Are cloth masks effective in protecting the coronavirus pandemic?

Last Tuesday, March 31, the Minister of Health, Luiz Henrique Mandetta, began mentioning the use of masks for other groups of the Brazilian population, in addition to health professionals and those who work at the front for controlling the contagion of the new coronavirus.

Even on Thursday, April 2, Mandetta reiterated the importance of using the protection method, even homemade with fabrics:

“People, cloth mask or community mask. It doesn't have many rules. I can put a suggestion there [on the website], a basic thing. You can make a fabric barrier mask. Use thick fabric. It does not need to go to technical specifications, it must be fabric A, B or C. What we use most appropriately in health environments is TNT (non-woven fabric)”, he highlighted in a press conference.

The theme gained great proportions of discussion and the Minister of Health himself highlighted the questions received. In view of this, the folder created a material with recommendations and

tips for producing masks on the Ministry of Health website.

In the published booklet it is evidenced that the mask works as a barrier to the Covid-19, having to be for individual use and have at least two layers of cloth. The booklet also highlights the limit of a maximum of two hours for use, which must be washed for a new use.

Absence of studies on efficacy

Experts point out that there is a lack of studies demonstrating the effectiveness in the use of homemade mask. Even though he understands Mandetta's recommendation, the head professor of infectology at the Federal University of Rio de Janeiro Grande do Sul (UFRGS), Luciano Goldani, warns of the lack of indications that prove the effectiveness of the equipment.

“He means well. He's trying to protect the population, he's worried about the lack of personal protective equipment (PPE). But, from a technical point of view, we need more data on these materials”, he points out.

In addition to the lack of proof of effectiveness in the use of equipment, the infectologist at Hospital Nossa Senhora da Conceição, André Luiz Machado, adds saying that, unlike the other models, the fabric mask tends to get wet faster, which hinders your efficiency. Another issue is that it does not have the filtering power, which decreases the level of protection.

“The fabric barrier reduces droplet shedding and offers some protection. I don't think the ministry is wrong in changing its position, as studies show that in countries where the use of masks is more frequent, such as Japan, there were fewer cases. But, in parallel, there must be an awareness effort by health agencies to explain how the mask should be used and taken off. I see people in the supermarket with masks only on their mouths. This generates a false sense of protection, ”he argues.

And there is another fear on the part of experts. The fact that, thinking they are protected, people tend to relax in personal hygiene care seen as more essential, such as wash hands, use the alcohol gel, maintain isolation and the respiratory labels.

Use and disposal are key

Another crucial and delicate issue in the Ministry of Health's recommendation refers to the handling of equipment, when putting it on, taking it off and discarding it, emphasizes the UFRGS professor. According to Goldani, to avoid contamination, it is essential to properly wash your hands before putting on the masks and after taking them off.

“There is the issue that the individual can be contaminated by using these masks. I use it and I don't know where to put it, how will I dispose of it? How to put? There is a whole didactics of use”.

However, Goldani recalls that there are professionals who remain in contact with many people in their workplace, such as in activities consideredessential, for example, bus drivers, recalled by Mandetta, who need this measure of protection. But it must be made with materials that are within the rules of the National Health Surveillance Agency (Anvisa).

“For those who have never worn a mask, it is difficult to adapt right now without being contaminated. You're going to put your hand in front of the PPE, you're going to use it wrong, doing more harm than good”, elucidates infectologist Machado.

* With information from GaúchaZH

See too:

• What to do to protect yourself from the coronavirus?
• What to do if you catch the coronavirus?
• What to do to not get coronavirus?
• What to do in case of suspected coronavirus?