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  • #31
    FluWatch report: April 26 to May 2, 2015 (Week 17)

    Posted 2015-05-08 For readers interested in the PDF version, the document is available for downloading or viewing:
    FluWatch report: April 26 to May 2, 2015 (Week 17) (PDF Version - 913 KB - 10 pages)

    Help with PDF documents

    Overall Summary
    • Influenza B continues to be the most common influenza virus circulating in Canada; however, influenza B is past its peak and remains within expected levels for this time of year.
    • Overall, influenza activity in Canada continues to decline; however, elevated activity was still reported in week 17 (mostly in Central Canada and parts of the Atlantic Provinces).
    • Influenza B is having a greater impact on adults less than 65 years of age, compared to influenza A(H3N2), which predominated earlier in the season.
    • Fewer influenza hospitalizations were reported this week compared to the previous week. The majority of hospitalizations were due to influenza A and in adults ≥65 years of age.

    Are you a primary health care practitioner (General Practitioner, Nurse Practitioner or Registered Nurse) interested in becoming a FluWatch sentinel for the 2014-15 influenza season? Contact us at FluWatch@phac-aspc.gc.ca
    Influenza/ILI Activity (geographic spread)

    In week 17, one region in QC and one region in NL reported widespread activity. Twelve regions reported localized activity: SK, MB, ON(7), QC, NL and NB. Twenty-five regions reported sporadic activity: NT, BC(4), AB(5), SK(2), MB(3), QC(4), NL, NB(4), and NS. Nineteen regions reported no activity: YK, NT, NU(3), BC, MB, NL, NB(2), NS(8), and PE.
    Figure 1. Map of overall influenza/ILI activity level by province and territory, Canada, Week 17
    Note: Influenza/ILI activity levels, as represented on this map, are assigned and reported by Provincial and Territorial Ministries of Health, based on laboratory confirmations, sentinel ILI rates and reported outbreaks. Please refer to detailed definitions at the end of the report. Maps from previous weeks, including any retrospective updates, are available on the FluWatch website.
    Text equivalent for figure 1Map of overall Influenza activity level by province and territory, Canada
    Influenza and Other Respiratory Virus Detections

    In week 17, the percentage positive for influenza A (0.9%) and B (9.2%) declined from the previous week (Figure 2). Influenza B remained the predominant virus in week 17, representing 90% of influenza detections. Most jurisdictions reported stable or declining levels of influenza detections over recent weeks. To date, 82% of influenza detections have been influenza A, and 99.6% of those subtyped have been A(H3N2) (Table 1). To date this season, detailed information on age and type/subtype has been received for 36,155 cases (Table 2). Adults ≥65 years of age have predominantly been affected by influenza A, accounting for 62% of influenza A detections. Influenza B, while much smaller in numbers, is mainly affecting individuals less than 65 years of age, they account for 59% of influenza B detections.
    Figure 2. Number of positive influenza tests and percentage of tests positive, by type, subtype and report week, Canada, 2014-15
    Text equivalent for figure 2Number of positive influenza tests and percentage of tests positive, by type, subtype and report week, Canada, 2014-15
    In week 17, detections for all other respiratory viruses decreased from the previous week (Figure 3). In recent weeks, detections of human metapneumovirus and parainfluenza have been higher than those reported in each of the past three seasons.
    For more details, see the weekly Respiratory Virus Detections in Canada Report.
    Figure 3. Number of positive laboratory tests for other respiratory viruses by report week, Canada, 2014-15
    RSV: Respiratory syncytial virus; hMPV: Human metapneumovirus
    Text equivalent for figure 3Overall Number of Influenza Outbreaks, Canada, by Report Week, 2014-2015
    B Total B Total
    1 Specimens from NT, YT, and NU are sent to reference laboratories in other provinces. Cumulative data includes updates to previous weeks.
    2 Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
    UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.
    2 0 0 2 30 3519 28 2626 865 415
    0 0 0 0 37 3699 14 3531 154 881
    1 0 0 1 16 1314 0 839 475 272
    0 0 0 0 20 1122 0 390 732 185
    9 0 8 1 80 11149 48 4709 6392 1297
    21 0 0 21 129 11408 4 422 11003 3737
    2 0 1 1 21 1195 0 193 1002 505
    0 0 0 0 4 511 1 123 387 258
    0 0 0 0 0 131 1 128 2 108
    2 0 0 2 7 622 0 123 499 48
    37 0 9 28 344 34691 96 13084 21511 7706
    9.7% 0.0% 24.3% 75.7% 90.3% 81.8% 0.3% 37.7% 62.0% 18.2%
    Total Total
    1 Specimens from NT, YT, and NU are sent to reference laboratories in other provinces. Cumulative data includes updates to previous weeks.
    2 Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
    3 Table 2 includes specimens for which demographic information was reported. These represent a subset of all positive influenza cases reported.
    UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.
    4 0 0 4 13 2091 22 809 1260 489 2580 7.1%
    1 0 0 1 21 1783 6 957 820 709 2492 6.8%
    2 0 0 2 33 3436 16 1669 1751 970 44406 12.1%
    3 0 1 2 41 3863 21 1658 2184 1626 5489 15.1%
    13 0 2 11 95 18721 15 7280 11426 2646 21367 58.6%
    0 0 0 0 0 120 0 101 19 7 127 0.3%
    23 0 3 20 203 30014 80 12474 17460 6447 36461 100.0%
    10.2% 0.0% 13.0% 87.0% 89.8% 82.3% 0.3% 41.6% 58.2% 17.7%
    Antiviral Resistance

    During the 2014-2015 influenza season, the NML has tested 1,382 influenza viruses for resistance to oseltamivir and 1,379 influenza viruses for resistance to zanamivir. All viruses were sensitive to zanamivir and one influenza A(H3N2) virus was resistant to oseltamivir. A total of 1,351 influenza A viruses (99.9%) were resistant to amantadine (Table 3).
    * NA - not applicable
    876 1 874 0 1338 1337 (99.9%)
    10 0 10 0 14 14 (100%)
    496 0 495 0 NA * NA *
    1382 1 1379 0 1352 1351
    Influenza Strain Characterizations

    During the 2014-2015 influenza season, the National Microbiology Laboratory (NML) has characterized 750 influenza viruses [185 A(H3N2), 15 A(H1N1) and 550 influenza B].
    Influenza A (H3N2): When tested by hemagglutination inhibition (HI) assay (n=185), one virus was antigenically similar to A/Texas/50/2012, five showed reduced titers to A/Texas/50/2012 and 179 were antigenically similar to A/Switzerland/9715293/2013, which is the influenza A(H3N2) component recommended for the 2015 Southern Hemisphere influenza vaccine. Additionally, 1,105 A(H3N2) viruses were unable to be tested by HI assay; however, sequence analysis showed that 1,103 belonged to a genetic group that typically shows reduced titers to A/Texas/50/2012. Influenza A(H1N1): Fifteen A(H1N1) viruses characterized were antigenically similar to A/California/7/2009. Influenza B: Of the 550 influenza B viruses characterized, 523 viruses were antigenically similar to B/Massachusetts/2/2012, three viruses showed reduced titers against B/Massachusetts/2/2012, and 24 were B/Brisbane/60/2008-like (Figure 4).
    Figure 4. Influenza strain characterizations, Canada, 2014-2015, N = 750

    The NML receives a proportion of the number of influenza positive specimens from provincial laboratories for strain characterization and antiviral resistance testing. Characterization data reflect the results of haemagglutination inhibition (HAI) testing compared to the reference influenza strains recommended byWHO.
    The recommended components for the 2014-2015 northern hemisphere trivalent influenza vaccine include: an A/California/7/2009(H1N1)pdm09-like virus, an A/Texas/50/2012 (H3N2)-like virus, and a B/Massachusetts/2/2012-like virus (Yamagata lineage). For quadrivalent vaccines, the addition of a B/Brisbane/60/2008-like virus is recommended.


    Text equivalent for figure 4Influenza strain characterizations, Canada, 2014-2015, N =3
    Influenza-like Illness (ILI) Consultation Rate

    In week 17, the national influenza-like-illness (ILI) consultation rate declined from the previous week to 18.7 consultations per 1,000 (Figure 5).
    Figure 5. Influenza-like-illness (ILI) consultation rates by report week, compared to the 1996-97 through to 2012-13 seasons (with pandemic data suppressed), Canada, 2014-2015
    Note: No data available for mean rate for weeks 19 to 39 for the 1996-1997 through 2002-2003 seasons. Delays in the reporting of data may cause data to change retrospectively. The calculation of the average ILI consultation rate over 17 seasons was aligned with influenza activity in each season. In BC, AB, and SK, data is compiled by a provincial sentinel surveillance program for reporting to FluWatch. Not all sentinel physicians report every week.
    Text equivalent for figure 5Influenza-like-illness (ILI) consultation rates by report week, compared to the 1996-97 through to 2012-13 seasons (with pandemic data suppressed), Canada, 2014-2015
    Influenza Outbreak Surveillance

    In week 17, eight new outbreaks of influenza were reported. All outbreaks were reported in long-term care facilities (LTCF) (Figure 6). and three of the eight outbreaks were associated with influenza B. To date this season, 1,254 outbreaks in LTCFs have been reported and the majority of those with known subtypes were attributable to A(H3N2). There have been a higher number of reported influenza outbreaks to date this season compared to the same period in previous seasons.
    Figure 6. Overall number of new influenza outbreaks by report week, Canada, 2014-2015
    1 All provinces and territories except NU report outbreaks in long-term care facilities. All provinces and territories with the exception of NU and QC report outbreaks in hospitals. Outbreaks of influenza or influenza-like-illness in other facilities are reported to FluWatch but reporting varies between jurisdictions. Outbreak definitions are included at the end of the report.
    Text equivalent for figure 6Overall number of new influenza outbreaks by report week, Canada, 2014-2015
    Pharmacy Surveillance

    Pharmacy surveillance for sales of influenza antivirals has ended for the 2014-2015 influenza season (Figure 7).
    Figure 7. Proportion of prescription sales for influenza antivirals by age-group and week, Canada, 2014-15
    Note: Pharmacy sales data are provided to the Public Health Agency of Canada by Rx Canada Inc. and sourced from major retail drug chains representing over 2,500 stores nationwide (excluding Nunavut) in 85% of Health Regions. Data provided include the number of new antiviral prescriptions (for Tamiflu and Relenza) and the total number of new prescriptions dispensed by Province/Territory and age group. Age-groups: Infant: 0-2y, Child: 2-18y; Adult: 19-64y, Senior: ≥65y
    Text equivalent for figure 7Proportion of prescription sales for influenza antivirals by age-group and week, Canada, 2014-15
    Sentinel Hospital Influenza Surveillance

    Paediatric Influenza Hospitalizations and Deaths (IMPACT)
    In week 17, nine laboratory-confirmed influenza-associated paediatric (≤16 years of age) hospitalizations were reported by the Immunization Monitoring Program Active (IMPACT) network. All cases were influenza B (Figure 8a). A greater proportion of cases have been reported with influenza B in recent weeks, following the trend in laboratory detections. Among the reported cases, four (44%) were <2 years of age and five (56%) were 2 to 9 years of age. No ICU cases were reported.
    To date this season, 676 hospitalizations have been reported by the IMPACT network, 509 (75%) of which were cases of influenza A. Among cases for which the influenza A subtype was reported, 98% (161/164) were A(H3N2) (Table 4). To date, 83 cases were admitted to the ICU, of which 46 (55%) were 2 to 9 years of age (Figure 9a). A total of 54 ICU cases reported to have at least one underlying condition or comorbidity. Four deaths have been reported.
    Note: The number of hospitalizations reported through IMPACT represents a subset of all influenza-associated paediatric hospitalizations in Canada. Delays in the reporting of data may cause data to change retrospectively.
    Adult Influenza Hospitalizations and Deaths (PCIRN)
    In week 17, five laboratory-confirmed influenza-associated adult (≥16 years of age) hospitalizations were reported by the Canadian Immunization Research Network (CIRN) Serious Outcomes Surveillance (SOS) network. All reported cases were influenza B. Three cases (60%) were in adults over the age of 65 (Figure 8b).
    To date this season, 2,228 cases have been reported; 1,912 (86%) with influenza A. The majority of cases (81%) were among adults ≥65 years of age (Table 5). One hundred and seventy two ICU admissions have been reported and 128 cases were adults ≥65 years of age. Among the 172 ICU admissions, 27 were due to influenza B (12 in adults 45 to 64 years of age and 15 in adults over the age of 65). A total of 123 ICU cases (72%) reported to have at least one underlying condition or comorbidity. Of the 123 ICU cases with known immunization status, 40 (33%) reported not having been vaccinated this season. One hundred and thirty-five deaths have been reported, 124 (92%) of the deaths were adults >65 years of age (Figure 9B).
    Note: The number of hospitalizations reported through PCIRN represents a subset of all influenza-associated adult hospitalizations in Canada. Delays in the reporting of data may cause data to change retrospectively.
    1 Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
    UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.
    81 0 18 63 12 93 (13.8%)
    114 2 36 76 34 148 (21.9%)
    124 1 38 85 45 169 (25.0%)
    129 0 44 85 49 178 (26.3%)
    61 0 25 36 27 88 (13.0%)
    509 3 161 345 167 676
    75.3% 0.6% 31.6% 67.8% 24.7% 100.0%
    1 Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
    UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.
    3 0 1 2 1 4 (%)
    106 1 56 49 16 122 (5%)
    217 3 99 115 76 293 (13%)
    1586 4 760 822 223 1809 (81%)
    1912 8 916 988 316 2228
    86% 0% 48% 52% 14% 100%
    Figure 8 - Number of cases of influenza reported by sentinel hospital networks, by week, Canada, 2014-15
    A) Paediatric hospitalizations (≤16 years of age, IMPACT)

    Text equivalent for figure 8aNumber of cases of influenza reported by sentinel hospital networks, by week, Canada, 2014-15: Paediatric hospitalizations (≤16 years of age, IMPACT)
    B) Adult hospitalizations (≥16 year of age, PCIRN-SOS)

    * See footnote above following the section related to PCIRN-SOS data.
    Text equivalent for figure 8bNumber of cases of influenza reported by sentinel hospital networks, by week, Canada, 2014-15: Adult hospitalizations (>16 year of age, PCIRN-SOS)
    Figure 9 - Percentage of hospitalizations, ICU admissions and deaths with influenza reported by age-group, Canada, 2014-15
    A) Paediatric hospitalizations (≤16 years of age, IMPACT)
    Text equivalent for figure 9aPercentage of hospitalizations, ICU admissions and deaths with influenza reported by age-group, Canada, 2014-15: Paediatric hospitalizations (≤16 years of age, IMPACT)
    B) Adult hospitalizations (≥16 year of age, PCIRN-SOS)

    Text equivalent for figure 9bPercentage of hospitalizations, ICU admissions and deaths with influenza reported by age-group, Canada, 2014-15: Adult hospitalizations (≥16 year of age, PCIRN-SOS)
    Provincial/Territorial Influenza Hospitalizations and Deaths

    In week 17, 88 laboratory-confirmed influenza-associated hospitalizations were reported from participating provinces and territories*, which is lower than the number reported the previous week. Of the 88 hospitalizations, 53 (60%) were due to influenza A and 45 (51%) were in patients ≥65 years of age.
    Since the start of the 2014-15 season, 7,375 hospitalizations have been reported; 6,471 (88%) with influenza A. Among cases for which the subtype of influenza A was reported, 99.3% were A(H3N2). The majority of cases (71%) were ≥65 years of age (Table 6). A total of 384 ICU admissions have been reported to date: 53% (n=202) were in adults ≥65 years of age and 33% (n=128) were in adults 20-64 years. A total of 555 deaths have been reported since the start of the season: three children <5 years of age, four children 5-19 years, 42 adults 20-64 years, and 506 adults ≥65 years of age. Adults 65 years of age or older represent 91% of all deaths reported this season. Detailed clinical information (e.g. underlying medical conditions) is not known for these cases
    * Note: Influenza-associated hospitalizations are not reported to PHAC by the following Provinces and Territory: BC, NU, QC, and NB. Only hospitalizations that require intensive medical care are reported by Saskatchewan. ICU admissions are not distinguished among hospital admissions reported from Ontario. Data may also include cases reported by the IMPACT and PCIRN networks. The number of new influenza-associated hospitalizations and deaths reported for the current week may include cases from Ontario that occurred in previous weeks, as a result of retrospective updates to the cumulative total. It is important to note that the hospitalization or death does not have to be attributable to influenza, a positive laboratory test is sufficient for reporting.
    Total # (%)
    1 Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
    UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.
    422 3 150 269 73 495 (7%)
    277 2 133 142 95 372 (5%)
    385 4 232 149 104 489 (7%)
    614 9 261 344 124 738 (10%)
    4717 3 2245 2469 488 5205 (71%)
    56 1 52 3 20 76 (1%)
    6471 22 3073 3376 904 7375
    87.7% 0.3% 47.5% 52.2% 12.3% 100.0%
    See additional data on Reported Influenza Hospitalizations and Deaths in Canada: 2009-10 to 2014-15 on the Public Health Agency of Canada website.
    Emerging Respiratory Pathogens

    Human Avian Influenza
    Influenza A(H7N9): Since the last FluWatch report, no new laboratory-confirmed cases of human infection with avian influenza A(H7N9) virus were reported by the World Health Organization. Globally to May 5, 2015, the WHO reported a total of 651 laboratory-confirmed human cases with avian influenza A(H7N9) virus, including 225 deaths. Documents related to the public health risk of influenza A(H7N9), as well as guidance for health professionals and advice for the public is updated regularly on the following websites:

    PHAC - Avian influenza A(H7N9)
    WHO - Avian Influenza A(H7N9)

    Middle East Respiratory Syndrome Coronavirus (MERS-CoV)
    Since the last FluWatch report, no new laboratory-confirmed cases of MERS-CoV have been reported by the World Health Organization. Globally, from September 2012 to May 5, 2015, the WHO has reported a total of 1,110 laboratory-confirmed cases of infection with MERS-CoV, including 422 deaths. All cases have either occurred in the Middle East or have had direct links to a primary case infected in the Middle East. The public health risk posed by MERS-CoV in Canada remains low (see the PHAC Assessment of Public Health Risk) and for the latest global risk assessment posted by the WHO on February 5, 2015: WHO MERS-CoV

    Documents related to the public health risk of MERS-CoV, as well as guidance for health professionals and advice for the public is updated regularly on the following websites:
    PHAC - Middle East respiratory syndrome coronavirus (MERS-CoV)
    WHO - Coronavirus infections

    Avian Influenza A(H5)
    The Canadian Food Inspection Agency (CFIA) is continuing its investigation into the second outbreak of highly pathogenic avian influenza H5N2 virus in Oxford County, Ontario. To date, there has been three infected commercial premises. Individual quarantines and Avian Influenza Control Zones have been established. No human cases have been reported. Avian influenza viruses do not pose risks to food safety when poultry and poultry products are properly handled and cooked. Avian influenza rarely affects humans that do not have consistent contact with infected birds. Further information on the outbreak is provided on the following CFIA website:

    CFIA - Notifiable Avian Influenza

    .../

    http://www.phac-aspc.gc.ca/fluwatch/.../index-eng.php

    "Safety and security don't just happen, they are the result of collective consensus and public investment. We owe our children, the most vulnerable citizens in our society, a life free of violence and fear."
    -Nelson Mandela

    Comment


    • #32
      FluWatch report: May 3 to May 9, 2015 (Week 18)

      Posted 2015-05-15 For readers interested in the PDF version, the document is available for downloading or viewing:
      FluWatch report: May 3 to May 9, 2015 (Week 18) (PDF Version - 915 KB - 10 pages)

      Help with PDF documents

      Overall Summary
      • Influenza B continues to be the most common influenza virus circulating in Canada; however, influenza B is past its peak and remains within expected levels for this time of year.
      • Overall, influenza activity in Canada continues to decrease; however, elevated activity was still reported in week 18 (mostly in Central Canada and parts of British Columbia).
      • Influenza B is having a greater impact on adults less than 65 years of age compared to influenza A(H3N2), which predominated earlier in the season.
      • As of week 18, 7,448 hospitalizations and 562 deaths have been reported from participating regions, which is more than were reported last year at this time (4,731 hospitalizations and 275 deaths).

      Are you a primary health care practitioner (General Practitioner, Nurse Practitioner or Registered Nurse) interested in becoming a FluWatch sentinel for the 2014-15 influenza season? Contact us at FluWatch@phac-aspc.gc.ca
      Influenza/ILI Activity (geographic spread)

      In week 18, one region in BC and one region in NL reported widespread activity. Ten regions reported localized activity: BC(2), ON(6), and QC(2). Twenty-six regions reported sporadic activity: NT, BC, AB(5), SK(3), MB(4), ON, QC(4), NL, NB(5), and NS. Twenty regions reported no activity: YK, NT, NU(3), BC, MB, NL(2), NB(2), NS(8), and PE.
      Figure 1. Map of overall influenza/ILI activity level by province and territory, Canada, Week 18
      Note: Influenza/ILI activity levels, as represented on this map, are assigned and reported by Provincial and Territorial Ministries of Health, based on laboratory confirmations, sentinel ILI rates and reported outbreaks. Please refer to detailed definitions at the end of the report. Maps from previous weeks, including any retrospective updates, are available on the FluWatch website.
      Text equivalent for figure 1Map of overall Influenza activity level by province and territory, Canada
      Influenza and Other Respiratory Virus Detections

      The number of positive influenza tests decreased from 381 in week 17 to 299 in week 18. Influenza B remained the predominant virus in week 18, representing 89% of influenza detections. Most jurisdictions reported stable or declining levels of influenza detections over recent weeks. To date, 81% of influenza detections have been influenza A, and 99.3% of those subtyped have been A(H3N2) (Table 1). To date this season, detailed information on age and type/subtype has been received for 36,794 cases (Table 2). Adults ≥65 years of age have predominantly been affected by influenza A, accounting for 62% of influenza A detections. Influenza B, while much smaller in numbers, is mainly affecting individuals less than 65 years of age. Adults under the age of 64 years accounted for 59% of influenza B detections.
      Figure 2. Number of positive influenza tests and percentage of tests positive, by type, subtype and report week, Canada, 2014-15
      Text equivalent for figure 2Number of positive influenza tests and percentage of tests positive, by type, subtype and report week, Canada, 2014-15
      In week 18, detections for all other respiratory viruses except rhinovirus and human metapneumovirus decreased from the previous week (Figure 3). The percent positive for rhinovirus increased from 13% in week 17 to 20% in week 18.
      For more details, see the weekly Respiratory Virus Detections in Canada Report.
      Figure 3. Number of positive laboratory tests for other respiratory viruses by report week, Canada, 2014-15
      RSV: Respiratory syncytial virus; hMPV: Human metapneumovirus
      Text equivalent for figure 3Overall Number of Influenza Outbreaks, Canada, by Report Week, 2014-2015
      1 Specimens from NT, YT, and NU are sent to reference laboratories in other provinces. Cumulative data includes updates to previous weeks.
      2 Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
      UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.
      3 0 3 0 18 3522 28 2629 865 433
      1 0 0 1 31 3700 14 3531 155 912
      0 0 0 0 5 1314 0 839 475 286
      2 1 0 1 12 1124 1 390 733 197
      8 0 1 7 87 11157 48 4710 6399 1400
      16 0 0 16 83 11445 4 422 11019 3820
      0 0 0 0 19 1195 0 193 1002 524
      0 0 0 0 2 511 1 123 387 260
      0 0 0 0 0 131 1 128 2 108
      2 0 0 2 10 624 0 123 501 58
      32 1 4 27 267 34723 97 13088 21538 7998
      10.7% 3.1% 12.5% 84.4% 89.3% 81.3% 0.3% 37.7% 62.0% 18.7%
      1 Specimens from NT, YT, and NU are sent to reference laboratories in other provinces. Cumulative data includes updates to previous weeks.
      2 Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
      3 Table 2 includes specimens for which demographic information was reported. These represent a subset of all positive influenza cases reported.
      UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.
      1 0 0 1 10 2092 22 809 1261 508 2600 7.1%
      0 0 0 0 20 1783 6 957 820 751 2534 6.9%
      3 0 0 3 25 3441 16 1671 1754 1018 4459 12.1%
      6 0 0 6 39 3869 21 1658 2190 1705 5574 15.1%
      9 0 0 9 78 18739 15 7286 11438 2761 21500 58.4%
      0 0 0 0 0 120 0 101 19 7 127 0.3%
      19 0 0 19 172 30044 80 12482 17482 6750 36794 100.0%
      9.9% 0.0% 0.0% 100.0% 90.1% 81.7% 0.3% 41.5% 58.2% 18.3%
      Antiviral Resistance

      During the 2014-2015 influenza season, the NML has tested 1,446 influenza viruses for resistance to oseltamivir and 1,444 influenza viruses for resistance to zanamivir. All viruses were sensitive to zanamivir and one influenza A(H3N2) virus was resistant to oseltamivir. A total of 1,365 influenza A viruses (99.9%) were resistant to amantadine (Table 3).
      * NA - not applicable
      890 1 888 0 1350 1349 (99.9%)
      15 0 15 0 16 16 (100%)
      541 0 541 0 NA * NA *
      1446 1 1444 0 1366 1365
      Influenza Strain Characterizations

      During the 2014-2015 influenza season, the National Microbiology Laboratory (NML) has characterized 849 influenza viruses [190 A(H3N2), 17 A(H1N1) and 642 influenza B].
      Influenza A (H3N2): When tested by hemagglutination inhibition (HI) assay (n=190), one virus was antigenically similar to A/Texas/50/2012, five showed reduced titers to A/Texas/50/2012 and 184 were antigenically similar to A/Switzerland/9715293/2013, which is the influenza A(H3N2) component recommended for the 2015 Southern Hemisphere influenza vaccine. Additionally, 1,129 A(H3N2) viruses were unable to be tested by HI assay; however, sequence analysis showed that 1,127 belonged to a genetic group that typically shows reduced titers to A/Texas/50/2012. Influenza A(H1N1): Seventeen A(H1N1) viruses characterized were antigenically similar to A/California/7/2009. Influenza B: Of the 642 influenza B viruses characterized, 602 viruses were antigenically similar to B/Massachusetts/2/2012, three viruses showed reduced titers against B/Massachusetts/2/2012, and 37 were B/Brisbane/60/2008-like (Figure 4).
      Figure 4. Influenza strain characterizations, Canada, 2014-2015, N = 849

      The NML receives a proportion of the number of influenza positive specimens from provincial laboratories for strain characterization and antiviral resistance testing. Characterization data reflect the results of haemagglutination inhibition (HAI) testing compared to the reference influenza strains recommended byWHO.
      The recommended components for the 2014-2015 northern hemisphere trivalent influenza vaccine include: an A/California/7/2009(H1N1)pdm09-like virus, an A/Texas/50/2012 (H3N2)-like virus, and a B/Massachusetts/2/2012-like virus (Yamagata lineage). For quadrivalent vaccines, the addition of a B/Brisbane/60/2008-like virus is recommended.


      Text equivalent for figure 4Influenza strain characterizations, Canada, 2014-2015, N =3
      Influenza-like Illness (ILI) Consultation Rate

      In week 18, the national influenza-like-illness (ILI) consultation rate increased from the previous week to 23.1 consultations per 1,000 (Figure 5).
      Figure 5. Influenza-like-illness (ILI) consultation rates by report week, compared to the 1996-97 through to 2012-13 seasons (with pandemic data suppressed), Canada, 2014-2015
      No data available for mean rate for weeks 19 to 39 for the 1996-1997 through 2002-2003 seasons. Delays in the reporting of data may cause data to change retrospectively. The calculation of the average ILI consultation rate over 17 seasons was aligned with influenza activity in each season. In BC, AB, and SK, data is compiled by a provincial sentinel surveillance program for reporting to FluWatch. Not all sentinel physicians report every week.
      Text equivalent for figure 5Influenza-like-illness (ILI) consultation rates by report week, compared to the 1996-97 through to 2012-13 seasons (with pandemic data suppressed), Canada, 2014-2015
      Influenza Outbreak Surveillance

      In week 18, 14 new outbreaks of influenza were reported: two due to influenza B, one due to influenza A and 11 for which the influenza type was not provided. Eleven outbreaks were reported in long-term care facilities (LTCF) and three in institutional or community settings (Figure 6). To date this season, 1,265 outbreaks in LTCFs have been reported and the majority of those with known subtypes were attributable to A(H3N2). There have been a higher number of reported influenza outbreaks to date this season compared to the same period in previous seasons.
      Figure 6. Overall number of new laboratory-confirmed influenza outbreaks by report week, Canada, 2014-2015
      1 All provinces and territories except NU report outbreaks in long-term care facilities. All provinces and territories with the exception of NU and QC report outbreaks in hospitals. Outbreaks of influenza or influenza-like-illness in other facilities are reported to FluWatch but reporting varies between jurisdictions. Outbreak definitions are included at the end of the report.
      Text equivalent for figure 6Overall number of new influenza outbreaks by report week, Canada, 2014-2015
      Pharmacy Surveillance

      Pharmacy surveillance for sales of influenza antivirals has ended for the 2014-2015 influenza season (Figure 7).
      Figure 7. Proportion of prescription sales for influenza antivirals by age-group and week, Canada, 2014-15
      Note: Pharmacy sales data are provided to the Public Health Agency of Canada by Rx Canada Inc. and sourced from major retail drug chains representing over 2,500 stores nationwide (excluding Nunavut) in 85% of Health Regions. Data provided include the number of new antiviral prescriptions (for Tamiflu and Relenza) and the total number of new prescriptions dispensed by Province/Territory and age group. Age-groups: Infant: 0-2y, Child: 2-18y; Adult: 19-64y, Senior: ≥65y
      Text equivalent for figure 7Proportion of prescription sales for influenza antivirals by age-group and week, Canada, 2014-15
      Sentinel Hospital Influenza Surveillance

      Paediatric Influenza Hospitalizations and Deaths (IMPACT)
      In week 18, six laboratory-confirmed influenza-associated paediatric (≤16 years of age) hospitalizations were reported by the Immunization Monitoring Program Active (IMPACT) network. All cases were influenza B (Figure 8a). A greater proportion of cases have been reported with influenza B in recent weeks, following the trend in laboratory detections. Among the reported cases, three (50%) were <2 years of age and three (50%) were 2 to 9 years of age. One ICU case was reported.
      To date this season, 681 hospitalizations have been reported by the IMPACT network, 509 (75%) of which were cases of influenza A. Among cases for which the influenza A subtype was reported, 98% (161/164) were A(H3N2) (Table 4). To date, 86 cases were admitted to the ICU, of which 49 (57%) were 2 to 9 years of age (Figure 9a). A total of 56 ICU cases reported to have at least one underlying condition or comorbidity. Four deaths have been reported.
      Note: The number of hospitalizations reported through IMPACT represents a subset of all influenza-associated paediatric hospitalizations in Canada. Delays in the reporting of data may cause data to change retrospectively.
      Adult Influenza Hospitalizations and Deaths (PCIRN)
      Surveillance has ended for the 2014-2015 influenza season.
      This season, 2,228 cases have been reported; 1,912 (86%) with influenza A. The majority of cases (81%) were among adults ≥65 years of age (Table 5). One hundred and seventy two ICU admissions have been reported and 128 cases were adults ≥65 years of age. Among the 172 ICU admissions, 27 were due to influenza B (12 in adults 45 to 64 years of age and 15 in adults over the age of 65). A total of 123 ICU cases (72%) reported to have at least one underlying condition or comorbidity. Of the 123 ICU cases with known immunization status, 40 (33%) reported not having been vaccinated this season. One hundred and thirty-five deaths have been reported, 124 (92%) of the deaths were adults >65 years of age (Figure 9B).
      Note: The number of hospitalizations reported through PCIRN represents a subset of all influenza-associated adult hospitalizations in Canada. Delays in the reporting of data may cause data to change retrospectively.
      1 Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
      UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.
      81 0 18 63 13 94 (13.8%)
      114 2 36 76 35 149 (21.9%)
      124 1 38 85 47 171 (25.1%)
      129 0 44 85 50 179 (26.3%)
      61 0 25 36 27 88 (12.9%)
      509 3 161 345 172 681
      74.7% 0.6% 31.6% 67.8% 25.3% 100.0%
      1 Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
      UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.
      3 0 1 2 1 4 (%)
      106 1 56 49 16 122 (5%)
      217 3 99 115 76 293 (13%)
      1586 4 760 822 223 1809 (81%)
      1912 8 916 988 316 2228
      86% 0% 48% 52% 14% 100%
      Figure 8 - Number of cases of influenza reported by sentinel hospital networks, by week, Canada, 2014-15
      A) Paediatric hospitalizations (≤16 years of age, IMPACT)

      Text equivalent for figure 8aNumber of cases of influenza reported by sentinel hospital networks, by week, Canada, 2014-15: Paediatric hospitalizations (≤16 years of age, IMPACT)
      B) Adult hospitalizations (≥16 year of age, PCIRN-SOS)

      * See footnote above following the section related to PCIRN-SOS data.
      Text equivalent for figure 8bNumber of cases of influenza reported by sentinel hospital networks, by week, Canada, 2014-15: Adult hospitalizations (>16 year of age, PCIRN-SOS)
      Figure 9 - Percentage of hospitalizations, ICU admissions and deaths with influenza reported by age-group, Canada, 2014-15
      A) Paediatric hospitalizations (≤16 years of age, IMPACT)
      Text equivalent for figure 9aPercentage of hospitalizations, ICU admissions and deaths with influenza reported by age-group, Canada, 2014-15: Paediatric hospitalizations (≤16 years of age, IMPACT)
      B) Adult hospitalizations (≥16 year of age, PCIRN-SOS)

      Text equivalent for figure 9bPercentage of hospitalizations, ICU admissions and deaths with influenza reported by age-group, Canada, 2014-15: Adult hospitalizations (≥16 year of age, PCIRN-SOS)
      Provincial/Territorial Influenza Hospitalizations and Deaths

      In week 18, 78 laboratory-confirmed influenza-associated hospitalizations were reported from participating provinces and territories*, which is lower than the number reported the previous week. Of the 78 hospitalizations, 46 (59%) were due to influenza A and 38 (49%) were in patients ≥65 years of age.
      Since the start of the 2014-15 season, 7,448 hospitalizations have been reported; 6,510 (87%) with influenza A. Among cases for which the subtype of influenza A was reported, 99.3% were A(H3N2). The majority of cases (70%) were ≥65 years of age (Table 6). A total of 382 ICU admissions have been reported to date: 53% (n=202) were in adults ≥65 years of age and 34% (n=128) were in adults 20-64 years. A total of 562 deaths have been reported since the start of the season: three children <5 years of age, four children 5-19 years, 43 adults 20-64 years, and 512 adults ≥65 years of age. Influenza A has been reported in 92% of deaths. Adults 65 years of age or older represent 91% of all deaths reported this season. Detailed clinical information (e.g. underlying medical conditions) is not known for these cases.
      * Note: Influenza-associated hospitalizations are not reported to PHAC by the following Provinces and Territory: BC, NU, and QC. Only hospitalizations that require intensive medical care are reported by Saskatchewan. ICU admissions are not distinguished among hospital admissions reported from Ontario. Data may also include cases reported by the IMPACT and PCIRN networks. The number of new influenza-associated hospitalizations and deaths reported for the current week may include cases from Ontario that occurred in previous weeks, as a result of retrospective updates to the cumulative total. It is important to note that the hospitalization or death does not have to be attributable to influenza, a positive laboratory test is sufficient for reporting.
      1 Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
      UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.
      424 4 150 270 76 500 (7%)
      256 0 118 138 86 342 (5%)
      319 4 168 147 70 389 (5%)
      711 11 347 353 185 896 (12%)
      4744 3 2260 2481 500 5244 (70%)
      56 1 52 3 21 77 (1%)
      6510 23 3095 3392 938 7448
      87.4% 0.4% 47.5% 52.1% 12.6% 100.0%
      See additional data on Reported Influenza Hospitalizations and Deaths in Canada: 2009-10 to 2014-15 on the Public Health Agency of Canada website.
      .../

      http://www.phac-aspc.gc.ca/fluwatch/.../index-eng.php

      "Safety and security don't just happen, they are the result of collective consensus and public investment. We owe our children, the most vulnerable citizens in our society, a life free of violence and fear."
      -Nelson Mandela

      Comment


      • #33
        FluWatch report: May 10 to May 16, 2015 (Week 19)

        Posted 2015-05-22 For readers interested in the PDF version, the document is available for downloading or viewing:
        FluWatch report: May 10 to May 16, 2015 (Week 19) (PDF Version - 916 KB - 10 pages)

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        Overall Summary
        • Influenza B continues to be the most common influenza virus circulating in Canada; however, influenza B is past its peak and remains within expected levels for this time of year.
        • Overall, influenza activity in Canada continues to decrease; however, elevated activity was still reported in week 19 (mostly in parts of Central Canada and Newfoundland).
        • Based on laboratory detections, influenza B is having a greater impact on adults less than 65 years of age compared to influenza A(H3N2), which predominated earlier in the season.
        • As of week 19, 7,549 hospitalizations and 576 deaths have been reported from participating regions, which is more than were reported last year at this time (4,862 hospitalizations and 291 deaths).

        Are you a primary health care practitioner (General Practitioner, Nurse Practitioner or Registered Nurse) interested in becoming a FluWatch sentinel for the 2014-15 influenza season? Contact us at FluWatch@phac-aspc.gc.ca
        Influenza/ILI Activity (geographic spread)

        In week 19, one region in QC and one region in NL reported widespread activity. Eight regions reported localized activity: MB, ON(5), QC, and NL. Twenty-three regions reported sporadic activity: BC(4), AB(5), SK(3), MB(2), ON(2), QC(4), NL, NB, and NS.
        Figure 1. Map of overall influenza/ILI activity level by province and territory, Canada, Week 19
        Note: Influenza/ILI activity levels, as represented on this map, are assigned and reported by Provincial and Territorial Ministries of Health, based on laboratory confirmations, sentinel ILI rates and reported outbreaks. Please refer to detailed definitions at the end of the report. Maps from previous weeks, including any retrospective updates, are available on the FluWatch website.
        Text equivalent for figure 1Map of overall Influenza activity level by province and territory, Canada
        Influenza and Other Respiratory Virus Detections

        The number of positive influenza tests decreased from 314 in week 18 to 220 in week 19. Influenza B remained the predominant virus in week 19, representing 93% of influenza detections. Most jurisdictions reported stable or declining levels of influenza detections over recent weeks. To date, 81% of influenza detections have been influenza A, and 99.2% of those subtyped have been A(H3N2) (Table 1). To date this season, detailed information on age and type/subtype has been received for 36,997 cases (Table 2). Adults ≥65 years of age have predominantly been affected by influenza A, accounting for 62% of influenza A detections. Influenza B, while much smaller in numbers, is mainly affecting individuals less than 65 years of age. Adults under the age of 64 years accounted for 59% of influenza B detections.
        Figure 2. Number of positive influenza tests and percentage of tests positive, by type, subtype and report week, Canada, 2014-15
        Text equivalent for figure 2Number of positive influenza tests and percentage of tests positive, by type, subtype and report week, Canada, 2014-15
        In week 19, detections for all other respiratory viruses decreased from the previous week and are approaching inter-seasonal levels (figure 3).
        For more details, see the weekly Respiratory Virus Detections in Canada Report.
        Figure 3. Number of positive laboratory tests for other respiratory viruses by report week, Canada, 2014-15
        RSV: Respiratory syncytial virus; hMPV: Human metapneumovirus
        Text equivalent for figure 3Overall Number of Influenza Outbreaks, Canada, by Report Week, 2014-2015
        1 Specimens from NT, YT, and NU are sent to reference laboratories in other provinces. Cumulative data includes updates to previous weeks.
        2 Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
        UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.
        3 0 0 3 33 3525 28 2629 868 466
        1 0 0 1 25 3701 14 3531 156 937
        0 0 0 0 11 1315 0 839 476 311
        0 0 0 0 17 1124 1 390 733 214
        3 0 3 0 49 11162 50 4714 6398 1456
        4 0 0 4 50 11449 4 422 11023 3870
        0 0 0 0 6 1195 0 193 1002 530
        0 0 0 0 1 511 1 123 387 261
        0 0 0 0 0 131 1 128 2 108
        5 0 0 5 12 629 0 123 506 70
        16 0 3 13 204 34742 99 13092 21551 8223
        7.3% 0.0% 18.8% 81.3% 92.7% 80.9% 0.3% 37.7% 62.0% 19.1%
        1 Specimens from NT, YT, and NU are sent to reference laboratories in other provinces. Cumulative data includes updates to previous weeks.
        2 Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
        3 Table 2 includes specimens for which demographic information was reported. These represent a subset of all positive influenza cases reported.
        UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.
        0 0 0 0 7 2091 22 809 1260 524 2615 7.1%
        0 0 0 0 14 1781 6 956 819 755 2536 6.9%
        1 0 1 0 32 3443 16 1672 1755 1065 4508 12.2%
        4 0 0 4 36 3874 22 1659 2193 1762 5636 15.2%
        2 0 1 1 44 18745 15 7289 11441 2830 21575 58.3%
        0 0 0 0 0 120 0 101 19 7 127 0.3%
        7 0 2 5 133 30054 81 12486 17487 6943 36997 100.0%
        5.0% 0.0% 28.6% 71.4% 95.0% 81.2% 0.3% 41.5% 58.2% 18.8%
        Antiviral Resistance

        During the 2014-2015 influenza season, the NML has tested 1,499 influenza viruses for resistance to oseltamivir and 1,444 influenza viruses for resistance to zanamivir. All viruses were sensitive to zanamivir and one influenza A(H3N2) virus was resistant to oseltamivir. A total of 1,390 influenza A viruses (99.9%) were resistant to amantadine (Table 3).
        * NA - not applicable
        901 1 888 0 1372 1371 (99.9%)
        17 0 15 0 19 19 (100%)
        581 0 541 0 NA * NA *
        1499 1 1444 0 1391 1390
        Influenza Strain Characterizations

        During the 2014-2015 influenza season, the National Microbiology Laboratory (NML) has characterized 898 influenza viruses [195 A(H3N2), 18 A(H1N1) and 685 influenza B].
        Influenza A (H3N2): When tested by hemagglutination inhibition (HI) assay (n=195), one virus was antigenically similar to A/Texas/50/2012, five showed reduced titers to A/Texas/50/2012 and 189 were antigenically similar to A/Switzerland/9715293/2013, which is the influenza A(H3N2) component recommended for the 2015 Southern Hemisphere influenza vaccine. Additionally, 1,143 A(H3N2) viruses were unable to be tested by HI assay; however, sequence analysis showed that 1,141 belonged to a genetic group that typically shows reduced titers to A/Texas/50/2012. Influenza A(H1N1): Eighteen A(H1N1) viruses characterized were antigenically similar to A/California/7/2009. Influenza B: Of the 685 influenza B viruses characterized, 643 viruses were antigenically similar to B/Massachusetts/2/2012, three viruses showed reduced titers against B/Massachusetts/2/2012, and 39 were B/Brisbane/60/2008-like (Figure 4).
        Figure 4. Influenza strain characterizations, Canada, 2014-2015, N = 898

        The NML receives a proportion of the number of influenza positive specimens from provincial laboratories for strain characterization and antiviral resistance testing. Characterization data reflect the results of haemagglutination inhibition (HAI) testing compared to the reference influenza strains recommended byWHO.
        The recommended components for the 2014-2015 northern hemisphere trivalent influenza vaccine include: an A/California/7/2009(H1N1)pdm09-like virus, an A/Texas/50/2012 (H3N2)-like virus, and a B/Massachusetts/2/2012-like virus (Yamagata lineage). For quadrivalent vaccines, the addition of a B/Brisbane/60/2008-like virus is recommended.


        Text equivalent for figure 4Influenza strain characterizations, Canada, 2014-2015, N =3
        Influenza-like Illness (ILI) Consultation Rate

        In week 19, the national influenza-like-illness (ILI) consultation rate increased from the previous week to 23.8 consultations per 1,000 (Figure 5).
        Figure 5. Influenza-like-illness (ILI) consultation rates by report week, compared to the 1996-97 through to 2012-13 seasons (with pandemic data suppressed), Canada, 2014-2015
        No data available for mean rate for weeks 19 to 39 for the 1996-1997 through 2002-2003 seasons. Delays in the reporting of data may cause data to change retrospectively. The calculation of the average ILI consultation rate over 17 seasons was aligned with influenza activity in each season. In BC, AB, and SK, data is compiled by a provincial sentinel surveillance program for reporting to FluWatch. Not all sentinel physicians report every week.
        Text equivalent for figure 5Influenza-like-illness (ILI) consultation rates by report week, compared to the 1996-97 through to 2012-13 seasons (with pandemic data suppressed), Canada, 2014-2015
        Influenza Outbreak Surveillance

        In week 19, 10 new outbreaks of influenza were reported. Eight outbreaks were reported in long-term care facilities (LTCF) and two in institutional or community settings (Figure 6). Among the outbreaks in which the influenza type was known (n=3), all were associated with influenza B. To date this season, 1,273 outbreaks in LTCFs have been reported and the majority of those with known subtypes were attributable to A(H3N2). There have been a higher number of reported influenza outbreaks to date this season compared to the same period in previous seasons.
        Figure 6. Overall number of new laboratory-confirmed influenza outbreaks by report week, Canada, 2014-2015
        1 All provinces and territories except NU report outbreaks in long-term care facilities. All provinces and territories with the exception of NU and QC report outbreaks in hospitals. Outbreaks of influenza or influenza-like-illness in other facilities are reported to FluWatch but reporting varies between jurisdictions. Outbreak definitions are included at the end of the report.
        Text equivalent for figure 6Overall number of new influenza outbreaks by report week, Canada, 2014-2015
        Pharmacy Surveillance

        Pharmacy surveillance for sales of influenza antivirals has ended for the 2014-2015 influenza season (Figure 7).
        Figure 7. Proportion of prescription sales for influenza antivirals by age-group and week, Canada, 2014-15
        Note: Pharmacy sales data are provided to the Public Health Agency of Canada by Rx Canada Inc. and sourced from major retail drug chains representing over 2,500 stores nationwide (excluding Nunavut) in 85% of Health Regions. Data provided include the number of new antiviral prescriptions (for Tamiflu and Relenza) and the total number of new prescriptions dispensed by Province/Territory and age group. Age-groups: Infant: 0-2y, Child: 2-18y; Adult: 19-64y, Senior: ≥65y
        Text equivalent for figure 7Proportion of prescription sales for influenza antivirals by age-group and week, Canada, 2014-15
        Sentinel Hospital Influenza Surveillance

        Paediatric Influenza Hospitalizations and Deaths (IMPACT)
        In week 19, three laboratory-confirmed influenza-associated paediatric (=16 years of age) hospitalizations were reported by the Immunization Monitoring Program Active (IMPACT) network. All cases were influenza B (Figure 8a). A greater proportion of cases have been reported with influenza B in recent weeks, following the trend in laboratory detections. Among the reported cases, two (67%) were <2 years of age and one (33%) was 10 to 16 years of age. No ICU admissions were reported.
        To date this season, 685 hospitalizations have been reported by the IMPACT network, 509 (74%) of which were cases of influenza A. Among cases for which the influenza A subtype was reported, 98% (161/164) were A(H3N2) (Table 4). To date, 85 cases were admitted to the ICU, of which 48 (57%) were 2 to 9 years of age (Figure 9a). A total of 56 ICU cases reported to have at least one underlying condition or comorbidity. Four deaths have been reported.
        Note: The number of hospitalizations reported through IMPACT represents a subset of all influenza-associated paediatric hospitalizations in Canada. Delays in the reporting of data may cause data to change retrospectively.
        Adult Influenza Hospitalizations and Deaths (PCIRN)
        Surveillance has ended for the 2014-2015 influenza season.
        This season, 2,228 cases have been reported; 1,912 (86%) with influenza A. The majority of cases (81%) were among adults ≥65 years of age (Table 5). One hundred and seventy two ICU admissions have been reported and 128 cases were adults ≥65 years of age. Among the 172 ICU admissions, 27 were due to influenza B (12 in adults 45 to 64 years of age and 15 in adults over the age of 65). A total of 123 ICU cases (72%) reported to have at least one underlying condition or comorbidity. Of the 123 ICU cases with known immunization status, 40 (33%) reported not having been vaccinated this season. One hundred and thirty-five deaths have been reported, 124 (92%) of the deaths were adults >65 years of age (Figure 9B).
        Note: The number of hospitalizations reported through PCIRN represents a subset of all influenza-associated adult hospitalizations in Canada. Delays in the reporting of data may cause data to change retrospectively.
        1 Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
        UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.
        81 0 18 63 14 95 (13.9%)
        114 2 36 76 36 150 (21.9%)
        124 1 38 85 47 171 (25.0%)
        129 0 44 85 50 179 (26.1%)
        61 0 25 36 29 90 (13.1%)
        509 3 161 345 176 685
        74.3% 0.6% 31.6% 67.8% 25.7% 100.0%
        1 Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
        UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.
        3 0 1 2 1 4 (%)
        106 1 56 49 16 122 (5%)
        217 3 99 115 76 293 (13%)
        1586 4 760 822 223 1809 (81%)
        1912 8 916 988 316 2228
        86% 0% 48% 52% 14% 100%
        Figure 8 - Number of cases of influenza reported by sentinel hospital networks, by week, Canada, 2014-15
        A) Paediatric hospitalizations (≤16 years of age, IMPACT)

        Text equivalent for figure 8aNumber of cases of influenza reported by sentinel hospital networks, by week, Canada, 2014-15: Paediatric hospitalizations (≤16 years of age, IMPACT)
        B) Adult hospitalizations (≥16 year of age, PCIRN-SOS)

        * See footnote above following the section related to PCIRN-SOS data.
        Text equivalent for figure 8bNumber of cases of influenza reported by sentinel hospital networks, by week, Canada, 2014-15: Adult hospitalizations (>16 year of age, PCIRN-SOS)
        Figure 9 - Percentage of hospitalizations, ICU admissions and deaths with influenza reported by age-group, Canada, 2014-15
        A) Paediatric hospitalizations (≤16 years of age, IMPACT)
        Text equivalent for figure 9aPercentage of hospitalizations, ICU admissions and deaths with influenza reported by age-group, Canada, 2014-15: Paediatric hospitalizations (≤16 years of age, IMPACT)
        B) Adult hospitalizations (≥16 year of age, PCIRN-SOS)

        Text equivalent for figure 9bPercentage of hospitalizations, ICU admissions and deaths with influenza reported by age-group, Canada, 2014-15: Adult hospitalizations (≥16 year of age, PCIRN-SOS)
        Provincial/Territorial Influenza Hospitalizations and Deaths

        In week 19, 37 laboratory-confirmed influenza-associated hospitalizations were reported from participating provinces and territories*, which is lower than the number reported the previous week. Of the 37 hospitalizations, 20 (54%) were due to influenza A and 15 (41%) were in patients ≥65 years of age.
        Since the start of the 2014-15 season, 7,549 hospitalizations have been reported; 6,540 (87%) with influenza A. Among cases for which the subtype of influenza A was reported, 99.2% were A(H3N2). The majority of cases (70%) were ≥65 years of age (Table 6). A total of 389 ICU admissions have been reported to date: 53% (n=203) were in adults ≥65 years of age and 76% were due to influenza A. A total of 576 deaths have been reported since the start of the season: three children <5 years of age, four children 5-19 years, 43 adults 20-64 years, and 526 adults ≥65 years of age. Influenza A has been reported in 91% of deaths. Adults 65 years of age or older represent 91% of all deaths reported this season. Detailed clinical information (e.g. underlying medical conditions) is not known for these cases.
        * Note: Influenza-associated hospitalizations are not reported to PHAC by the following Provinces and Territory: BC, NU, and QC. Only hospitalizations that require intensive medical care are reported by Saskatchewan. ICU admissions are not distinguished among hospital admissions reported from Ontario. Data may also include cases reported by the IMPACT and PCIRN networks. The number of new influenza-associated hospitalizations and deaths reported for the current week may include cases from Ontario that occurred in previous weeks, as a result of retrospective updates to the cumulative total. It is important to note that the hospitalization or death does not have to be attributable to influenza, a positive laboratory test is sufficient for reporting.
        1 Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
        UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.
        425 5 150 270 83 508 (7%)
        258 0 120 138 90 348 (5%)
        321 4 168 149 77 398 (5%)
        718 12 352 354 197 915 (12%)
        4762 4 2274 2484 541 5303 (70%)
        56 1 52 3 21 77 (1%)
        6540 26 3116 3398 1009 7549
        86.6% 0.4% 47.6% 52.0% 13.4% 100.0%
        See additional data on Reported Influenza Hospitalizations and Deaths in Canada: 2009-10 to 2014-15 on the Public Health Agency of Canada website.

        .../
        http://www.phac-aspc.gc.ca/fluwatch/.../index-eng.php

        "Safety and security don't just happen, they are the result of collective consensus and public investment. We owe our children, the most vulnerable citizens in our society, a life free of violence and fear."
        -Nelson Mandela

        Comment


        • #34
          FluWatch report: May 17 to May 23, 2015 (Week 20)

          Posted 2015-05-29 For readers interested in the PDF version, the document is available for downloading or viewing:
          FluWatch report: May 17 to May 23, 2015 (Week 20) (PDF Version - 915 KB - 10 pages)

          Help with PDF documents

          Overall Summary
          • Influenza B continues to be the most common influenza virus circulating in Canada; however, influenza B is past its peak and remains within expected levels for this time of year.
          • Overall, influenza activity in Canada continues to decrease as we approach the end of the influenza season.
          • Based on laboratory detections, influenza B is having a greater impact on adults less than 65 years of age compared to influenza A(H3N2), which predominated earlier in the season.
          • As of week 20, 7,602 hospitalizations and 579 deaths have been reported from participating regions, which is more than were reported last year at this time (4,867 hospitalizations and 293 deaths).

          Please Note: This is the final weekly report for the 2014-15 influenza season. Bi-weekly reports will start on June 12th (for weeks 21 and 22). Laboratory detections reported through the RVDSS will be updated weekly on the FluWatch website.
          Influenza/ILI Activity (geographic spread)

          In week 20, nine regions reported localized activity: BC, ON(5), QC and NL(2). Twenty-one regions reported sporadic activity: BC(3), AB(5), SK(3), MB(2), ON(2), QC(5), and NB.
          Figure 1. Map of overall influenza/ILI activity level by province and territory, Canada, Week 20
          Note: Influenza/ILI activity levels, as represented on this map, are assigned and reported by Provincial and Territorial Ministries of Health, based on laboratory confirmations, sentinel ILI rates and reported outbreaks. Please refer to detailed definitions at the end of the report. Maps from previous weeks, including any retrospective updates, are available on the FluWatch website.
          Text equivalent for figure 1Map of overall Influenza activity level by province and territory, Canada
          Influenza and Other Respiratory Virus Detections

          The number of positive influenza tests decreased from 233 in week 19 to 124 in week 20. Influenza B remained the predominant virus in week 20, representing 98% of influenza detections. All jurisdictions reported declining levels of influenza detections this week. To date, 81% of influenza detections have been influenza A (Table 1). To date this season, detailed information on age and type/subtype has been received for 37,126 cases (Table 2). Adults ≥65 years of age have predominantly been affected by influenza A, accounting for 62% of influenza A detections. Influenza B, while much smaller in numbers, is mainly affecting individuals less than 65 years of age. Adults under the age of 64 years accounted for 59% of influenza B detections.
          Figure 2. Number of positive influenza tests and percentage of tests positive, by type, subtype and report week, Canada, 2014-15
          Text equivalent for figure 2Number of positive influenza tests and percentage of tests positive, by type, subtype and report week, Canada, 2014-15
          In week 20, detections for all other respiratory viruses decreased from the previous week and are approaching inter-seasonal levels (figure 3).
          For more details, see the weekly Respiratory Virus Detections in Canada Report.
          Figure 3. Number of positive laboratory tests for other respiratory viruses by report week, Canada, 2014-15
          RSV: Respiratory syncytial virus; hMPV: Human metapneumovirus
          Text equivalent for figure 3Overall Number of Influenza Outbreaks, Canada, by Report Week, 2014-2015
          1 Specimens from NT, YT, and NU are sent to reference laboratories in other provinces. Cumulative data includes updates to previous weeks.
          2 Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
          UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.
          0 0 0 0 14 3525 28 2629 868 480
          1 0 1 0 21 3702 14 3533 155 957
          0 0 0 0 9 1315 0 839 476 334
          0 0 0 0 6 1124 1 390 733 220
          2 0 0 2 33 11164 50 4714 6400 1498
          0 0 0 0 32 11449 4 422 11023 3902
          0 0 0 0 0 1195 0 193 1002 530
          0 0 0 0 0 511 1 123 387 261
          0 0 0 0 0 131 1 128 2 108
          0 0 0 0 6 629 0 123 506 76
          3 0 1 2 121 34745 99 13094 21552 8366
          2.4% 0.0% 33.3% 66.7% 97.6% 80.6% 0.3% 37.7% 62.0% 19.4%
          1 Specimens from NT, YT, and NU are sent to reference laboratories in other provinces. Cumulative data includes updates to previous weeks.
          2 Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
          3 Table 2 includes specimens for which demographic information was reported. These represent a subset of all positive influenza cases reported.
          UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.
          0 0 0 0 10 2091 22 809 1260 541 2632 7.1%
          0 0 0 0 17 1781 6 956 819 774 2555 6.9%
          0 0 0 0 20 3443 17 1673 1753 1094 4537 12.2%
          0 0 0 0 15 3874 22 1659 2193 1783 5657 15.2%
          1 0 1 0 30 18746 15 7290 11441 2872 21618 58.2%
          0 0 0 0 0 120 0 101 19 7 127 0.3%
          1 0 1 0 92 30055 82 12488 17485 7071 37126 100.0%
          1.1% 0.0% 100.0% 0.0% 98.9% 81.0% 0.3% 41.6% 58.2% 19.0%
          Antiviral Resistance

          During the 2014-2015 influenza season, the NML has tested 1,561 influenza viruses for resistance to oseltamivir and 1,559 influenza viruses for resistance to zanamivir. All viruses were sensitive to zanamivir and one influenza A(H3N2) virus was resistant to oseltamivir. A total of 1,427 influenza A viruses (99.9%) were resistant to amantadine (Table 3).
          * NA - not applicable
          901 1 900 0 1408 1407 (99.9%)
          18 0 18 0 20 20 (100%)
          642 0 641 0 NA * NA *
          1561 1 1559 0 1428 1427
          Influenza Strain Characterizations

          During the 2014-2015 influenza season, the National Microbiology Laboratory (NML) has characterized 961 influenza viruses [198 A(H3N2), 21 A(H1N1) and 742 influenza B].
          Influenza A (H3N2): When tested by hemagglutination inhibition (HI) assay (n=198), one virus was antigenically similar to A/Texas/50/2012, five showed reduced titers to A/Texas/50/2012 and 192 were antigenically similar to A/Switzerland/9715293/2013, which is the influenza A(H3N2) component recommended for the 2015 Southern Hemisphere influenza vaccine. Additionally, 1,160 A(H3N2) viruses were unable to be tested by HI assay; however, sequence analysis showed that 1,158 belonged to a genetic group that typically shows reduced titers to A/Texas/50/2012. Influenza A(H1N1): Twenty-one A(H1N1) viruses characterized were antigenically similar to A/California/7/2009. Influenza B: Of the 742 influenza B viruses characterized, 683 viruses were antigenically similar to B/Massachusetts/2/2012, three viruses showed reduced titers against B/Massachusetts/2/2012, and 56 were B/Brisbane/60/2008-like (Figure 4).
          Figure 4. Influenza strain characterizations, Canada, 2014-2015, N = 961

          The NML receives a proportion of the number of influenza positive specimens from provincial laboratories for strain characterization and antiviral resistance testing. Characterization data reflect the results of haemagglutination inhibition (HAI) testing compared to the reference influenza strains recommended byWHO.
          The recommended components for the 2014-2015 northern hemisphere trivalent influenza vaccine include: an A/California/7/2009(H1N1)pdm09-like virus, an A/Texas/50/2012 (H3N2)-like virus, and a B/Massachusetts/2/2012-like virus (Yamagata lineage). For quadrivalent vaccines, the addition of a B/Brisbane/60/2008-like virus is recommended.


          Text equivalent for figure 4Influenza strain characterizations, Canada, 2014-2015, N =3
          Influenza-like Illness (ILI) Consultation Rate

          In week 20, the national influenza-like-illness (ILI) consultation rate decreased from the previous week to 16.1 consultations per 1,000 (Figure 5).
          Figure 5. Influenza-like-illness (ILI) consultation rates by report week, compared to the 1996-97 through to 2012-13 seasons (with pandemic data suppressed), Canada, 2014-2015
          No data available for mean rate for weeks 19 to 39 for the 1996-1997 through 2002-2003 seasons. Delays in the reporting of data may cause data to change retrospectively. The calculation of the average ILI consultation rate over 17 seasons was aligned with influenza activity in each season. In BC, AB, and SK, data is compiled by a provincial sentinel surveillance program for reporting to FluWatch. Not all sentinel physicians report every week.
          Text equivalent for figure 5Influenza-like-illness (ILI) consultation rates by report week, compared to the 1996-97 through to 2012-13 seasons (with pandemic data suppressed), Canada, 2014-2015
          Influenza Outbreak Surveillance

          In week 20, four new outbreaks of influenza were reported. Two outbreaks were reported in long-term care facilities (LTCF) and two in institutional or community settings (Figure 6). To date this season, 1,275 outbreaks in LTCFs have been reported and the majority of those with known subtypes were attributable to A(H3N2). There have been a higher number of reported influenza outbreaks to date this season compared to the same period in previous seasons.
          Figure 6. Overall number of new laboratory-confirmed influenza outbreaks by report week, Canada, 2014-2015
          1 All provinces and territories except NU report outbreaks in long-term care facilities. All provinces and territories with the exception of NU and QC report outbreaks in hospitals. Outbreaks of influenza or influenza-like-illness in other facilities are reported to FluWatch but reporting varies between jurisdictions. Outbreak definitions are included at the end of the report.
          Text equivalent for figure 6Overall number of new influenza outbreaks by report week, Canada, 2014-2015
          Pharmacy Surveillance

          Pharmacy surveillance for sales of influenza antivirals has ended for the 2014-2015 influenza season (Figure 7).
          Figure 7. Proportion of prescription sales for influenza antivirals by age-group and week, Canada, 2014-15
          Note: Pharmacy sales data are provided to the Public Health Agency of Canada by Rx Canada Inc. and sourced from major retail drug chains representing over 2,500 stores nationwide (excluding Nunavut) in 85% of Health Regions. Data provided include the number of new antiviral prescriptions (for Tamiflu and Relenza) and the total number of new prescriptions dispensed by Province/Territory and age group. Age-groups: Infant: 0-2y, Child: 2-18y; Adult: 19-64y, Senior: ≥65y
          Text equivalent for figure 7Proportion of prescription sales for influenza antivirals by age-group and week, Canada, 2014-15
          Sentinel Hospital Influenza Surveillance

          Paediatric Influenza Hospitalizations and Deaths (IMPACT)
          In week 20, nine laboratory-confirmed influenza-associated paediatric (≤16 years of age) hospitalizations were reported by the Immunization Monitoring Program Active (IMPACT) network. All cases were influenza B (Figure 8a). A greater proportion of cases have been reported with influenza B in recent weeks, following the trend in laboratory detections. Among the reported cases, two (22%) were <2 years of age, three (33%) were 2 to 9 years of age and four (44%) were 10 to 16 years of age. One ICU admission was reported.
          To date this season, 697 hospitalizations have been reported by the IMPACT network, 510 (73%) of which were cases of influenza A. Among cases for which the influenza A subtype was reported, 98% (162/165) were A(H3N2) (Table 4). To date, 88 cases were admitted to the ICU, of which 48 (55%) were 2 to 9 years of age (Figure 9a). A total of 55 ICU cases reported to have at least one underlying condition or comorbidity. Five deaths have been reported.
          Note: The number of hospitalizations reported through IMPACT represents a subset of all influenza-associated paediatric hospitalizations in Canada. Delays in the reporting of data may cause data to change retrospectively.
          Adult Influenza Hospitalizations and Deaths (PCIRN)
          Surveillance has ended for the 2014-2015 influenza season.
          This season, 2,228 cases have been reported; 1,912 (86%) with influenza A. The majority of cases (81%) were among adults ≥65 years of age (Table 5). One hundred and seventy two ICU admissions have been reported and 128 cases were adults ≥65 years of age. Among the 172 ICU admissions, 27 were due to influenza B (12 in adults 45 to 64 years of age and 15 in adults over the age of 65). A total of 123 ICU cases (72%) reported to have at least one underlying condition or comorbidity. Of the 123 ICU cases with known immunization status, 40 (33%) reported not having been vaccinated this season. One hundred and thirty-five deaths have been reported, 124 (92%) of the deaths were adults >65 years of age (Figure 9B).
          Note: The number of hospitalizations reported through PCIRN represents a subset of all influenza-associated adult hospitalizations in Canada. Delays in the reporting of data may cause data to change retrospectively.
          1 Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
          UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.
          82 0 19 63 14 96 (13.8%)
          114 2 36 76 40 154 (22.1%)
          124 1 38 85 49 173 (24.8%)
          129 0 44 85 51 180 (25.8%)
          61 0 25 36 33 94 (13.5%)
          510 3 162 345 187 697
          73.2% 0.6% 31.8% 67.6% 26.8% 100.0%
          1 Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
          UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.
          3 0 1 2 1 4 (%)
          106 1 56 49 16 122 (5%)
          217 3 99 115 76 293 (13%)
          1586 4 760 822 223 1809 (81%)
          1912 8 916 988 316 2228
          86% 0% 48% 52% 14% 100%
          Figure 8 - Number of cases of influenza reported by sentinel hospital networks, by week, Canada, 2014-15
          A) Paediatric hospitalizations (≤16 years of age, IMPACT)

          Text equivalent for figure 8aNumber of cases of influenza reported by sentinel hospital networks, by week, Canada, 2014-15: Paediatric hospitalizations (≤16 years of age, IMPACT)
          B) Adult hospitalizations (≥16 year of age, PCIRN-SOS)

          * See footnote above following the section related to PCIRN-SOS data.
          Text equivalent for figure 8bNumber of cases of influenza reported by sentinel hospital networks, by week, Canada, 2014-15: Adult hospitalizations (>16 year of age, PCIRN-SOS)
          Figure 9 - Percentage of hospitalizations, ICU admissions and deaths with influenza reported by age-group, Canada, 2014-15
          A) Paediatric hospitalizations (≤16 years of age, IMPACT)
          Text equivalent for figure 9aPercentage of hospitalizations, ICU admissions and deaths with influenza reported by age-group, Canada, 2014-15: Paediatric hospitalizations (≤16 years of age, IMPACT)
          B) Adult hospitalizations (≥16 year of age, PCIRN-SOS)

          Text equivalent for figure 9bPercentage of hospitalizations, ICU admissions and deaths with influenza reported by age-group, Canada, 2014-15: Adult hospitalizations (≥16 year of age, PCIRN-SOS)
          Provincial/Territorial Influenza Hospitalizations and Deaths

          In week 20, 38 laboratory-confirmed influenza-associated hospitalizations were reported from participating provinces and territories*. Of the 38 hospitalizations, 25 (66%) were due to influenza A and 22 (58%) were in patients ≥65 years of age.
          Since the start of the 2014-15 season, 7,602 hospitalizations have been reported; 6,565 (86%) with influenza A. Among cases for which the subtype of influenza A was reported, 99.1% were A(H3N2). The majority of cases (70%) were ≥65 years of age (Table 6). A total of 391 ICU admissions have been reported to date: 52% (n=203) were in adults ≥65 years of age and 75% were due to influenza A. A total of 579 deaths have been reported since the start of the season: three children <5 years of age, four children 5-19 years, 43 adults 20-64 years, and 529 adults ≥65 years of age. Influenza A has been reported in 91% of deaths. Adults 65 years of age or older represent 91% of all deaths reported this season. Detailed clinical information (e.g. underlying medical conditions) is not known for these cases.
          * Note: Influenza-associated hospitalizations are not reported to PHAC by the following Provinces and Territory: BC, NU, and QC. Only hospitalizations that require intensive medical care are reported by Saskatchewan. ICU admissions are not distinguished among hospital admissions reported from Ontario. Data may also include cases reported by the IMPACT and PCIRN networks. The number of new influenza-associated hospitalizations and deaths reported for the current week may include cases from Ontario that occurred in previous weeks, as a result of retrospective updates to the cumulative total. It is important to note that the hospitalization or death does not have to be attributable to influenza, a positive laboratory test is sufficient for reporting.
          1 Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
          UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.
          426 6 150 270 85 511 (7%)
          258 0 120 138 93 351 (5%)
          322 4 169 149 80 402 (5%)
          720 12 354 354 203 923 (12%)
          4783 5 2291 2487 554 5337 (70%)
          56 1 52 3 22 78 (1%)
          6565 28 3136 3401 1037 7602
          86.4% 0.4% 47.8% 51.8% 13.6% 100.0%
          See additional data on Reported Influenza Hospitalizations and Deaths in Canada: 2009-10 to 2014-15 on the Public Health Agency of Canada website.
          .../

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