Study: Asymptomatic COVID-19 Carriers Can Spread Virus as Easily as Those with Symptoms

The study, led by Seungjae Lee of Soonchunhyang University and published Thursday in the American journal Jama Internal Medicine, focused on an outbreak of infections in a South Korean religious group in Daegu in February. Positive cases with few or no symptoms were placed in isolation. Healthcare personnel assigned to this study "meticulously monitored the evolution of their symptoms and regularly tested their viral load".

The group consisted of young people, with an average age of 25. Out of 303 people, 89 never developed symptoms, a proportion of 29%. The study reveals that "21 people initially presented as coronavirus positive and asymptomatic, but ultimately had symptoms." The main lesson is that virus concentrations in asymptomatic people were "similar to those of symptomatic patients".

According to the same source, "finding residual viral particles in the nose, throat or lungs does not necessarily mean these people were contagious." The authors also stressed that "the detection of viral RNA is not synonymous with the presence of an infectious and transmissible virus".