A study in the Proceedings of the National Academy of Sciences recently published a stunning finding: People with the flu could contaminate the air around them simply by breathing.
That’s right: You might have thought that sneezing into the crook of your arm and coughing away from other humans might help. But research indicates that that’s not the case. More importantly, it proves this: We still don’t quite understand how the flu works.
The team’s findings come from swabbing and collecting the breath samples of 142 volunteers using the Gesundheit 2, a cone-shaped machine that people breathe into for 30 minutes, to figure out how much of the infectious agent they’re shedding into the air.
After a few visits from these participants, one thing was clear: You don’t have to cough to spread the flu.
“People who are coughing are shedding a lot of virus, but people who aren’t coughing aren’t necessarily shedding nothing—they’re still shedding virus and it’s still infectious,” Donald Milton, a professor of environmental health at the University of Maryland, College Park and co-author of the study, told The Daily Beast.
The influenza virus is viciously rampant across the U.S. this year, with more than 160,000 people being diagnosed since October. During the week of February 11, the Centers for Disease Control and Prevention reported that 39 states were experiencing high influenza-like illness activity.
The CDC’s website, for its part, recommends what you’ve probably heard ad nauseum through every flu season: Stay away from sick people, keep your hands off your eyes, nose and mouth, and get the yearly flu vaccine.
But unless you wrap yourself in a giant bubble for the remainder of the season, it’s increasingly clear that there’s really no completely failsafe technique—not even the vaccine. While vaccines should certainly not be avoided, the CDC reported that so far this season the H3N2 viruses have been most common, a strain that flu vaccines don’t combat quite as effectively as some of the others.
In fact, at a time when we can treat cancer using a patients’ own cells and use digital drugs for mental illness, there’s still an awful lot we don’t know about how respiratory viruses are transmitted and how to keep people healthy.
Milton said that people ask him all the time about how to keep from getting the flu. Should I wash my hands constantly? Should I wear a mask when I’m out in public? Should I keep my distance from people coughing or sneezing?
“The problem is that there isn’t very good data to suggest that any of these things make a huge difference,” he said.
But Milton and his colleagues at the University of Maryland are trying to find out what will. Along with his team, Milton is studying some of the 270 freshmen college students that just happen to live within 100 yards of their clinic.
When one of these students get’s sick, the researchers take swabs to determine what virus they have, looking specifically for influenza, adenovirus, RSV and coronavirus, and have them fill out a questionnaire about everything from their sleep habits to their stress level. Another aid: the Gesundheit 2 machine, measuring breath droplets to see how else the influenza is passed without sneezing and coughing.
The team also takes swabs and blood for an entire week from four of the people these students spend a lot of time with, and track their interactions and face-to-face contact using a university-created phone app.
Milton said their plan is to take all of this information, along with an analysis of everyone’s virus, and put it into a computer program. The program will analyze this giant data set to figure out the important factors influencing how people get the flu. Whether it has to do with the amount of virus an individual sheds into the air or the building they live in, Milton said this information will help them put a stop to (or at least drastically curb) the spread of the flu.
“I think we’re going to learn a lot about how things are moving through populations and hopefully help develop some better models for building design and how we treat patients who are sick,” Jennifer German, the project’s student engagement coordinator, said.
The team is making some progress, though they’ve had some interruptions. They started working with students at the end of last semester, paused for winter break, and then returned the week of January 22. But with the help of some monetary compensation—including $100 for students who stop by after getting sick—they’ve already had more than a dozen students come to the lab with flu-like symptoms and many more fill out the survey and download the tracking app, German said.
The researchers hope to figure out how influenza travels. As they write in their study in PNAS: "Sneezing was rare, and sneezing and coughing were not necessary for infectious aerosol generation. Our observations suggest that influenza infection in the upper and lower airways are compartmentalized and independent." In other words, the flu is a lot more sinister in its mode of travel than we think.
Milton called the previous findings a huge accomplishment, and said their current research work will build on this published discovery, further unlocking the secrets to influenza’s sometimes-deadly power. One thing is for certain, though: It’s a lot more complicated than covering your mouth when you sneeze.