Against those who, like the Danish or Sibeth Ndiaye, the deem " unnecessary ", the supporters of the masks will now have an argument massue : the study of the "hamsters hidden" from the university of hong Kong. Presented Sunday, the results of this experiment conducted on 45 hamsters show that " the effectiveness of wearing a mask against the pandemic coronavirus is enormous ", is excited about the professor Yuen Kwok-yung, department of infectious diseases, faculty of medicine, with 60% to 75% transmission thanks to simple surgical masks.
Yuen Kwok-yung is not anyone : a veteran of the Sars, it was one of the first to sound the alarm on the Covid-19, in going from the 17 January to Wuhan, where, with a group of chinese scientists on the continent, he found the transmission between human beings. It is their report to Beijing, which eventually forced the authorities to admit the gravity of the situation. Since, it is one of the most ardent supporters of the masks, arguing that they are one of the decisive elements, if this is not the " most important ", in the response against the epidemic.
also Read Denmark : this country who do not believe in masks
66 % of infected hamsters without a mask, between 35% and 15% with
Wanting to demonstrate his fact, he used the great means and recruited the cutest guinea pigs : hamsters. No question, however, to make masks on able. Small rodents would be unable to wear them... The researchers of his laboratory have, therefore, placed a group of animals infected and another in good health in two cages separated. Surgical masks (FFP1 so) have been stretched on some cages, a blower propelling the air out of the cage of the sick to that of hamsters healthy. Without a mask, two-thirds of the hamsters healthy were infected in a week. With a mask over the cage of the hamsters are healthy, only one-third was infected. With a mask over the cage of an infected animal, the infection rate drops to 15 % among the hamsters ! And don't worry, all hamsters are now healed...
" We now know that a large part of those infected do not show symptoms, therefore, the port's universal mask is really important ", summarized the expert of the faculty of medicine of the university of hong Kong. Of course, several points call for caution and more research : "This new study has not yet been published for the time being, and one should always be careful not to rely too preprints ", recalls Benjamin Cowling, a professor at the school of public health, the university of hong Kong, author of a thorough study on the effectiveness of the mask on the coronavirus seasonal (like the common cold), published in April. "It uses small animals rather than humans, and it is not certain that the infection would spread in the same way in humans. But it remains an important study. "
Not a armor, but a shield is essential
Why ? "This is the first study that observes specifically the effects of the masks on the Covid-19 ", details there. "It shows that the surgical masks can be used to block the active transmission, if worn by infected persons, but can also be used to protect the porters who would not be infected. "The trick is to understand that the use of the mask by the "general public" was not for the purpose of reaching a full protection, waterproof against any contamination, such as in laboratory conditions, or as it is necessary for occupations at risk, such as caregivers, who will, themselves, turn to masks FFP2 protection to nearly 100 %.
Read also Demorand – 10 things to know in order to wear a face mask
The purpose of the use of surgical masks by the public is a collective protection measure to combat the epidemic, imperfect, but which slows down significantly the spread of the virus on a large scale. "I do not think that it is necessary to believe that the masks provide total protection, but only a certain form of protection. It is better to wear it than not wear it, " says Benjamin Cowling. In sum, a mask is not armor full, but it is a lightweight shield, indispensable in the war in the long-term against the virus.
Read also Coronavirus : how the asian Tigers have tamed the epidemic
Finally, the professor of the university of hong Kong warns against those who would like to do masks the alpha and the omega of the fight against the pandemic : "The largest part of the world has been facing a shortage of masks," he recalls. "There are many factors responsible for the successful responses by the authorities in Asia. The most important is to test, to isolate the sick, trace and quarantine (the strategy of “Test and plot”), and most regions of Asia have also used social distancing to reduce transmission. The surgical masks will help, no doubt, but I do not believe that they are the main reason for the success. "
