Americans have to tighten or double their masks, the CDC says

Federal health officials on Wednesday urged Americans to leave the mask on and take steps to make the mask fit better, or to layer a cloth over the surgical mask. A new study said masks were shown to significantly reduce the spread of coronavirus.

Recent laboratory experiments have shown that viral infections can be reduced by 96.5% when Americans wear a snug surgical mask or a combination of cloth and surgical mask. In publishing the findings, Dr. Rochelle P. Warrensky, director of the Centers for Disease Control and Prevention, begged Americans to wear “appropriate masks.”

“It’s not time to roll back the mask requirements, as cases, hospitalizations and deaths are still so high,” she said. “This is what matters. The mask works, fits well, and works when worn correctly.”

Masking is currently required for federal assets and domestic and international shipping. “All masks are excellent,” said Dr. John T. Brooks, CDC’s chief medical officer and lead author of the CDC, in a study conducted at a home in Beijing, a beauty salon in Missouri, and an aircraft carrier in Guam. It states. A new study by the agency on masking.

“Wearing a mask reduces spread and reduces new infections in the mask-wearing community,” said Dr. Brooks.

However, while the mask reduces respiratory droplets and aerosols exhaled by the infected wearer and protects the uninfected wearer, air leaks around the edges of the mask can reduce its effectiveness. .. The institution’s new laboratory experiments have shown how to solve the problem.

One option is to wear a cloth mask over the surgical mask. Another option is to fit the surgical mask tighter on the face. “Knot and push” — That is, tie the two strands of the ear loop and attach them to the end of the mask. Then fold the excess cloth flat at the edge of the mask and push it in for a tight seal.

The agency’s experiments relied on three layers of surgical masks and cloth masks, and only one type of each mask was tested. No other combination has been tested, such as doubling the cloth mask, wearing two surgical masks, or layering the surgical mask on top of the cloth mask.

Advice arrives even when the state has begun to lift measures aimed at delaying the transmission of the virus. Approximately 30 states have masking requirements, but Iowa completed its mission on Monday and joined the Mississippi River and North Dakota a few months ago.

The state is rushing to reopen its businesses and schools. For example, New York Governor Andrew Cuomo announced on Wednesday that fans could return to stadiums and arenas for sporting events and concerts. New York City will allow 25% capacity to resume indoor dining on Friday.

It surged in the United States in November, and the still high virus-related deaths appear to be steadily declining.New cases and hospitalization Started to fall last month..

However, the CDC warns that new variants can spike infections if Americans are vigilant, even if the number of cases decreases.The first case of a more contagious viral variant found in the United Kingdom Doubles in the US about every 10 days.. CDC Warning last month It could become the dominant variant nationwide by March.

Dr. William Schaffner, an infectious disease specialist at Vanderbilt University, said he “wants to control this” until the majority of adults are vaccinated. Masks are an effective and easy way to avoid another catastrophic “roller coaster”.

“The less chance this virus has to propagate, the less likely it is to mutate and to acquire new variants,” says Dr. Schaffner.

Dr. Monica Gandhi, an infectious disease specialist at the University of California, San Francisco, is a co-author of the following treatise: Make the mask more effective That was the impetus for new research at the CDC.

“We want to do our best to weaken the transmission, using all the factors such as masking, distance, hand hygiene and ventilation,” she said. “If you reduce infection and at the same time mass vaccination, the virus has no chance to evade the vaccine.”

The CDC has outlined some additional options to improve the effectiveness of the mask, such as using a mask fitter (a frame that outlines the face) on top of the mask. Recent studies show that fitters can increase protection against viral aerosols by more than 90%.

Surprisingly, the agency probably suggested that people consider wearing thin nylon sock material sleeves around their necks and pulling them over a cloth or surgical mask.

The CDC recommendations were based in part on ideas explicitly stated by Dr. Gandhi and Linsey Marr, Virginia Tech Aerosol Transmission Experts. They also have a surgical mask covered with a tight-fitting cloth mask, or a three-layer cloth mask consisting of two outer layers of tightly woven cloth that hugs the face and an intermediate layer of filter material such as vacuum bag material. Is recommended.

Both tight fit and filtration are important, Dr. Ma said. A good fit is essential even with the types of N95 breathing masks used by healthcare professionals.

More and more Americans say they support wearing masks, but resistance continues in some circles and in some areas. Dr. Ma said he hopes the CDC’s new advice will receive some ridicule.

“The register is sure to say,’What’s next? Three masks? Four masks?'” Dr. Ma said. “But there is a lot of interest from people who want to know how good a mask is and how it can be made better. People want the best possible protection.”

CDC experiments simulated the production of aerosols from cough and estimated their absorption. The knotless surgical mask blocked 42% of the particles and only the cloth mask blocked 44.3%, while the combination of surgical mask and cloth mask blocked 92.5% of the coughing particles, Dr. Brooks said. His colleague discovered.

Exposure to receivers was reduced by 96.4% and 95.9% when mask combinations or knotted surgical masks were attached to both the aerosol source and the exposed foam.

Dr. Brooks said neither of the two methods, in which knots and indentations reduce the surface of the mask and may be suitable for people with small faces, was perfect.

Similarly, the combination of cloth and surgical mask works well, but the mask becomes thicker and can make it difficult for some people to breathe. Additional layers can also interfere with peripheral vision and increase the risk of tripping or falling.

Breathability is also important, Dr. Ma said. “Too many things that make breathing difficult can be counterproductive. Air is more likely to leak through the gap,” she said.

Dr. Brooks emphasized that masking is not “insufficient,” as Americans are now practicing it. But the new advice does provide “an opportunity to take it to the next level.”

“Now I’m worried about the form of the virus that can infect more efficiently and undermine the usefulness of existing diagnoses, treatments and vaccines,” he added. “To slow down the virus and slow it down, we need to enhance the game.”

Cheryl Geystorberg contributed to the report from Washington.