Tight-fit masks or double masking with cloth and surgical masks increases protection, CDC says

TWO MASKS & KNOTTING – The CDC urges wearing two masks – a cloth mask worn over a surgical mask, or if using one mask, knotting the ear loops (picture at right) that tightens the gaps around the mask’s edges.

Wearing a mask — any mask — reduces the risk of infection with the coronavirus, but wearing a more tightly fitted surgical mask, or layering a cloth mask atop a surgical mask, can vastly increase protections to the wearer and others, the Centers for Disease Control and Prevention reports.

New research by the agency shows that transmission of the virus can be reduced by up to 96.5 percent if both an infected individual and an uninfected individual wear tightly fitted surgical masks or a cloth-and-surgical-mask combination.

Dr. Rochelle P. Walensky, director of the CDC, announced the findings last week during a White House coronavirus briefing, and coupled them with a plea for Americans to wear “a well-fitting mask” that has two or more layers.

Walensky said masks are especially crucial given the concern about new variants circulating.

“With cases, hospitalizations and deaths still very high, now is not the time to roll back mask requirements,” she said, adding, “The bottom line is this: masks work, and they work when they have a good fit and are worn correctly.”

Virus-related deaths, which resurged sharply in the United States in November and still remain high, appear to be in a steady decline; new virus cases and hospitalizations began to drop last month. But researchers warn that a more contagious virus variant first found in Britain is doubling roughly every 10 days in the United States. The CDC cautioned last month that it could become the dominant variant in the nation by March.

As of Feb. 1, 14 states and the District of Columbia had implemented universal masking mandates; masking is now mandatory on federal property and on domestic and international transportation. But while masks are known to both reduce respiratory droplets and aerosols exhaled by infected wearers and to protect the uninfected wearer, their effectiveness varies widely because of air leaking around the edges of the mask.

“Any mask is better than none,” said Dr. John Brooks, lead author of the new CDC study. “There are substantial and compelling data that wearing a mask reduces spread, and in communities that adopt mask wearing, new infections go down.”

One option for reducing transmission is to wear a cloth mask over a surgical mask, the agency said. The alternative is to fit the surgical mask more tightly on the face by “knotting and tucking” — that is, knotting the two strands of the ear loops together where they attach to the edge of the mask, then folding and flattening the extra fabric at the mask’s edge and tucking it in for a tighter seal.

Brooks cautioned that the new study was based on laboratory experiments, and it’s unclear how these masking recommendations will perform in the real world (the experiments used three-ply surgical and cloth masks).“But it’s very clear evidence that the more of us who wear masks and the better the mask fits, the more each of us benefit individually.”

Other effective options that improve the fit include using a mask-fitter — a frame contoured to the face — over a mask, or wearing a sleeve of sheer nylon hosiery material around the neck and pulled up over a cloth or surgical mask, the CDC said.

Even as vaccines are being slowly rolled out across the country, the emergence of the new variants, which may respond differently to treatments or dodge the immune system to some degree, has prompted public health officials to emphasize that Americans should continue to take protective measures like masking.

(Edited and reprinted from the New York Times.)

Tips for improving mask fit and comfort

Here’s a quick reference on latest information on the use of masks from the Centers for Disease Control and Prevention (CDC):

• Double masking – wearing a cloth mask over a disposable surgical mask. However, the quality of the mask is the most important issue. A thin cloth mask does not provide the level of filter protection that a multi-layered mask does.

Knotting – improving the fit of a single surgical mask by knotting the ear loops and tucking in the sides close to the face to prevent air from leaking out around the edges and to form a closer fit.

Both methods reduced exposure to potentially infectious aerosols by more than 95 percent in a laboratory experiment using dummies, the CDC reports.

On the comfort side, Hana Akselrod, an infectious-disease physician at George Washington University, recommends wearing a surgical mask with ear loops, and on top of that a cloth mask that ties behind your head. Although the surgical mask has ear loops, a cloth mask with ties in the back will take pressure off of your ears and may fit better than a mask with ear loops.

(Information from the Washington Post and the CDC.)

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