The CDC Says Its New 'Best Estimate' Is That 0.4 Percent of People With Symptoms and COVID-19 Will Die

An anonymous reader quotes a report from CNN: In new guidance for mathematical modelers and public health officials, the U.S. Centers for Disease Control and Prevention is estimating that about a third of coronavirus infections are asymptomatic. The CDC also says its "best estimate" is that 0.4% of people who show symptoms and have Covid-19 will die, and the agency estimates that 40% of coronavirus transmission is occurring before people feel sick.

The numbers are part of five planning scenarios that "are being used by mathematical modelers throughout the federal government," according to the CDC. Four of those scenarios represent "the lower and upper bounds of disease severity and viral transmissibility." The fifth scenario is the CDC's "current best estimate about viral transmission and disease severity in the United States." In that scenario, the agency described its estimate that 0.4% of people who feel sick with Covid-19 will die. For people age 65 and older, the CDC puts that number at 1.3%. For people 49 and under, the agency estimated that 0.05% of symptomatic people will die. The CDC cautions that these numbers are based on real data collected by the agency before April 29 and are subject to change. Still, the "current best estimate" number of 0.4% is significantly lower than the 3.4% mortality rate the World Health Organization warned in early March.

"As I see it, the 'best estimate' is extremely optimistic, and the 'worst case' scenario is fairly optimistic even as a best estimate. One certainly wants to consider worse scenarios," biologist Carl Bergstrom of the University of Washington told CNN. "By introducing these as the official parameter sets for modeling efforts, CDC is influencing the models produced by federal agencies, but also the broader scientific discourse because there will be some pressure to use the CDC standard parameter sets in modeling papers going forward," he said. "Given that these parameter sets underestimate fatality by a substantial margin compared to current scientific consensus, this is deeply problematic."

UPDATE (5/28): An epidemiologist at the Johns Hopkins Center for Health Security also contradict the CDC's low numbers, saying that after reviewing new widespread testing, "The current best estimates for the infection fatality risk are between 0.5% and 1%," according to NPR.

"But even a virus with a fatality rate less than 1% presents a formidable threat, Rivers says."