Washington (AFP)
"It's time to take care of the aerial transmission of the Covid-19", write 239 international scientists in an article calling on the health authorities of the planet and in particular the World Health Organization (WHO) to actively recommend the ventilation of interior public spaces.
To date, WHO and other health authorities, including those in the United States, believe that the coronavirus responsible for Covid-19 disease is mainly transmitted by droplets sprayed by coughing, sneezing and speak directly to the faces of people nearby, or present on surfaces where they can survive for hours or days.
But several studies, on the SARS-CoV-2 virus and other respiratory viruses, have shown that viral particles present inside microdroplets in the air exhaled by an infected person could remain in suspension in the indoor air, potentially several hours, where they could then be inspired by others. It is not yet proven that these particles can cause infections, but the clues are mounting.
"We call upon the medical community and the competent national and international organizations to recognize the potential of aerial transmission of Covid-19", write in the journal Clinical Infectious Diseases of Oxford two scientists, Lidia Morawska of the University of Queensland and Donald Milton from the University of Maryland, in an article to which 237 other signatories declared or contributed at the end have contributed or support.
"There is a significant potential for the risk of inhalation of viruses contained in microscopic respiratory droplets (microdroplets) at short and medium distances (up to several meters, on the order of the scale of a room), and we promote the use of preventive measures to prevent this route of airborne transmission, "they continue.
As a priority, better ventilate workplaces, schools, hospitals and retirement homes, and install infection control tools such as high-level air filtration and special ultraviolet rays that kill people. microbes.
These recommendations are often inexpensive, they argue, such as opening doors and windows; but in current health guidelines, priority remains given to hand washing, masks and physical distance.
"Transmission by air of SARS-CoV-2 is not universally accepted; but our collective opinion is that there is enough evidence to apply the precautionary principle," say the scientists.
WHO distinguishes between air-borne viruses like measles and others, but "it's not a dichotomy problem," one of the signatories, Professor Caroline, told AFP. Duchaine, director of the bioaerosol laboratory at the University of Laval in Quebec.
"We make a mistake if we make an opposition between transmission by viruses like measles and by Covid-19", she said.
For the coronavirus, "it is certainly not the main mode of transmission", but if we want to apply the precautionary principle, "we must add air control" to the sanitary arsenal, insists Professor Duchaine.
© 2020 AFP