Paris (AFP)
More and more cities impose the wearing of the mask outside and the Prime Minister called to "extend as much as possible" this obligation. But there is no consensus on its usefulness in the fight against the Covid-19 epidemic.
Marseille, Carcassonne, more recently Paris, Grenoble, and Bordeaux from Saturday ... Faced with the rise in the number of cases of contamination in recent weeks, many municipalities - 330 according to Jean Castex - require the wearing of a mask in the street, especially in markets or certain busy streets.
"We must go beyond," said the chief executive on Tuesday during a trip to Montpellier, announcing the sending of a circular to the prefects asking them "to develop as much as possible the places where there are a requirement to wear a mask ".
This speech contrasts radically with the message of the authorities at the start of the epidemic. In a context of shortage of masks, they assured that this object was intended for caregivers and the sick and "useless for anyone in the street", in the words of the Director General of Health (DGS), Jérôme Salomon.
The discourse evolved over the weeks (and scientific knowledge), culminating in an obligation in all enclosed public places on July 20.
But in the open air, is there really a risk of contamination?
- "common sense gesture" -
"Wearing a mask is a gesture of common sense in crowded places and when the minimum distance of one meter can not be respected," said the Ministry of Health on Monday in its daily press release.
An opinion shared by the professor of immunology Jean-François Delfraissy, at the head of the Scientific Council: "common sense must guide decisions. In the crowded street of a seaside resort, wearing a mask is essential", estimated he Sunday in the Sunday Journal, saying, however, prefer "incitement" to coercion.
"If we stand at a respectable distance, one to two meters, that should be enough, but the Prime Minister is right to say that there are crowded areas, where (...) we can not stand social distances, and this is obviously where wearing a mask is really essential ", observed Tuesday on RTL Anne-Claude Crémieux, infectious disease specialist at Saint-Louis hospital (AP-HP).
"Outside, there is such a mixing of air that we do not arrive at a sufficient viral concentration to be infectious", judges Martin Blachier, public health doctor interviewed by AFP.
Epidemiological studies show that outbreaks of grouped cases ("clusters") occur almost exclusively in closed places and allow to estimate that the risk of contamination is about 20 times higher inside than outside, adds the co-manager of the consulting company Public Health Expertise.
"It is a political decision and not of public health, to say + we are taking the full measure of this epidemic +", also estimated with AFP Yonathan Freund, fearing that this measure that "nothing scientifically justifies" creates " distrust in the population ".
- "Psychological bet" -
"It is impossible to know if the effect of" wearing a mask outside "is real", because it would be "unethical" to test this hypothesis in real conditions, adds Michaël Rochoy, general practitioner member of the Collective Stop Postillons, which has been advocating since March for a wider use of the mask in the fight against the coronavirus.
"But faced with a zero risk" linked to the wearing of the mask itself, "the decision deserves to be taken in the densest places, where there are the most concentrations of people", he explained. to AFP.
The doctor is also cautious in the face of the few contaminations outside officially recorded: "when you contaminate yourself in the street, it is very difficult to know: it is not a single place, you do not cross it the same people for several hours at a time ", whereas when several cases are detected in the same company, it is very likely that the contamination has taken place in these premises.
Beyond the scientific aspect, some mayors point to the psychological interest of such a measure: "it is a measure which aims to reassure" the population, "to say that we can go out, we can go to a commerce, we can stroll ", argued on the local channel Eric Fournier, mayor of Chamonix-Mont-Blanc (Haute-Savoie), who opted on August 3 for the compulsory mask in the city center.
A risky "psychological bet", according to Martin Blachier, because the refractory to the wearing of the mask could on the contrary be tempted "to find themselves indoors", in private places where the wearing of the mask cannot be controlled and where the risk of contamination is much higher.
© 2020 AFP