Doctors may have to require recovered COVID-19 patients to stay longer at hospitals because of the risk of transmission. Researchers have found that some people continued to spread the coronavirus eight days after their symptoms disappeared.
The new study, published in the American Journal of Respiratory and Critical Care Medicine, shows that the virus remained in some patients in China even after they were considered recovered. Researchers suggested that hospitals extend the isolation period of patients beyond the recommended 14 days.
The team from Yale University School of Medicine analyzed the conditions of 16 patients with mild cases of COVID-19. All participants were admitted to the Treatment Center of PLA General Hospital in Beijing between January 28 and February 9.
Patients experienced different symptoms of COVID-19, such as coughing, fever, shortness of breath and pain in the pharynx. Researchers took throat swabs from the patients until they were discharged and tested negative for the novel coronavirus.
By the end of the study, the team found that the patients who left the hospital after their symptoms ended remain contagious. Some people even continued spreading the virus for up to eight days after recovery.
“The most significant finding from our study is that half of the patients kept shedding the virus even after resolution of their symptoms,” Lokesh Sharma, co-lead study author and an instructor at Yale School of Medicine, said, as quoted by Daily Mail. “More severe infections may have even longer shedding times.”
The Centers for Disease Control and Prevention (CDC) requires people with COVID-19 to isolate for three days after their fever or cough stopped. However, researchers warned that patients who have appeared to recover may still spread the coronavirus.
“COVID-19 patients can be infectious even after their symptomatic recovery, so treat the asymptomatic/recently recovered patients as carefully as symptomatic patient,” the team said in a report.
Those who were advised to self-isolate at home should also extend their quarantine to help avoid transmission. People who had mild respiratory symptoms of COVID-19 should stay at home for another two weeks after recovery “to ensure that you don’t infect other people,” according to Lixin Xie, corresponding study author and a professor at PLA General Hospital in Beijing.