The World Health Organization stated on Saturday that it was analysing the reports of a few coronavirus or COVID-19 patients who tested positive again after initially testing negative for the virus even after being considered for discharge.

Officials from South Korea reported on Friday that 91 patients tested positive again for the disease after getting discharged. Jeong Eun-kyeong, the director of the Korea Centers for Disease Control and Prevention, mentioned in a briefing that the virus might have been "reactivated" rather than the patients getting re-infected.

WHO investigating coronavirus cases

Coronavirus
Workers make face masks at the workshop of a company in Wuhan, central China's Hubei Province, Jan. 28, 2020. To help fight the outbreak of pneumonia caused by novel coronavirus, workers of local medical material companies in Hubei Province rushed back to work to make protective masks, clothing and other protective equipment to guarantee the supplies. (Xinhua/Cai YangIANS) Xinhua/IANS

The Geneva-based WHO, asked about the report from Seoul, told Reuters in a brief statement: "We are aware of these reports of individuals who have tested negative for COVID-19 using PCR (polymerase chain reaction) testing and then after some days testing positive again.

"We are closely liaising with our clinical experts and working hard to get more information on those individual cases. It is important to make sure that when samples are collected for testing on suspected patients, procedures are followed properly," it said. According to the WHO's guidelines on clinical management, a patient can be discharged from hospital after two consecutive negative results in a clinically recovered patient at least 24 hours apart, it added.

Re-appearance of coronavirus cases in South Korea

Based on current studies, there is a period of about two weeks between the onset of symptoms and clinical recovery of patients with mild COVID-19 disease, the agency said. "We are aware that some patients are PCR positive after they clinically recover, but we need systematic collection of samples from recovered patients to better understand how long they shed live virus," it said.

South Korean health officials said on Friday that it remains unclear what is behind the trend, with epidemiological investigations still underway. "As COVID-19 is a new disease, we need more epidemiological data to draw any conclusions of virus shedding profile," the WHO said. The number of deaths linked to the novel coronavirus reached 100,000 on Friday, as reported cases passed 1.6 million, according to a Reuters tally.

(With agency inputs)