South Korean health officials are investigating several possible explanations for a small but growing number of recovered coronavirus patients who later test positive for the virus again.
Among the main possibilities are re-infection, a relapse, or inconsistent tests, experts say.
South Korea had reported 141 such cases as of Thursday, according to the Korea Centers for Disease Control and Prevention (KCDC).
Citizens being reinfected by the coronavirus were likely based on flawed tests, The New York Times reports.
In a news conference, Oh Myoung-don, the head of South Korea¡¯s central clinical committee, said there is a "high possibility" that tests claiming people got reinfected for the second time were based on bad test results.
He said the tests detected the ribonucleic acid of the dead virus.
In China as well, there are a number of patients that have been reinfected.
¡°A lot of the tests that came back in China that you read about, where it looks like people were reinfected, those look extremely likely to be the result of testing errors,¡± Nita Bharti, a biologist at the Center for Infectious Disease Dynamics at Penn State, told The Hill.
¡°If you¡¯re testing a lot of people like they did in China, you¡¯re likely to get a lot of false positives and a lot of false negatives,¡± she added.
Reports suggest the tests cannot distinguish whether the virus is alive or dead and this can lead to false positives.
The resurgence of virus in patients has become a massive cause of worry for scientists and researchers across the world who are working to develop a vaccine for the novel virus.