South Korean coronavirus patients re-diagnosed after they recovered

South Korean officials have announced 91 patients who were thought to have recovered from COVID-19 have re-tested positive.

Jeong Eun-kyeong, the director of the Korea Centers for Disease Control and Prevention (KCDC), says the virus appears to have been "reactivated" rather than the patients being reinfected, Reuters reported.

The number of patients has grown after 51 were announced on Monday and officials say it brings doubt into what it means for a patient to be cleared of the virus and when they should be allowed to return home.

Bloomberg reported a patient is currently deemed fully recovered when two tests conducted with a 24-hour interval show negative results.