South Korea says recovered coronavirus patients who tested positive again did not relapse: Tests picked up ‘dead virus fragments’

  • Experts in South Korea said that recovered coronavirus patients who tested positive again were not reinfected and that their virus was not reactivated, as was previously feared.
  • More than 260 people who recovered and tested negative subsequently tested positive again. The Korea Centers for Disease Control and Prevention worried that the virus had reactivated after going dormant.
  • But the country’s infectious-disease experts said on Thursday that the tests were detecting dead fragments of the virus left in patients’ bodies.


Scientists said the wave of South Koreans who tested positive for COVID-19 even after they recovered did not have the virus reactivate after going dormant and that they were not reinfected. South Korea announced in early April that some patients who had recovered from and tested negative for the virus later tested positive, suggesting that the virus could reactivate or that patients could be reinfected. The country has recorded this happening in 263 patients, The Korea Herald reported.

But the country’s infectious-disease experts said on Thursday that the positive test results were likely caused by flaws in the testing process, where the tests picked up remnants of the virus without detecting whether the person was still infected, The Herald reported.

The Herald described the experts as saying that “dead virus fragments” were lingering in patients’ bodies after they recovered and that the virus did not appear to be active in the patients.

Dr. Oh Myoung-don, a professor of medicine and the head of Seoul National University Hospital’s division of infectious diseases, said that the committee studying the cases found little reason to believe that the patients had been reinfected or that the virus had reactivated, according to The Herald.

“The tests detected the ribonucleic acid of the dead virus,” said Oh, an adviser to the Korean government and the Korea Centers for Disease Control and Prevention.

Experts were already skeptical about the theory that the virus could reactivate

Jeong Eun-kyeong, the director-general of the KCDC, said earlier in April that the positive test results in these patients could mean that the virus “reactivated” after going dormant, Business Insider’s Holly Secon reported.

Jeong said the tests were conducted within a “relatively short time” after the patients were cleared, so it was unlikely that they were reinfected.

“While we are putting more weight on reactivation as the possible cause, we are conducting a comprehensive study on this,” Jeong said. “There have been many cases when a patient during treatment will test negative one day and positive another.”

But many experts said it was unlikely that the virus would go dormant and then reactivate in people. Instead, they said, it was more likely that patients’ bodies still had some fragments of the virus. This would mean a person could get a positive test but not be ill or able to infect others.

Dr. Keiji Fukuda, the director of Hong Kong University’s School of Public Health, told the Los Angeles Times in March that this was the most likely scenario.

“The test may be positive, but the infection is not there,” Fukuda said.