Weekly influenza reports

November 12, 2023 to November 18, 2023 (week 46)

At the national level, influenza activity is increasing and has crossed the seasonal threshold of 5% positivity. If percent positivity remains above this threshold next week, the start of the influenza season will be declared. Most surveillance indicators are increasing but remain within expected levels typical of this time of year.

Virologic

• In week 46, the percentage of tests positive for influenza was 6.8% and a total of 1,849 laboratory detections (1,811 influenza A and 38 influenza B) were reported.

Syndromic

• The percentage of visits for influenza-like illness (ILI) was 2.0% in week 46. The percentage of visits for ILI is within levels typical of this time of year.
• The percentage of FluWatchers reporting cough and fever was 1.9% in week 46. The percentage of FluWatchers reporting cough and fever is within levels typical of this time of year.

Outbreaks

• From August 27, 2023 to November 18, 2023 (weeks 35 to 46), 51 laboratory-confirmed influenza outbreaks have been reported (10 laboratory-confirmed influenza outbreaks were reported in week 46).

Severe Outcomes

• From August 27, 2023 to November 18, 2023 (weeks 35 to 46), 332 influenza-associated hospitalizations were reported by participating provinces and territories. Adults aged 65 years of age and older accounted for 46% of reported hospitalizations.

Other Notes

• Weekly reporting of laboratory detections of influenza, SARS-CoV-2, and other seasonal respiratory viruses will continue via our Respiratory Virus Detections Surveillance System.
• Weekly reporting of SARS-CoV-2 specific trends can be found on the COVID-19 epidemiology update page.