COVID-19: Asymptomatic patients not main drivers of spread – WHO

By Dapo Falade

The World Health Organisation (WHO) has allayed fears over concerns that the virus could be difficult to contain due to asymptomatic infections, as it declared that patients without symptoms are not driving its spread.

At the initial outbreak of the virus, there were indications that it could spread through person-to-person contact, even without any symptoms, but WHO, on Monday, claimed that, while asymptomatic spread can occur, it was not the main means of transmission.

Head of WHO’s Emerging Diseases and Zoonosis Unit, Dr Maria Van Kerkhove, said at a news briefing at the United Nations Agency’s headquarters, Geneva, said: “From the data we have, it still seems to be rare that an asymptomatic person actually transmits onward to a secondary individual.”

She advised that government should focus on detecting and isolating infected people with symptoms and tracking anyone who might have come into contact with them.

She, however, acknowledged that some studies have indicated asymptomatic or presymptomatic spread in nursing homes and in household settings.

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

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

If asymptomatic spread proved  not to be a main driver of coronavirus transmission, the policy implications could tremendously help in reducing the mounting tension among the people in respect of social distancing.

A report from the United States Center for Disease Control and Prevention, published on April 1 cited the “potential for presymptomatic transmission” as a reason for the importance of social distancing.

“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.

Van Kerkhove, insisted that while asymptomatic and presymptomatic spread of the virus still appeared to be happening, such remained rare, even as the importance of the findings are its implications on how to screen for the virus and limit its spread.

“What we really want to be focused on is following the symptomatic cases. If we actually followed all of the symptomatic cases, isolate those cases, follow the contacts and quarantine those contacts, we would drastically reduce the outbreak,” she added.