Troubling headlines have been cropping up across Asia: Patients who were diagnosed with COVID-19 and seemingly recovered have been readmitted to the hospital after testing positive for the virus again. More than 1,154,014 COVID-19 patients round the globe are tested positive for the coronavirus after having recovered, raising alarm that the virus might be capable of “reactivating” or infecting people more than once. RNA fragments still can exist in a cell even if the virus is inactivated. Because SARS-CoV-2, the novel coronavirus that causes COVID-19, was only discovered a few months ago, scientists are still trying to answer many big questions related to the virus and the disease it causes. Rather, the method used to detect the coronavirus, called polymerase chain reaction (PCR), cannot distinguish between genetic material (RNA or DNA) from infectious virus and the “dead” virus fragments that can linger in the body long after a person recovers. the coronavirus is not one of those viruses and instead it stays outside of the host cell’s nucleus, before quickly bursting out and infiltrating the next cell.
To determine whether or not someone is harboring infectious virus or has been reinfected with the virus, a completely different type of test would be needed, one that is not typically performed. The COVID-19 virus does not invade inside of the cell nucleus and combine with a patient’s DNA. It means that the virus does not create chronic infections. Reassuringly, the virus is currently undergoing very small genetic changes that are “too tiny” to evade the immune systems of people who have already been infected. The genetic changes would have to be substantial enough that a person’s existing antibodies to SARS-CoV-2 would no longer work against a new strain. body’s antibody response, triggered by the onset of a virus, means it is unlikely that patients who have recovered from COVID-19 can get re-infected so soon after contracting the virus. Antibodies are normally produced in a patient’s body around seven to 10 days after the initial onset of a virus. With other coronavirus strains, experts say the antibodies that patients produce during infection give them immunity to the specific virus for months or even years, but researchers are still figuring out if and how that works with COVID-19. It is impossible for the virus to be reactivated unless the virus causes chronic infections, adding that COVID-19 was different from diseases such as HIV and Hepatitis B where the virus can stay dormant inside of a cell nucleus and later cause a chronic infection.
The World Health Organization (WHO) is investigating the reports of patients testing positive after being released from treatment, but said it has no findings yet. “We are closely liaising with our clinical experts and working hard to get more information on those individual cases. A positive test after recovery could also be detecting the residual viral RNA that has remained in the body, but not in high enough amounts to cause disease. The answer has huge implications for the spread of the disease, since researchers believe it will continue to crash across the world in waves, hitting the same country multiple times. testing positive after recovery could just mean the tests resulted in a false negative and that the patient is still infected. “It may be because of the quality of the specimen that they took and may be because the test was not so sensitive. The reports of patients who seemed to have recovered but then tested positive again were not examples of re-infection, but were cases where lingering infection was not detected by tests for a period of time.