A balanced article on this topic
People without symptoms can pass on the virus, but estimating their contribution to outbreaks is challenging.
www.nature.com
As part of a large population study in Geneva, Switzerland, researchers modelled viral spread among people living together. In a manuscript posted on medRxiv this month
2, they report that the risk of an asymptomatic person passing the virus to others in their home is about one-quarter of the risk of transmission from a symptomatic person.
Although there is a lower risk of transmission from asymptomatic people, they might still present a significant public-health risk because they are more likely to be out in the community than isolated at home, says Andrew Azman, an infectious-disease epidemiologist at the Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland, who is based in Switzerland and was a co-author on the study. “The actual public-health burden of this massive pool of interacting ‘asymptomatics’ in the community probably suggests that a sizeable portion of transmission events are from asymptomatic transmissions,” he says.