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).
The same has been recorded in China, where some coronavirus patients tested positive after seeming to recover, although there are no official figures.
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 Friday. It is not clear how many of the people who have recovered have been tested again. But patients retesting positive is still a concern around the world, including in countries like South Korea where authorities appear to have brought the outbreak under control.
KCDC deputy director Kwon Joon-wook said that so far, there’s no indication that patients who retest positive are contagious, even though about 44% of them showed mild symptoms.
But he cautioned there is still a lot scientists don’t know about the virus, including the issue of naturally acquired immunity.
“Covid-19 is the most challenging pathogen we may have faced in recent decades,” Kwon said. “It is a very difficult and challenging enemy.”
Can a person who has retested positive infect others?
Kwon says there is no evidence so far of a person who has retested positive being infectious, adding: “At the moment, we think that there is no danger of further secondary or tertiary transmission.”
That’s also a concern weighing on the minds of people in the US.
Responding to a question about patients retesting positive at the CNN Town Hall on Thursday night, Dr. Deborah Birx, the White House coronavirus response coordinator, said the jury was still out on whether a person who had recovered could still shed infectious RNA strands.
“That’s a question that’s still outstanding — it hasn’t been answered in the studies to date, although people are really working on that now and culturing the virus and seeing if that potential exists,” she added.
After coronavirus patients are declared recovered, the KCDC recomends two more weeks of self-isolation. In an article published in BMJ medical journal this week, Sung-Il Cho, a professor of epidemiology at the Seoul National University Graduate School of Public Health, also advised discharged patients to remain isolated or quarantined for a while to make sure there’s no re-detection of the virus.
News credit CNN update