There could be 10 hidden coronavirus cases for every reported one, CDC director says
A top health official said Thursday there could be significantly more coronavirus cases than what’s been confirmed.
Dr. Robert Redfield, director of the Centers for Disease Control and Prevention, said during a Thursday news conference that the agency estimates there are 10 more infections for every coronavirus case reported.
“Our best estimate right now is that for every case that was reported, there actually were 10 other infections,” he said during the news conference.
As of Thursday evening, 2.4 million COVID-19 cases have been confirmed in the United States, according to Johns Hopkins University. But based on what Redfield said, that number would be closer to 24 million.
The estimate is based on antibody testing data, Redfield said.
“This virus causes so much asymptomatic infection, and again we don’t know the exact numbers — there’s ranges between 20% as high as 80% in different groups,” he said during the conference. “But clearly it causes significant asymptomatic infection. The traditional approach of looking for symptomatic illness and diagnosing it underestimated the total amount of infections.”
He said in the early stages of the pandemic, the CDC didn’t aggressively pursue diagnostic testing in young people who were asymptomatic.
But with the ability to test for antibodies, the CDC has “established surveillance.”
“The estimates that we have right now that I mentioned, and again this will continue with more and more surveillance, is that about 10 times more people have antibodies ... that had documented infections.”
This testing looks for the presence of antibodies — which are proteins made in response to infections — in the blood, according to the CDC. In general, they are “presumed” to indicate a person has been infected with COVID-19 in the past. However, it doesn’t mean they are currently infected and there’s not enough evidence to say the presence of antibodies means a person in immune from further infection.
Additionally, current antibody tests are not 100% accurate and false positive and false negative results are possible, per the CDC.
Health experts have said before that coronavirus cases worldwide have likely been under-counted since the start of the pandemic, as many people may contract the virus without knowing or without getting tested and because of a lack of testing in some areas.
The death toll is likely higher as well, many health experts have agreed. Some cite a lack of testing, misclassification of illnesses and varying standards between states, McClatchy News previously reported.
