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Just Curious

What Do Surgical Masks Really Protect Against?

By Joe Sugarman
Lisa Maragakis is senior director of Healthcare Epidemiology and Infection Control for the Johns Hopkins Health System and director of the Department of Hospital Epidemiology and Infection Control for Johns Hopkins Hospital.

Surgical masks have been part of a doctor’s wardrobe since the 1890s when French surgeon Paul Berger covered his mouth, nose, and prodigious mustache with a mask fashioned from six layers of gauze and secured it around the back of his head. But how effective are they?

“Have you ever seen slow-motion video or a photograph of someone sneezing?” asks epidemiologist Lisa Maragakis. “It’s really disgusting. The droplets go about 6 feet in the air and then start to fall.”

Surgical masks are designed to offer two-way protection, according to Maragakis: They provide a physical barrier for a health care worker’s nose and mouth from bacteria or virus-containing fluids expelled by a patient, and they safeguard the patient from fluids let out by the provider.

That 6 foot number is key when it comes to setting safeguards for wearing masks at a hospital like Johns Hopkins. Policy dictates that if a health care provider is within 2 yards of a “droplet precaution patient” —i.e., someone with an infectious disease—he or she must wear a mask, a small-particle filtering respirator, and eye protection.

Ensuring such safety measures falls under Maragakis’ role as senior director of Healthcare Epidemiology and Infection Control at the hospital. Maragakis and her staff are responsible for establishing—and monitoring—the hospital’s dress code, including in the operating room, where all personnel must wear surgical face masks, hair covers, and, if necessary, beard hoods. “We all shed small bits of skin and hair all the time, and that’s not something you want going into a wound,” she says.

Maragakis notes, however, that wearing surgical masks in the operating room is not without controversy. Despite masks being more than 100 years old, there remains a surprising lack of empirical evidence to prove their efficacy, and she says in Europe and other countries some doctors choose to forgo them. The few studies that have been done showed that wearing surgical masks had virtually no bearing on patient outcomes when surgeries were performed by healthy doctors in sanitary operating rooms.

Still, picturing a surgeon without a mask is like imagining a fireman without a helmet. “There are some things that we do that seem to be common sense, even if we don’t have a lot of randomized controlled data showing they actually play a significant role in preventing infections,” says Maragakis.

Berger would surely feel right at home sporting today’s surgical mask in the OR. The masks are constructed of several layers of cotton or synthetic fibers instead of gauze, but the general design hasn’t radically changed since he donned the first in an operating room more than a century ago.

Illustration of a girl wearing a surgical mask
Illustration by Mark Allen Miller

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