Influenza hospitalizations so far this fall have been too low for the Centers for Disease Control and Prevention to run its model on the burden of the flu season.
“CDC, can’t run their flu model; too few hospitalizations,” columnist Phil Kerpen noted on Twitter while sharing a snapshot of the CDC website.
“The model used to generate influenza in-season preliminary burden estimates uses current season flu hospitalization data,” the CDC website says. “Reported flu hospitalizations are too low at this time to generate an estimate.”
CDC can’t run their flu model; too few hospitalizations.https://t.co/DRPOY7HqRg pic.twitter.com/AkA0YBImRv
— Phil Kerpen (@kerpen) December 7, 2020
Every flu season, the CDC provides a weekly preliminary estimate on “in-season numbers of flu illnesses, medical visits, hospitalizations, and deaths in the United States.” The CDC notes that it “does not know the exact number of people who have been sick and affected” by the flu because it is not a “reportable disease,” instead depending on a “mathematical model” developed in 2010 that estimates the burden of the flu season.
A September CDC report found that flu “activity” was low in the “United States and globally” for the time of year, with positive test results decreasing from more than 20% last year to 2.3% this year, which have “remained at historically low” levels.
“After recognition of widespread community transmission of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), by mid- to late February 2020, indicators of influenza activity began to decline in the Northern Hemisphere,” the report said. “These changes were attributed to both artifactual changes related to declines in routine health seeking for respiratory illness as well as real changes in influenza virus circulation because of widespread implementation of measures to mitigate transmission of SARS-CoV-2.”
The report speculated that interventions designed to stop the spread of COVID-19 transmission could help to reduce the impact of the 2020-21 flu season but noted that “other factors, such as the sharp reductions in global travel or increased vaccine use, might have played a role in decreasing influenza spread; however, these were not assessed.”
