(By Massimiliano D'Elia) The spread of the Covid-19 virus occurs quickly and it seems that the containment measures implemented are not effective enough, decisive. The social distance set at one meter, the use of masks (surgical and with filters, type FFP2-3), the limitations imposed on every activity to be carried out outdoors and many other measures seem to be mitigating the contagion, even if the dead in Italy are still of the order of 700 per day. It is not clear, however, whether the new cases of infected, albeit in smaller numbers than twenty days ago, are referred to the tail of the contagion, when Italy had not yet been declared a red zone, or were infected by incorrect behavior. or from something that everyone has missed.
Maybe we were not careful about the use of the masks? Have we not worn them well and always everywhere? Should I always wear them? If we were to wear them all the time, do we have enough for around 60 million Italians? Questions that are haunting political decision-makers and experts from the scientific community in these hours.
Marina Davola, director of the Department of Epidemiology of the Lazio region, in an article by la Repubblica speaks of the correct use of masks and the attention to be paid to the hygiene of the rooms: "Remember that the mask is not a magic formula that saves us from contagion. The most important thing remains attention and hygiene. And then if you use it you have to be very careful, remembering that it is a disposable device that has rules for being put on and taken off. For example, too many people touch the outside with their hands and risk getting infected once they take it off. I would not like to wear it more harm than good, because it gives an invulnerable feeling".
The WHO suggests the use of masks only to those who have symptoms or who care for the sick. Given that it would not be rash to decide to let everyone wear them, perhaps there is something that could have escaped: " What if it spreads through the air? "
The possibility has not been excluded so much so that in the USA it has been recommended to always use masks when you are in public or in the vicinity of your family within the home.
The opinions of some experts on the subject are also reported on the Republic. David Heymann, of the WHO at the BBC explains: "We are studying new scientific evidence and are ready to change the guidelines if necessary".
Paolo D'Ancona, epidemiologist of the Italian Institute of Health says: "We know that the coronavirus is mainly transmitted through droplets in the air. In hospitals with many mechanically ventilated patients, however, it could also be dispersed with aerosols".
Difference between droplets and aerosols
The difference lies in the size of the saliva balls that carry the virus. The droplets travel 1-2 meters from the person who emits them and immediately fall to the ground. The aerosol remains suspended in the air and can reach greater distances. A search for the New England Journal of Medicineof March 17 showed that the virus can resist aerosols for up to three hours, with an amount that is halved in an hour. An experiment from the MITpublished in Jama on March 26 showed that the virus it travels both on droplets and in aerosols, and that the latter can reach 7-8 meters with a strong sneeze. In China, traces of coronavirus have been found on window sills and grates of ventilation systems in hospitals that have treated coronavirus patients.
In light of these recent studies and the evidence found in the environments, WHO could shortly review the containment measures. If so, they would have a greater impact on the quality of daily life of the world population.