Weekly influenza reports

January 14 to January 20, 2024 (week 3)

At the national level, most indicators of influenza activity remained similar, or decreased slightly, compared to the previous week. All surveillance indicators are within or below expected levels typical of this time of year.

Virologic

• In week 3, the percentage of tests positive for influenza was 11.1% and a total of 3,859 laboratory detections (3,590 influenza A and 269 influenza B) were reported.

Syndromic

• The percentage of visits for influenza-like illness (ILI) was 1.4% in week 3. The percentage of visits for ILI is within levels typical of this time of year.
• The percentage of FluWatchers reporting cough and fever was 1.3% in week 3. The percentage of FluWatchers reporting cough and fever remains below expected for this time of year.

Outbreaks

• From August 27, 2023 to January 20, 2024 (weeks 35 to 3), 573 laboratory-confirmed influenza outbreaks have been reported (52 laboratory-confirmed influenza outbreaks were reported in week 3).

Severe Outcomes

• From August 27, 2023 to January 20, 2024 (weeks 35 to 3), 3,300 influenza-associated hospitalizations were reported by participating provinces and territories. Adults aged 65 years of age and older accounted for 48% of reported hospitalizations. The highest cumulative hospitalization rates were among adults 65 years of age and older (108/100,000) and children under 5 years of age (66/100,000).
• From October 1, 2023 to January 20, 2024 (weeks 40 to 3), 452 influenza-associated pediatric hospitalizations were reported from a total of 1,884 positive influenza tests across eight sentinel hospital sites.

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.