NEW YORK – The US Centers for Disease Control and Prevention issued guidance on Wednesday that the public avoid winter holiday travel in order to reduce the spread of COVID-19. The agency also guided that if travel is unavoidable, people should be tested for the SARS-CoV-2 virus before leaving and after they return home.
In a call with the media, CDC representatives further guided that the quarantine time can be reduced in some cases, and that people who decide to travel should reduce non-essential activities for a period upon returning, whether or not they test negative.
The agency still recommends 14 days of quarantine following potential exposure to the virus.
"Additionally, after reviewing and analyzing new research and evolving data, CDC has identified two acceptable alternative quarantine periods," Henry Walke, CDC's COVID-19 incident manager said on the call.
Quarantine can end after 10 days without a COVID-19 test if a person has reported no symptoms, he said, or after seven days with a negative test result.
"We are sharing these options with public health agencies across the country so that they can determining how long quarantine periods should last in their jurisdictions based on local conditions and needs," Walke said, adding, "Everyone should follow the specific guidance of their local public health authorities." Walke also noted that people should still watch for symptoms for a full 14 days, especially if quarantine is discontinued early.
"Reducing the length of quarantine might make it easier for people to take this critical public health action," Walke said, specifically by reducing the economic and psychological burden, and potentially making people more willing to comply with quarantine and to assist in contact tracing.
John Brooks, chief medical officer for CDC's COVID-19 response, said on the call that the quarantine recommendation is based on extensive modeling done by CDC and other agencies and partners which suggests a 1 percent residual risk when quarantine is reduced from 14 to 10 days, with an upper risk limit of 12 percent. For seven days of quarantine after a negative test, the residual risk is 5 percent, he said, but noted that these risks are estimated in the context of people monitoring for symptoms and isolating if they become symptomatic.
For people who decide to travel, CDC is recommending they consider getting tested for SARS-CoV-2 one to three days prior, and again three to five days after traveling.
"This should be combined with reducing non-essential activities for a full seven days after travel," Brooks said, and for 10 days without testing after traveling.
"Testing does not eliminate all risk, but when combined with reducing non-essential activities, symptom screening, and continuing with precautions like wearing masks, social distancing, and hand washing, it can make travel safer," he said.
The agency specifically guided for testing to be either PCR or antigen assays performed on a specimen collected within 48 hours prior to the end of the quarantine period, reiterating that a person would need to have the negative result in hand to discontinue quarantine after seven days. Regarding PCR versus antigen tests Brooks said, "In our modeling, either test came out with about the same residual risk."
The CDC is offering the options that do not have a testing component in part to help address capacity problems. "We recognize that testing is difficult in some locations, and that our public health partners now have options to choose something that will suit the circumstance in their community, based on those circumstances and the relative resources that they have available," Brooks said.