Masks mandatory for everyone in public: WHO is ready to review the guidelines. According to new studies, they are essential to avoid contagion
Use of masks mandatory for everyone in public. L'WHO is ready to review the guidelines, in the light of the new studies that show how the virus can resist in the air, that is, spread with the breath over large distances, and for much longer than previously thought.
Until now, the World Health Organization has always recommended masks only if you suspect you have contracted the coronavirus and experience symptoms such as coughing or sneezing, or if we are caring for a person with suspected new coronavirus infection.
This position has created a wide debate, both among citizens and among experts. Many, in fact, had clamored to revise these indications. Starting from China, where instead the masks were used systematically, up to MIT, which with a new study showed just a few days ago how a sneeze can infect up to 8 meters away.
The masks, therefore, would be a fundamental defense to prevent infections, along with the other measures. Now a new Japanese study has also discovered a "third way" of contagion, represented by microparticles that could cause the much faster spread of the coronavirus.
"We are studying the latest scientific evidence", explains the WHO, because even if complete studies are lacking, it is now highly probable that the spread of the virus can also take place through the air, where the infected droplets that we emanate are able to remain for a while long enough to infect those nearby.
Change of WHO guidelines
Just MIT had turned to WHO in recent days, openly asking to review the guidelines on masks. And now a group of consultants from the World Health Organization will evaluate research on the possibility of projecting the virus further than was previously known.
This was confirmed by the group leader of this team of experts, the infectious disease specialist David Heymann, to BBC News. This new research could lead to a change in alignment guidelines:
"WHO is reopening the discussion and is examining new evidence to see if there really should be a change in the advice regarding the masks. "
In a note, the World Health Organization stated:
"WHO closely monitors emerging evidence on this critical topic and will update this science brief as more information becomes available," he said in a note at the release of the MIT article. And so it was.
What the WHO is currently saying about masks
WHO currently recommends keeping a distance of at least 1m from anyone who coughs or sneezes to avoid the risk of infection.
Only people who are sick and show symptoms should wear masks. He recommends wearing them only to those who care for people suspected of being infected or suffering from coughs and colds.
Emphasize that masks are only effective when combined with frequent hand washing and used and disposed of properly.
Just last March 29, the WHO, with a scientific brief, had reiterated that the transmission of the virus that causes Covid-19 was not by air but only by respiratory droplets with a diameter greater than 5-10 μm. The study of the New England Journal of Medicine, which evaluated the persistence of the virus in the air, was therefore also downplayed, considering it limited to "laboratory" conditions. For this reason, the WHO reiterated the use of certified masks only for those in close contact with the infected.
The WHO confirms: the coronavirus is not transmitted by air, but only by saliva droplets
Only a few days ago, therefore, the WHO had confirmed the validity of its provisions, which are listed below:
How (and why) to wear a mask correctly. WHO advice
Now, however, they will in all probability be revised, after the MIT study which returns to question the same WHO experts.
What our Ministry of Health says
Basically it is based on the WHO guidelines. And he confirms to “use the mask only if you suspect you are sick or if you are providing assistance to sick people”.
Studio del MIT
Researchers at the Massachusetts Institute of Technology (MIT) in Cambridge, United States, used high-speed cameras and sensors to accurately assess what happens after a cough or sneeze.
They found that a small, fast-moving cloud of gas is generated that can contain liquid droplets of various sizes - and that the smallest of these can be carried in the cloud over long distances.
The study, conducted in the laboratory, found that the cough can project liquid up to 6 meters away and that sneezing, which involve much higher speeds, can reach as much as 8 meters away. For this she appealed to WHO to ask for a review of the guidelines on masks.
Coronavirus: a sneeze could infect up to 8 meters. The new MIT study
The Chinese experts sent to Europe also said so. In particular, George Gao, general director of the Chinese Center for Disease Control and Prevention, had indicated the not widespread and widespread use of masks as one of the main errors to be attributed to European countries. I'm too few masks around, He said.
“This virus - explains Gao in an interview with“ Sciencemag.org ”- is transmitted by droplets and by close contact between people. Droplets in particular play a fundamental role. When we talk, droplets come out of our mouth all the time, which is why we have to wear the mask. Many people have asymptomatic infections or are in a presymptomatic stage of the disease. By wearing the mask they can prevent the droplets that carry the virus from infecting others ”.
Just a few days ago Austria joined the small club of European countries, including the Czech Republic and Bosnia-Herzegovina, which made the use of masks mandatory in public spaces. Because, if everyone wore it, the chain of contagion could be broken more easily. Just like it happened in China.
Japanese study, the "third way" of contagion
To cause even more concern, now comes a Japanese study, which points to one "Third way of contagion". According to Kazuhiro Tateda, president of the Japanese Association for Infectious Diseases, these are micrometric particles. It is they, says the expert on NHK, who transmit the coronavirus when people are close to each other.
So far, scientists have always said that coronavirus spreads when droplets from coughs and sneezes travel through the air. But, as Tateda and other Japanese scientists theorize, micrometer-sized particles can spread even when people are conversing or are simply close to each other. Experts are now examining this new infection mechanism as a key to preventing further spread of the virus.
And while it is true that broadcasts also occur during conversations (and even when people are at a certain distance away), not even the use of mandatory masks for everyone could be enough.
Both surgical masks and N-95 masks cannot prevent coronavirus viral particles from entering your body. If coronavirus particles are suspected to be micrometer-sized particles, it becomes even more difficult to stop the infection. The viral particles are too small and the filtration capacity of the surgical masks is insufficient. N-95 masks also do not protect. Widespread self-quarantine remains, therefore, the most effective strategy to combat the pandemic.
In one experiment, NHK found that when a person coughs once in an enclosed space the size of a classroom, about 100.000 droplets can be released within seconds. The largest drops fall to the floor within 20-30 seconds. The micro droplets, however, remain in the air for a longer period of time, leaving other people vulnerable to possible infections. With a single cough you are able to spread 100.000 droplets, the micro droplets could spread even during simple conversations. This leaves people at risk of infection virtually all of the time.
All this, however, remains to be confirmed. The scientific community will be able to provide more information, because coronavirus studies are constantly evolving.
Also review the safety distance
Even the safety distance of 1 meter may not be sufficient, so much so that in some countries, such as the UK, it has been set at 2 meters. Perhaps the distance would also need to be reviewed, since it would seem that the coronavirus can travel twice as far as the safe distance recommended so far, or 4-5 meters compared to the almost two months considered sufficient.
Another Chinese study had already arrived at a similar result but, considered circumstantial (it examined the situation in buses) it had been discredited and withdrawn from publication.
Coronavirus: in closed spaces it would resist in the air for 30 minutes and up to 4,5 meters. The Chinese study inside a bus
Masks not available
In light of all this, in any case, it therefore appears even more certain that the WHO will be forced to review the guidelines on masks. But one problem remains: the masks are difficult to find and it seems really difficult to supply them to the whole population.
While it is true that specific masks are not necessary for the general population, they are impossible to find and are reserved for healthcare personnel who are in close contact with Covid19 + patients, even the simple ones could be useful. DIY fabric masks. They are not a medical device, but they can stop the droplets that come out of the mouth, at least the most macroscopic ones.
How to make DIY fabric masks
Sources: BBC, WHO, MIT, Ministry of Health, ScienceMag, CNN, NHK
DIY masks: yes, but under these conditions (and not to prevent contagion)
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