SEOUL (THE KOREA HERALD/ASIA NEWS NETWORK) - A Seoul woman in her 20s tested positive for the coronavirus for a second time in April, Korean health authorities said on Monday (Sept 21), after she was declared recovered approximately a week earlier.
Dr Jung Eun-kyeong, chief of the Korea Disease Control and Prevention Agency, said in a news briefing that the young woman was diagnosed for a second time in only about six days since two consecutive RT-PCR assays showed she was negative.
"The investigation on this case is not yet complete to conclude that this counts as a 'reinfection'," she said.
The national disease control agency's deputy chief Kwon Jun-wook said in a Monday briefing that the Seoul woman's case is suspected to be "successive infections with different clades of the virus".
So far, there have been 705 documented instances of a "second positive" since February.
The clinical committee for emerging infectious diseases within the National Medical Centre announced in an April press conference that the "second positive" cases were the assays responding to "inactive fragments of the dead virus".
Infectious disease expert Dr Kim Woo-joo said: "A close follow-up of former patients who are experiencing symptoms may be necessary to determine if there are patients who have been reinfected with the coronavirus."
If reinfection is a possibility, this means that Covid-19 may have become endemic much like the influenza, he said.
"But good news is that so far, the new coronavirus seems to mutate at a slower rate than the influenza."
Meanwhile, the proportion of "untraceable" infections among those recently confirmed keeps setting new records.
For 28.8 per cent of Seoul patients diagnosed between Sept 13 and 19, the point of transmission was unknown. Since mid-August, the rate has consistently remained above 20 per cent.
Preventive medicine specialist Dr Ki Mo-ran of the National Cancer Centre said the contact tracing failures may be attributable to the higher number of older patients being discovered in the lingering resurgence from last month.
"Case investigation and contact tracing rely heavily on technologies such as smartphone data and credit card records. This may not work well for older patients who tend to be less digitally connected," she said.
Dr Ki said as contact tracing efforts fall short, there could be several dozens of people who are going undiagnosed.
"We are walking on thin ice here," she said. "The numbers have to be brought down to manageable levels with strict physical distancing."
Health authorities said there will be "special physical distancing restrictions" put in place for the upcoming Chuseok holiday, falling on Sept 30 to Oct 4, the details of which will be disclosed later in the week.
Korea confirmed 70 more cases of the coronavirus in the last 24 hours ending Sunday at midnight, pushing the cumulative total to 23,045.
Two more patients died. So far, there have been 385 known deaths related to Covid-19, which brings the overall fatality rate to 1.67 per cent. For those over 80, the rate is 20.6 per cent.
As of Sunday, 91 per cent of the country's 517 intensive care beds were full, leaving only 46 available. At designated coronavirus hospitals, whose combined bed capacity is 4,120, the occupancy rate was 32.5 per cent.
The number of recoveries reached 20,248, up 90 from a day prior, bringing the recovery rate to 87.8 per cent.
In late June, the bar for discharging patients was adjusted to allow patients who remain free of symptoms for 10 consecutive days after diagnosis to be released from isolation. Previously, two consecutive negative results on RT-PCR tests with at least a 24-hour interval were required to be deemed recovered.
Korea has carried out 2,206,365 tests since Jan 3. This translates to around 43,518 tests performed per million people. Of all the tests taken, around 1 per cent yielded positive results.