A lucky break? Covid-19 measures seem to have killed the flu season

In New York City, influenza-like illnesses' numbers are running at less than one-third of the recent norm for the first half of December

The pandemic is meeting many of the worst expectations that public health experts in the US and Europe had for fall and winter.

There’s one thing they worried about that doesn’t seem to be happening, though: a “twindemic” of Covid and seasonal influenza.

Instead, the flu is AWOL — so far at least. In New York City, which publishes a handy daily count of emergency-room visits for influenza-like illnesses and other conditions, numbers are running at less than one-third of the recent norm for the first half of December.
 

This seeming absence of influenza is almost certainly not just a lucky break. It’s also not the result of a cover-up in which the authorities count flu cases as Covid-19 cases (apparently a popular theory in some Covid-denialist circles). It is conceivable that New York emergency rooms are less likely to count coronavirus cases as influenza-like illnesses than they were last March, when Covid tests were scarce and health-care workers less familiar with Covid symptoms. It’s also possible people are just avoiding emergency rooms if they at all can. But positive influenza test results tracked on the US Centers for Disease Control and Prevention’s FluView show an even more dramatic decline.
 

That dark-blue line that’s pretty much indistinguishable from zero for most of the year is 2020. The positive-test total for the week ending December 5 — the most recent data available — was just 56. In the same week last year it was 6,435. The start of flu season in the northern hemisphere is deemed to be the 40th week of the year, which ended on October 3, making December 5 the end of the 49th week.
 

Yes, the 2011-2012 flu season started out with an even lower positive-test count. But that’s misleading, given that the number of flu tests performed has risen a lot since then (although it’s still nowhere near the number of Covid-19 tests performed this year). Those 511 positives in the first 10 weeks of the 2011-2012 flu season were out of 40,150 tests, for a positivity rate of 1.3%. This year’s 602 positives are out of 401,112 tests, for a positivity rate of 0.15%.