South Korea scrambles to study recurring Covid-19 cases
A TOTAL of 163 patients previously declared cured of Covid19 have tested positive again in South Korea as of Friday, up 22 from a day earlier, giving the government a fresh headache in its fight against the virus.
The recurring cases account for 2.1 per cent of the 7,829 people released from quarantine after recovering. Studies are underway to find out why said the Korea Centres for Disease Control and Prevention (KCDC).
It took 13.5 days on average for these patients to test positive again after being deemed clear of Covid-19 – as little as one day and as long as 35.
Currently, to be declared recovered and released from quarantine one needs two negative results from tests conducted at 24-hour intervals.
An epidemiological and clinical analysis of 137 recurring cases showed that more than half of them, 72 people, had no symptoms and 61 people showed mild symptoms, said the KCDC. Analysis is underway for the other four.
Those who test positive again after release from quarantine are usually detected through regular testing required by some municipalities or when they show symptoms and seek testing themselves.
Health officials here have cautiously dismissed the possibility of patients being reinfected with the virus.
The virus, despite being present at undetectable levels in patients’ bodies, could have been reactivated due to their weakened immune systems, or the tests could have picked up “dead” remnants of the virus, the officials said. There is also the possibility that the test results were in error.
To find out whether those who test positive again can i nfect others, the health authorities ran an antibody analysis of 28 recurring cases. In six of the cases, the virus could not be cultivated, meaning those people were less contagious. Analysis is underway for the other 22 cases.
At a briefing on Friday, KCDC director-general Jeong Eunkyeong said: “We could not find the virus that was alive [in recovered patients who tested positive again], so we think it will not be highly infectious.
“In the cases testing positive again within one week after a full recovery, many of them produce negative and positive results alternately before eventually producing positive results due to remaining pieces of the virus in the body,” she said.
As of Friday, there were no cases of secondary transmission from recovered patients who had tested positive again, said the KCDC.
Some 294 people came into contact with the patients who tested positive again, with 256 of them under government monitoring.
While 22 recovered patients were back in self-quarantine after testing positive again on Friday, Korea saw 22 new infections.
The number of recurring cases has more than tripled from 51 on April 6, keeping the authorities on t heir toes despite the country largely having brought the virus situation under control, with fewer than 30 new cases per day for the past week.
There were no such recurring cases of severe acute respiratory syndrome or Middle East respiratory syndrome, the authorities said a day earlier, calling the novel coronavirus “evil”.
Recurr i ng posi t i v e t e s t results were reported in all age groups, though people in their 20s accounted for the highest proportion, 23.3 per cent. This appears to be partial because this age group accounts for the largest portion of the country’s total cases, 27.35 per cent.
Of the recurring cases, 19.6 per cent were in their 50s, 14.7 per cent in their 30s, 11.6 per cent in their 40s, 11 per cent in their 60s, 9.2 per cent in their 80s, 3.7 per cent in their 70s, 3.7 per cent in the 10-19 age group and 3.1 per cent younger than 10.
By gender, 66.9 per cent of the recurring cases involved women. Of the country’s total cases, 59.7 per cent are women.
By region, Daegu, once South Korea’s epicentre of the novel coronavirus, reported the most cases with 67, making up 41.1 per cent of all recurring cases. Daegu represents the majority of the country’s total cases, accounting for 64.2 per cent.
Some 33 per cent of the cases were registered in North Gyeongsang province, eight per cent in Gyeonggi province and five per cent in Seoul.