Geneva: The World Health Organization published new guidance Thursday, saying it can’t rule out the possibility that the coronavirus can be transmitted through air particles in closed spaces indoors, including in gyms and restaurants.
The WHO previously acknowledged that the virus may become airborne in certain environments, such as during “medical procedures that generate aerosols.” The new guidance recognizes some research that suggests the virus may be able to spread through particles in the air in “indoor crowded spaces.” It cited “choir practice, in restaurants or in fitness classes” as possible areas of airborne transmission.
Until now, the WHO had maintained that this virus is generally spread by contaminated droplets — which are a fraction of the width of a human hair but much larger and heavier than aerosols, which float in the air. Droplets typically drop to the ground soon after they leave the mouth or nose of an infected person.
But after hundreds of scientists and engineers drafted an open letter targeted at the WHO earlier this week, begging the agency to reconsider its stance, the WHO issued a new scientific brief on coronavirus transmission.
The WHO said in its guidance that while early evidence suggests the possibility of airborne transmission in such environments, spread by droplets and surfaces could also explain transmission in those cases.
“However, the detailed investigations of these clusters suggest that droplet and fomite transmission could also explain human-to-human transmission within these clusters,” the guidance said.