According to scientists of the viral particles present inside microdroplets in the air exhaled by an infected person may remain suspended in the indoor air, potentially several hours, where they could then be inspired by others.
July 6, 2020 13h36
Scientists call the principle of precaution against the possible transmission of the sars coronavirus by the air
WASHINGTON — “It is time to take care of the air-borne transmission of the COVID-19” write 239 international scientists in an article calling on the authorities of health of the planet and in particular the world Health Organization (WHO) to recommend active ventilation of indoor public spaces.
To this day, the WHO and other health authorities, including those of the United States, believe that the coronavirus responsible for the disease of the COVID-19 is mainly transmitted by droplets projected by coughing, sneezing and speaking directly into the faces of people nearby, or present on surfaces where they can survive for hours or days.
But several studies on the virus SARS-CoV-2, and other respiratory viruses have shown that viral particles present inside microdroplets in the air exhaled by an infected person could remain suspended 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 evidence is accumulating.
“We call on the medical community and national and international agencies with the ability to recognize the potential of air-borne transmission of the COVID-19”, write in the journal Clinical Infectious Diseases Oxford two scientists, Lidia Morawska, university of Queensland, and Donald Milton of the university of Maryland, in an article which have contributed to or supported 237 other signatories reported at the end.
“There is a significant potential of risk of inhalation of virus contained in respiratory droplets, from microscopic (micro-droplet) to short and middle distance (up to several meters, of the order of the scale of a room), and we promote the use of preventive measures to prevent this route of transmission air”, they write.
As a priority, it is better to ventilate the places of work, schools, hospitals and retirement homes, and install more tools to fight infections such as filtration of air of high-level and ultraviolet rays special that kill microbes.
These recommendations are often inexpensive, argue-they, like to open doors and windows; but in the safety instructions current, the priority is still given to the washing of hands, masks and distancing physical.
“The 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”, the scientists say.
WHO makes the distinction between viruses transmitted by air, like measles, and the other, but “this is not a problem of dichotomy”, told AFP one of the signatories, professor Caroline Duchaine, director of the laboratory on bioaerosols at the university of Laval in Quebec.
“We made a mistake if there is an opposition between the transmission of the virus, such as measles and by the COVID-19,” she said.
For the coronavirus, “this is certainly not the primary mode of transmission”, but if one wants to apply the precautionary principle, “it is necessary to add the control of the air” at arsenal, a health, insisted the professor Duchaine.