Latest flu report: Influenza B is spreading in Canada

Latest flu report: Influenza B is spreading in Canada

According to Canada's Flu Watch, there has been a minor increase in influenza cases across the country in recent weeks. This is remarkable less for the overall numbers than for the fact that an increase in influenza B infections is the only cause of the increase.

A total of 510 laboratory detections of influenza were detected nationwide in Week 13 of 2023, according to the report, which is released weekly and tracks confirmed influenza cases across the nation. These figures are typical for this time of year.

364 of these confirmed flu cases (of which there were 146 instances of influenza A) were caused by influenza B. Read more from Health Canada about the many viruses.

In contrast to influenza A's supremacy in 2022, influenza B is now responsible for 71% of detections.

According to the most recent Flu Watch, the percentage of tests that came back positive for influenza increased to 2.4% in Week 13 from 0.8% in Week 7, a rise that can only be attributed to the rise in influenza B.

Compared to previous year, the strain is now circulating at significantly higher levels.

The majority of infections during the peak of flu season at the end of 2022 were caused by influenza A, with influenza B hardly making a mark.

Additionally, during the five weeks of flu monitoring in March and April of last year, there were only four cases of influenza B, compared to 1,283 cases of influenza A.

In Week 13, there were 15 paediatric influenza-related hospitalizations, 14 of which were caused by influenza B.

The total influenza activity that is being observed right now, across all strains, is typical for interseasonal influenza activity, or the level that is anticipated between flu seasons.

According to the most recent Flu Watch, only 1% of visits to medical professionals in Week 13 were because of "influenza-like illness," which is "slightly below expected levels for this time of year."

In Week 13, more than 9,500 individuals shared their health statuses with Flu Watchers in order to provide data on the prevalence of specific respiratory symptoms among the general public, whether or not they had the flu. 1.5% of the sample reported cough and fever, which is less than seasonal averages.

There have been 67,806 influenza detections since August 22 through April 1; 97% of these have been influenza A. 4,008 hospitalisations linked to the flu have been reported by participating provinces and territories during the same time frame. Ninety-nine percent of these cases involved influenza A.