July 28, 2020

Estimation of Viral Aerosol Emissions From Simulated Individuals With Asymptomatic to Moderate Coronavirus Disease 2019

Category: Article Summary

Topic: Transmission

• A modeling study indicated that an individual with COVID-19 who is coughing or breathing normally releases large numbers of viruses, but the estimated infectious risk from an individual with a typical viral load in a space the size of a medical exam room was low. Riediker and Tsai simulated the release of viruses from individuals with asymptomatic to moderate COVID-19 infection during normal breathing and while coughing. Viral loads across different droplet sizes produced under various conditions were derived from literature. The authors applied a compartmental model to estimate virus load in a perfectly mixed 50m3 room with one individual as the source, assuming a virus half–life of 1.1 hours, under normal breathing and with coughing every 30 seconds. Concentration plateaued in higher ventilation settings (10 exchanges/hour) after 30 minutes, versus 70 minutes in lower ventilation settings (3 exchanges/hour).  

Riediker and Tsai. (July 2020). Estimation of Viral Aerosol Emissions From Simulated Individuals With Asymptomatic to Moderate Coronavirus Disease 2019. JAMA Network Open. https://doi.org/10.1001/jamanetworkopen.2020.13807