Study Suggests Coronavirus Victims Could Stay Contagious Even After Symptoms End

A security police officer controls the temperature of a government official at the entrance to the La Moneda presidential palace.
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Scientists and researchers are still working to learn more about the novel coronavirus, but a new study suggests that those who are infected could remain contagious for over a week after their symptoms resolve.

As the New York Post reports, a small study in the American Journal of Respiratory and Critical Care Medicine showed that half of the people who tested positive for the virus were still carriers for up to eight days after their symptoms ended. These individuals could potentially spread the disease to other people.

The study involved 16 patients in Beijing who were classified as having a mild case of COVID-19.

Dr. Lokesh Sharma from the Yale School of Medicine said that some of those patients — who were treated in a hospital between January 28 and February 9 — showed evidence of carrying the virus for an average of two-and-a-half-days.

“The most significant finding from our study is that half of the patients kept shedding the virus even after resolution of their symptoms,” he said.

This means that some people could be carrying the disease and spread it to others well after becoming asymptomatic — something that some scientists say is supported by other recent studies.

The Centers for Disease Control and Prevention says that people should continue to isolate themselves for at least 3 days after the “resolution of a fever without fever-reducing medications.”

But the study’s co-author, Dr. Lixin Xie of the Chinese PLA General Hospital, says that it might be smart if people stayed isolated for even longer than that.

“If you had mild respiratory symptoms from COVID-19 and were staying at home so as not to infect people, extend your quarantine for another two weeks after recovery to ensure that you don’t infect other people,” he advised.

Better understanding the virus could help limit its spread.

“This information can provide useful tool for clinicians and policymakers to ensure that recovered patients do not spread the virus,” the researchers who conducted the study said.

But the authors were careful to advise people to be aware that the study was small, and that more research would be needed. The scientists involved with the study noted that outside of China, not enough people have been treated — and released — to have garnered reliable information about the virus.

Across the globe, over 752,000 people have tested positive for the virus, with over 158,000 recoveries. Over 36,000 people have died so far, and scientists have tentatively identified at least eight strains of the virus.