It has been analyzed that the case of being diagnosed as 'positive' again after the corona 19 is cured is due to the technical limitations of the diagnostic test.

The genetic material of the 'dead virus' was found in the cells of the healer and then amplified during the test.

Chairman of the Central Clinical Committee of Corona 19, Oh Myung-don, said in a news conference held today (29th) at the National Medical Center that "most of the re-positive cases were RNA of dead virus (ribonucleic acid, a type of genetic material)."

As of the 26th, 263 of the corona19 cures were judged as 're-positive' in Korea.

The cause of this re-positive case has been cited as 're-infection', where the virus remains in the patient's body and then re-infects the virus, such as 'reactivating', but the central clinical trial has interpreted it as 'test error'.

"In Korea, we use a 'PCR' test that amplifies and detects the gene of the virus for diagnosis of corona19, and the re-positive case is due to the technical limitations inherent in PCR testing," said Oh.

"PCR tests cannot tell whether a virus is alive or dead, and if the amount of viral genetic material contained in epithelial cells is small, the reliability of the test results decreases," he added.

"Our respiratory epithelial cells have a long lifespan, so half-life (half-life) is possible for up to 3 months," he said. "The viral RNA contained in these cells can be detected in PCR tests 1-2 months after the cells have fallen off." "I added.

The Clinic concluded that corona19 re-positivity is very unlikely due to virus reactivation or reinfection.

First of all, I thought it was virtually impossible for the Corona19 virus to remain in the body and reactivate it again.

"The process by which the Corona19 virus produces a new virus only occurs in the host cytoplasm and does not invade the cell nucleus," said Oh. "This does not mean chronic or recurrent infections."

"Hepatitis B virus, HIV (Human Immunodeficiency Virus), etc. enter the cell nucleus and integrate into the host's nucleic acid," he said. "These viruses are asleep and can wake up and cause chronic infections. "I added.

Regarding the possibility of reinfection, Chairman Oh said, "If you look at the results of Corona19 animal experiments, the immunity in vivo is maintained for more than one year after the first virus infection." After being infected with the virus, the antibody that neutralizes the virus is generated in the body, so the same virus It is unlikely to get caught again. "

On the other hand, he said that further studies are needed for cases in which fever and respiratory symptoms appear even after re-positive diagnosis.

"It is indistinguishable from the symptoms of corona19 and the common cold," Oh said. "If you do other respiratory virus tests, such as influenza, along with the corona19 test, you will also find many infections caused by other viruses."

(Photo = Yonhap News)