Flu virus can be spread by simply breathing
DEAR DOCTOR: How does the flu virus spread? I’ve always thought it was mostly from coughing, which contaminates the air and the surfaces we touch. But now I’ve heard that people who are sick actually breathe the virus out.
DEAR READER: One of the more challenging points to get across regarding the flu has been just how contagious a sufferer is and how early into a bout of the illness that contagion begins. Now comes research that makes understanding (and acting on) this information all the more crucial.
You’re correct that the assumption has been that it’s by coughing that we pump aerosolized droplets of moisture, which contain the flu virus, into the air and onto the surfaces around us. We’ve known for some time that these droplets can hang in the air for up to several hours and can live on hard surfaces for several days. But the results of a recently published study by scientists at the University of Maryland’s School of Public Health show that by simply breathing, a person who is sick with the flu is exhaling the virus.
An earlier study from the University of Hong Kong concluded that half of flu infections within households are passed
along via aerosolized droplets. The study also looked into whether wearing a surgical mask would prevent infection. The answer echoes the findings of several similar studies: Basically, no. Though masks may slightly reduce risk by screening out the largest droplets, they are not effective against the fine aerosolized mist from the breath. According to the Centers for Disease Control and Prevention, the people who really should be wearing facial masks are individuals who are ill.
But the main advice is what physicians have been giving — and patients have been ignoring — for generations:
Stay home when you’re sick.
Not only do you really and truly need to rest in order to give your body the best shot at recovering from influenza, but venturing forth while you’re actively ill puts everyone around you at risk.
Elizabeth Ko, M.D., is an internist and primary care physician at UCLA Health.
Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA 90095.