TheCable

South Korean infectious disease experts say dead virus is responsible for the positive test in patients who recovered from COVID-19.

According to the Korea Centers for Disease Control and Prevention (KCDC), over 260 patients who recovered from COVID-19 have retested positive.

Similar cases have been reported in China, which could mar global efforts to contain the disease.

On Thursday, South Korea’s infectious disease experts said there are fragments of the dead virus in recovered patients which showed in a retest.

The experts said the PCR tests, used for COVID-19 diagnosis, cannot differentiate if the virus is alive or dead. They said this leads to false positives.

Oh Myoung-don, head of the central clinical committee for emerging disease control, ruled out the cases in recovered COVID-19 patients as reinfection or reactivation of the virus as the discharged patients develop antibodies.

“The tests detected the ribonucleic acid of the dead virus,” Oh said.

“PCR testing that amplifies genetics of the virus is used in Korea to test COVID-19, and relapse cases are due to technical limits of the PCR testing.

“The respiratory epithelial cell has a half-life of up to three months, and RNA virus in the cell can be detected with PCR testing one to two months after the elimination of the cell.

“The process in which COVID-19 produces a new virus takes place only in host cells and does not infiltrate the nucleus. This means it does not cause chronic infection or recurrence.”