Understanding the difference in deaths due to flu and deaths due to COVID-19 requires an understanding of how the CDC calculates flu deaths annually. Flu is dramatically underreported each year. Some of the reasons for that undercounting include a fairly narrow window for detecting the virus through testing (i.e. even if a patient has flu, the test may not detect the virus if the test is done outside of the window for testing), the fact that older patients who die from flu may never even be tested, and even if tested and positive, death certificates may list associated pneumonia instead of flu as the cause of death.
In order to adjust for this gross undercounting, the CDC uses algorithms based of of actual positives recorded each year in the FluSurv-Net influenza surveillance system to retroactively estimate total numbers of deaths from flu. They start by adjusting the influenza confirmed test-positive hospital deaths to account for under-detection (reasons stated above like false negatives) to arrive at an estimate of influenza hospital deaths. Because not everyone with influenza dies in the hospital, they then look at death certificates to reach a determination of deaths due to influenza that occurred outside of the hospital. They assess multiple causes of death like pneumonia and other respiratory causes and compare those ratios with the actual deaths related to influenza from the FluSurv-Net surveillance system to reach a total disease burden and estimated annual deaths. This is all done retrospectively so data for the current year is generally not available for some time.
This method of determining influenza burden has clear benefits. It’s important for Americans and healthcare workers to understand the cost in lost lives from influenza each year. Because virtually all of us have someone we love who is considered high risk for death from influenza, maintaining high vaccination rates are critical to preventing dramatic increases in deaths. But in a year with COVID-19, this estimated death toll from influenza is problematic and has led some pundits, elected officials and millions of google-trained virologists and epidemiologists to erroneously conclude that COVID-19 is no worse than flu and that a shutdown was/is unnecessary. This, however, is not a valid comparison as no similar algorithm for missed COVID-19 cases is in play. Only actual test-positive COVID-19 cases are counted with a few very specific exceptions.
In an interesting opinion piece in Scientific American, ER physician Dr. Jeremy Faust of Brigham and Women’s and Harvard Medical School suggested that this false comparison and the damage it does to understanding the scope and severity of COVID-19 may necessitate that the CDC move to reporting only test-positive cases of influenza. When Dr. Faust compared the confirmed flu deaths from each of the last seven years with the confirmed COVID-19 deaths of 2020, a clearer picture of COVID-19’s severity became clear.
This year alone, confirmed COVID-19 deaths are nearly 10 times higher than confirmed flu deaths. Dr. Faust also looked deaths for just one week of COVID-19 and compared those deaths to the previous seven seasons of flu.
If we compare, for instance, the number of people who died in the United States from COVID-19 in the second full week of April to the number of people who died from influenza during the worst week of the past seven flu seasons (as reported to the CDC), we find that the novel coronavirus killed between 9.5 and 44 times more people than seasonal flu. In other words, the coronavirus is not anything like the flu: It is much, much worse.
Jeremy Faust, MD/Scientific American
Changing the way we report flu deaths by listing only test-confirmed cases could have serious adverse consequences when it comes to influenza vaccination rates. If Americans see the smaller totals and think that confirmed flu cases are an accurate representation of flu burden they may be less likely to vaccinate. That could have a devastating effect on protecting vulnerable populations from flu in future seasons. Still, during this COVID-19 crisis the apples to oranges comparison of COVID-19 deaths to annual flu deaths has led many Americans to erroneously and dangerously conclude that COVID-19 is no worse than flu. It’s vital that Americans understand the substantial difference and maintain vigilance against COVID-19, evidenced by the extremely unwise increase in mass anti-lockdown protests popping up around the country. As Dr. Faust suggests, the CDC should consider modifying its flu reporting to at least include data for test-confirmed cases with their algorithmic estimates of influenza burden.
CHRIS DAEL 