Will a Face Mask Keep You From Getting Sick?

This week, the World Health Organization declared the Wuhan coronavirus an international public health emergency. But despite climbing numbers—more than 300 people have died, with about 17,00 infections confirmed—still little is known about the deadly virus.

While it's clear that it's transmissible between humans, experts aren't certain whether contact with the cough droplets of an infected person is required to pass it on, or if simply being in their presence is all it takes to contract it.

All this mystery (and fear) has caused people to start wearing cheap, disposable face masks to protect themselves from getting sick. In China, where the outbreak started, demand for protective face masks has caused pandemonium. Sales in the U.S. are also climbing.

But before you run out and buy medical face masks for the whole family, it's worth noting that experts aren't convinced that they are the most effective way for people to protect themselves against dangerous viruses and bacteria.

As HuffPost points out, there is some evidence that, when used correctly, face masks can slow the spread of airborne viruses. One study found that mask-wearers were 80% less likely to get the flu. Another found that, in conjunction with frequent hand-washing, face masks lowered the risk of contracting the flu by about 70%. Some infectious disease experts have also suggested that wearing a face mask may have some value simply because they can deter you from touching your face and nose, NPR reports.

But—and this is a huge but—they're not foolproof.

"Masks of any kind would be helpful because then they are covering up your nose and mouth so they aren't going to touch those, but they still leave your eyes open so you can touch and transmit the virus that way," Michael Ison, an infectious disease specialist with Northwestern Medicine, told HuffPost. "It can reduce the risk of some transmissions but doesn't take the risk to zero."

Fortunately, the risk of an coronavirus outbreak in the United States is still low. According to the CDC, unless you're traveling in and around China, there's currently no need to wear face masks.

"We generally do not recommend the use of either masks or respirators for the general public. Of course, persons who desire to be extra cautious about their exposure to germs when in public may choose to wear a mask," Richard Martinello, a Yale Medicine infectious disease specialist, told HuffPost.

Furthermore, the hoarding of face masks by those who do not exhibit respiratory symptoms could pose a risk for people who actually need them, like medical workers and individuals with compromised immune systems.

"Panic purchases of face masks in low-risk countries like the U.S. is not warranted. People who are well should refrain from hoarding masks 'just in case' they need it, as this may lead to a lack of masks in settings that really need it," Annelies Wilder-Smith, a professor of emerging infectious diseases at the London School of Hygiene and Tropical Medicine, told CNBC.

If you do feel the need to wear one, make sure you're wearing it right, that means snug over your nose with the correct side facing outward, the loops secured behind your ears, and with any gaps around your jawline sealed off.