A model from Stanford University developed in March looked at the places of contamination with the coronavirus.

Unsurprisingly, enclosed and poorly ventilated areas represent the greatest risk for visitors, with two determining factors.

DECRYPTION

If there is a "slowdown" in the progression of the coronavirus epidemic, the peak is yet to come in hospitals.

On Wednesday, the national death toll rose to 329 additional deaths (42,535 deaths in total), with 351 new patients in intensive care, where the threshold of 5,000 patients is approaching.

But as the weeks of health crisis go by, a decisive question remains unanswered: where do we catch Covid-19 and what are the most contaminating places?

An American study provides some valuable information on this key parameter in the fight against the epidemic.

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Stanford University modelers combined mobility data from nearly 100 million Americans in the country's ten largest cities.

Their movements between their places of life and the different types of businesses have been scrutinized.

The first lesson of this study is the following: the majority of contamination is linked to a small number of places.

Thus, in Chicago, 85% of the contaminations take place in 10% of the places examined.

Useful to prepare for deconfinement

Unsurprisingly, it is the restaurants, sports halls, cafes and hotels that are at the top of this ranking of places of super-contamination.

In fact, these are all the enclosed spaces, poorly ventilated and which welcome a lot of people.

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Second lesson of this study: the two main factors that determine the risks for visitors are the time spent in these places and the density of people.

"This study makes it possible to identify which places are the most favorable to infections and perhaps those on which we have the most room to reduce these densities and these past times", explains Pascal Crepey, epidemiologist at the School of advanced studies in public health.

The Institut Pasteur is preparing a study

On the other hand, there is a downside in this study, carried out last March, at the start of the first wave: the health protocols were not yet applied in these places and no one was wearing a mask.

Scientists also decided not to include companies in their study for practical reasons.

For the moment, there is no similar survey in France.

But the Institut Pasteur is currently preparing a study to determine the most contaminating places.

There is no doubt that it will be watched very closely by the government when decisions are made for deconfinement.