

CDC has genetically characterized 2,848 influenza viruses collected since September 28, 2025.

A/H1	634
		5a.2a	3 (0.5%)	C.1.9.3	3 (0.5%)
5a.2a.1	631 (99.5%)	D.3.1	226 (35.6%)
D.3.1.1	405 (63.9%)
A/H3	1,754
		2a.3a.1	1,754 (100%)	J.2	4 (0.2%)
J.2.2	5 (0.3%)
J.2.3	57 (3.2%)
J.2.4	62 (3.5%)
K	1,626 (92.7%)
B/Victoria	460
		3a.2	460 (100%)	C.3	14 (3.0%)
C.3.1	292 (63.5%)
C.5.1	34 (7.4%)
C.5.6	17 (3.7%)
C.5.6.1	74 (16.1%)
C.5.7	29 (6.3%)
B/Yamagata	0
		Y3	0	Y3	0

CDC antigenically characterizes influenza viruses by hemagglutination inhibition (HI) assay (H1N1pdm09, H3N2, and B/Victoria viruses) or neutralization-based HINT (H3N2 viruses) using antisera from ferrets infected with reference viruses representing the recommended cell-based or recombinant influenza vaccines for the 2025-2026 Northern Hemisphere season. Antigenic differences between viruses are determined by comparing how well the antibodies raised against the vaccine reference viruses recognize the circulating viruses, which were grown in cell culture. Ferret antisera are useful because antibodies raised against a particular virus can often recognize small changes in the surface proteins of other viruses. In HI assays, viruses are deemed antigenically similar when their HI titer differences are less than or equal to 4-fold. In HINT, viruses with similar antigenic properties have antibody neutralization titer differences of less than 8-fold. Circulating viruses with antigenic testing results that show titer differences greater than 4-fold by HI or equal to or greater than 8-fold by HINT) are considered "low reactors" or antigenically drifted compared to the vaccine virus. From the recent genetically characterized viruses, a subset is selected for antigenic characterization based on identified genetic changes in their surface proteins. The subset tested may not be proportional to the number of such viruses circulating in the United States. Influenza A Viruses

A(H1N1)pdm09: 150 A(H1N1)pdm09 viruses collected since September 28, 2025, were antigenically characterized by HI, and 147 (98.0%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer) by ferret antisera to cell-grown A/Wisconsin/67/2022-like reference viruses representing the A(H1N1)pdm09 component for the cell- and recombinant-based influenza vaccines.
A(H3N2): 196 A(H3N2) viruses collected since September 28, 2025, were antigenically characterized by HI or HINT, and 4 (2.0%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer in HI or reacting at titers that were less than 8-fold of the homologous virus in HINT) by ferret antisera to cell-grown A/District Of Columbia/27/2023-like reference viruses representing the A(H3N2) component for the cell- and recombinant-based influenza vaccines.

Influenza B Viruses

B/Victoria: 99 influenza B/Victoria-lineage viruses collected since September 28, 2025, since were antigenically characterized by HI, and 32 (32.3%) were well-recognized (reacting at titers that were within 4-fold of the homologous virus titer) by ferret antisera to cell-grown B/Austria/1359417/2021-like reference viruses representing the B/Victoria component for the cell- and recombinant-based influenza vaccines.
B/Yamagata: No influenza B/Yamagata-lineage viruses were available for antigenic characterization.

Assessment of Virus Susceptibility to Antiviral Medications

CDC assesses susceptibility of influenza viruses to the antiviral medications including the neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) and the PA endonuclease inhibitor baloxavir using next generation sequence analysis supplemented by laboratory assays. Information about antiviral susceptibility test methods can be found at U.S. Influenza Surveillance: Purpose and Methods | CDC.

Viruses collected in the U.S. since September 28, 2025, were tested for antiviral susceptibility as follows:

Neuraminidase Inhibitors	Oseltamivir	Viruses Tested	2790	615	1729	446
Reduced Inhibition	12 (0.4%)	12 (2.0%)	0	0
Highly Reduced Inhibition	4 (0.1%)	4 (0.7%)	0	0
Peramivir	Viruses Tested	2790	615	1729	446
Reduced Inhibition	2 (0.1%)	0	0	2 (0.4%)
Highly Reduced Inhibition	4 (0.1%)	4 (0.7%)	0	0
Zanamivir	Viruses Tested	2790	615	1729	446
Reduced Inhibition	0	0	0	0
Highly Reduced Inhibition	0	0	0	0
PA Cap-Dependent Endonuclease Inhibitor	Baloxavir	Viruses Tested	2737	594	1695	448
Decreased Susceptibility	0	0	0	0

Four A(H1N1)pdm09 viruses had NA-H275Y amino acid substitution conferring highly reduced inhibition by oseltamivir and peramivir. Twelve A(H1N1)pdm09 viruses had amino acid substitutions NA-I223V and NA-S247N and showed reduced inhibition by oseltamivir. Two B viruses had amino acid substitution NA- M464T and showed reduced inhibition by peramivir.

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, use of these antivirals for treatment and prevention of influenza A virus infection is not recommended and data from adamantane resistance testing are not presented.

Outpatient and Emergency Department Illness Surveillance

Outpatient Respiratory Illness Visits

The U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) monitors outpatient visits for respiratory illness referred to as influenza-like illness [ILI (fever plus cough or sore throat)], not laboratory-confirmed influenza, and will therefore capture respiratory illness visits due to infection with any pathogen that can present with similar symptoms, including influenza virus, SARS-CoV-2, and RSV. It is important to evaluate syndromic surveillance data, including that from ILINet, in the context of other sources of surveillance data to obtain a complete and accurate picture of influenza, SARS-CoV-2, and other respiratory virus activity.

Nationally, during Week 10, 3.3% of patient visits reported through ILINet were due to respiratory illness that included fever plus a cough or sore throat, also referred to as ILI. This week's national percentage decreased (change of > 0.1 percentage points) compared to Week 9 but remains above the national baseline for the fifteenth consecutive week. ILI activity decreased in HHS regions 3, 4, 5, 6, 7, 9, and 10 and remained stable in regions 1, 2, and 8 compared to Week 9. Regions 1, 5, 7, 8, and 10 are above their respective baselines while the remaining regions (2, 3, 4, 6, and 9) are below their respective baselines. Multiple respiratory viruses are co-circulating, and the relative contribution of influenza virus infection to ILI varies by location.

_{*Some calendar years do not include an epidemiologic Week 53. In those years, the Week 53 value shown is the average between Week 52 and Week 1.}

_{**Effective October 3, 2021 (Week 40), the respiratory illness definition (fever plus cough or sore throat) no longer includes "without a known cause other than influenza."}

Outpatient Respiratory Illness Visits by Age Group

About 70% of ILINet participants provide both the number of patient visits for respiratory illness and the total number of patient visits for the week broken out by age group. Based on these data, the percentage of visits for respiratory illness decreased (change of > 0.1 percentage points) in all age groups (0-4 years, 5-24 years, 25-49 years, 50-64 years, and 65 years and older) this week compared to Week 9.

Outpatient Respiratory Illness Activity Map

Data collected in ILINet are used to produce a measure of ILI activity* by state/jurisdiction and Core Based Statistical Areas (CBSA).

Week 10 (Week ending Mar. 14, 2026)	Week 9 (Week ending Mar. 7, 2026)	Week 10 (Week ending Mar. 14, 2026)	Week 9 (Week ending Mar. 7, 2026)
Very High	0	1	3	11
High	10	15	52	87
Moderate	10	11	91	128
Low	17	13	227	214
Minimal	18	15	339	273
Insufficient Data	0	0	217	216

_{*Data collected in ILINet may disproportionally represent certain populations within a jurisdiction or CBSA, and therefore, may not accurately depict the full picture of influenza activity for the entire jurisdiction or CBSA. Differences in the data presented here by CDC and independently by some health departments likely represent differing levels of data completeness with data presented by the health department likely being the more complete.}

Additional information about medically attended visits for ILI for current and past seasons:

Surveillance Methods | FluView Interactive: National, Regional, and State Data or ILI Activity Map

National Syndromic Surveillance System (NSSP)

The national percentage of emergency department (ED) visits with a discharge diagnosis (DD) of influenza reported in NSSP was 1.9% during Week 10, which decreased (change of > 0.1 percentage points) compared to the previous week. Nationally, the percentage of ED visits with a DD of influenza decreased among all age groups compared to the previous week. The percentage of ED visits with a DD of influenza remained stable in HHS Regions 1, 2, and 8 and decreased (change of > 0.1 percentage points) this week compared to the previous week in all other HHS regions (3, 4, 5, 6, 7, 9, and 10). Age group trends varied by region. RegionNationalRegion 1Region 2Region 3Region 4Region 5Region 6Region 7Region 8Region 9Region 10
Season
2025-2026x
2024-2025x

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2.0%4.0%6.0%8.0%10.0%12.0%14.0%16.0%18.0%20.0%Perc ent of Emergency Department Visits for InfluenzaWeek 43 of 2024Week 47 of 2024Week 51 of 2024Week 3 of 2025Week 7 of 2025Week 11 of 2025Week 15 of 2025Week 19 of 2025Week 23 of 2025Week 27 of 2025Week 31 of 2025Week 35 of 2025Week 39 of 2025Week 43 of 2025Week 47 of 2025Week 51 of 2025Week 2 of 2026Week 6 of 2026Week 10 of 2026

Age Group

Skip Data Table
Data Table Download Data (CSV)
Skipped data table.

Additional information about emergency department visits for flu for current and past seasons:‎‎‎

Surveillance Methods | Emergency Department Visits for COVID-19, flu, and RSV

Hospitalization surveillance

FluSurv-Net

Influenza-Associated Hospitalizations: The Influenza Hospitalization Surveillance Network (FluSurv-NET) conducts population-based surveillance for laboratory-confirmed influenza-related hospitalizations in select counties in 14 states and represents approximately 10% of the U.S. population. FluSurv-NET hospitalization data are preliminary. As data are received each week, prior case counts and rates are updated accordingly.

A total of 27,881 laboratory-confirmed influenza-associated hospitalizations were reported by FluSurv-NET sites between October 1, 2025, and March 14, 2026. The weekly hospitalization rate observed during Week 10 was 1.1 per 100,000 population, which decreased from last week. After accounting for reporting delays, the estimated rate during Week 10 likely ranges from 1.5 to 1.9. The cumulative hospitalization rate observed in Week 10 was 80.0 per 100,000 population, which is the third highest cumulative rate thus far since the 2010-2011 season.

Among all hospitalizations, 25,698 (92.2%) were associated with influenza A virus, 2,025 (7.3%) with influenza B virus, 39 (0.1%) with influenza A virus and influenza B virus co-infection, and 119 (0.4%) with influenza virus for which the type was not determined. Among those with influenza A subtype information, 6,674 (88.9%) were A(H3N2), and 835 (11.1%) were A(H1N1)pdm09.

When examining rates by age, the highest rate of hospitalization per 100,000 population was among adults aged 65 and older (261.5), followed by children aged 0-4 years (85.4), adults aged 50-64 years (70.6), children aged 5-17 years (34.8), and adults aged 18-49 years (31.7).

Among children, the peak weekly rate was the highest going back to the 2010-2011 season in Week 52 (7.0). The cumulative rate for pediatric cases was the second highest since 2010-2011 (47.7). Among children, rates were highest among infants aged less than 1 year (131.7), followed by children aged 1-4 years (74.0).

When examining age-adjusted rates by race and ethnicity, the highest rate of hospitalization per 100,000 population was among non-Hispanic Black persons (136.0), followed by American Indian or Alaska Native persons (85.7), Hispanic persons (73.9), non-Hispanic White persons (69.2), and Asian and/or Pacific Islander persons (36.8).

Among 3,066 hospitalized adults with information on underlying medical conditions, 95.7% had at least one reported underlying medical condition; the most commonly reported were hypertension, cardiovascular disease, chronic metabolic disease, and chronic lung disease. Among 3,232 hospitalized women of childbearing age (15-49 years) with information on pregnancy status, 29.6% were pregnant. Among 1,252 hospitalized children with information on underlying medical conditions, 57.1% had at least one reported underlying medical condition; the most commonly reported was asthma, followed by neurologic disorder, and obesity.

Additional FluSurv-NET data are available on FluView Interactive including hospitalization rates for the current and past seasons by age, sex, and race/ethnicity (http://gis.cdc.gov/GRASP/Fluview/FluHospRates.html) as well as data on patient characteristics at: (http://gis.cdc.gov/grasp/fluview/FluHospChars.html.)

FluSurv-NET data are used to generate national estimates of the total numbers of influenza cases, medical visits, hospitalizations and deaths. This season, CDC is reporting preliminary cumulative in-season estimates, which are available at Estimated US Flu Disease Burden | Flu Burden | CDC

_{**In this figure, weekly rates for all seasons prior to the 2025-26 season reflect end-of-season rates. For the 2025-26 season, rates for recent hospital admissions are subject to reporting delays and are shown as a dashed line for the current season. As hospitalization data are received each week, prior case counts and rates are updated accordingly.}

Additional FluSurv-NET hospitalization surveillance information for current and past seasons and additional age groups:

Surveillance Methods | FluView Interactive: Rates by Age, Sex, and Race/Ethnicity or Data on Patient Characteristics | RESP-NET Interactive

National Healthcare Safety Network (NHSN) Hospital Respiratory Data

Hospitals report to NHSN the weekly number of patients with laboratory-confirmed influenza who were admitted to the hospital. Nationally, during Week 10, 7,348 laboratory-confirmed influenza-associated hospitalizations were reported. This week's influenza-associated hospital admission rate (2.2 per 100,000 population) decreased (difference of > 0.2) compared to Week 9.

Laboratory-confirmed influenza-associated hospital admission rates per 100,000 population decreased in HHS Regions 1, 4, 5, 6, 7, 9, and 10 and remained stable in HHS Regions 2, 3, and 8. Region admission rates during Week 10 ranged from 1.1 (Region 1) to 3.8 (Region 3).

When examining rates by age for Week 10, the 5-17 years age group remained stable compared to the previous week, while the remaining age groups (0-4 years, 18-49 years, 50-64 years, and 65 years and older) decreased. The highest hospital admission rate per 100,000 population was among those 65 years and older (5.1), followed by the 0-4 years age group (3.1), and the 50-64 years age group (1.7).

Additional NHSN Hospital Respiratory Data information:

Surveillance Methods | Additional Data | FluView Interactive

National Healthcare Safety Network (NHSN) Long-Term Care Respiratory Pathogens & Vaccination Module

Long-term care facilities (LTCFs [e.g., Nursing homes/skilled nursing facilities]) report respiratory pathogen (e.g., COVID-19, influenza, and RSV) data, including vaccination, cases, and hospitalizations among residents, to the NHSN Long-Term Care Respiratory Pathogens & Vaccination Module.

Nationally, during Week 10, the hospitalization rate for residents with a positive influenza test in the prior 10 days was 8.6 per 100,000 residents. The national rate and rates in HHS Regions 2, 4, 5, 7, 8, 9, and 10 are trending downward. The rate remains stable in Region 1. In HHS Regions 3 and 6, the rate does not show a consistent trend. View Larger Download National Healthcare Safety Network (NHSN) Long-Term Care Respiratory Pathogens & Vaccination Module
Mortality surveillance

National Center for Health Statistics (NCHS) Mortality Surveillance

Based on NCHS mortality surveillance data available on March 19, 2026, 0.5% of the deaths that occurred during the week ending March 14, 2026 (Week 10) were due to influenza. This percentage decreased (≥ 0.1 percentage point change) compared to Week 9. The data presented are preliminary and may change as more data are received and processed.

Additional pneumonia, influenza and COVID-19 mortality surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive

Influenza-Associated Pediatric Mortality

Fourteen influenza-associated pediatric deaths occurring during the 2025-2026 season were reported to CDC during Week 10. The deaths occurred between weeks 43 of 2025 and 10 of 2026 (the weeks ending October 25, 2025, and March 14, 2026). Three deaths were associated with influenza A viruses. Two of the influenza A viruses had subtyping performed; one was an A(H1N1) virus and the other one was an A(H3N2) virus. Eleven deaths were associated with influenza B viruses. Two of the influenza B viruses had lineage determined and both were B/Victoria viruses. Among children who were eligible for influenza vaccination and with known vaccination status, approximately 85% of reported pediatric deaths this season have occurred in children who were not fully vaccinated against influenza.

Additional pediatric mortality surveillance information for current and past seasons:

Surveillance Methods | FluView Interactive
All data in this report are preliminary and may change as more reports are received.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component, is available on the surveillance methods page.

Additional information on the current and previous influenza seasons for each surveillance component are available on FluView Interactive.

Additional National and International Influenza Surveillance Information

Indicators Status by System

Increasing:
Decreasing:
Stable:

Clinical Labs: Up or down arrows indicate a change of greater than or equal to 0.5 percentage points in the percent of specimens positive for influenza compared to the previous week.
Outpatient Respiratory Illness (ILINet): Up or down arrows indicate a change of greater than 0.1 percentage points in the percent of visits due to respiratory illness (ILI) compared to the previous week.
NHSN Hospitalizations: Up or down arrows indicate change of greater than or equal to 0.2 in the rate of hospital admissions or greater than or equal to 691 patients admitted with laboratory-confirmed influenza compared to the previous week.
NHSN Long- Term Care (LTC): Up or down arrows indicate change of greater than or equal to 5% in hospitalization rates for residents in LTC facilities who were hospitalized with laboratory-confirmed influenza compared to the previous week.
NCHS Mortality: Up or down arrows indicate change of greater than 0.1 percentage points of the percent of deaths due to influenza compared to the previous week.

Additional surveillance information

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.

National Institute for Occupational Safety and Health: Monthly surveillance data on the prevalence of health-related workplace absenteeism among full-time workers in the United States are available from NIOSH.

U.S. State and local influenza surveillance: Select a jurisdiction below to access the latest local influenza information.

Alabama	Alaska	Arizona	Arkansas	California
Colorado	Connecticut	Delaware	District of Columbia	Florida
Georgia	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	Oklahoma	Oregon	Pennsylvania	Rhode Island
South Carolina	South Dakota	Tennessee	Texas	Utah
Vermont	Virginia	Washington	West Virginia	Wisconsin
Wyoming	New York City	Puerto Rico	Virgin Islands

Public Health Agency of Canada:
The most up-to-date influenza information from Canada is available in Canada's weekly FluWatch report.

Public Health England:
The most up-to-date influenza information from the United Kingdom is available from Public Health England.

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.

A description of the CDC influenza surveillance system, including methodology and detailed descriptions of each data component is available on the surveillance methods page.

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US FluView - Weekly Surveillance Flu report 2025/2026 season - for trend analysis

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