FluWatch report: January 9, 2022 to January 15, 2022 (week 2)
Organization: Public Health Agency of Canada
Published: 2022-01-21
Related Topics
Weekly Highlights
- Influenza activity across Canada remains low for this time of year. Sporadic detections of influenza continue to be reported; however, there remains no evidence of community circulation of influenza.
Virologic
- In week 02, a total of 25 influenza detections (23 influenza A and 2 influenza B) were reported.
- The number of laboratory detections of influenza has decreased in recent weeks. Current trends may be influenced by changes in laboratory testing practices.
Syndromic
- The percentage visits for influenza-like illness (ILI) was 1.7% in week 02. The percentage of visits for ILI in recent weeks has been at the highest level seen in the past two seasons.
- The percentage of FluWatchers reporting fever and cough was 1.0% in week 02. The percentage of participants reporting cough and fever in recent weeks has also been at the highest level seen in the past two seasons.
Outbreaks
- In week 02, one ILI outbreak was reported.
- From August 29, 2021 to January 15, 2022 (weeks 35 to 02), 15 ILI outbreaks and no laboratory-confirmed influenza outbreaks have been reported.
Severe Outcomes
- From August 29, 2021 to January 15, 2022 (weeks 35 to 02), less than five influenza-associated hospitalizations have been reported from participating provinces and territories.
On this page
- Influenza/Influenza-like Illness Activity - Geographic Spread
- Laboratory-Confirmed Influenza Detections
- Syndromic / Influenza-like Illness Surveillance
- Influenza Outbreak Surveillance
- Influenza Severe Outcomes Surveillance
- Influenza Strain Characterization
- Antiviral Resistance
- Influenza Vaccine Monitoring
- Provincial and International Influenza Reports
Influenza/Influenza-like Illness Activity - Geographic Spread
In week 02, twelve regions in seven provinces (B.C., Alta., Sask., Man., Ont., Que., and N.S.) reported sporadic influenza/ILI activity. All other surveillance regions reported no influenza/ILI activity (Figure 1).
Number of Regions Reporting in Week 02: 44 out of 53
Figure 1 - Text description
Province | Influenza Surveillance Region | Activity Level |
---|---|---|
N.L. | Eastern | No Activity |
N.L. | Labrador-Grenfell | No Activity |
N.L. | Central | No Activity |
N.L. | Western | No Activity |
P.E.I. | Prince Edward Island | No Activity |
N.S. | Zone 1 - Western | No Activity |
N.S. | Zone 2 - Northern | Sporadic |
N.S. | Zone 3 - Eastern | No Activity |
N.S. | Zone 4 - Central | No Activity |
N.B. | Region 1 | No Data |
N.B. | Region 2 | No Data |
N.B. | Region 3 | No Data |
N.B. | Region 4 | No Data |
N.B. | Region 5 | No Data |
N.B. | Region 6 | No Data |
N.B. | Region 7 | No Data |
Que. | Nord-est | No Activity |
Que. | Québec et Chaudieres-Appalaches | No Activity |
Que. | Centre-du-Québec | No Activity |
Que. | Montréal et Laval | Sporadic |
Que. | Ouest-du-Québec | No Activity |
Que. | Montérégie | No Activity |
Ont. | Central East | Sporadic |
Ont. | Central West | No Activity |
Ont. | Eastern | No Activity |
Ont. | North East | No Activity |
Ont. | North West | Sporadic |
Ont. | South West | Sporadic |
Ont. | Toronto | No Activity |
Man. | Northern Regional | No Activity |
Man. | Prairie Mountain | No Activity |
Man. | Interlake-Eastern | Sporadic |
Man. | Winnipeg | No Activity |
Man. | Southern Health | No Activity |
Sask. | North | Sporadic |
Sask. | Central | No Data |
Sask. | South | No Data |
Alta. | North Zone | No Activity |
Alta. | Edmonton | Sporadic |
Alta. | Central Zone | No Activity |
Alta. | Calgary | Sporadic |
Alta. | South Zone | No Activity |
B.C. | Interior | No Activity |
B.C. | Fraser | Sporadic |
B.C. | Vancouver Coastal | Sporadic |
B.C. | Vancouver Island | No Activity |
B.C. | Northern | Sporadic |
Y.T. | Yukon | No Activity |
N.W.T. | North | No Activity |
N.W.T. | South | No Activity |
Nvt. | Qikiqtaaluk | No Activity |
Nvt. | Kivalliq | No Activity |
Nvt. | Kitimeot | No Activity |
Laboratory-Confirmed Influenza Detections
In week 02, 25 laboratory detections of influenza were reported (23 influenza A and 2 influenza B).
Overall, the percentage of laboratory tests positive for influenza remains at exceptionally low levels, despite the elevated levels of testing. In week 02, 22,582 tests for influenza were performed at reporting laboratories and the percentage of tests positive for influenza was 0.11%. Compared to the past six pre-pandemic seasons (2014-2015 to 2019-2020), an average of 13,289 tests were performed for this time period, with an average of 23.0% of tests positive for influenza (Figure 3).
To date this season (August 29, 2021 to January 15, 2022), 474 influenza detections (365 influenza A and 109 influenza B) have been reported, which is lower than what we have seen historically in the past six pre-pandemic seasons, where an average of 15,304 influenza detections were reported at this point in the season. Among subtyped influenza A detections (105), influenza A(H3N2) accounted for 92% of detections.
Detailed information on age and type/subtype has been received for 379 laboratory-confirmed influenza detections (Figure 4). Among the 379 detections, 312 (82%) were in individuals under the age of 45.
Testing for influenza and other respiratory viruses has been influenced by the current COVID-19 pandemic. Changes in laboratory testing practices may affect the comparability of data to previous weeks or previous seasons.
For more detailed weekly and cumulative influenza data, see the text descriptions for Figures 2 and 3 or the Respiratory Virus Detections in Canada Report.
Number of Laboratories Reporting in Week 2: 31 out of 34
For one province, only data from subtyped influenza A specimens are included in the weekly number of positive influenza tests in Figure 2. The number of positive tests reported in Figure 2 may not equal the total number of positive tests in the report body text.
Figure 2 - Text description
Surveillance Week | A(Unsubtyped) | A(H3N2) | A(H1N1) | Influenza B | Percent Positive A | Percent Positive B |
---|---|---|---|---|---|---|
35 | 3 | 0 | 0 | 0 | 0.0 | 0.0 |
36 | 1 | 0 | 0 | 0 | 0.0 | 0.0 |
37 | 1 | 3 | 0 | 0 | 0.0 | 0.0 |
38 | 0 | 0 | 0 | 0 | 0.0 | 0.0 |
39 | 0 | 0 | 1 | 0 | 0.0 | 0.0 |
40 | 0 | 0 | 0 | 2 | 0.0 | 0.0 |
41 | 2 | 1 | 0 | 3 | 0.0 | 0.0 |
42 | 0 | 1 | 1 | 2 | 0.0 | 0.0 |
43 | 2 | 1 | 0 | 3 | 0.0 | 0.0 |
44 | 1 | 2 | 0 | 16 | 0.1 | 0.1 |
45 | 2 | 9 | 0 | 10 | 0.1 | 0.1 |
46 | 3 | 8 | 0 | 9 | 0.1 | 0.1 |
47 | 4 | 11 | 0 | 12 | 0.2 | 0.1 |
48 | 11 | 7 | 0 | 28 | 0.2 | 0.2 |
49 | 29 | 6 | 0 | 9 | 0.2 | 0.1 |
50 | 19 | 12 | 1 | 4 | 0.3 | 0.0 |
51 | 25 | 12 | 1 | 6 | 0.2 | 0.0 |
52 | 10 | 12 | 1 | 2 | 0.1 | 0.0 |
1 | 10 | 11 | 1 | 1 | 0.1 | 0.0 |
2 | 16 | 1 | 2 | 2 | 0.1 | 0.0 |
The shaded area represents the maximum and minimum number of influenza tests or percentage of tests positive reported by week from seasons 2014-2015 to 2019-2020. Data from week 11 of the 2019-2020 season onwards are excluded from the historical comparison due to the COVID-19 pandemic.
Included in the cumulative detections this season are 11 co-infections of influenza A and B (total of 22 detections) that were suspected to be associated with live attenuated influenza vaccine (LAIV) receipt. Beginning in week 44 co-infections known or reported to be associated with recent LAIV were removed by the submitting laboratory or by the Public Health Agency of Canada as they do not represent community transmission of seasonal influenza viruses.
Figure 3 - Text description
Surveillance Week | Number of Tests, 2021-2022 | Number of Tests, 2020-2021 | Maximum Number of Tests | Minimum Number of Tests | Average Number of Tests |
---|---|---|---|---|---|
35 | 7140 | 4996 | 1979 | 1311 | 1705 |
36 | 8012 | 5192 | 2208 | 1323 | 1707 |
37 | 9317 | 5335 | 2631 | 1778 | 2135 |
38 | 9821 | 6024 | 3039 | 1987 | 2502 |
39 | 9691 | 6707 | 3356 | 2365 | 2859 |
40 | 10776 | 7127 | 4078 | 2443 | 3134 |
41 | 10372 | 6817 | 4339 | 2673 | 3240 |
42 | 12507 | 6755 | 4649 | 2648 | 3526 |
43 | 13339 | 8227 | 4996 | 3084 | 3862 |
44 | 15442 | 9615 | 4966 | 2994 | 4020 |
45 | 17547 | 10748 | 5912 | 3117 | 4508 |
46 | 16418 | 11955 | 5589 | 3176 | 4564 |
47 | 16923 | 13103 | 6541 | 3587 | 5018 |
48 | 18563 | 18762 | 7416 | 3569 | 5645 |
49 | 19982 | 19649 | 8559 | 3836 | 6377 |
50 | 22549 | 16189 | 9464 | 4017 | 7155 |
51 | 28471 | 14059 | 11142 | 3487 | 8822 |
52 | 29557 | 12290 | 11338 | 4272 | 9184 |
1 | 28414 | 11681 | 14932 | 5371 | 12552 |
2 | 22582 | 14097 | 16104 | 5315 | 13289 |
3 | N/A | 17002 | 15001 | 5270 | 11820 |
4 | N/A | 15391 | 15414 | 5873 | 11441 |
5 | N/A | 16607 | 16595 | 6739 | 11456 |
6 | N/A | 12949 | 16121 | 8324 | 11339 |
7 | N/A | 20727 | 14443 | 8074 | 10842 |
8 | N/A | 21290 | 14024 | 7606 | 10865 |
9 | N/A | 21891 | 14520 | 7507 | 10956 |
10 | N/A | 20896 | 17681 | 7005 | 11084 |
11 | N/A | 21220 | 12714 | 6435 | 9175 |
12 | N/A | 23087 | 10431 | 5976 | 8238 |
13 | N/A | 25811 | 9989 | 6063 | 7699 |
14 | N/A | 26303 | 8830 | 4773 | 7046 |
15 | N/A | 26284 | 7836 | 5090 | 6527 |
16 | N/A | 26792 | 6826 | 5000 | 5890 |
17 | N/A | 29154 | 6603 | 4440 | 5305 |
18 | N/A | 22152 | 5640 | 4143 | 4780 |
19 | N/A | 12725 | 5480 | 3680 | 4311 |
20 | N/A | 9738 | 5097 | 3046 | 3862 |
21 | N/A | 7442 | 4001 | 2577 | 3197 |
22 | N/A | 6765 | 3790 | 2424 | 2944 |
23 | N/A | 6341 | 3257 | 1969 | 2591 |
24 | N/A | 5942 | 3120 | 2034 | 2449 |
25 | N/A | 5774 | 2659 | 1731 | 2148 |
26 | N/A | 5972 | 2600 | 1573 | 1988 |
27 | N/A | 5213 | 2163 | 1554 | 1833 |
28 | N/A | 4900 | 2223 | 1451 | 1857 |
29 | N/A | 5122 | 2256 | 1436 | 1796 |
30 | N/A | 5275 | 1950 | 1463 | 1664 |
31 | N/A | 5398 | 2022 | 1386 | 1671 |
32 | N/A | 4692 | 1928 | 1269 | 1574 |
33 | N/A | 5616 | 2089 | 1251 | 1671 |
34 | N/A | 5851 | 2098 | 1374 | 1698 |
Surveillance Week | Percentage of tests positive, 2021-2022 | Percentage of tests positive, 2020-2021 | Maximum Percentage of Tests Positive | Minimum Percentage of Tests Positive | Average Percentage of Tests Positive |
---|---|---|---|---|---|
35 | 0.04 | 0.02 | 1.87 | 0.11 | 0.82 |
36 | 0.01 | 0.00 | 2.28 | 0.30 | 1.13 |
37 | 0.04 | 0.00 | 1.78 | 0.40 | 0.99 |
38 | 0.00 | 0.02 | 2.35 | 0.55 | 1.30 |
39 | 0.01 | 0.00 | 2.95 | 0.67 | 1.71 |
40 | 0.02 | 0.00 | 2.33 | 1.08 | 1.70 |
41 | 0.06 | 0.01 | 3.02 | 1.32 | 1.72 |
42 | 0.05 | 0.00 | 3.40 | 0.87 | 2.18 |
43 | 0.05 | 0.01 | 5.32 | 0.84 | 2.83 |
44 | 0.21 | 0.07 | 8.55 | 1.20 | 3.70 |
45 | 0.14 | 0.04 | 10.10 | 1.39 | 4.63 |
46 | 0.16 | 0.03 | 14.11 | 1.51 | 6.05 |
47 | 0.23 | 0.07 | 15.36 | 1.44 | 7.71 |
48 | 0.35 | 0.05 | 18.20 | 0.84 | 10.61 |
49 | 0.28 | 0.04 | 19.71 | 1.64 | 13.01 |
50 | 0.27 | 0.01 | 27.02 | 2.36 | 16.82 |
51 | 0.20 | 0.01 | 29.09 | 3.30 | 20.11 |
52 | 0.10 | 0.00 | 34.54 | 4.28 | 24.48 |
1 | 0.10 | 0.00 | 31.66 | 5.85 | 23.41 |
2 | 0.11 | 0.00 | 29.10 | 7.06 | 23.01 |
3 | N/A | 0.01 | 30.07 | 12.24 | 23.63 |
4 | N/A | 0.00 | 29.45 | 15.89 | 23.96 |
5 | N/A | 0.00 | 30.62 | 19.60 | 24.90 |
6 | N/A | 0.02 | 32.39 | 17.89 | 25.00 |
7 | N/A | 0.01 | 32.51 | 16.28 | 25.05 |
8 | N/A | 0.00 | 32.87 | 17.45 | 25.14 |
9 | N/A | 0.00 | 34.28 | 16.80 | 24.59 |
10 | N/A | 0.00 | 35.99 | 16.05 | 23.22 |
11 | N/A | 0.01 | 31.41 | 16.19 | 21.41 |
12 | N/A | 0.00 | 30.03 | 15.03 | 20.10 |
13 | N/A | 0.00 | 28.25 | 14.50 | 19.56 |
14 | N/A | 0.00 | 23.16 | 12.66 | 17.86 |
15 | N/A | 0.01 | 20.73 | 11.95 | 16.27 |
16 | N/A | 0.00 | 18.52 | 11.64 | 14.48 |
17 | N/A | 0.00 | 17.30 | 9.76 | 12.83 |
18 | N/A | 0.00 | 13.02 | 7.88 | 10.26 |
19 | N/A | 0.00 | 11.95 | 4.96 | 8.98 |
20 | N/A | 0.01 | 9.13 | 3.19 | 7.22 |
21 | N/A | 0.01 | 7.45 | 2.97 | 5.60 |
22 | N/A | 0.00 | 4.96 | 2.19 | 3.86 |
23 | N/A | 0.00 | 4.39 | 0.87 | 2.86 |
24 | N/A | 0.02 | 4.36 | 0.81 | 2.25 |
25 | N/A | 0.00 | 3.95 | 0.63 | 1.88 |
26 | N/A | 0.00 | 3.08 | 0.69 | 1.81 |
27 | N/A | 0.00 | 2.83 | 0.42 | 1.48 |
28 | N/A | 0.00 | 1.84 | 0.41 | 0.91 |
29 | N/A | 0.00 | 1.55 | 0.47 | 1.09 |
30 | N/A | 0.04 | 1.46 | 0.46 | 0.90 |
31 | N/A | 0.00 | 1.93 | 0.58 | 1.11 |
32 | N/A | 0.00 | 1.19 | 0.52 | 0.92 |
33 | N/A | 0.00 | 1.69 | 0.40 | 0.85 |
34 | N/A | 0.02 | 1.57 | 0.42 | 0.92 |
Figure 4 - Text description
Age Group | Proportion of Influenza A | Proportion of Influenza B | Total Number Influenza Detections |
---|---|---|---|
0 to 4 | 70.2% | 29.8% | 104 |
5 to 19 | 79.7% | 20.3% | 74 |
20 to 44 | 79.1% | 20.9% | 134 |
45 to 64 | 71.4% | 28.6% | 35 |
65+ | 75.0% | 25.0% | 32 |
Age Group | Proportion of A(H1N1) | Proportion of A(H3N2) | Total Number of Subtyped Influenza Detections |
---|---|---|---|
0 to 4 | 26.7% | 73.3% | 15 |
5 to 19 | 7.7% | 92.3% | 13 |
20 to 44 | 2.9% | 97.1% | 34 |
45 to 64 | 0.0% | 100.0% | 8 |
65+ | 0.0% | 100.0% | 8 |
Syndromic / Influenza-like Illness Surveillance
Healthcare Practitioners Sentinel Surveillance
In week 02, 1.7% of visits to healthcare professionals were due to influenza-like illness (ILI). Since the beginning of the surveillance season, the percentage of visits for ILI has been within or near expected pre-pandemic levels (Figure 5). ILI symptoms are not specific to any one respiratory pathogen and can be due to influenza, or other respiratory viruses, including respiratory syncytial virus and even SARS-CoV-2, the virus that causes COVID-19.
This indicator should be interpreted with caution as there have been changes in healthcare seeking behavior of individuals and a smaller number of sentinels reporting compared to previous seasons.
Number of Sentinels Reporting in Week 02: 52
The shaded area represents the maximum and minimum percentage of percentage of participants reporting cough and fever by week, from seasons 2014-2015 to 2019-2020. Data from week 11 of the 2019-2020 season onwards are excluded from the historical comparison due to the COVID-19 pandemic.
Figure 5 - Text description
Surveillance Week | 2021-2022 | 2020-2021 | Average | Min | Max |
---|---|---|---|---|---|
35 | 0,6% | 0,1% | 0,6% | 0,4% | 0,9% |
36 | 1,2% | 0,2% | 0,6% | 0,4% | 0,9% |
37 | 0,6% | 0,4% | 0,7% | 0,5% | 1,0% |
38 | 0,9% | 0,3% | 0,7% | 0,6% | 1,0% |
39 | 1,0% | 0,4% | 0,9% | 0,5% | 1,2% |
40 | 0,5% | 0,2% | 1,2% | 0,8% | 1,7% |
41 | 1,1% | 0,4% | 1,7% | 0,8% | 2,8% |
42 | 1,2% | 0,5% | 1,6% | 1,2% | 2,1% |
43 | 0,9% | 0,3% | 1,2% | 0,8% | 1,7% |
44 | 0,6% | 0,3% | 1,2% | 0,7% | 1,7% |
45 | 1,0% | 0,4% | 1,2% | 0,9% | 1,5% |
46 | 0,9% | 0,8% | 1,4% | 1,2% | 1,8% |
47 | 0,7% | 0,3% | 1,6% | 1,1% | 2,2% |
48 | 1,1% | 0,5% | 1,5% | 1,1% | 2,2% |
49 | 0,9% | 0,5% | 1,7% | 1,0% | 2,8% |
50 | 1,1% | 0,4% | 1,5% | 1,1% | 1,7% |
51 | 1,7% | 0,5% | 1,9% | 1,4% | 2,7% |
52 | 1,5% | 0,5% | 2,0% | 1,0% | 3,1% |
1 | 2,1% | 0,7% | 3,4% | 1,9% | 5,4% |
2 | 1,7% | 0,4% | 3,4% | 1,8% | 5,7% |
3 | N/A | 0.2% | 2.3% | 1.3% | 3.7% |
4 | N/A | 0.3% | 2.0% | 1.1% | 2.9% |
5 | N/A | 0.2% | 2.1% | 1.4% | 3.1% |
6 | N/A | 0.5% | 2.4% | 1.4% | 4.0% |
7 | N/A | 0.3% | 2.4% | 0.9% | 3.5% |
8 | N/A | 0.2% | 2.3% | 0.8% | 3.4% |
9 | N/A | 0.2% | 2.3% | 0.9% | 3.1% |
10 | N/A | 0.2% | 2.0% | 1.0% | 2.8% |
11 | N/A | 0.2% | 1.9% | 1.1% | 2.8% |
12 | N/A | 0.3% | 1.6% | 0.6% | 2.6% |
13 | N/A | 0.4% | 1.6% | 1.1% | 2.6% |
14 | N/A | 0.2% | 1.7% | 1.1% | 3.0% |
15 | N/A | 0.3% | 1.3% | 0.9% | 1.9% |
16 | N/A | 0.3% | 1.2% | 0.8% | 1.7% |
17 | N/A | 0.4% | 1.2% | 0.7% | 1.7% |
18 | N/A | 0.5% | 1.3% | 0.5% | 2.0% |
19 | N/A | 0.3% | 0.9% | 0.6% | 1.3% |
20 | N/A | 0.5% | 1.1% | 0.6% | 1.5% |
21 | N/A | 0.3% | 0.9% | 0.5% | 1.3% |
22 | N/A | 0.3% | 0.7% | 0.3% | 1.0% |
23 | N/A | 0.2% | 0.8% | 0.6% | 1.0% |
24 | N/A | 0.2% | 0.7% | 0.6% | 1.0% |
25 | N/A | 0.2% | 0.6% | 0.4% | 0.8% |
26 | N/A | 0.2% | 0.8% | 0.5% | 1.4% |
27 | N/A | 0.3% | 0.6% | 0.5% | 0.7% |
28 | N/A | 0.1% | 0.7% | 0.5% | 1.3% |
29 | N/A | 0.3% | 0.9% | 0.6% | 1.7% |
30 | N/A | 0.2% | 0.6% | 0.2% | 0.9% |
31 | N/A | 0.2% | 0.4% | 0.2% | 0.6% |
32 | N/A | 0.2% | 0.8% | 0.3% | 1.2% |
33 | N/A | 0.3% | 0.7% | 0.4% | 1.3% |
34 | N/A | 0.5% | 0.7% | 0.4% | 1.5% |
FluWatchers
In week 02, 12,752 participants reported to FluWatchers, of which 1.0% reported symptoms of cough and fever (Figure 6). The percentage of participants reporting cough and fever in recent weeks has been at the highest level seen in the past two seasons.
The reports of cough and fever are not specific to any one respiratory pathogen and can be due to influenza, or other respiratory viruses, including respiratory syncytial virus, rhinovirus, and even SARS-CoV-2, the virus that causes COVID-19. FluWatchers reporting is not impacted by changes in health services or health seeking behaviours.
Among the 121 participants who reported cough and fever:
- 46% consulted a healthcare professional;
- 79% reported days missed from work or school, resulting in a combined total of 357 missed days of work or school (average of 3.8 days).
The Northwest Territories had the highest participation rate this week (53 participants per 100,000 population) and the neighbourhood of K0A had the highest number of participants (153) See what is happening in your neighbourhood! Downloadable datasets are also available on Open Maps.
If you are interested in becoming a FluWatcher, sign up today.
Number of Participants Reporting in Week 02: 12,752
The shaded area represents the maximum and minimum percentage of percentage of participants reporting cough and fever by week, from seasons 2014-2015 to 2019-2020. Data from week 11 of the 2019-2020 season onwards are excluded from the historical comparison due to the COVID-19 pandemic.
Figure 6 - Text description
Surveillance Week | 2021-2022 | 2020-2021 | Average | Min | Max |
---|---|---|---|---|---|
35 | 0.23% | 0.22% | N/A | N/A | N/A |
36 | 0.28% | 0.21% | N/A | N/A | N/A |
37 | 0.49% | 0.38% | N/A | N/A | N/A |
38 | 0.54% | 0.29% | N/A | N/A | N/A |
39 | 0.54% | 0.45% | N/A | N/A | N/A |
40 | 0.58% | 0.49% | 2.51% | 2.18% | 2.71% |
41 | 0.46% | 0.44% | 2.18% | 1.81% | 2.57% |
42 | 0.38% | 0.33% | 1.80% | 1.61% | 2.03% |
43 | 0.53% | 0.17% | 1.87% | 1.49% | 2.18% |
44 | 0.51% | 0.26% | 1.57% | 1.39% | 1.78% |
45 | 0.54% | 0.29% | 1.83% | 1.42% | 2.32% |
46 | 0.41% | 0.28% | 1.83% | 1.22% | 2.15% |
47 | 0.57% | 0.31% | 1.93% | 1.44% | 2.39% |
48 | 0.51% | 0.26% | 2.43% | 1.67% | 3.35% |
49 | 0.40% | 0.17% | 2.56% | 1.97% | 3.16% |
50 | 0.60% | 0.15% | 2.91% | 2.12% | 3.79% |
51 | 1.03% | 0.22% | 3.18% | 2.53% | 3.95% |
52 | 1.51% | 0.10% | 3.98% | 2.81% | 5.38% |
1 | 1.08% | 0.12% | 3.84% | 2.85% | 4.76% |
2 | 0.95% | 0.21% | 2.94% | 1.90% | 3.93% |
3 | 0.00% | 0.12% | 3.25% | 2.35% | 4.84% |
4 | 0.00% | 0.12% | 3.12% | 2.13% | 4.23% |
5 | 0.00% | 0.17% | 3.19% | 2.62% | 3.59% |
6 | 0.00% | 0.11% | 3.47% | 2.76% | 4.28% |
7 | 0.00% | 0.16% | 3.18% | 2.58% | 3.79% |
8 | 0.00% | 0.06% | 3.09% | 2.54% | 3.65% |
9 | 0.00% | 0.10% | 2.81% | 2.38% | 3.53% |
10 | 0.00% | 0.18% | 2.58% | 2.12% | 3.11% |
11 | 0.00% | 0.16% | 2.33% | 1.89% | 2.63% |
12 | 0.00% | 0.17% | 2.60% | 2.46% | 2.82% |
13 | 0.00% | 0.17% | 2.48% | 1.99% | 3.06% |
14 | 0.00% | 0.19% | 2.13% | 1.35% | 2.58% |
15 | 0.00% | 0.21% | 1.78% | 1.60% | 1.93% |
16 | 0.00% | 0.14% | 2.00% | 1.47% | 2.44% |
17 | 0.00% | 0.22% | 1.73% | 1.40% | 2.31% |
18 | 0.00% | 0.15% | 1.50% | 1.19% | 2.09% |
19 | 0.00% | 0.14% | N/A | N/A | N/A |
20 | 0.00% | 0.15% | N/A | N/A | N/A |
21 | 0.00% | 0.09% | N/A | N/A | N/A |
22 | 0.00% | 0.10% | N/A | N/A | N/A |
23 | 0.00% | 0.08% | N/A | N/A | N/A |
24 | 0.00% | 0.13% | N/A | N/A | N/A |
25 | 0.00% | 0.12% | N/A | N/A | N/A |
26 | 0.00% | 0.16% | N/A | N/A | N/A |
27 | 0.00% | 0.11% | N/A | N/A | N/A |
28 | 0.00% | 0.20% | N/A | N/A | N/A |
29 | 0.00% | 0.20% | N/A | N/A | N/A |
30 | 0.00% | 0.22% | N/A | N/A | N/A |
31 | 0.00% | 0.21% | N/A | N/A | N/A |
32 | 0.00% | 0.25% | N/A | N/A | N/A |
33 | 0.00% | 0.31% | N/A | N/A | N/A |
34 | 0.00% | 0.50% | N/A | N/A | N/A |
Influenza Outbreak Surveillance
In week 02, one ILI outbreak in a school and/or daycare was reported.
To date this season (August 29, 2021 to January 15, 2022), 15 ILI outbreaks and no laboratory-confirmed influenza outbreaks have been reported. The most recent laboratory-confirmed influenza outbreak occurred in week 24 (week ending June 13, 2020) of the 2019-2020 season.
All ILI outbreaks have been reported in schools and/or daycares. The number of ILI outbreaks reported to date this season is lower than the 2020-2021 season but higher than in pre-pandemic seasons. This is not unexpected given changes to outbreak surveillance, specifically increased vigilance in schools to monitor and report absenteeism due to ILI, and the increased restrictions on attendance for children with symptoms of viral respiratory illness.
Outbreaks of ILI are not specific to any one respiratory pathogen and can be due influenza, or other respiratory viruses, including respiratory syncytial virus, rhinovirus, and even COVID-19. Many respiratory viruses in addition to the flu commonly circulate during the fall and winter, and can cause clusters of cases with respiratory illness which could be captured as ILI. For more information on the respiratory viruses currently circulating in Canada, please refer to the Respiratory Virus Detections in Canada.
Number of provinces and territoriesFootnote 1 reporting in week 02: 12 out of 13
Influenza Severe Outcomes Surveillance
Provincial/Territorial Influenza Hospitalizations and Deaths
In week 02, no influenza-associated hospitalizations were reported by participating provinces and territoriesFootnote 2.
To date this season (August 29, 2021 to January 15, 2022), less than five influenza-associated hospitalizations were reported by participating provinces and territories.
Number of provinces and territories reporting in week 02: 8 out of 9.
Pediatric Influenza Hospitalizations and Deaths
In week 02, no (≤16 years of age) influenza-associated hospitalizations were reported by the Immunization Monitoring Program Active (IMPACT) network.
To date this season (August 29, 2021 to January 15, 2022), seven pediatric influenza-associated hospitalizations and less than five intensive care unit (ICU) admissions were reported by the IMPACT network.
Adult Influenza Hospitalizations and Deaths
In week 02, no influenza-associated adult (≥16 years of age) hospitalizations were reported by the Canadian Immunization Research Network (CIRN) Serious Outcomes Surveillance (SOS) network.
To date this season (August 29, 2021 to January 15, 2022), less than five influenza-associated adult (≥16 years of age) hospitalizations have been reported by the CIRN SOS network.
Influenza Strain Characterization
To date this season (August 29, 2021 to January 15, 2022), the National Microbiology Laboratory (NML) has characterized 16 influenza viruses (14 A(H3N2), 2 A(H1N1)) received from Canadian laboratories.
Influenza A(H3N2)
Genetic Characterization
Among the nine influenza A(H3N2) viruses genetically characterized, sequence analysis of the HA gene of these viruses showed that they all belonged to genetic group 3C.2a1b.2a2.
A/Cambodia/e0826360/2020 (H3N2)-like virus is the influenza A(H3N2) component of the 2021-2022 Northern Hemisphere seasonal influenza vaccine and belongs to genetic group 3C.2a1b.2a1.
A/Darwin/6/2021 (H3N2)-like virus is the influenza A(H3N2) component of the 2022 Southern Hemisphere seasonal influenza vaccine and belongs to the genetic group 3C.2a1b.2a2.
Antigenic Characterization
Among the 14 A(H3N2) viruses characterized:
- 2 viruses were antigenically similar to A/Cambodia/e0826360/2020 (H3N2) )-like virus
- 12 showed reduced titers with antisera raised against egg-grown A/Cambodia/e0826360/2020 (H3N2)-like virus.
Influenza A(H1N1)
Antigenic Characterization
Among the two A(H1N1) viruses characterized:
- One H1N1 virus characterized was antigenically similar to A/Wisconsin/588/2019.
- One H1N1 showed reduced titer with ferret antisera raised against cell culture-propagated A/Wisconsin/588/2019
A/Wisconsin/588/2019 is the influenza A(H1N1) component of the 2021-2022 Northern Hemisphere seasonal influenza vaccine.
Antiviral Resistance
The NML also tests influenza viruses received from Canadian laboratories for antiviral resistance.
Oseltamivir
15 influenza viruses (13 A(H3N2) and 2 A(H1N1)) were tested for resistance to oseltamivir:
- All influenza viruses were sensitive to oseltamivir.
Zanamivir
15 influenza viruses (13 A(H3N2) and 2 A(H1N1)) were tested for resistance to zanamivir:
- All influenza viruses were sensitive to zanamivir.
Influenza Vaccine Monitoring
Vaccine monitoring refers to activities related to the monitoring of influenza vaccine coverage and effectiveness.
Vaccine Coverage
Influenza vaccine coverage estimates for the 2021-2022 season are anticipated to be available in February or March 2022.
Vaccine Effectiveness
Influenza vaccine effectiveness estimates for the 2021-2022 season are anticipated to be available in February or March 2022, pending the resumption of community transmission of seasonal influenza.
Provincial and International Surveillance Links
See Influenza surveillance resources
Notes
The data in the FluWatch report represent surveillance data available at the time of writing. All data are preliminary and may change as updates are received.
To learn more about the FluWatch program, see the Overview of influenza monitoring in Canada page.
For more information on the flu, see our Flu (influenza) web page.
We would like to thank all the FluWatch surveillance partners participating in this year's influenza surveillance program.
This report is available on the Government of Canada Influenza webpage.
Ce rapport est disponible dans les deux langues officielles.
- Footnote 1
-
All Provinces and Territories (PTs) participate in the FluWatch outbreak surveillance system. This outbreak system monitors influenza and ILI outbreaks in long-term care facilities(LTCF), acute care facilities, schools and daycares, remote and/or isolated communities, and facilities categorized as ‘other’. Not all reporting PTs report outbreaks in all these settings. All PTs report laboratory confirmed outbreaks in LTCF. Four PTs (NB, NL, NS and YK) report ILI outbreaks in schools and/or daycares and other facilities.
- Footnote 2
-
Influenza-associated hospitalizations are reported by Alberta, Manitoba, New Brunswick, Newfoundland and Labrador, Northwest Territories, Nova Scotia, Prince Edward Island and Yukon. Only hospitalizations that require intensive medical are reported by Saskatchewan.
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