The CDC on Wednesday announced that COVID-19 quarantines can be shortened to seven days after negative test results and no symptoms.
CDC COVID-19 incident manager Henry Walke said 14 days remains the baseline quarantine recommendation for people exposed to someone diagnosed with the coronavirus. But the shortened time periods — 10 days without symptoms and 7 days with no symptoms and a negative test — are intended to give people more options for returning to work.
That negative test should be from a genetic PCR test, not a rapid test, which is more likely to return a false negative if someone is not tested at the peak of their infection.
This change does not affect people who have tested positive for COVID-19, who are still required to self-isolate for 10 days.
The chances of people spreading illness after these shorter time periods fall into a "sweet spot," for acceptable risks, said Walke. The estimate is a 1% chance of actually turning out to be sick after 10 days without symptoms leading to transmission, and a 5% chance after seven days without symptoms and a negative test.
"We may get a greater compliance overall with people completing a full quarantine in seven days," he said.
Epidemiologist Saskia Popescu, an affiliate of the Georgetown University Center for Global Health Science and Security, suggested on Twitter that the CDC's shift reflected the difficulty of getting people to quarantine for a full two weeks. "Glad to see a movement in this direction," she added, but expressed concern that the CDC's suggestion to test on the fifth day of a seven-day quarantine, for example, might lead to some missed COVID-19 cases.
As well as the shift in guidelines, CDC officials on the briefing call urged people to avoid travel this Christmas, citing surging COVID-19 caseloads nationwide.