Whoa! Study says it’s way easier to pass on the flu than you thought

Ever wonder why the flu spreads like wildfire at your house? It's because even just breathing can pass flu germs from one person to another. So all the disinfecting in the world won't keep you safe.

Though experts used to think that you had to come into contact with an influenza-contaminated surface or with droplets from an infected person's sneeze or cough (ick!) to get the flu, a new study from researchers at the University of Maryland suggests that simply sharing the same air as a flu sufferer can transmit the virus.

The study, which was published in Proceedings of the National Academy of Sciences, looked at the breath of 142 people with confirmed cases of influenza on the first, second and third days of their illness, and it found all kinds of infectious cells within their exhaled air. In 35 percent of the breath samples they took, the researchers found the infectious form of the virus. Interestingly, sneezing didn't seem to transmit the virus any more than breathing. 

"People with flu generate infectious aerosols (tiny droplets that stay suspended in the air for a long time) even when they are not coughing, and especially during the first days of illness," explains the lead researcher, Donald Milton, professor of environmental health in the University of Maryland School of Public Health.

All of that is to say: When you have the flu, stay home from work! When your kids are sick, keep them home from school! Anyone they even breathe near could be infected. Even if the flu seems like just an annoyance (albeit a rather gross one) to you, it can be life-threatening to small children, the elderly and those with pre-existing respiratory conditions or compromised immune systems. In other words, quarantining yourself at home is basically a public service.

Of course, keeping surfaces clean and washing your hands (and your kids') is still important, but actually staying away from other people at the first sign of a fever, body aches, coughing, vomiting or diarrhea is the best way to stop the spread. And don't forget your that your best defence against the flu is the flu shot.

The study's authors hope that this new information might be used to develop better public health interventions and perhaps inspire improvements in ventilation systems in offices, schools and subway cars to reduce the transmission of the virus. And, of course, they hope that we'll all get the message and take a sick day.

Read more:
Why everyone should get the flu shot—even babies and pregnant women
Getting the flu shot cuts your kid's risk of dying of influenza in half