September 15, 2020 13:06
Only one in 1,440 Koreans in a second round of serology tests has coronavirus antibodies, if the test conducted by the Korea Centers for Disease Control and Prevention proves reliable. That translates into just 0.07 percent.
The second round of tests was conducted between June 10 and Aug. 13 on subjects in 13 cities to see if they might have had symptomatic infections.
Given 20 percent of COVID-19 infections over the last couple of weeks were not traceable, health officials have believed that quite a number of people would show antibodies.
The KCDC announced the results of its first serology test on July 9 which showed only one out of 3,055 test cases had coronavirus antibodies (0.03 percent).
The accuracy of the first test, however, was minimal since nobody in Daegu, a hotbed of the epidemic earlier this year, had been tested. The latest one did include subjects from Daegu, but the sample was minimal.
The dubious nature of the test method is further highlighted by comparison with tests abroad, which showed as much as 24.7 percent of subjects in New York had antibodies, 17 percent in London, 3.2 percent in Wuhan, China and 0.1 percent in Tokyo.
At that rate of divergence, almost any theory about the virus can be backed up with some sort of evidence from somewhere.
Earlier, a team of researchers at Daegu Catholic University Medical Center and Kyungpook National University School of Medicine tested 198 outpatients who did not catch the virus and their families and found that 7.6 percent had antibodies. But of the 145 Daegu residents who participated in the second round, none had antibodies.
The sole person with antibodies came from Seoul.
KCDC chief Jung Eun-kyeong said, "Different countries use different types of testing methods and the use of 'rapid kits' tends to yield a slightly higher number of positive [antibody] results." But she explained that rapid kits detect not only COVID-19 but any number of coronaviruses including seasonal flu.
Kim Woo-joo at Korea University Guro Hospital said, "The test samples are too small and the results are unreliable since it was conducted before August, when a major resurgence in infections occurred."
Jung said the KCDC will now appoint a private company to test around 10,000 people across the country in late September or early October to see if more people acquired antibodies amid the resurgence.
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