By Dorothy Brooks

In a move that affects healthcare workers and their patients, the CDC has refined its guidance regarding the length of quarantine for individuals exposed to COVID-19.

Previously, CDC recommendations stated those exposed to someone with the virus should quarantine for 14 days to prevent the potential spread of the disease to others. However, experts have concluded a shorter quarantine period should be safe in most cases.

“After reviewing and analyzing new research and modeling data, CDC has identified two acceptable alternative quarantine periods,” explained Henry Walke, MD, the incident manager for the CDC’s COVID-19 response, during a media briefing about the new guidance on Dec. 2. “Under these options, quarantine can end after 10 days without a COVID-19 test if the person has reported no symptoms, or after seven days with a negative test if the person has reported no symptoms.”

Although this guidance has been shared with public health agencies across the country, Walke stressed providers and patients should follow the specific guidance regarding quarantine length issued from their local public health authorities. “People should still watch for symptoms ... for a full 14 days after exposure, especially if quarantine is discontinued early,” he said.

Shorter Quarantine Reduces Hardships

Walke expressed hope that reducing the length of quarantine would make it somewhat easier for people to abide by public recommendations. Namely, a shorter quarantine window reduces the economic hardship associated with staying out of work. “In addition, a shorter quarantine period can lessen stress on the public health system and communities, especially when new infections are rapidly rising,” Walke said.

The new recommendations are based on extensive modeling performed by CDC and other agencies, including academic centers and some public health departments, noted John Brooks, MD, the chief medical officer for the CDC’s COVID-19 response, who also spoke during briefing.

“All of this points in the same direction, which is that we can safely reduce the length of quarantine, but accepting there is a small residual risk that a person who is leaving quarantine early can transmit to someone if they become infectious,” he said.

‘Acceptable Risk’

Specifically, Brooks noted that in cases where quarantine is cut to 10 days, researchers calculated the residual risk is about 1%, and the upper limit of that risk is about 12%. “That’s an acceptable risk I think for many people,” Brooks said, noting that it aligns with the CDC’s recommendations around isolation for someone diagnosed with COVID-19, which the agency is not currently changing. “Isolation can end in 10 days if a person has had more than 24 hours of recovery after their illness.”

In the case of a seven-day quarantine, the residual risk with a negative test is about 5%. The upper limit of that risk is about 10%. However, Brooks stressed the timing of the test is important.

“Our modeling was based on collecting the specimen within 48 hours prior to the time of anticipated discharge,” he said. “It could be a test that is done that day [of discharge], if it is an antigen test, but we provide the possibility of collecting the specimen up to 48 hours beforehand if [people] have a PCR test, which may take a day or two to get the results back.”

Relief for Healthcare Authorities

The adjustments to the quarantine guidance should provide some relief to healthcare authorities at a time when case counts are surging along with the number of people who need to quarantine.

“That is a lot of burden, not just on the people who have to quarantine but on public health. Many times, the public health authorities are responsible for monitoring people during quarantine, and they have to follow them to the end,” Brooks observed. “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 ... and if we get more people on board to complete that overall, that will result in fewer infections.”

With better adherence to quarantine, the CDC is hopeful contact tracing will prove more effective, too.

“If a person is willing to be more compliant with a shorter quarantine, [he or she] may also be willing to share the names of contacts,” Brooks said. “We know that people sometimes don’t do that because they don’t want to potentially give out the name of a friend or neighbor and force them into quarantine. As well, we hope this will increase the willingness of people to pick up the phone and answer public health calls because they’ve been one of the people who have been named.”