Dead coronavirus fragments likely caused positive test results in recovered South Koreans, officials say

South Korean infectious disease experts suspect that dead coronavirus fragments likely caused recovered patients to test positive for the coronavirus, they announced Thursday.

Oh Myoung-don, who heads the central clinical committee for emerging disease control, said the committee did not find evidence that the recovered patients became reinfected, The Korea Herald reported. 

Health professionals around the world worried when South Korea reported earlier this month that patients who had recovered from the virus days and weeks ago had tested positive another time. If people could be reinfected, it would make fighting the virus worldwide all the more difficult. 

As of Sunday, 263 people in South Korea tested positive after being considered cleared from the virus, 17 of whom were minors, according to the Herald. 

“The tests detected the ribonucleic acid of the dead virus,” Oh said in a Thursday press conference. 

The polymerase chain reaction tests used to detect COVID-19 amplifies the genetic material of the virus but cannot distinguish between living or dead virus cells, leading to false positives. Oh said it could take months before the dead virus cells leave a person’s body system. 

The Korean Centers for Disease Control and Prevention concluded that recovered patients who tested positive seemed to have little or no contagiousness, according to the Herald.

The reports of reinfections sparked concerns that the country would see a resurgence in coronavirus cases after seemingly flattening the curve. South Korea has seen about 10 new cases every day for 11 days, including nine on Wednesday.

The country has documented 10,765 infections, leading to 247 deaths, according to Johns Hopkins University’s data.