A new research adds to the growing body of evidence that airborne transmission of Covid-19 spreads more quickly in enclosed spaces.
Researchers were able to link a community outbreak of Covid-19 in China to a source patient who likely spread the virus to fellow bus riders through the bus’s air conditioning system. “Our study provided epidemiologic evidence of transmission over long distances, which was likely airborne,” said study lead author Ye Shen from University of Georgia in the US. According to the study, published in the journal JAMA Internal Medicine, it was largely believed that close contact through droplets is a major route of transmission for Covid-19.
Some of the attendees, it turns out, took two buses to the event creating a unique natural experiment for the researchers. Both buses had closed windows and had air conditioning running, said Changwei Li, study co-author, but one bus carried a patient infected with the virus, and the other did not.
Of the passengers who later got sick, the majority of them rode on the same bus as the source patient.
These findings highlight scenarios where Covid-19 could be spread through fine aerosol particles being circulated in an enclosed space.