US government scientists believe the new coronavirus is most likely transmitted by people when they speak and breathe. Logical consequence: Americans are now officially advised to cover their faces outside their homes, to help curb contagions. But the White House tenant will not lead by example.
Leave medical masks to caregivers
President Donald Trump made the announcement Friday evening, insisting it was a non-binding recommendation. The health authorities therefore call on the population to cover their faces with handmade masks, scarves or bandanas, in order to reserve medical masks for carers, a shortage requires.
In New York, the mayor had already asked residents to cover their faces outside their homes, and as of Friday, just under half of the pedestrians were applying the order in Manhattan. However, seen from Asia, where surgical masks are omnipresent, the delay in Western countries is an aberration. But health officials in the United States or France, as well as the World Health Organization, have so far argued that the mask is not necessary for healthy people unless they are in contact with the sick.
For several days, a flip-flop has been preparing, under pressure from an audience that does not understand why the masks would protect nurses but not ordinary citizens. In France, the French Academy of Medicine recommended the compulsory wearing of a mask on Friday as a “logical addition to the barrier measures”.
In the United States, on Friday, the director of the Institute of Infectious Diseases, Anthony Fauci, member of the White House working group on the coronavirus, had mentioned on Fox News data indicating that “the virus can actually be transmit when people are just talking, rather than just when they sneeze or cough. ” Airborne transmission would provide a long-sought explanation for the high apparent contagiousness of the virus, since it appears that infected but symptomless people are responsible for much of the contagion.
The little scientific evidence converges
What is the scientific evidence? There are few, but they converge. The American Academies of Sciences cited in a letter to the White House Wednesday four studies tipping the balance in favor of a transmission of the virus via the air exhaled by people, and no longer only by droplets and postillons projected onto a sneeze directly onto other people’s faces or onto surfaces. Harvey Fineberg, chairman of the US committee on emerging infectious diseases, says more is needed to better understand the real risk of infection. If the virus is actually present in respiration, it is not known whether this quantitatively represents an important route of transmission.
In a study, researchers at the University of Nebraska found portions of the virus’s genetic code in the air of rooms where patients were isolated. Researchers at the University of Hong Kong recently observed that wearing masks reduced the amount of coronavirus exhaled by patients. Finally, researchers in Wuhan took air samples from various hospital rooms and found high concentrations of the new coronavirus, especially in the toilets and rooms where caregivers removed their protective equipment.