In South Korea, health officials are trying to solve a mystery: why 163 people who recovered from coronavirus have retested positive, according to the Korea Centers for Disease Control and Prevention (KCDC).
In South Korea, the proportion of cases that retest positive is low — of the 7,829 people who have recovered from coronavirus there, 2.1% retested positive, the KCDC said.
For now, the most likely explanation of why people are retesting positive seems to be that the test is picking up remnants of the virus.
The KCDC has re-investigated three cases from the same family where patients tested positive after recovering, Kwon says.
In each of these cases, scientists tried to incubate the virus but weren’t able to — that told them there was no live virus present.
The KCDC plans to test 400 specimens from people who have been infected and recovered to see how much — if any — immunity having Covid-19 might give people. Kwon says those tests may take several weeks.
In the end, [KCDC deputy director Kwon Joon-wook] said, it comes down to this: “We don’t know much about Covid-19.”