WHO Says Spread Of Coronavirus By Asymptomatic Patients Is ‘Very Rare’

The World Health Organization (WHO) said on Monday that spread of the coronavirus by asymptomatic patients is “very rare,” casting new doubts on earlier research that suggested the viral disease could be difficult to contain due to asymptomatic infections.

“From the data we have, it still seems to be rare that an asymptomatic person actually transmits onward to a secondary individual,” said Dr. Maria Van Kerkhove, who leads the WHO’s diseases and zoonosis unit, during a press briefing in Geneva.

“We have a number of reports from countries who are doing very detailed contact tracing,” Van Kerkhove added. “They’re following asymptomatic cases. They’re following contacts. And they’re not finding secondary transmission onward. It’s very rare.”

More research and data are needed to “truly answer” the question of whether the coronavirus can spread widely through asymptomatic carriers, Van Kerkhove added.

Van Kerkhove said that containment responses should focus on detecting and isolating infected people with symptoms, and tracking anyone who might have come into contact with them.

Earlier research had indicated that the virus could spread from person-to-person contact, even if the carrier didn’t have symptoms. But WHO officials now say that while asymptomatic spread can occur, it is not the main way it’s being transmitted.

A research by Centers for Disease Control and Prevention (CDC) suggested that asymptomatic patients could be a hidden factor causing the spread of virus causing the respiratory illness in others.

“These findings also suggest that to control the pandemic, it might not be enough for only persons with symptoms to limit their contact with others because persons without symptoms might transmit infection,” the CDC study said.