What are the highest risk places for Covid-19? A question an American study carried out by the Stanford University tried to answer on Tuesday November 10, 2020 in the Nature magazine. How did the scientific team entrusted with the study manage to list these places? Carried out by modeler Serina Chang, the scientists cross-referenced the data from about 100 million people in 10 big cities in the United States of America between March and May, including data on the evolution of the epidemic in these cities.
An hour-by-hour-based assessment enabled to precisely establish the highest risk place for contaminations, tracking on the same occasion the evolution of the spread of the virus on the American territory. And results are clear: restaurants, gyms, bars, cafés and hotels are the highest risk places for infections. for instance, the city of Chicago – for which the study established that 85% of the contaminations happened in these kinds of places (only 10% of places visited by city dwellers).
Yet, the lowest risk places are computer stores, car dealerships, and even more surprising, pharmacies yet visited by many sick people potentially infected with Covid-19. How can this high risk of contamination be explained? The study confirms a hypothesis suggested by many scientists, naming – as explained by Express – “the longer one stays in a crowded place, the higher the risk”. The density of populations in a place has a very important role to play, this explains why restaurants, bars, cafés and other aforementioned places are logically places the virus spread the most in.
“This study is particularly precise and matches with the many observational studies” INSERM research director Vittoria Colizza tells Figaro. She goes on: “Environments where it is impossible to keep distancing are those with the highest risks. It seems obvious, but studies like this one enable to quantify risks and shall guide our decisions to lift lockdown”.
A study that could help France – and other countries – to reopen non-necessary places with a limited number of people. With the example of Chicago, this study explains that opening up these places with only 20% of their capacity could only lead to a 10% growth in cases, against 39% if there is no limit implemented. Note that schools, junior highs, high schools and universities, as well as retirement homes, as well as companies and public transit have not been listed in the assessments of this study, limiting the results of the study a lot.