A recent study has suggested that people with mild or no symptoms of coronavirus may be infectious for not more than about 10 days.
The study has been published in the journal Infection Control and Hospital Epidemiology. The researchers reviewed a dozen studies at Oregon Health and Science University and Oregon State University that suggests people may shed virus for prolonged periods. And the ones who are severely ill from COVID-19 may be infectious for as long as 20 days.
This is in line with the guidance provided by the US Centers for Disease Control and Prevention, confirming recommendations for the length of time people should isolate the following infection with SARS-CoV-2.
As per the authors, “Detection of viral RNA may not correlate with infectivity since available viral culture data suggests shorter durations of shedding of viable virus.” “Additional data is needed to determine the duration of shedding of viable virus and the implications for risk of transmission.”
Researchers decided to conduct the review to gain more information on transmission and to help inform infection control practices, said co-author Monica Sikka, MD, assistant professor of medicine (infectious diseases) in the OHSU School of Medicine.
“Even though people can shed virus for a prolonged period, the studies we reviewed indicated that live virus, which may predict infectiousness, was only detected up to nine days in people who had mild symptoms,” Sikka said.
77 studies have been identified by researchers worldwide that include the 59 that had been peer-reviewed and combed through the results.
Using standard methods to identify the virus by replicating it through a process called a polymerase chain reaction, or PCR, all studies reported assessments of viral shedding.
“Although PCR positivity can be prolonged, culture data suggest that virus viability is typically shorter in duration,” the authors added