Jeong Eun-kyeong, director of the Korean Centers for Disease Control and Prevention (KCDC), said in a briefing that the virus may have been “reactivated” rather than the reinfected patients.
South Korean health officials said the reasons for the trend were still unclear, as epidemiological investigations were still underway.
The prospect of re-infection of people with the virus is an international concern, as many countries hope that infected populations will develop sufficient immunity to prevent a resurgence of the pandemic.
The South Korean figure had dropped from 51 such cases on Monday.
Almost 7,000 South Koreans have reportedly been recovered from COVID-19, the disease caused by the new coronavirus.
“The number will only increase, 91 is just the beginning now,” said Kim Woo-joo, professor of infectious diseases at Korea Guro University Hospital.
The KCDC Jeong raised the possibility that instead of re-infecting patients, the virus could have been “reactivated”.
A woman wearing a preventive face mask has her temperature checked, as a safety precaution to prevent the spread of coronavirus, before voting in the legislative elections at a polling station in Seoul, South Korea, April 10, 2020. REUTERS / Heo Ran
Kim also said the patients likely “relapsed” rather than being re-infected.
Fake test results may also be at fault, according to other experts, or remnants of the virus may still be found in patients’ systems but not be infectious or dangerous to the host or others.
“There are different interpretations and many variables,” said Jung Ki-suck, professor of pulmonary medicine at Sacred Heart Hospital at Hallym University.
“The government must find answers for each of these variables.”
South Korea reported 27 new cases on Friday, its lowest level after daily cases peaking at more than 900 at the end of February, according to KCDC, adding that the total was 10,450 cases.
The death toll rose from seven to 211, the statement said.
The city of Daegu, which suffered the first major coronavirus outbreak outside of China, reported no new cases for the first time since late February.
With at least 6,807 confirmed cases, Daegu accounts for more than half of all infections in South Korea.
The spread of infections in a Daegu church led to a spike in cases in South Korea from late February.
The epidemic initially pushed the count of confirmed cases much higher than anywhere else outside of China, before the country used general tests and social distancing measures to drive the numbers down.
Report by Josh Smith and Sangmi Cha; edited by Michael Perry and Jason Neely
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