FluWatch report: July 23 to August 26, 2023 (weeks 30-34)

Weekly Highlights: At the national level, influenza activity has been stable and remains at inter-seasonal levels. Sporadic influenza activity continues to be reported in many regions across Canada.

Virologic: In week 34, the percentage of tests positive for influenza was 0.6% and a total of 72 laboratory detections (66 influenza A and 6 influenza B) were reported.

FluWatch report: June 18 to July 22, 2023 (weeks 25-29)

Weekly Highlights: At the national level, influenza activity has been stable and remains at inter-seasonal levels. Sporadic influenza activity continues to be reported in many regions across Canada.

Virologic: In week 29, the percentage of tests positive for influenza was 0.5% and a total of 56 laboratory detections (49 influenza A and 7 influenza B) were reported.

FluWatch report: May 21, 2023 to June 17, 2023 (weeks 21-24)

Weekly Highlights: At the national level, influenza activity has been stable and remains at inter-seasonal levels. Sporadic influenza activity continues to be reported in many regions across Canada.

Virologic: In week 24, the percentage of tests positive for influenza was 1% and a total of 135 laboratory detections (70 influenza A and 65 influenza B) were reported. 

FluWatch report: April 30 to May 20, 2023 (weeks 18-20)

Weekly Highlights: At the national level, influenza activity has been stable and remains at inter-seasonal levels. Sporadic influenza activity continues to be reported in many regions across Canada.

Virologic: In week 20, the percentage of tests positive for influenza was 2.1% and a total of 345 laboratory detections (213 influenza B and 132 influenza A) were reported. Influenza B detections (62%) are predominant.

FluWatch report: April 16 to April 29, 2023 (weeks 16-17)

Weekly Highlights: At the national level, influenza activity has been stable and remains at inter-seasonal levels. Sporadic influenza activity continues to be reported in many regions across Canada.

Virologic: In week 17, the percentage of tests positive for influenza was 2.2% and a total of 448 laboratory detections (362 influenza B and 86 influenza A) were reported. Influenza B detections (81%) are predominant.

FluWatch report: April 2 to April 15, 2023 (weeks 14-15) 

Weekly Highlights: At the national level, influenza activity has increased slightly in recent weeks but remains at inter-seasonal levels. This increase in influenza activity is due to influenza B. Influenza activity continues to be reported in most provinces.

Virologic: In week 15, the percentage of tests positive for influenza was 2.5% and a total of 578 laboratory detections (439 influenza B and 139 influenza A) were reported. Influenza B detections (76%) are predominant.

FluWatch report: March 19 to April 1, 2023 (weeks 12-13)

Weekly Highlights: At the national level, influenza activity has increased slightly in recent weeks but remains at inter-seasonal levels. This increase in influenza activity is due to influenza B. Influenza activity continues to be reported in most provinces.

Virologic: In week 13, the percentage of tests positive for influenza was 2.4% and a total of 510 laboratory detections (364 influenza B and 146 influenza A) were reported. Influenza B detections (71%) are predominant.

FluWatch report: March 5 to March 18, 2023 (weeks 10-11)

Weekly Highlights: At the national level, influenza activity remains low at levels typically seen in late spring/early summer. Influenza activity continues to be reported in most provinces.

Virologic: In week 11, the percentage of tests positive for influenza was 1.6% and a total of 392 laboratory detections (268 influenza B and 124 influenza A) were reported. Influenza B detections (68%) are predominant. Among subtyped influenza A detections in week 11, 74% (23) were influenza A(H1N1).

FluWatch report: February 26 to March 4, 2023 (week 9)

Weekly Highlights: At the national level, influenza activity remains low at levels typically seen in late spring/early summer. Influenza activity continues to be reported in almost all provinces.

Virologic: In week 9, the percentage of tests positive for influenza was 1.3% and a total of 326 laboratory detections (173 influenza B and 153 influenza A) were reported. Influenza A and B are circulating at similar levels. Among subtyped influenza A detections in week 9, 63% (25) were influenza A(H1N1).

FluWatch report: February 19 to February 25, 2023 (week 8)

Weekly Highlights: At the national level, influenza activity remains low at levels typically seen in late spring/early summer. Influenza activity continues to be reported in almost all provinces.

Virologic: In week 8, the percentage of tests positive for influenza was 1.1% and a total of 268 laboratory detections (144 influenza A and 124 influenza B) were reported. The proportion of influenza B detections (46%) has increased in recent weeks. Among subtyped influenza A detections in week 8, 53% (27) were influenza A(H1N1).

FluWatch report: February 12 to February 18, 2023 (week 7)

Weekly Highlights: At the national level, influenza activity remains low at levels typically seen in late spring/early summer. Influenza activity continues to be reported in almost all provinces.

Virologic: In week 7, the percentage of tests positive for influenza was 0.8% and a total of 216 laboratory detections (141 influenza A and 75 influenza B) were reported. The proportion of influenza B detections (35%) has increased in recent weeks. Among subtyped influenza A detections in week 7, 73% (27) were influenza A(H1N1). The proportion of laboratory detections of influenza A(H1N1) has been increasing in recent weeks.

FluWatch report: February 5 to February 11, 2023 (week 6)

Weekly Highlights: At the national level, influenza activity remains low at levels typically seen in late spring/early summer. Influenza activity continues to be reported in almost all provinces.

Virologic: In week 6, the percentage of tests positive for influenza was 1.0% and a total of 282 laboratory detections (190 influenza A and 92 influenza B) were reported. The proportion of influenza B detections (33%) has increased in recent weeks. Among subtyped influenza A detections in week 6, 69% (27) were influenza A(H1N1). The proportion of laboratory detections of influenza A(H1N1) has been increasing in recent weeks. Among detections for which age information (207) was reported in week 6, 56 (27%) of detections were in individuals aged 20-44 years.

FluWatch report: January 29, 2023 to February 4, 2023 (week 5)

Weekly Highlights: Nationally, influenza activity remains low at levels typically seen in late spring and early summer.

Virological: In week 5, the percentage of tests positive for influenza was 1.0% and a total of 285 laboratory detections (206 influenza A cases and 79 influenza B cases) were reported. The proportion of influenza B detections (28%) has increased in recent weeks. Of the influenza A subtyped detections, 60% (34) were influenza A(H1N1). The proportion of laboratory detections of influenza A(H1N1) has increased in recent weeks. Of the detections with age information (213) reported at week 5, 59 (28%) were in people aged 20-44 years.

FluWatch report: January 22 to January 28, 2023 (week 4)

Weekly Highlights: At the national level, influenza activity is low and continues to decline. Influenza activity is at levels typically seen in late spring/early summer.

Virologic: In week 4, the percentage of tests positive for influenza was 1.0% and a total of 290 laboratory detections (249 influenza A and 41 influenza B) were reported. Among subtyped influenza A detections, 54% (34) were influenza A(H3N2) and 46% (29) were influenza A(H1N1). Among detections for which age information was reported in week 4, similar proportions of detections (26%) were in individuals aged 20 to 44 years old and 65+ years old.

FluWatch report: January 15 to January 21, 2023 (week 3)

Weekly Highlights: At the national level, influenza activity continues to decline. Influenza activity is now at levels typically seen in late spring/early summer.

Virologic: In week 3, the percentage of tests positive for influenza was 1.5% and a total of 449 laboratory detections (410 influenza A and 39 influenza B) were reported. Among subtyped influenza A detections in week 3, 52% (44) were influenza A(H1N1) and 48% (41) were influenza A(H3N2). Among detections for which age information was reported in week 3, 33% (119) of detections were in individuals aged 65+ years old.

FluWatch report: January 8 to January 14, 2023 (week 2)

Weekly Highlights: At the national level, influenza activity continues to decline. Influenza activity is now at levels typically seen in late spring/early summer.

Virologic: In week 2, a total of 798 laboratory detections (779 influenza A and 19 influenza B) were reported. Among subtyped influenza A detections in week 2, 71% (116) were influenza A(H3N2) and 29% (47) were influenza A(H1N1). Among detections for which age information was reported in week 2 (495), 47% (234) of detections were in individuals aged 65+ years old.

FluWatch report: January 1 to January 7, 2023 (week 1)

Weekly Highlights: At the national level, influenza continues to circulate but has declined sharply from the peak that occurred in week 47 (end of November) and is now below expected pre-pandemic levels. All surveillance indicators are decreasing and almost all indicators are within expected levels typical of this time of year.

Virologic: In week 1, a total of 1,749 laboratory detections (1,721 influenza A and 28 influenza B) were reported. Among subtyped influenza A detections in week 1, 77% (266) were influenza A(H3N2) and 23% (80) were influenza A(H1N1). Among detections for which age information was reported in week 1 (1,181), 48% (561) of detections were in individuals aged 65+ years old, an increase from 40% (784) in week 52.

FluWatch: Weekly Canadian Influenza Reports 2022

FluWatch report: December 11 to December 31, 2022 (weeks 50-52)

Weekly Highlights: At the national level, influenza continues to circulate but has declined sharply from the peak that occurred in week 47 (end of November). Most surveillance indicators are decreasing and almost all indicators are within expected levels typical of this time of year.

Virologic: In week 52, a total of 2,841 laboratory detections (2,818 influenza A and 23 influenza B) were reported. Among subtyped influenza A detections in week 52, 81% (360) were influenza A(H3N2) and 19% (85) were influenza A(H1N1). Among detections for which age information was reported in week 52 (1,949), 40% (784) of detections were in individuals aged 65+ years old, an increase from 32% (1,062) in week 51.

FluWatch report: December 4 to December 10, 2022 (week 49)

Weekly Highlights: At the national level, influenza continues to circulate at peak levels. Most surveillance indicators are steady, with some reporting small decreases from the previous week. Almost all indicators are still above expected levels typical of this time of year.

Virologic: In week 49, a total of 9,393 laboratory detections (9,365 influenza A and 28 influenza B) were reported. Among subtyped influenza A detections in week 49, 95% (1,685) were influenza A(H3N2) and 5% (87) were influenza A(H1N1). Among detections for which age information was reported in week 49 (5,690), 38% (2,156) of detections were in individuals aged 0-19 years old, down slightly from 41% (2,454) in week 48.

FluWatch report: November 27, 2022 to December 3, 2022 (week 48)

Weekly Highlights: Nationally, influenza activity continues to remain above typical levels expected for this time of year as we enter week six of the national influenza outbreak. Nationally, all monitoring indicators are stable or increasing and almost all are above typical levels expected for this time of year.

Virologic: In week 48, 9,855 influenza detections (9,842 influenza A and 13 influenza B) were reported. Of the week 48 subtyped influenza A detections, 97% (2132) were influenza A(H3N2) and 3% (67) were influenza A(H1N1). Of detections with age information received at week 48 (6,009), 41% (2,454) of detections were from individuals aged 0-19, a slight decrease from 45% (2,575) over of week 47.

FluWatch report: November 20 to November 26, 2022 (week 47)

Weekly Highlights: At the national level, influenza activity has continued to increase steeply as we enter the fifth week of the national influenza epidemic. All surveillance indicators are increasing, and all are above expected levels typical of this time of year.

Virologic: In week 47, a total of 8,242 laboratory detections (8,226 influenza A and 16 influenza B) were reported. Among subtyped influenza A detections in week 47, 95% (2,214) were influenza A(H3N2) and 5% (119) were influenza A(H1N1). Among detections for which age information was reported in week 47 (5,096), 2,339 (46%) of detections were in individuals aged 0-19 years old.

FluWatch report: November 13 to November 19, 2022 (week 46)

Weekly Highlights: At the national level, influenza activity has continued to increase steeply as we enter the fourth week of  the national influenza epidemic. Most surveillance indicators are increasing, and all are above expected levels typical of this time of year. 

Virologic: In week 46, a total of 5,891 laboratory detections (5,876 influenza A and 15 influenza B) were reported. Among subtyped influenza A detections in week 46, 97% (2,213) were influenza A(H3N2) and 3% (73) were influenza A(H1N1). Among detections for which age information was reported in week 46 (3,256), 1,605 (49%) of detections were in individuals aged 0-19 years old.

FluWatch report: November 6 to November 12, 2022 (week 45)

Weekly Highlights: At the national level, influenza activity has continued to increase steeply as we enter the third week of the national influenza epidemic. All surveillance indicators are increasing and are above expected levels typical of this time of year.

Virologic: In week 45, a total of 3,909 laboratory detections (3,897 influenza A and 12 influenza B) were reported. Among subtyped influenza A detections in week 45, 97% (1,785) were influenza A(H3N2) and 3% (56) were influenza A(H1N1). Among detections for which age information was reported in week 45 (2,151), 1,215 (56%) of detections were in individuals aged 0-19 years old.

FluWatch report: October 30 to November 5, 2022 (week 44)

Weekly Highlights: At the national level, influenza activity has crossed the seasonal threshold, indicating the start of an influenza epidemic. All surveillance indicators are increasing and most are above expected levels typical of this time of year.

Virologic: In week 44, a total of 2,234 laboratory detections (2,231 influenza A and 3 influenza B) were reported. Among subtyped influenza A detections in week 44, 96% (1,149) were influenza A (H3N2) and 4% (44) were influenza A (H1N1). Among detections for which age information was reported in week 44 (1,197), 739 (64%) of detections were in individuals aged 0-19 years old.

FluWatch report: October 16, 2022 to October 29, 2022 (weeks 42-43)

Weekly Highlights: At the national level, influenza activity is increasing steeply and has crossed the seasonal threshold of 5% positivity; if percent positivity remains above this threshold next week, the start of an influenza epidemic will be declared.

Virologic: In weeks 42 to 43, a total of 1,508 laboratory detections (1,493 influenza A and 26 influenza B) were reported. Influenza A(H3N2) is the dominant subtype, representing 90% of sub-typed influenza A detections this season (August 28, 2022 to October 29, 2022). Among detections with detailed age information to date (August 28, 2022 to October 29, 2022), more than half (54%) were in children and teenagers (ages 0 to 19 years).

FluWatch report: October 2, 2022, to October 15, 2022 (weeks 40-41)

Weekly Highlights At the national level, influenza activity is increasing but remains at inter-seasonal levels.

Virologic In weeks 40 to 41, a total of 394 laboratory detections (380 influenza A and 14 influenza B) were reported. Influenza A(H3N2) is the dominant subtype, representing 77% of sub-typed influenza A detections this season (August 28, 2022 to October 15, 2022). Among detections with detailed age information to date (August 28, 2022 to October 15, 2022), 45% were in children and teenagers (ages 0 to 19 years). In weeks 40 to 41, a total of 394 laboratory detections (380 influenza A and 14 influenza B) were reported. Influenza A(H3N2) is the dominant subtype, representing 77% of sub-typed influenza A detections this season (August 28, 2022 to October 15, 2022). Among detections with detailed age information to date (August 28, 2022 to October 15, 2022), 45% were in children and teenagers (ages 0 to 19 years).

FluWatch report: August 28 to October 1, 2022 (weeks 35-39)

Weekly Highlights At the national level, influenza activity is low and remains at inter-seasonal levels.

Virologic In weeks 35 to 39, a total of 254 laboratory detections (235 influenza A and 19 influenza B) were reported. Influenza A(H3N2) is the dominant subtype, representing 93% of sub-typed influenza A detections this season (August 28, 2022 to October 1, 2022). From August 28, 2022 to October 1, 2022 (weeks 35 to 39), among detections with detailed age information, 41% were in children and teenagers (ages 0 to 19 years).

FluWatch Reports - Public Health Agency of Canada provides updates on flu activity across the country. Subscriptions to the service are free-of-charge. Reports indicate type of Influenza virus that is circulating in all major regions of the country. Influenza and other respiratory viruses are monitored weekly and results reported every Thursday in the Respiratory Virus Detections in Canada Report. More information is available through the following link: https://www.canada.ca/en/public-health/services/diseases/flu-influenza/influenza-surveillance.html