WHO is looking into reports of COVID-19 patients testing positive again

The World Health Organisation (WHO) has been looking into reports of some COVID-19 patients testing positive again after initially testing negative for the disease while being considered for discharge.

The WHO told Reuters in a brief statement, on Saturday: "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.

South Korean officials on Friday reported 91 patients thought cleared of the new coronavirus had tested positive again. To this end, Jeong Eun-kyeong, director of the Korea Centers for Disease Control and Prevention, said the virus may have been "reactivated" rather than the patients being re-infected.

WHO had asked South Korea for a report on this.

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. 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. 

South Korean health officials said on Friday that it remains unclear what is behind the trend, with epidemiological investigations still under way.

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.