Enlarge /. Self-sewn face masks in a fabric store on April 3, 2020 in Jena, Germany.
With COVID-19 cases increasing rapidly across the country, some health experts are now recommending that apparently healthy members of the public wear cloth masks on the go. On April 3, President Trump announced a new federal recommendation calling on the public to wear cloth masks to prevent people who are infected but may not have symptoms from unwittingly spreading the disease.
The recommendation is a U-turn from previous instructions on using masks. To date, officials from the World Health Organization, the United States Centers for Disease Control and Prevention, and other agencies worldwide have prevented the public from wearing masks unless they are sick or care for someone who is sick. They found that there is little evidence of mass masking and that the limited data we have suggests that they could, at best, slightly reduce disease transmission.
With reference to a lack of benefits, experts also expressed concerns about possible damage. Wearing masks can give people a false sense of security, some experts said. This may result in some members of the public being negligent with other, much more critical precautions, such as: B. stay two meters away from others, limit trips and wash your hands frequently and thoroughly.
In addition, putting on an uncomfortable, uncomfortable mask can cause some people to touch their faces more, some argued. Every touch on the face can transfer virus particles from contaminated hands to entry points such as eyes, nose and mouth. And even if the hands of a mask wearer are clean from the start, simply touching the mask can contaminate the hands if viral particles get caught on the outside. If this is the case, a mask wearer could inadvertently transfer virus particles from his mask to his face, nullifying the benefit of the mask. They can also transfer the virus from their mask to their surroundings by touching surfaces on which the virus particles can be picked up by other people.
Lastly, they argued, the masks that would most effectively stop the new corona virus – SARS-CoV-2 – are things like N95 respirators and surgical masks that are in short supply worldwide. Without a doubt, these should be kept at the forefront of heroic health workers who risk their lives every day to treat patients with COVID-19 during this overwhelming pandemic.
While experts unanimously agree on this last point – that suitable medical masks should go to healthcare workers first – the other points are now up for debate.
Since SARS-CoV-2 is now widespread and no longer controlled in the country's municipalities, experts are taking a more favorable look at the limited data behind masks that prevent the spread of diseases in public. In a recent commentary published in The Lancet, a group of UK and Hong Kong researchers argued that "there is a significant difference between the lack of evidence and the lack of evidence." And although there are no large, high quality studies dealing with the use of public masks, there is some data that supports the use of masks.
Regarding possible damage when wearing masks – such as B. Face problems and loosening of other precautions by wearers – experts are now rejecting the concerns. Wearing a mask in public could alert people to current public health risks, some experts say. An eye-catching mask attached to your head is a constant reminder just above your nose to watch out for possible transmission of viruses. And – as a bonus – if everyone wears a mask, this can reduce the likelihood of stigmatization of those who wear them because they are sick.
Of course, wearing a mask does not replace other measures, such as B. a distance of two meters or good hand hygiene, says Joseph Allen, expert in exposure assessment science at the Department of Environmental Health at Harvard T.H. Chan School of Public Health. "It's just another layer of protection."
"The scale and scope of what lies ahead will require or require all of the precautions we can do," he says.
Some experts – Dr. Including everyone – are now in favor of the healthy public wearing self-made cotton masks or other face coverings that could act as a basic physical barrier.
"It's not as good (like medical masks), but it's better than nothing," argues Dr. Everyone.
What does the data on masks actually show in view of the contradicting reasoning and logic? How were you released before, but now hugged? Here you will find an overview of relevant data.
To understand why masks can help block SARS-CoV-2 transmission, it is first important to understand how the corona virus is transmitted. And frankly, we still don't know all the answers to this question.
So far, SARS-CoV-2 appears to move mainly from one person to another by starting in relatively large breath droplets. These are triggered when an infected person breathes, speaks, coughs or sneezes. These droplets are relatively heavy, generally do not move much more than two meters from their starting point and follow a ballistic trajectory, ie they fall to the ground after they have been blasted off. However, if they land on a person's face beforehand or fall on a surface that a person will soon touch, they can cause a new infection.
There is also the possibility that SARS-CoV-2 will spread in smaller breath droplets, so-called aerosols (less than 5 micrometers). These are droplets that we exhale and are so small that they can hang in the air for minutes to hours. Experts from WHO and elsewhere say data so far suggests that aerosol transmission is not the primary way of spreading the virus, although it is still possible. So far, the transmission of aerosols appears to be a problem, especially for healthcare workers when performing certain medical procedures on COVID-19 patients, e.g. B. inserting a tube into the airways to support breathing (intubation). This can cause the virus to aerosolize in hospital rooms and remain in the air.
Whether SARS-CoV-2 is aerosolized in everyday life is still unknown and is up for debate. Some experts like Dr. Everyone believes this could happen. Others are skeptical of the idea, since infected people only infect two to three other people on average. If every COVID-19 patient created infectious SARS-CoV-2 clouds everywhere, some experts would expect the patients to infect far more people on average. For example, measles has been linked to airborne transmission for decades, and each measles patient can infect an average of 12 to 18 people – or more. There is even evidence that the measles virus can spread through ventilation systems.
Although this does not appear to be the case with SARS-CoV-2, experts like Allen warn that the size of virus-containing breath droplets is a continuum that is not subject to any clear limits or strict rules. There are indications that the virus can survive in the air for hours under laboratory conditions if SARS-CoV-2 gets into aerosols.
Finally, there is evidence that SARS-CoV-2 particles that land on surfaces or objects hang around and may be picked up by others. These contaminated surfaces and objects, which can then transmit the infectious virus particles, are called fomites. Masks can prevent a wearer from placing a hand contaminated with Fomite on his face, but masks can also act as Fomites.