2 min read.Updated: 05 Jan 2022, 08:15 PM ISTBrianna Abbott, The Wall Street Journal
The agency has been criticized for its shortened recommended isolation period without asking people to get tested
The Centers for Disease Control and Prevention on Tuesday updated its guidance for people infected with the virus that causes Covid-19, including new details for people who want to test before leaving isolation. But the agency stopped short of saying that people must get a test before going back to work or resuming social activities.
The U.S. agency said that if an infected person has access to testing and wants to get tested, the best method would be to use an antigen test, also known as a rapid test, toward the end of their five-day isolation period. The person should continue to isolate until day 10 if the test is positive, but can end isolation after five days if they get a negative result, as long as the individual wears a well-fitting mask around others.
“If people wear a mask—a good mask—after day five, it’s probably going to be okay for most people," said Peter Chin-Hong, an infectious-disease specialist at the University of California, San Francisco. But if a person, such as a healthcare worker, is going to be around people at risk of getting severe disease, he said he would recommend getting a test before exiting isolation.
The CDC first changed its guidance on isolation last week, cutting in half the time that a person needs to isolate after getting a positive Covid-19 test, from 10 days to five, as long as they don’t have symptoms or their symptoms had improved and they continue to wear a mask for the next five days.
The guidance opened the door for people to more quickly return to work or other public spaces, as soaring Covid-19 cases have crippled staffing at airlines, healthcare centers and other businesses.
The earlier recommendation received pushback from some public health experts and doctors, who said that ending isolation around day five without a negative Covid-19 test could further the coronavirus’s spread and put people at risk, since some people could still be infectious.
On Tuesday, the CDC said that if a person had access and wanted a test, the best approach would be to use an antigen test, which hunts for pieces of virus protein. They work best when people are carrying a lot of virus and are most likely to be infectious. In contrast, molecular PCR tests search for pieces of the virus’s genetic material, which may linger weeks after a coronavirus infection. People can still test positive, even if they are likely no longer contagious.
Rapid antigen tests have been in short supply in recent weeks, as holiday gatherings and a surge in cases caused by the Omicron variant have driven up demand.
The agency said people should also avoid travel for the 10 days after first testing positive, or else wear a well-fitting mask after day five if they have to travel.
“Do not go to places where you are unable to wear a mask, such as restaurants and some gyms, and avoid eating around others at home or work until a full 10 days after your first day of symptoms," the agency said.