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The thesis of the transmission of the coronavirus through the air that everyone breathes and inhales instead of through droplets expelled by coughing or sneezing was initially neglected by health authorities around the world, but the situation has changed this summer, under the pressure of numerous epidemiologists and the multiplication of studies on the presence of viral particles in microdroplets suspended in the air, generated even if only by speech.
In January, at the beginning of what would become the COVID-19 pandemic, an infected and asymptomatic passenger contaminated a third of the people he was traveling with for less than an hour in a stuffy bus. Today, this case appears to be a new indication that SARS-CoV-2 is highly likely to be transmissible by aerosols, Agerpres reports.
In an article published Tuesday by the American magazine Jama Internal Medicine, summarized by AFP, experts from the Chinese Center for Disease Control describe the case of some people who traveled by bus on January 19 to a Buddhist event in Ningbo, a route that lasted 50 minutes, with the return on the same buses and with the same passengers. . Nobody wore a mask.
One asymptomatic person contracted another 23
A person over 60 years of age, asymptomaticIt is very likely that she is the “patient zero” of this series of infections, since she had previously had contacts in Wuhan, the city where the epidemic broke out. This person stood on the right side in the middle of the bus, between two other passengers.
Of the 68 passengers on this bus, 23 were contaminated as a result of the trip. However, no contamination was found among the passengers of the other bus.
It is noteworthy that the circle of contamination was much wider, beyond the few rows around the asymptomatic person, being infected people in the rear and front of the vehicle.
However, if the virus were transmitted only through the largest droplets expelled by coughing or sneezing, they could not infect at such a great distance as they fall within a perimeter of one to two meters. In fact, this “patient zero” was not coughing, as he was asymptomatic at the time.
Pointed ventilation system
On the other hand, the air conditioning system of the bus recirculated the air inside, which undoubtedly contributed to the spread of the virus. “This research suggests that, indoors where the air is recirculated, SARS-CoV-2 is a highly transmissible pathogen,” the research authors note.
Their detailed study, which also shows a diagram of the seats in the vehicle, with the position of each contaminated person, is confirmed by others going in the same direction, especially a case that reveals multiple contaminants among the occupants of a restaurant in Guangzhou. . also favored by a ventilation system that does not cool the indoor air.
Web edition: Luana Păvălucă
