As many as 442,000 Los Angeles County residents might have already been infected with the coronavirus by early April, a number far higher than the 8,000 cases confirmed at the time, according to a report released Monday.
In the first large-scale study of adults tested for COVID-19 antibodies in their blood, initial results show researchers found that 4.1% have the antibodies, an indication that they have already been exposed to the virus.
“That translates to roughly 221,000 to 442,000 adults who have recovered from an infection, once margin of error is taken into account, according to the researchers conducting the study,” the Los Angeles Times reported. “The estimated infection numbers are 28 to 55 times higher than the 7,994 confirmed COVID-19 cases L.A. County had reported at the time of the study in early April.”
The study, conducted by the University of Southern California and the Los Angeles County Department of Public Health, tested more than 860 people deemed representative of L.A. County, the researchers told The Times.
“We haven’t known the true extent of COVID-19 infections in our community because we have only tested people with symptoms, and the availability of tests has been limited,” said lead investigator Neeraj Sood, professor of public policy at the USC Price School for Public Policy. “The estimates also suggest that we might have to recalibrate disease prediction models and rethink public health strategies.”
Said The Times: “The findings suggest the fatality rate may be much lower than previously thought. But although the virus may be more widespread, the infection rate still falls far short of herd immunity that, absent a vaccine, would be key to return to normal life.”