CDC says 14-day Covid-19 quarantine can be shortened to 7 to 10 days

By Jamie Gumbrecht and Naomi Thomas, CNN

(CNN) - Covid-19 quarantine periods can be as short as seven to 10 days for some people, the US Centers for Disease Control and Prevention said Wednesday, but a 14-day quarantine after coronavirus exposure remains the safest option.

In new guidance, CDC says people could leave quarantine without taking a test if they do not develop any symptoms 10 days after being exposed to someone else with coronavirus, or after seven days with a negative test result and no symptoms.

The change comes as Covid-19 cases, hospitalizations and deaths are on the rise around the United States -- and with that, more people facing quarantine.

The new quarantine guidance was based on "extensive" modeling by CDC and other agencies that showed the risk is low, Dr. John Brooks, chief medical officer for CDC's Covid-19 response, said during a telebriefing Wednesday. Many people end quarantine early because of pressure to return to work and school, CDC officials said, and some aren't willing to share names of contacts they fear will then be required to quarantine.

But if the quarantine period is reduced from 14 days, more people may be willing to stay home after exposure, the CDC said -- and that may result in fewer coronavirus infections.

"We believe that if we can reduce the burden a little bit, accepting that it comes at a small cost, we may get a greater compliance overall with people completing a full quarantine," Brooks said. "If we get more people on board to complete that overall, that will result in fewer infections."

Risk of transmission after ending quarantine early

There's still some risk a person who left quarantine before 14 days could transmit the virus to others.

"We can safely reduce the length of quarantine, but accepting there is a small residual risk that a person who is leaving quarantine early could transmit to someone else if they became infectious," Brooks said.

If a person quarantined for 10 days and had no symptoms and no test, the residual risk of transmitting coronavirus to someone else after quarantine is estimated to be about 1%, with an upper limit of about 10%, the CDC said on its website.

If a person quarantined for seven days and had no symptoms and a negative test, the risk of transmitting coronavirus is about 5%, with an upper limit of about 12%.

A PCR or antigen test should be collected within 48 hours before the end of quarantine, CDC says, but quarantine should not end before seven days, even if rest results are returned earlier.

People who have been exposed should still watch for symptoms for 14 days, especially if they end quarantine early, Dr. Henry Walke, CDC's Covid-19 incident manager, said Wednesday.

And if a person goes on to develop symptoms, they should contact their local health authorities and health care provider, seek out testing and isolate.

Local public health agencies' recommendations may differ from CDC's, too.

"Everyone should follow this specific guidance from their local public health authorities about how long they should quarantine," Walke said.

Read More on CNN