BEIJING, April 21 (Xinhua) -- Most of the discharged COVID-19 patients retesting positive in nucleic acid tests showed no obvious symptoms, and very few saw their symptoms worsen, a health expert said Tuesday.

"Discharged patients who retest positive are required to be quarantined at designated hospitals for medical observation since they might be infectious," said Wang Guiqiang, an infectious disease expert with the Peking University First Hospital, at a press conference.

Recovered COVID-19 patients should stay in quarantine for 14 days after being discharged, with their temperatures taken and health conditions checked daily, according to a recently released trial protocol for discharged COVID-19 patients.

Wang also stressed that discharged patients should wear masks and be quarantined in separate rooms during their isolation period.