As this year’s flu season ramps up to be one of the most intense in years, avoiding this wily virus has become increasingly important.

Latest development: An ambitious team of researchers has found that it’s easier to catch the flu than previously thought—and that hand washing and avoiding others’ sneezes and coughs isn’t enough.

Background: People often don’t take the flu as seriously as they should, even though the virus causes intense illness and tens of thousands of deaths annually.

One redeeming quality of the virus, it has been thought, is that although it is definitely contagious, it’s not as easy to catch as something like, say, measles, which is exceptionally contagious. Most experts believed that people who got the flu were mainly infected by touching surfaces contaminated with the virus or from exposure to airborne droplets expelled by coughs and sneezes.

Recent finding: A new study, published in the Proceedings of the National Academy of Sciences, upends that thinking. Donald Milton, MD, DrPH, lead author of the study and professor of environmental health at  University of Maryland School of Public Health, College Park, noted that people with flu “contaminated the air around them with infectious virus just by breathing, without coughing or sneezing.”

Study details: The research team recruited volunteers with confirmed cases of influenza. The volunteers sat for a half-hour in front of a machine known as Gesundheit II, which captured the particles that were expelled when they talked, coughed or sneezed—or merely breathed.

What the study found: Flu patients who were merely breathing expelled large volumes of infectious aerosols, tiny droplets loaded with viruses that are light enough to hover in the air—and potentially infect the next person who shares the same air space.

Bottom line: According to Dr. Milton’s research, expert recommendations for preventing flu don’t go far enough. If you happen to be near someone who has the flu—and that person is breathing—you’re at risk of getting the illness.

WHAT ABOUT A FACE MASK?

The CDC’s flu-prevention advice focuses on getting a flu shot (considered the most effective way to prevent flu)…and washing your hands frequently. Along with that, you need to avoid touching your eyes, nose and mouth—the areas in which germs enter the body.

Hand washing is particularly important (if often overlooked) after shaking hands or touching likely sources of contamination such as handrails, credit card readers, ATM pads and doorknobs, says Miryam Z. Wahrman, PhD, a professor of biology at William Paterson University in Wayne, New Jersey, and the author of The Hand Book: Surviving in a Germ-Filled World.

But Professor Wahrman advises people to take one extra step—one that doctors themselves do routinely. “Face masks can definitely help,” she says. “If you have someone at home with the flu, you might want to protect yourself by asking him/her to don a mask…or wear one yourself. It doesn’t seem like a friendly thing to do, but you want to be safe.”

So if you’re the flu sufferer or caregiver, how long should you mask up? According to the CDC, the flu can be transmitted from about one day before symptoms appear and for five to seven days after getting ill. Flu may be contagious even longer in children. You can keep those facts in mind, but also use your judgment to decide how much contact you want to have, for example, with someone who has the flu in your household.

The surgical-style face masks sold in drugstores don’t provide a perfect, germ-proof barrier. For that, you’d need to wear a respirator and a whole-body suit. But the drugstore masks—as long as they fit snugly and cover the nose as well as the mouth and chin—will block at least some infectious viruses.

In Asian countries, people commonly wear surgical masks when they leave the house. It’s an accepted practice that doesn’t draw a second glance. In the US, you’ll get some funny looks…but that’s better than spending a flu-wracked week or two in bed. “When you’re on the subway or in close contact with a lot of people, wearing a face mask makes sense,” says Dr. Wahrman.

To use a face mask properly: In addition to making sure that your mouth, nose and chin are covered, you should place the white side of the mask against your face, and the metallic strip should be bent and molded to your nose. Change the mask at least once a day, and wash your hands with soap and water after handling and disposing of a used mask.

Following all the steps above will give you the best possible odds of staying well this flu season!