Thread by @Aaron_Derfel

1) Canada's chief public health officer confirmed for the first time Friday that the country has officially entered uncharted territory, confirming the long-dreaded but now-realized triple calamity of influenza, RSV and SARS-CoV-2 viruses "co-circulating." What does this mean?

2) It means in addition to the #COVID pandemic, Canada has plunged into a much earlier-than-expected flu epidemic where "the highest cumulative hospitalization rates are among children under 5 years of age (26/100,000 population) and adults 65 years of age and older 21/100,000)."

3) It means so far this year, up to 4 Canadian children have died from the flu, among 58 intensive-care admissions and 482 hospitalizations. The near-vertical line in the chart below points to pediatric flu hospitalizations this year. Compare that to the dotted line average.

4) At the other end of the age spectrum, those at least 65 years old are also being hospitalized for the flu and are quite vulnerable. If this flu epidemic occurred in any year before #COVID's appearance, it would likely be considered a national health emergency on its own.

5) Meanwhile, the #COVID pandemic that has so far killed at least 47,850 Canadians is still far from over, particularly in Quebec. That province has registered four days of rising #pandemic hospitalizations (1,807), health-worker absences due to COVID (3,749) and outbreaks (365).

6) As if the co-circulation of SARS-CoV-2 and influenza were not enough, Canada is firmly in the grip of a third epidemic involving Respiratory Syncytial Virus that is sending children to emergency rooms, but that also poses a "high risk" to seniors. Please see below.

7) If there is one glimmer of potentially good news, it's that "activity of RSV is stabilizing (1,944 detections; 7.6% positive)," according to the Public Health Agency of Canada. However, "RSV activity remains above expected levels for this time of year." Please see below.

8) So could this co-circulation of viruses lead to co-infections? U.K. researchers warned in an April study following the lifting of public health protections "we expect that SARS-CoV-2 will circulate with other respiratory viruses, increasing the probability of co-infections."

9) It's not just U.K. researchers who've been warning about co-infections. On Nov. 2, U.S. researchers found a "high prevalence" of #COVID19 and influenza co-infections during the 2021-2022 flu season. One caveat: that study observed a co-infection rate of 7.1% last January.

10) The repercussions of this triple viral calamity are crushing hospitals across this country, especially in emergency rooms. Yet confoundingly, Canada's politicians appear to be in no rush to reinstate public health projections. End of thread.

ADDENDUM: In tweet 10, I meant "protections," not projections. That's one of the reasons why I prefer posting these threads to ad-free Mastodon. It has an edit button.