People with mild COVID-19 symptoms may remain PCR-positive for two-three weeks after the symptom onset, while the people with a more severe case of infection can stay PCR-positive for much longer, Maria van Kerkhove, the technical lead for the World Health Organization (WHO) Health Emergencies Programme, said Friday
MOSCOW (Pakistan Point News / Sputnik - 05th June, 2020) People with mild COVID-19 symptoms may remain PCR-positive for two-three weeks after the symptom onset, while the people with a more severe case of infection can stay PCR-positive for much longer, Maria van Kerkhove, the technical lead for the World Health Organization (WHO) Health Emergencies Programme, said Friday.
The polymerase chain reaction (PCR) is a method used to diagnose infectious diseases, including the COVID-19. Scientists can extract the virus genome from the sample, multiply its parts and study the resulting large sample to determine if they are dealing with SARS-CoV-2.
What we know is that mild patients, people with mild infections that don't require hospitalization necessarily, can be PCR-positive for two-three weeks from the time of symptom onset ... We know that people who have severe disease, who end up in hospital, can be PCR-positive for much longer, for weeks and weeks and I don't have the upper bound of that," van Kerkhove told a press conference.
The scientists can determine the viral load the amount of virus in the sample but do not know yet what it means in terms of infectiousness, van Kerkhove said.
There have been some studies that have tried to isolate virus to get some understanding of how infectious a person is. In people with mild symptoms, virus can be isolated during up to eight-nine days from the time of symptom onset. This could serve as a clue to how long someone can stay infectious, although it does not offer solid proof, van Kerkhove said. Another unpublished study suggested that virus could be isolated in severe patients during up to three weeks.
