Facial visors should NOT stop infected patients from spreading coronavirus, warns a public health expert
Facial visors may stop uninfected patients spreading the coronavirus, a leading public health expert warned.
British people are now encouraged to wear face masks on public transport and in situations where social distance is not possible, such as in shops.
Retailers like Marks & Spencer and Waitrose have even purchased transparent visors that staff can wear to protect them from COVID-19.
But Professor Linda Bauld of the University of Edinburgh said the visor cannot prevent people from spreading the virus to other people.
While masks are thought to have the opposite benefit – preventing spread, but not necessarily infection -, Professor Bauld said visors are unlikely to be good enough to contain breath drops exhaled by the wearer.
Facial visors are worn all over the world by people who try to protect themselves against the coronavirus, but experts are skeptical that they can prevent someone from spreading the virus if they are worn without a mask (pictured: a guard in Belgium with a visor)
“I don’t think there are strong indications that they should routinely carry the public,” said Professor Bauld The Guardian.
The most important thing is to cover the mouth and nose.
“The facial covers that people are encouraged to use on public transport, for example, are not to protect the wearer, but to protect other people.”
Professor Linda Bauld, from the University of Edinburgh, told The Guardian: “I don’t think there’s strong evidence that they should carry the public on a routine basis.”
Compared to face masks, the visor is supposed to prevent droplets of breath, coughing or sneezing from floating in the wearer’s face, but the air is unlikely to come out of their own nose and mouth.
Masks are such a popular subject because of the way the coronavirus spreads – it infects people by dripping on the back on drops of fluid expelled from the lungs when they breathe.
These continue when someone coughs or sneezes, and if inhaled by someone else, the viruses can attach to cells in the airways and cause COVID-19.
Professor Bauld explained the one-sided advantage of a visor, adding, “The reason for a visor that would cover the top half of your face would be if you regularly come in closer contact with the audience, and you could become exposed to someone who releases tiny droplets that we all know can carry the virus very efficiently. ‘
Professor Bauld’s comments come after University of Iowa doctors last month claimed that face shields “offer some benefits” in fighting the pandemic.
In an article published in the Journal of the American Medical Association (JAMA), they said, “Face shields can be reused indefinitely and are easy to clean with soap and water, or regular household disinfectants.
“They are comfortable to wear, protect the portals from viral entry and reduce the chance of auto-inoculation by preventing the wearer from touching their face.”
“People who wear medical masks often have to remove them to communicate with others around them; this is not necessary for face shields.
WHAT DO EXPERTS SAY ABOUT FACE SHIPS?
In a battle to find ways to protect people from the coronavirus, masks, goggles, visors and gloves have all been touted as potential layers of protection.
Some people have even been seen making homemade attempts, such as carrying lunch boxes or water bottles over their faces.
But do visors work?
Epidemiologist Dr. Eli Perencevich and a team of scientists from the University of Iowa said that a visor can reduce the amount of virus someone has inhaled by up to 92 percent from 2 feet from the source.
They said it is unlikely that a scientific study could be done soon enough to be useful, adding, “Face shields … should be included as part of strategies to safely and significantly reduce transmission in the community.”
Dr. Robert Glatter, a physician at Lenox Hill Hospital in New York City, said, “While we do not currently have hard trials or data on the efficacy of face shields, early data on its use in patients with influenza [which is droplet-spread] is promising, ‘ Medical Xpress reported.
But research conducted before the pandemic doesn’t show clear benefits from using visors alone, other scientists say.
A study called “Face shields for infection control: a review” by Dr. Raymond Roberge of the U.S. Centers for Disease Control & Prevention (CDC) was conducted in 2016.
After reviewing evidence from other studies, Dr. Roberge that face shields have no evidence for the claimed benefits of using them alone.
He said viruses or bacteria can penetrate the edges of the visor and still cause an infection.
In the Journal of Occupational and Environmental Hygiene he wrote: ‘Due to the lack of a good peripheral face seal that allows aerosol penetration, face shields should not be used as lone face / eye protection, but rather as [an addition] other PPE (protective face masks, goggles, etc.).
“Given the lack of available data on the proper use of face shields for infection control, scientifically sound research should be conducted on the use of this form of personal protective equipment.”
“Using a face shield is also a reminder to maintain social distance, but allows visibility of facial expressions and lip movements for speech perception.”
The play written by Iowa’s Dr. Eli Perencevich, said shields “seem to significantly reduce the amount of inhaled virus.”
Some studies have shown that people are at risk of becoming more seriously ill with COVID-19 if they develop a larger “viral load” – the first dose of viruses they are infected with.
Dr. Perencevich and colleagues pointed to a study that simulated how much of a flu virus a health worker would have been exposed to with a visor.
The results showed that they inhaled about 92 percent less of the virus when they were 2 meters away – the strict social distance advice.
But the same study found that shields were less effective after 30 minutes, when the particles had spread into the surrounding chamber.
Dr Perencevich and colleagues added that “important policy recommendations should be evaluated using clinical studies.”
But they said, “It is unlikely that a randomized study of face shields can be completed in time to verify efficacy.
No clinical trial has been conducted to assess the efficacy of widespread testing and contact detection, but that approach is based on years of experience.
“Face shields … should be included as part of strategies to safely and significantly reduce transmission in the community.”
Tech giant Apple announced last month that it will produce its own face shields for emergency responders to fight the pandemic.
Chief executive Tim Cook said it also designed its own transparent protective visor and began mass production at its factories in the US and China.
Last week, Apple revealed that it plans to sell them to the public soon and that it would sell shields at cost, meaning it won’t make a profit on them.
British chocolate giant Cadbury has also started making visors, in collaboration with engineering firm 3P Innovation to produce thousands of gadgets.
The visors are made using 3D printing technology, which is normally used to make chocolate sculptures at the Bournville chocolate factory.
Frontline NHS employees, including nurses treating coronavirus patients in intensive care, are told to wear visors.
Doctors are also instructed to wear shields during aerosol generating procedures, such as intubating a patient.
In ‘extremely scarce supply’, doctors are urged to reuse single-use visors. They should cover the forehead, reach below the chin and wrap around the face.
They need to be cleaned with a detergent – the same decontamination process used for every bit of PPE to be put on again.
Visors will break off with repeated cleaning, according to the guidelines, which state that they “ need to be refilled regularly. ”
Waitrose announced that it had ordered protective visors in late March, showing that staff could wear them at work if they wanted to stay safe.
Marks and Spencer followed suit weeks later, giving front-line workers plastic face shields to protect them from COVID-19.
And Co-op introduced visors earlier this month, giving thousands of employees the opportunity to wear the gadgets during their shift if they wanted to.
It comes after a survey last week that men are less likely to wear face masks than women because they are perceived as “not cool” and “a sign of weakness.”
Experts surveyed nearly 2,500 American adults, and found that men previously viewed face masks as “embarrassing” and were put off by the alleged stigma.
Eight percent of men and five percent of women said they would certainly not wear a face mask if they were outdoors.