Confusion about lethality comparisons may be owing to "a knowledge gap" in how the CDC reports on seasonal influenza and COVID-19.
New research shows that counted deaths from COVID-19 in mid-April were about 20 times greater than seasonal influenza counted deaths recorded during peak weeks of the past seven flu seasons.
If true, the assessment would provide a stinging rebuttal to policy makers and politicians who've maintained that the coronavirus is no more deadly than the seasonal flu. As of Wednesday, April 20, COVID-19 has killed more than 93,500 Americans.
"The demand on hospital resources during the COVID-19 crisis has not occurred before in the US, even during the worst of influenza seasons," co-authors Jeremy Samuel Faust, MD, of Harvard Medical School, and Carlos Del Rios, MD, of Emory University School of Medicine wrote in JAMA Internal Medicine.
"Yet public officials continue to draw comparisons between seasonal influenza and SARS-CoV-2 mortality, often in an attempt to minimize the effects of the unfolding pandemic," they wrote.
"This apparent equivalence of deaths from COVID-19 and seasonal influenza does not match frontline clinical conditions, especially in some hot zones of the pandemic where ventilators have been in short supply and many hospitals have been stretched beyond their limits."
The researchers said the confusion about lethality comparisons may be owing to "a knowledge gap" in how the Centers for Disease Control and Prevention reports on seasonal influenza and COVID-19.
The CDC, they note "like many similar disease control agencies around the world, presents seasonal influenza morbidity and mortality not as raw counts but as calculated estimates based on submitted International Classification of Diseases codes."
Thus, between 2013 and 2019, the yearly seasonal influenza deaths ranged from 23,000 to 61,000. However, the actual number of counted influenza deaths over that timespan ranged between 3,448 and 15,620 deaths each year. On average, the researchers said, CDC influenza death estimates are about six times greater than the number of counted deaths.
Conversely, COVID-19 deaths are not estimated, but counted and reported directly. The researchers suggested that a more valid measure would be to compare weekly counts of COVID-19 deaths to weekly counts of seasonal influenza deaths.
So, they did.
During two weeks in mid-April, 29,933 COVID-19 deaths were counted in the United States. In contrast, according to CDC, counted deaths during the peak week of the influenza seasons from 2013-2020 ranged from 351 (2016) to 1626 (2018).
The mean number of counted deaths during the peak week of influenza seasons from 2013-2020 was 752.4.
"These statistics on counted deaths suggest that the number of COVID-19 deaths for the week ending April 21 was 9.5-fold to 44.1-fold greater than the peak week of counted influenza deaths during the past 7 influenza seasons in the US, with a 20.5-fold mean increase," the researchers said.
"The ratios we present are more clinically consistent with frontline conditions than ratios that compare COVID-19 fatality counts and estimated seasonal influenza deaths," they wrote. "We infer that either the CDC's annual estimates substantially overstate the actual number of deaths caused by influenza or that the current number of COVID-19 counted deaths substantially understates the actual number of deaths caused by SARS-CoV-2, or both."
Faust Raps CDC Methodology
In an email exchange with HealthLeaders, Faust challenged the way CDC tracks seasonal influenza deaths.
"The CDC believes that flu counts are underestimated at several points in the healthcare system. But if that were true, we’d see increases in overall death counts in bad flu seasons. We simply don’t observe that. Their explanation in here. But the assumptions it make are simply not supported by reality. If they were, again we would see more “all cause” deaths in bad flu seasons. That does not occur," Faust wrote.
Faust said it's possible that CDC is reporting larger numbers of influenza deaths in the hopes of encouraging the public to use better hygiene and get flu shots.
"But I believe those aims can be achieved without that tactic. In fact, we tend to make the opposite argument for other vaccines. The proof that measle/mumps/rubella vaccines are so effective? That there are so few cases these days," he wrote.
Faust says he not quite clear why CDC sticks to these estimates for seasonal flu, rather than counting deaths, which they do with pediatric influenza.
"However, if they did that, they’d have to borrow those deaths from other causes, like heart failure," he wrote.
"Interestingly, if the CDC counted all of these and reported them directly it might very well be that the raw counts would come down even further than they are now," he wrote.
"If official documents are only 'allowed' to count one cause of death, that means the yearly total of deaths in the United States needs to add up to 2.5 million. In that regime, medical examiners would have to choose between causes of death," he wrote.
"For those dying of flu after a three-year battle with cancer? I’d give cancer the credit. The big question becomes: is this also happening with COVID-19? The answer is very little so far. How do we know? Because unlike a bad flu season, total numbers of deaths are up. That’s what makes this 'real.'"
“Public officials continue to draw comparisons between seasonal influenza and SARS-CoV-2 mortality, often in an attempt to minimize the effects of the unfolding pandemic.”
Study authors Jeremy Samuel Faust, MD, and Carlos Del Rios, MD.
John Commins is a content specialist and online news editor for HealthLeaders, a Simplify Compliance brand.
On average, CDC seasonal influenza death estimates are about six times greater than the number of counted deaths.
Conversely, COVID-19 deaths are not estimated, but counted and reported directly.
During two weeks in mid-April, 29,933 COVID-19 deaths were counted in the United States.
CDC counted deaths during the peak weeks of the influenza seasons from 2013-2020 ranged from 351 in 2016 to 1,626 in 2018.