Negative COVID-19 Test May Be Required After Isolation Among Asymptomatic

Right now, Americans who have tested positive for COVID-19 but have no symptoms are advised by the U.S. Centers for Disease Control and Prevention to isolate for five days and then wear a mask for another five days when around others. But they could soon be asked to also receive a negative antigen test before ending their isolation, Anthony Fauci, M.D., said Sunday.

The nation's top infectious disease expert appeared on national news programs over the weekend, saying that the CDC is considering adding the extra safeguard after getting some "pushback" on its Dec. 27 guidance that shortened isolation times, the Associated Press reported.

"There has been some concern about why we don't ask people at that five-day period to get tested," Fauci said. "Looking at it again, there may be an option in that, that testing could be a part of that, and I think we're going to be hearing more about that in the next day or so from the CDC."

Fauci also addressed the question about the sensitivity of rapid at-home COVID-19 tests. While the U.S. Food and Drug Administration said last week that preliminary research suggests at-home rapid COVID-19 tests may have reduced sensitivity when detecting omicron, the agency is still studying the variant and the tests. Fauci said Americans "should not get the impression that those tests are not valuable."

"I think the confusion is that rapid antigen tests have never been as sensitive as the polymerase chain reaction (PCR) test," Fauci added. "They're very good when they are given sequentially. So if you do them like maybe two or three times over a few-day period, at the end of the day, they are as good as the PCR. But as a single test, they are not as sensitive."