Oh, you feel like coughing or sneezing? "Cover your mouth!" they say so that you won't spread the virus. But what if I tell you that you can spread the flu just by breathing? Mind. Blown.
“People shed a lot of virus all the time, even when they don’t cough,” says Donald Milton, author of the study published in PNAS and a professor of environmental health at the University of Maryland School of Public Health. “As a result, it’s important to realize you can be infectious at any time.”
Milton and his team studied 142 University of Maryland students with active influenza in 2012-2013. They wanted to know how and when are virus particles expelled. They asked each student to sit in a machine to measure the droplets they shed while breathing, talking, coughing or sneezing.
Results showed that almost half of the aerosol particles collected in the absence of coughing still contains flu matter. This means that when you breathe in germ-ridden air, you're already vulnerable to such sickness. Moreover, men showed to shed more flu virus per cough than women. Also, the higher you body mass index, the more viral particles you expel.
“If that person next to you looks really sick, even if they’re not coughing, they can probably infect you,” Milton says. “The take-home message is to stay away from other people when you’re sick with flu-like symptoms, even if you’re not coughing,” he says. Unfortunately, even the flu mask may not help as previous research showed that flu masks do little to stop certain fine particles.
“There’s not much evidence that any of that works very well,” he says. “Surgical masks block mostly the large droplet spray, but the surgical masks don’t block the fine particle aerosols very well. The route of infection matters.”
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