![Covid-19: a link between severe forms and cold](https://img.passeportsante.net/1000x526/2020-12-15/i98117-covid-19-froid-et-formes-graves.jpeg)
It was three researchers from Valenciennes, in the Hauts-de-France region, who established a correlation between the climate and severe forms of the disease, the results of which were published in the scientific journal PLOS One.
A link and not a cause and effect relationship
This is the first study of this kind published in France. Scientists were looking to find out whether the climate, especially ambient temperature, had any influence on Covid-19. Last November, the Minister of Health, Olivier Véran, declared: “We noticed in October an epidemic acceleration when it started to get cold“. Since June, three researchers from the Valenciennes hospital center, Mehdi Mejdoubi, Xavier Kyndt and Mehdi Djennaoui, have looked into the issue. According to them, the more the temperatures drop, the more intensive care admissions and the number deaths are increasing. They also note a lag, between the decrease in temperatures and severe cases, of eight days for intensive care admissions and fifteen days for deaths. To carry out their study, the researchers compared daily temperature readings in Île-de-France with the number of people admitted to intensive care and the number of deaths recorded in hospital.They chose the data declared between March 12 and May 10, 2020, i.e. during the first wave of the epidemic of coronavirus. However, they observe a relationship between the different curves that evolve together and not a causal link between the drop in temperatures and severe forms of Covid: “Study results show previously observed negative correlation of ambient temperature with Covid-19 severity indicators“.
A relationship that must be proven
According to the National Academy of Medicine, it is interesting “d” integrate the climate factor into the modeling of the epidemic phenomenon and take into account weather forecasts in decision-making bodies relating to the management of the Covid-19 health crisis “. Indeed, “Several studies show that the rise in temperature and humidity levels affects the viability of the virus and reduces the number of infections. The importance of this correlation could be quantified, a 1 degree increase in temperature being associated with a 3.1% decrease in new cases and a 1.2% decrease in deaths.“. Several researchers have carried out work, but scientific evidence is still lacking to date. On the other hand, several professionals agree that behaviors influence the spread of the virus. When it is cold, people go out. less time and spend more time in closed spaces. However, aerosols are dispersed more quickly outside. It is therefore necessary to continue to apply barrier measures, especially at home, by regularly ventilating the rooms.