CDC on Wednesday updated its recommendations on how long people who've been exposed to the new coronavirus should quarantine.
People exposed to coronavirus may quarantine for 7 or 10 days, CDC says
CDC recommends that people quarantine if they have been in close contact with someone who has tested positive for Covid-19. The agency defines a close contact as a Covid-19 positive patient who you cared for at home; had direct physical contact with, such as a hug or kiss; shared eating or drinking utensils with; were within 6 feet of for at least 15 minutes; or were near when they sneezed or coughed.
CDC recommends that based on existing data, persons who meet the above criteria should quarantine at home for 14 days. However, in the latest update, the agency recognized that some people have difficulty quarantining for the full 14 days. As such, the agency is recommending "two additional options" for people who were in close contact with a Covid-19 positive individual but are not exhibiting symptoms. The agency said those individuals could choose to quarantine for at least seven days if they've tested negative for the virus, or for 10 days if they haven't received a coronavirus test.
In the guidance, CDC added that people who quarantine for shorter periods should watch for Covid-19 symptoms—including a cough, fever, loss of taste, or loss of smell—for 14 days after their initial exposure—and if they develop symptoms, they should quarantine immediately. They should also wear a mask for the full 14-day period, CDC said.
John Brooks, CMO for the CDC coronavirus response said CDC's revised guidance is based "on extensive modeling, not just by CDC but by other agencies and partners." Brooks said scientists determined that for people who quarantine for seven days under the agency's new guidelines, the "residual post-quarantine transmission risk" is about 5%, with an upper limit of 12%. That risk decreases to nearly 1% for people who quarantine for 10 days under the agency's guidelines, with an upper limit of 10%, he said.
Ultimately, Brooks said CDC's new recommendations on shorter quarantine periods are designed to capture the majority of potentially infectious people and increase compliance with guidelines on quarantining, which is the most effective way of mitigating the coronavirus's spread.
"Reducing the length of quarantine may make it easier for people to take this critical public health action by reducing the economic hardship associated with a longer period, especially if they cannot work during that time," Henry Walke, the CDC's incident manager for its COVID-19 response, told reporters on a conference call Wednesday. "In addition, a shorter quarantine period can lessen stress on the public health system and communities, especially when new infections are rapidly rising."
CDC issues new testing guidance around holiday-related travel
While CDC continues to advise against holiday-related travel, the agency also updated its guidance for testing before and after taking any trips. According to CDC, people planning to travel should be tested one to three days prior to departure and again three to five days after they return from their trip.
Public health experts largely praised CDC's move to shorten quarantine periods for individuals who've been exposed to the coronavirus but are not exhibiting symptoms, noting the latest data suggest people are most infectious early on.
For instance, a new analysis found people who develop Covid-19, the disease caused by the new coronavirus, are most infectious about two days before symptoms start and for five days afterward, the New York Times reports.
"Behind the scenes, many of us had been urging the CDC to move forward with this because I think it's in the best interest of public health, and it's in the best interest of the economy, and it's in the best interest of the mental health of people who have to be quarantined," said William Schaffner, a professor of infectious-disease at the Vanderbilt University Medical Center. "This is a win all around."
Jennifer Nuzzo, a senior scholar at the Johns Hopkins Center for Health Security, said, "Shortening the recommended quarantine period is an important, pragmatic move. It allows health officials to focus their efforts on the period of time that people are most likely to become contagious, which will hopefully boost public compliance with quarantine recommendations."
Former FDA Commissioner Scott Gottlieb in an interview with CBS News' "Face the Nation" said the shorter quarantine periods should continue to capture the "majority" of coronavirus infections.
However, a senior federal official, who spoke to the Washington Post on the condition of anonymity, acknowledged that in issuing the new recommendations CDC is "accepting some risk in exchange for reduction in burden that will allow us to better control this epidemic" (Dwyer, NPR, 12/2; Achenbach, Washington Post, 12/2; Mishra/O'Donnell, Reuters, 12/2; Mandavilli, New York Times, 11/29; Quinn/Tillett, CBS News, 11/29).