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Do face masks really protect against coronavirus?

Do face masks protect against coronavirus?

As cases of coronavirus rise, some people are doing what they can to try to protect themselves against the potentially deadly virus. The World Health Organization declared the outbreak a global health emergency on Thursday. 

The face mask industry is booming amid concerns about the outbreak, leading one surgical mask manufacturer to run out of its stock of masks in China; it has been working overtime to meet demand from worried Chinese citizens who were urged to wear masks in public.

But the U.S. Centers for Disease Control and Prevention says there is no reason for most people to wear masks. Updated guidance on the CDC's website says: "Do not use facemasks. CDC does not recommend the use of facemasks for the general public to prevent the spread of 2019-nCoV [coronavirus]." 

The health agency only recommends face masks for people who are sick with the virus or believe they may be infected, and for people who live with or care for them when they're in the same room. 

At a news conference January 28, Heath and Human Services Secretary Alex Azar said wearing a face mask is unnecessary for most people.

"In the United States, the risk to any individual American is extremely low," Azar said.

Dr. Frank Esper, a pediatric infectious disease specialist at the Cleveland Clinic, explained the circumstances when some really sick people should wear a mask.

"If they are coughing, if they are feeling like they have symptoms, we do ask them to put on mask when they are coming to our waiting room or ER or into a public space," he said. "It helps prevent the spread of infection."

Coronavirus: do masks help prevent the spread?
Passengers wear face masks to protect against the spread of the coronavirus as they arrive on a flight from Asia the Los Angeles International Airport on January 29, 2020. Getty

Esper and other experts say washing your hands frequently is the best way to prevent the spread of infectious illnesses like coronavirus or, more commonly, the flu. The CDC advises washing your hands often with soap and water for at least 20 seconds, or use an alcohol-based hand sanitizer that contains at least 60% alcohol if soap and water are not available.

You should also avoid touching your eyes, nose, and mouth with unwashed hands, avoid contact with sick people, cover your mouth when you cough and sneeze, and disinfect objects and surfaces frequently, the CDC says.

So far, the coronavirus has sickened thousands of people, mostly in China, and spread to more than 20 countries around the world. 

There are only a handful of confirmed cases in the U.S., including two instances of person-to-person spread. Hundreds of people, including some who recently traveled to Wuhan, China, where the outbreak began, are being tested or monitored after possible exposure.

Health officials are concerned the rapid spread of the virus could mimic the outbreak of the SARS virus (Severe Acute Respiratory Syndrome) in the early 2000's, during which many people also wore masks for protection.

Following the SARS outbreak, which also originated in China, researchers in Australia wanted to test data that suggested transmission of the viral respiratory infection was significantly reduced with the use of face masks as well as other infection control measures.

The study, published in the International Journal of Infectious Diseases in 2008, found that masks were 80% effecting in protecting against clinical influenza-like illness when worn consistently. There wasn't much difference between the two types of masks tested — P2 masks and surgical masks — according to the study. However, the researchers also noted that "compliance with mask use was less than 50%," meaning half the people in the study did not actually keep wearing them as directed.

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