Annual influenza reports

2019-2020 influenza season

• The public health measures instituted to reduce the impact of the COVID-19 pandemic also greatly impacted the 2019-2020 influenza season in Canada.
• Nationally, the 2019-2020 influenza season in Canada began on week 47 (November 17 to 23, 2019), peaked in late January (week 5) and ended early and abruptly on week 13 (March 22 to 28, 2020), eight weeks earlier than the average end of season.
• Record low numbers of reported influenza detections, hospitalizations, and outbreaks were observed from mid-March to the end of the season; this pattern was observed for all influenza surveillance indicators presented in this report.
• During the active influenza season (mid-November to mid-March), all seasonal influenza types and subtypes (A(H1N1), A(H3N2) and B/Victoria) circulated concurrently, resulting in higher than average numbers of influenza detections and hospitalizations being reported during that time period.
• Overall, influenza A was the dominant influenza type (59% of detections) and A(H1N1) the dominant sub-type (68% of sub-typed influenza A).
• Influenza A affected all age groups, with influenza A(H3N2) primarily affecting adults 65 years of age and older and influenza A(H1N1) primarily affecting individuals under 65 years of age. Influenza B primarily affected younger people, with detections predominantly reported in individuals 5 years of age and under.

• 2019-2020 influenza season
• 2018-2019 influenza season