CHINA / SOCIETY
A few discharged COVID-19 patients test positive again in Shanghai
Published: Jan 25, 2021 11:39 PM

Residents of Zhaotong residential area board buses to be taken to hotels for quarantine on Thursday in Shanghai, after their community was put under lockdown due to new COVID-19 cases. Photo: Yang Hui/GT 

A few people in Shanghai tested positive for COVID-19 again after being discharged from hospitals, the local health authority said on Monday.

The "re-positive" cases were found while they were completing quarantine after leaving hospitals, said Shanghai Health Commission on Monday. The city requires recovered COVID-19 patients to undergo another 14-day period of isolation at their homes or local quarantine sites after being discharged from hospital.

Re-positive patients will be sent to Shanghai's designated hospitals for further examination and treatment, said the commission.

It also asked local hospitals to perform follow-up visits for their recovered COVID-19 patients for four more weeks after their 14-day isolation is complete to ensure they remain updated on their health conditions.

Sporadic cases of people testing positive for the coronavirus again after they recover have also been reported in some of China's most populous regions — including Guangdong and Henan provinces — this week, causing people to be concerned about possible virus transmission as Chinese New Year approaches.

Some of these cases are likely to be unrecovered patients who happened to test negative twice before leaving hospital, said Lu Hongzhou, co-director of the Shanghai Public Health Clinical Center at Fudan University.

Various sampling methods may lead to different testing results, Lu said. "Nasopharyngeal swab samples usually contain more coronavirus than oral swab ones," Lu told the Global Times Monday, saying that it is possible that a few patients tested positive through nasopharyngeal swabs but negative for oral swab tests.

But there is no need to worry about the infectivity of re-positive patients, who generally don't carry as much virus compared to other COVID-19 patients, epidemiologists said. 

In China, there haven't been reported cases of people becoming infection through contact with "re-positive" patients.

Lu also denied a recent rumor that said Shanghai's latest round of virus outbreak in January was triggered by an overseas returnee who tested positive again after being discharged from hospital.

Shanghai's health authority hasn't released its traceability investigation results of this outbreak, however, where 13 local confirmed COVID-19 patients have been reported since January 21.