Can masks help prevent the spread of COVID-19 coronavirus? Yes, facemasks combined with other precautions (such as frequent hand washing and staying away from society) can help stop the spread of the virus.

So, why is it not recommended to wear a facemask at the beginning of a pandemic? At that time, experts did not yet know how far people infected with VID-19 could spread the virus before symptoms appeared. Some people are not known to have COVID-19, but there are no symptoms. Both groups can spread the virus to others without knowing it.

These findings led the Centers for Disease Control and Prevention (CDC) to perform face mask treatments. The Centers for Disease Control and Prevention has updated its guidelines, recommending the widespread use of simple fabric covers to prevent people with COVID-19 who don’t know it from spreading the virus.

Some public health organizations believe that facemasks should be reserved for medical personnel, and point to a serious shortage of surgical masks and N95 masks. The CDC recognized this concern when it recommended fabric masks to the public instead of the surgical masks and N95 masks needed by health care providers.

First study in the world has the answer

To date, the most comprehensive study of virus prevention measures details the benefits of physical alienation, mask use and eye and face protection. Experts say this depends entirely on how these tools are used.

Although initially, because of extreme shortages, health authorities begged people not to go into pharmacies to buy them because the coronavirus pandemic is spreading around the world, today it poses the opposite requirement: everyone must wear a mask. But what is the real impact of wearing one? Many: according to a study published in the scientific journal “The Lancet” this Monday, combining its use with maintaining social distance greatly reduces the possibility of acquiring new cases of coronavirus.

For the analysis, an international team of researchers reviewed 172 observational studies from 16 countries, evaluating distance measurements, masks and glasses to prevent infection or possible infection with Covid-19, Sars or Mers Propagation among patients. And people close to them, such as family members or health-care workers, until May 3. Therefore, we grouped 44 comparative studies with more than 25,000 participants, focusing on seven studies in Covid-19 (6,674 participants), six studies in Sars (15,928), and eleven in Mers Studies (3,095).

Covid-19 is most commonly transmitted through respiratory tract drip, especially when people cough and sneeze, either directly or by hand touching contaminated surfaces, and then get it into their eyes and then into their eyes, nose, and mouth.

A study by McMaster University in Canada found that maintaining a distance of at least one meter from others reduced the risk of transmission to 2.6%, compared to 13% for closer contacts. The study’s author adds that a distance of two meters may be more effective.

Similarly, the survey indicates that for every additional metre (up to three metres), the likelihood of infection is halved.

In terms of eye protection, they found that masks, glasses and goggles are associated with a lower risk of infection compared to the absence of any of these items. The results show that the risk of infection or spread is 16% when this tool is not used, and this number drops to 6% when such protection is used. The benefits of the masks were also found, because the risk of infection was 17% and 7% when using the accessory. The evidence focuses on the use of masks within the family and among contacts from confirmed cases.

In addition, the research also emphasizes the effectiveness of N95 masks and multi-layer fabric masks that provide maximum protection, and the latter are better than single-layer masks. Although recommendations for the use of masks have increased, this is the first time accurate figures are provided on their effectiveness.

Dr. Holger Sch√ľnemann, a professor of clinical epidemiology and medicine at McMaster University and co-author of the report, said: “These three measures may be the best approach.

Probability problem

“This is very surprising. We believe that the effect of this mask is poor, considering that it was initially recommended not to use the World Health Organization and Ministry of Health masks at the same time,” Ignacio Neumann, an expert in internal medicine. University of California School of Medicine and co-author of the study.

The experts point out that “all these interventions depend on the risk of infection: one thing people think is that if they are exposed to someone with a coronavirus, they have a 100 percent chance of infection, which is not the case. He added: “Studies have shown that medical personnel who have been exposed to COVID-19 without any protection still have a 15% or 16% chance of being infected, which is not high.

In fact, in high-risk situations, masks, face protection and social distance are very effective and reduce the risk to 2%. So what happens on the street? Newman noted that, in this case, the probability of infection is less than 15%, so the effectiveness of the mask will also be reduced. In this sense, in low-risk situations, social distance is theoretically sufficient.

“However, if this social distance cannot be maintained, such as in subways or mini-vehicles, masks really do make sense. Therefore, in high-risk situations such as hospitals, it is reasonable to wear masks, face protection and distance,” he added. According to the academics, “people intuitively think that the risk of infection is greater than 15%, but only a fraction of all unprotected exposed people are infected. If not, we will all be infected by then.

“Now, we have to consider that we are talking about an exposure, because if an exposure is exposed repeatedly, the issue will be different. Like pregnancy, this possibility is rare, but if it is exposed repeatedly, a woman will become pregnant. Hannibal Vivaceta. Department of Public Health, University of Valparaiso School of Medicine, explained: “Distance is essential to prevent the spread of the virus, and as distance increases, its effectiveness will increase.

Vivaceta added that, although the study is not conclusive, “physical distance has proven to be a relevant protective measure. The recommended distance is greater than the recommended distance and should be considered. The academic said that, with regard to masks and glasses, “although the data show an effective trend, it depends largely on the type of mask: in N95, the mask is much larger than surgery or clothing. But it is very important how you wear it “.

“The author cautiously said that this study is about the right type of mask, people generally don’t wear this type of mask because it will give people the wrong sense of security. He concluded: “The good news is that some areas require masks on a mandatory basis, and we can use this to test whether this measure is effective.