Knowledge of masks against coronavirus is developing and eliminating doubts about effectiveness – 12/24/2020 – balance and health

There is no longer any doubt that the masks can reduce transmission of the Sars-CoV-2 coronavirus when properly made and used. People who still resist the measure are ignoring solid scientific evidence recorded long before the current pandemic, which has increased significantly in recent months.

“In the photos from the Spanish flu season (1918) you can see people on the streets covering their faces with masks or handkerchiefs. We already knew that the masks are effective and prevent the spread of infections, ”says Viviane Alves, microbiologist and professor at the Institute for Biosciences at the Federal University of Minas Gerais (ICB / UFMG).

Today, the world’s leading health authorities recommend the universal use of masks to combat the transmission of the virus.

During a press conference on December 16, Health Monitoring Secretary Arnaldo Medeiros stated that the use of the mask is recommended by the Ministry and is essential to reduce the transmission of the virus.

Still, President Jair Bolsonaro and other government officials refuse to use the protection in public, even suggesting that it is unnecessary. The president had Covid-19 in July but it is not yet known how long the immunity acquired by the infection can last, and cases of coronavirus re-infection have already been confirmed in Brazil, including with symptoms returning.

The first evidence of masks being used in hospital rooms dates back to the late 19th century when patients used gauze masks to prevent the infection from spreading, reports an article published in 2013 by researchers in Australia in the International Journal of Infection became control (IJIC).

The Institute for Infectious Diseases in Chicago, USA, was the first of its kind to recommend the use of masks for the protection of health professionals.

Durand Hospital Municipal Hospital introduced the use of equipment by its employees in 1913 and saw a decline in respiratory infection rates among workers.

When Sars-CoV-2 emerged and Covid-19 quickly spread around the world, one of the primary tasks of the scientific community was to decipher how the virus spread and passed on from one person to another. Only then would it be possible to make an effective recommendation to prevent infection.

But science takes time, and it wasn’t until July that scientists around the world and institutions like the World Health Organization (WHO) began to detect airborne transmission of coronavirus through aerosols – very small droplets of saliva that are suspended in the air and longer can carry the virus until someone else breathes it in.

Until then, it was believed that the main routes of transmission of the virus were contaminated surfaces and larger droplets of saliva.

Studies with Sars-CoV-2 have shown that the virus can infect cells in the mouth and nose. In these areas, it uses the machinery of human cells to multiply and spread to other parts of the body.

An article published in The Lancet Microbe in November showed that Covid-19 patients had the highest number of active viruses in their nose and throat in the first five days after symptoms appeared, suggesting that this period has been more contagious The virus can get into the air in these regions through speech, coughing, or sneezing.

The recognition of airborne transmission increased the need to use masks and posed a major challenge: managing the high demand for professional equipment such as surgical masks or the N95 that threatened hospital supplies.

According to Viviane Alves, studies with masks could endorse models aimed at professional use, and a recommendation for universal use at the onset of the pandemic could lead to the groups in need of it most, such as B. Healthcare Professionals, have no equipment.

To meet this challenge, scientists from around the world have mobilized to quickly test and study various designs and materials for the masks.

The Brazilian Association of the Medical and Dental Equipment and Equipment Industries (Abimo) today states that there is no risk of mask shortage. However, the knowledge gained by researchers during this time was essential in fighting the pandemic and should be helpful in combating other diseases that are contagious.

Scientific articles citing the terms “face mask” grew 420% year over year in 2020, according to Scopus, one of the most important foundations for scientific articles worldwide. It is the largest academic production ever, with more than 700 articles published.

Studies over the past few months have shown that masks made from three-layer cotton fabric are as effective as surgical masks.

One of the most recent articles published this month in the journal Aerosol Science and Technology by scientists from the CDC (Centers for Disease Control and Prevention in the United States) showed that masks made from three layers of cotton fabric have a spreadable power of 51% of the weight Aerosols that a person may expel when they cough. A surgical mask can block 59% of aerosols in the same situation.

In Brazil, the challenge motivated a group of USP researchers from different fields to join the project (breathe! Test and design a mask to be used initially by professionals from the Hospital das Clínicas, the Faculdade de Medicina and the Universidade de São Paulo could Paulo (HC / USP) in a possible lack of equipment.

The union worked, and the project has already produced more than 1 million masks that have been distributed for use by the university – 250,000 of which were hand-made by seamstresses.

“We learned a lot and still generated income,” says Vanderley John, professor and researcher at Inova.USP (USP’s innovation center) and Poli-USP (Polytechnic School of the University of São Paulo) and one of the people responsible for the project.

The group, which evaluated more than 200 different types of masks, also plans to use the knowledge acquired to develop a general guidelines document that guides the making of more effective masks.

According to the researcher, the masks must be light and comfortable so as not to make breathing difficult. TNT (non-woven) masks are typically more effective than cotton masks, and the nose clip, a small piece of metal that holds the mask over the nose, makes the equipment more effective by preventing openings.

The scientist also suggests that the masks be light colored to avoid discomfort in the heat.

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