Weekly influenza reports

November 19, 2023 to November 25, 2023 (week 47)

At the national level, influenza activity has crossed the seasonal threshold, indicating the start of influenza season. Most surveillance indicators are increasing but remain within expected levels typical of this time of year.

Virologic

• In week 47, the percentage of tests positive for influenza was 7.5% and a total of 2,143 laboratory detections (2,115 influenza A and 28 influenza B) were reported.

Syndromic

• The percentage of visits for influenza-like illness (ILI) was 1.6% in week 47. The percentage of visits for ILI is within levels typical of this time of year.
• The percentage of FluWatchers reporting cough and fever was 2.1% in week 47. The percentage of FluWatchers reporting cough and fever is within levels typical of this time of year.

Outbreaks

• From August 27, 2023 to November 25, 2023 (weeks 35 to 47), 57 laboratory-confirmed influenza outbreaks have been reported (13 laboratory-confirmed influenza outbreaks were reported in week 47).

Severe Outcomes

• From August 27, 2023 to November 25, 2023 (weeks 35 to 47), 555 influenza-associated hospitalizations were reported by participating provinces and territories. Adults aged 65 years of age and older accounted for 45% of reported hospitalizations.

Other Notes

• Interested in reading a more in-depth analysis on the previous influenza season? Check out the FluWatch 2022-23 annual report: Canada's first fall epidemic since 2019 from the October edition of the Canada Communicable Disease Report.
• Weekly reporting of laboratory detections of influenza, SARS-CoV-2, and other seasonal respiratory viruses will continue via our Respiratory Virus Detections Surveillance System.