Weekly influenza reports

April 17, 2022 to May 7, 2022 (weeks 16-18)

• Since the beginning of April, detections of influenza have sharply increased. All indicators of influenza activity have increased in recent weeks. Influenza activity has reached seasonal thresholds.  

Virologic

• In weeks 16 to 18, 4,816 laboratory detections (4,810 influenza A and 6 influenza B) were reported.
• Among detections with detailed age information, the majority of detections were in individuals under the age of 45 years.

Syndromic

• The percentage of visits for influenza-like illness (ILI) was 2.1% in week 18. The percentage visits for ILI has now exceeded the pre-pandemic levels typical of this time of year.
• The percentage of FluWatchers reporting fever and cough was 1.4% in week 18. The percentage of FluWatchers who reported cough and fever in weeks 16-18 is within levels seen pre-pandemic.

Outbreaks

• In weeks 16 to 18, 15 laboratory-confirmed influenza outbreaks were reported. 
• From August 29, 2021 to May 7, 2022 (weeks 35 to 18), 30 laboratory-confirmed influenza outbreaks  have been reported to date this season.

Severe Outcomes

• From August 29, 2021 to May 7, 2022 (weeks 35 to 18), 249 influenza-associated hospitalizations have been reported from participating provinces and territories.
• The IMPACT network is reporting a sharp increase in influenza-associated hospitalizations among the pediatric population.

Other Notes

• The next scheduled FluWatch report (week 19) will be published May 20, 2022.
• Weekly reporting of laboratory detections of influenza and other seasonal respiratory viruses will continue via our Respiratory Virus Detections Surveillance System