CDC Shortens Covid Isolation Time With Omicron Cases Surging

(Bloomberg) -- People who have Covid-19 can leave isolation after five days if they are no longer experiencing symptoms, U.S. health officials said, cutting the previously recommended period in half as the omicron variant spurs a jump in infections.

The Centers for Disease Control and Prevention said in a statement Monday that following the initial five-day isolation period, people with Covid-19 should wear a mask for another five days when around other people. The new guidance supplants previous recommendations that said people who have tested positive for the virus should isolate for 10 days. 

Covid-19 cases are expected to soar in the U.S. following the holidays, threatening to upend the lives of workers and students who are infected or exposed to the virus. Shorter isolation and quarantine periods will allow people to return to work or to school sooner, potentially helping reduce widespread disruptions that could close schools or snarl supply chains.

Studies suggesting that illness caused by omicron isn’t as severe, especially for people who have been vaccinated and received booster shots, has increased pressure on public-health officials to ease their stance on when infected or exposed people can return to their routines. 

Last week, the CDC shortened its isolation guidance for health-care workers, saying those with mild or moderate Covid-19 could return to work after seven days with a negative antigen test.

“This is terrific -- consistent with the evidence and data for contagiousness,” tweeted Ashish Jha, dean of the Brown University School of Public Health, who previously called for a shorter isolation period paired with a negative Covid test. “And exactly what our country needs right now.”

Early Transmission

The CDC’s shift in guidance was motivated by science showing that the majority of coronavirus transmission occurs early in the course of the illness, in the first day or two before the onset of symptoms and the two to three days that follow, the agency said.

The CDC also updated its recommended quarantine period for people who have been exposed to Covid-19. For individuals who are unvaccinated, or for those who are eligible for a booster shot but haven’t yet received one, the agency recommends a five-day quarantine followed by strict use of a mask for five more days. 

However, if a five-day quarantine isn’t feasible, an exposed person should wear a well-fitting mask, such as an N95, at all times when around others for 10 days after exposure.

Individuals who have received a booster shot don’t need to quarantine following an exposure, but should wear a mask for 10 days, the CDC said. If symptoms occur, individuals should quarantine until a negative test confirms that they don’t have Covid-19.

The Biden administration has recently been pushing to get booster shots into the arms of more vaccinated people, and the new guidance could entice more Americans to seek another dose of a vaccine. Just under one-third of fully vaccinated people in the U.S. have received a booster, according to the CDC.

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