Seasonal Influenza in Alberta
Influenza data included in the interactive data application are aggregated by week and up-to-date as of end of week 29 (July 22, 2023), unless stated otherwise.
Highlights
Note: aggregate data in highlights are cumulative for the entire 2022-2023 season
cases 📈
influenza A 📈
influenza B 📈
hospitalizations 🚑
ICU admissions 🏥
deaths ⚱
dominant subtype
Summary
Cases (n) | Influenza A cases (n) | Influenza B cases (n) | Hospitalizations (n) | ICU admissions (n) | Deaths (n) | |
---|---|---|---|---|---|---|
Alberta | 9,731 | 9,025 | 706 | 2,236 | 235 | 121 |
Calgary Zone | 3,311 | 3,050 | 261 | 850 | 94 | 32 |
Central Zone | 1,134 | 1,080 | 54 | 255 | 26 | 23 |
Edmonton Zone | 2,871 | 2,616 | 255 | 638 | 65 | 31 |
North Zone | 1,685 | 1,599 | 86 | 269 | 27 | 16 |
South Zone | 721 | 671 | 50 | 216 | 23 | 19 |
Unknown | 9 | 9 | 0 | 8 | 0 | 0 |
Figure 1: Laboratory-confirmed influenza cases by subtype
Figure 2: Laboratory-confirmed influenza cases by subtype from the previous five seasons
Figure 3: Laboratory-confirmed seasonal influenza cases in Alberta since the 2009-2010 season
Geospatial
Figure 4: Laboratory-confirmed seasonal influenza cases in the previous 5 seasons by zone
Characteristics
Figure 5: Cases and rates (per 100,000 population) of laboratory-confirmed influenza by age group, 2022-2023
Severe Outcomes
Figure 6: Cumulative hospitalizations, ICU admissions and deaths among people with laboratory-confirmed influenza cases by age group, 2022-2023
Age group
|
Hospitalizations
|
ICU admissions
|
Deaths
|
|||
---|---|---|---|---|---|---|
Count | Population rate | Count | Population rate | Count | Population rate | |
Under 1 year | 99 | 197.8 | 14 | 28.0 | 0 | 0.0 |
1-4 years | 273 | 131.6 | 30 | 14.5 | 1 | 0.5 |
5-9 years | 157 | 55.2 | 10 | 3.5 | 1 | 0.4 |
10-19 years | 87 | 15.7 | 11 | 2.0 | 1 | 0.2 |
20-29 years | 78 | 13.2 | 10 | 1.7 | 0 | 0.0 |
30-39 years | 138 | 19.1 | 20 | 2.8 | 4 | 0.6 |
40-49 years | 111 | 17.4 | 19 | 3.0 | 5 | 0.8 |
50-59 years | 147 | 26.8 | 28 | 5.1 | 10 | 1.8 |
60-69 years | 373 | 73.6 | 54 | 10.7 | 25 | 4.9 |
70-79 years | 400 | 137.6 | 30 | 10.3 | 32 | 11.0 |
80-89 years | 282 | 235.2 | 8 | 6.7 | 27 | 22.5 |
90+ years | 91 | 321.1 | 1 | 3.5 | 15 | 52.9 |
Unknown | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 |
Laboratory Testing
Table 3: Summary of influenza viruses, 2022-2023Respiratory virus | Number of tests in the current week (n) | Cumulative number of tests in the season (n) | Percent positivity in the current week (%) | Rolling percent positivity (%; previous 3 weeks) |
---|---|---|---|---|
Influenza A | 2,028 | 163,552 | 0.4 | 0.7 |
Influenza B | 2,029 | 163,224 | 0.0 | 0.1 |
Figure 7: Influenza tests and positivity by week
Outbreaks
Table 4: Influenza outbreaks by outbreak setting, 2022-2023Influenza | Acute Care Facility | Long Term Care Facility | Other | Supportive Living/Home Living Sites | Total |
---|---|---|---|---|---|
COVID-19 and Influenza A (H1N1) | 0 | 2 | 0 | 2 | 4 |
COVID-19 and Influenza A (H3N2) | 2 | 7 | 0 | 20 | 29 |
COVID-19 and Influenza A (Untyped) | 0 | 0 | 1 | 4 | 5 |
COVID-19 and Influenza B | 0 | 0 | 0 | 0 | 0 |
Influenza A (H1N1) | 1 | 2 | 0 | 1 | 4 |
Influenza A (H3N2) | 9 | 12 | 0 | 25 | 46 |
Influenza A (Untyped) | 2 | 5 | 1 | 3 | 11 |
Influenza B | 0 | 0 | 1 | 0 | 1 |
Influenza Mixed | 0 | 0 | 0 | 0 | 0 |
Total | 14 | 28 | 3 | 55 | 100 |
Respiratory virus | Calgary Zone | Central Zone | Edmonton Zone | North Zone | South Zone | Total |
---|---|---|---|---|---|---|
COVID-19 and Influenza A (H1N1) | 3 | 1 | 0 | 0 | 0 | 4 |
COVID-19 and Influenza A (H3N2) | 10 | 7 | 8 | 0 | 4 | 29 |
COVID-19 and Influenza A (Untyped) | 1 | 3 | 0 | 1 | 0 | 5 |
COVID-19 and Influenza B | 0 | 0 | 0 | 0 | 0 | 0 |
Influenza A (H1N1) | 1 | 1 | 1 | 1 | 0 | 4 |
Influenza A (H3N2) | 11 | 14 | 13 | 6 | 2 | 46 |
Influenza A (Untyped) | 6 | 4 | 1 | 0 | 0 | 11 |
Influenza B | 0 | 1 | 0 | 0 | 0 | 1 |
Influenza Mixed | 0 | 0 | 0 | 0 | 0 | 0 |
Total | 32 | 31 | 23 | 8 | 6 | 100 |
Immunizations
Data Notes
More information
Data sources
Communicable Disease Reporting System (CDRS), Alberta Health Provincial Surveillance Information (PSI), Alberta Health Alberta Health Care Insurance Plan (AHCIP) Quarterly Population Registry, Alberta Health Immunization/Adverse Reactions to Immunization (Imm/ARI), Alberta Health
Definitions
Influenza Deaths
A death resulting from a clinically compatible illness in a laboratory-confirmed influenza case, unless there is a clear alternative cause of death identified (e.g. trauma, poisoning, drug overdos, etc.).
A Medical Officer of Health or relevant public health authority may use their discretion when determining if a death was due to influenza, and their judgement will supersede the above criteria.
A death due to influenza may be attributed when influenza is the cause of death or is a contributing factor.
Influenza Outbreaks
Influenza outbreaks that occur in group settings such as hospitals, residential institutions, schools, and child care facilities are reported to Alberta Health. Outbreaks are defined as the occurrence of a communicable disease in a community, region, or setting where the number of cases is more than would be expected for a defined period of time. Influenza outbreaks in hospitals, residential institutions, and other closed communities are defined as two or more cases of influenza-like illness, with at least one laboratory-confirmed case. School influenza outbreaks require greater than 10 per cent absenteeism or absenteeism that is 10 per cent higher than baseline levels. Please see the Public Health Disease Management Guidelines: Influenza, Seasonal and Public Health Disease Management Guidelines: Epidemics for more information.
Lab Positivity
Influenza percent positivity in Alberta is calculated using the Test Over Test method, which is the same method employed by the US Centers for Disease Control and Prevention. The calculation is as follows:
Daily Number of Positive Tests / (Daily Number of Positive Tests + Daily Number of Negative Tests) Q/RT-PCR tests are the only COVID-19 tests included in this calculation.
Vaccine coverage
Individuals who received one dose was calculated as (# of individuals who received at least one dose) / (population estimate).
Immunizations
*‘Other Providers’ include Alberta Health Services (AHS) non-Public Health, non-AHS (including Long-term care (LTC) sites) and Physicians from AHS, IDSM, and First Nations and Inuit Health Branch (FNIHB). Includes influenza immunization doses administration data from AHS (AHS non-Public Health, non-AHS (including LTC sites) and Physicians), AH (IDSM, WHS and Covenant OHS) and FNIHB for the month of Oct, Nov, Dec, Jan, Feb, Mar 2021/22.
Disclaimer
The content and format of this report are subject to change. Cases are under investigation and numbers may fluctuate as cases are resolved.
Doses Administered 💉
Coverage 📈
Influenza Weekly Immunization Report to 06 May, 2023 (Fluwatch week 18)
1,276,970 doses of influenza vaccine have been administered in Alberta
217,111 doses of influenza vaccine have been administered by AHS
971,602 doses of influenza vaccine have been administered by pharmacies
88,257 doses of influenza vaccine have been administered by other providers*
27.7% of Albertans have received an influenza vaccine
- 63.9% of Albertans 65 years of age and older have received an influenza vaccine (429,458 doses administered)
Previous Season:
- This week, in the 2021-2022 season, a total of 1,209,464 doses were administered (Provincial coverage = 26.9%)
Cumulative influenza vaccine doses administered by week in Alberta
Influenza vaccine doses administered by week in Alberta
Influenza vaccine coverage by week and age group in Alberta
Table 1: Influenza vaccine doses administered and coverage by AHS health zone and provider
Zone | AHS | Pharmacy | Other | Total administered | Population | Coverage (%) |
---|---|---|---|---|---|---|
Calgary Zone | 80,898 | 429,612 | 49,232 | 559,742 | 1,783,370 | 31.0 |
Central Zone | 14,718 | 89,158 | 3,141 | 107,017 | 479,950 | 22.1 |
Edmonton Zone | 82,907 | 330,739 | 25,661 | 439,307 | 1,487,160 | 29.1 |
North Zone | 21,338 | 59,370 | 3,989 | 84,697 | 476,094 | 17.6 |
South Zone | 16,289 | 61,580 | 5,305 | 83,174 | 316,187 | 26.0 |
Unknown | 961 | 1,143 | 929 | 3,033 | 0 | 0.0 |
Alberta | 217,111 | 971,602 | 88,257 | 1,276,970 | 4,542,761 | 27.8 |
Table 2: Influenza vaccine doses administered and coverage by age group (5-year groups) and provider
Age groups | AHS | Pharmacy | Other | Total administered | Population | Coverage (%) |
---|---|---|---|---|---|---|
under 1 year | 20,457 | 14 | 508 | 20,979 | 50,054 | 27.0 |
1-4 years | 63,057 | 3 | 2,036 | 65,096 | 207,462 | 27.6 |
5-9 years | 14,088 | 41,108 | 2,400 | 57,596 | 284,474 | 19.9 |
10-14 years | 3,944 | 42,511 | 2,126 | 48,581 | 286,812 | 16.9 |
15-19 years | 2,074 | 32,393 | 2,496 | 36,963 | 268,559 | 13.8 |
20-24 years | 4,594 | 24,981 | 3,932 | 33,507 | 281,123 | 11.9 |
25-29 years | 9,546 | 29,876 | 4,476 | 43,898 | 307,765 | 14.3 |
30-34 years | 19,028 | 40,308 | 5,766 | 65,102 | 353,845 | 18.4 |
35-39 years | 21,587 | 49,710 | 6,424 | 77,721 | 369,898 | 21.0 |
40-44 years | 13,209 | 53,905 | 6,147 | 73,261 | 340,631 | 21.5 |
45-49 years | 7,685 | 54,397 | 5,903 | 67,985 | 298,715 | 22.8 |
50-54 years | 6,755 | 60,897 | 6,286 | 73,938 | 274,974 | 26.9 |
55-59 years | 6,747 | 75,449 | 6,646 | 88,842 | 273,030 | 32.5 |
60-64 years | 6,688 | 101,204 | 7,030 | 114,922 | 273,345 | 42.0 |
65-69 years | 5,002 | 111,815 | 6,656 | 123,473 | 233,396 | 52.9 |
70-74 years | 3,505 | 94,472 | 5,468 | 103,445 | 172,263 | 60.1 |
75-79 years | 2,877 | 70,745 | 4,405 | 78,027 | 118,531 | 65.8 |
80-84 years | 2,261 | 44,709 | 3,472 | 50,442 | 74,805 | 67.4 |
85-89 years | 2,096 | 26,775 | 2,880 | 31,751 | 45,099 | 70.4 |
90+ years | 1,902 | 16,205 | 3,178 | 21,285 | 28,340 | 75.1 |
Unknown | 9 | 125 | 22 | 156 | 0 | 0.0 |
All ages | 217,111 | 971,602 | 88,257 | 1,276,970 | 4,543,121 | 27.7 |
6 months - 4 years | 83,448 | 6 | 2,349 | 85,803 | 234,212 | 30.1 |
65+ years | 18,730 | 383,411 | 27,317 | 429,458 | 672,434 | 63.9 |
Table 3: Influenza vaccine doses administered and coverage by season and provider
Influenza Season | Public Health | Pharmacy | Other | Total | Coverage (%) |
---|---|---|---|---|---|
2010-2011 | 529350 | 45353 | 179327 | 754030 | 20 |
2011-2012 | 548567 | 89854 | 235624 | 874045 | 23 |
2012-2013 | 545076 | 170359 | 203912 | 919347 | 24 |
2013-2014 | 614966 | 329548 | 213035 | 1157549 | 29 |
2014-2015 | 522380 | 485669 | 246900 | 1254949 | 31 |
2015-2016 | 444107 | 475331 | 227130 | 1146568 | 28 |
2016-2017 | 408663 | 533053 | 230108 | 1171824 | 28 |
2017-2018 | 384984 | 616625 | 227741 | 1229350 | 29 |
2018-2019 | 359718 | 723986 | 233955 | 1317659 | 31 |
2019-2020 | 314343 | 878820 | 245703 | 1438866 | 33 |
2020-2021 | 217883 | 1098136 | 335136 | 1651105 | 37 |
2021-2022 | 181204 | 898476 | 130126 | 1209806 | 27 |
2022-2023 | 217111 | 971602 | 88257 | 1276970 | 28 |