The new coronavirus might spread through the air via normal breathing and speaking, a top US scientist said yesterday as the government was poised to recommend the use of face masks for everyone.
As it stands, the official advice is that only sick people need to cover their faces, as well as those caring for them at home.
It said that though the research isn’t yet conclusive, “the results of available studies are consistent with aerosolisation of virus from normal breathing.” Until now, US health agencies have said that the primary pathway of transmission is respiratory droplets, about one millimetre in diameter, expelled by sick people when they sneeze or cough.
These quickly fall to the ground around a meter away. But if the virus can be suspended in the ultrafine mist we expel when we exhale, in other words, an aerosol, it becomes much harder to prevent its spread, which in turn is an argument in favour of everyone covering their faces.
A Chinese research paper, on the other hand, raised concerns that personal protective gear used by health care workers could itself be a source of airborne virus.
The team studied hospitals in Wuhan and found that there were two major areas where the virus was aerosolized: the bathrooms of patients, and rooms where medical staff removed their protective gear. This may be because doffing protective gear causes the particles to get re-suspended in the air.
So far, the World Health Organisation (WHO) has been more cautious on the airborne threat. In an analysis published on March 29, it wrote that aerosol transmission was only known to occur during particular medical treatments that required assisted breathing.