Photo/Illutration A gate is set up to check body temperatures in Shanghai’s busy New World area. (Kanako Miyajima)

SHANGHAI--Fourteen percent of the COVID-19 patients who were treated and released from hospitals have tested positive again for the infectious disease, Guangdong province officials announced on Feb. 25. 

At a news conference, government officials in the southern Chinese province urged hospitals to keep monitoring the health of COVID-19 patients for 14 days after releasing them.

Officials said if such patients have built up antibodies in their immune system to defend against the coronavirus, the risk of passing the infection to others is low.

It takes about two weeks for young people to develop antibodies, but the elderly, who need longer to do so, “should be strictly monitored in order not to become an infection source again,” officials said.

In Guangzhou, the capital of the province, 13 patients have tested positive for the coronavirus for a second time.

Subsequently, 104 people who had been in close contact with the 13 patients were tested. None has been infected with the coronavirus so far, officials said.