Coronavirus patients declared recovered who later test positive for the disease are still expelling dead lung cells rather than getting a new infection, according to the WHO.
More than 100 cases like this were reported in South Korea in April. In an interview with BBC, Maria Van Kerhove, a WHO epidemiologist, explained the dead cell theory.
“As the lungs heal, there are parts of the lung that are dead cells that are coming up. These are fragments of the lungs that are actually testing positive,” she said.
“It is not infectious virus, it’s not reactivation. It is actually part of the healing process.”
Van Kerhove also said that it is still unknown whether recovered patients have immunity, or a strong protection against reinfection. People infected with the coronavirus start building up antibodies approximately one week after infection or the onset of symptoms. But it is unclear whether the body systematically builds up enough immunity to ward off another attack.
According to the WHO, more research is needed on patients who test negative after infection, only to test positive again weeks later.
“We need systematic collection of samples from recovered patients to better understand how long they shed live virus……We also need to understand if this means they can pass the virus to other people – having live virus does not necessarily mean it can be passed to another person,” according to a WHO spokesperson.
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