Flu Season Has Peaked, Now Declining Sharply: Public Health Agency

A pedestrian walks by a sign in a store window encouraging people to receive a seasonal flu shot in Toronto on Oct. 19, 2021. (The Canadian Press/Evan Buhler)

Canada’s flu season has peaked and is showing signs of being nearly over, according to the latest national FluWatch report released on Jan. 13.

The report said that for the week of Jan.1 to Jan.7, influenza had “declined sharply” from the peak that occurred at the end of November 2022, and is now “below expected pre-pandemic levels.”

FluWatch is the Public Health Agency of Canada’s (PHAC) national flu surveillance system and releases reports every Friday during active influenza season.

The report said that flu levels are now at the expected levels typical for this time of year.

The number of children hospitalized has also declined sharply—from a peak of 247 hospitalizations that occurred during the week of Nov. 27 to Dec. 3, 2022—and is now within normal levels. In the first week of January, 30 pediatric hospitalizations associated with influenza were reported.

Flu Season

The flu season started earlier in 2022, beginning on Aug 28, and by Jan. 7 had resulted in a reported 3,690 flu-related hospitalizations, 311 admissions to ICU, and 218 deaths. Of those 1,534 were children.

From Aug. 28, 2022, to Jan. 7, 572 laboratory-confirmed influenza outbreaks were reported, of those 16 were new outbreaks in the first week of 2023, and 11 of these occurred in long-term care facilities.

For flu figures where age information was available, 48 percent of flu indicators were among those aged 65 and older, which increased by 40 percent from the last week of December.

In terms of medical visits, only 1.7 percent were for influenza symptoms, which was slightly lower than typical levels around this time of year. The percentage of coughs and fever reported was also 1.7 percent, which is below seasonal levels.

The highest cumulative hospitalization rate for week one of 2023 was among adults over the age of 65 (120/100,000 population) and in children under five years old (116/100,000 population).

Pediatric

During the first half of November, children’s hospitals across the country reported being in an emergency situation due to respiratory syncytial virus (RSV) admissions. RSV activity, which typically peaks in the winter, was above expected levels for that time of year, according to PHAC data.

Some 1,309 cases were detected among 16,856 tests conducted for the week ending Nov. 5. This was a test positivity rate of 7.77 percent, more than double the rate of 3.57 percent from three weeks earlier, when just over 500 cases were detected out of 14,114 tests.

Influenza A was another respiratory virus currently with cases above expected levels in the fall of 2022, according to PHAC. The test positivity rate for influenza A was 6.44 percent, for the week ending Oct. 29, with 1,077 positive cases, compared with 1.53 percent for the week ending Oct. 15.