In their study, experts from the University of Oregon monitored 35 students who had confirmed coronavirus between January and May 2021, and they spent ten days in quarantine in separate dorm rooms.
Scientists have placed Petri dishes in each room, as well as special devices for capturing aerosols in the air. Several times a day, they collected samples from surfaces in all rooms and took swabs from the nasopharynx of infected students.
The researchers then analyzed all samples taken for the presence of the virus using a PCR test. The results showed a clear relationship between viral load in the upper respiratory tract of an infected person and the number of viral particles in the space where he is located. Even asymptomatic carriers shed large amounts of infection and could potentially pose a danger to others. As the students recovered, as the viral load gradually decreased, the amount of pathogen in the aerosols circulating in the room also decreased.
The study authors also calculated mechanical ventilation rates for each room and asked students to report how often they opened their windows. It turned out that the viral load was, on average, half as much in those rooms where there was no ventilation.
“Ventilation is very important, but I think we are just beginning to understand how important it is in a pandemic,” said study co-author Leslie Dietz.