Flu season in Ontario may have peaked

Provincial data show influenza activity in Ontario declined after a peak around Dec. 14–20, but test positivity remains high and ICU admissions for flu increased following the holiday period.

Ontario is reporting a recent decline in reported influenza activity after a spike in December, though overall activity remains high. Public Health Ontario said activity declined over the past two weeks and indicated the peak occurred during the week of Dec. 14–20. Hospital volumes remain elevated even as some admission measures fall, and experts say certain pressures on the system continue. Officials and clinicians caution that some indicators, such as ICU use and test positivity, have not fully eased. Key points: - Influenza cases rose from late October to a peak of about 41.7 cases per 100,000 people on Dec. 14, falling to 24.8 per 100,000 by Jan. 3. - Public Health Ontario reported 4,066 influenza cases in Ontario from Dec. 28 to Jan. 3. - The percent of tests returning positive is still around 25 percent, a level described as quite high by clinicians. - Hospital admissions for flu declined from about 1,400 the week of Christmas to 1,095 the week of Dec. 28–Jan. 3, with 1,209 people in hospital at the most recent count (down 42 from the previous week). - ICU admissions for flu patients rose from 130 to 142 the week after Christmas; by comparison, there were about 52 people in ICUs with the flu around the same time last year. - H3N2 (Influenza A) has been the dominant strain this season and is affecting older adults and young children; PHO reported percent positivity highest in children aged 1–4 (40.7%) and 5–11 (34.3%). Summary: The reported decline in several measures suggests influenza activity peaked in mid-December and some hospital admissions have eased. However, ICU admissions remain elevated and test positivity is still high, so officials describe overall influenza activity as still substantial. Next developments, including whether further waves will occur, are undetermined at this time.