When you get a flu — or any other virus — those closest to you are in peril. You're one big walking, germ-infested petri dish, ready to spread your sickness to others.

And that's an opportunity Dr. Don Milton just can't turn down.

Milton, a professor in the University of Maryland School of Public Health, is so intrigued by the mechanics of virus transmission that he runs the aptly named Gesundheit machine. The machine is just one part of his "C.A.T.C.H. (Characterizing And Tracking College Health) the Virus" research, which boasts the memorable catchphrase, "Snot your average research study."

"We are studying what makes people infected with influenza and other respiratory viruses contagious, so we can prevent the spread of disease," Milton tells MNN. "We are looking at biomarkers in blood that can reveal if someone is about to become contagious or may be more likely to pass a virus to others than someone else."

Students don't have to be sick to initially enroll in the study. But if and when they start feeling puny, they go in for the first round of testing. If they have the "right" combination of symptoms, including a temperature, they're invited to give blood samples, nose and throat swabs, and even a swab of their cellphone. But the interesting part is the G-II, or the Gesundheit machine.

The volunteers step into a booth with zip-up vinyl sides and breathe into a reverse megaphone-shaped contraption that collects their breath for about 30 minutes. (Claustrophobics probably need not apply.)

"The G-II captures the breath exhaled by a sick person and from that, we are able to analyze the sample to see how much virus is being shed in the fine particles that come from their lungs. A recent paper we published ... provided evidence that people with flu who we tested in the G-II shed a lot of virus into the air around them just by breathing."

It's you, and your 4 best buds

A student volunteer is engulfed in the Gesundheit machine. A student volunteer is engulfed in the Gesundheit machine. (Photo: University of Maryland School of Public Health)

To see how the virus is spread, volunteers also give researchers information about their four closest contacts. The researchers then chart those people's sickness quotient, checking nose and throat swabs and collecting blood samples over the next week. They're basically trying to figure out what your sickness does to those closest to you.

"We are identifying what makes someone contagious and biomarkers that can predict who is about to become contagious," Milton says. "So, we want to determine as best as we can from whom someone caught the virus they are infected with to identify who among our cases was contagious and who was not. We are using genomic deep sequencing to confirm if a person who gets sick caught it from one of their close contacts or from someone else."

For students willing to breathe deeply into the odd Gesundheit machine and hand over their closest friends, there's also monetary compensation.

The amount depends on the type of visit and whether blood is drawn. Volunteers can receive more than $300 for participating. They can also get paid for downloading the smartphone app and completing online questionnaires.

Although students may enjoy the financial perks of the experience, Milton and his undergraduate research assistants have a much bigger goal in mind.

"We are hoping to provide more information that will help us prevent the spread of acute respiratory diseases," Milton says, explaining that the researchers are taking two approaches.

"First, we are trying to detect biomarkers in blood that predict who will infect other people so that individuals can be targeted for high priority treatment or other intervention. Second, by understanding better how much virus individuals eject into the air around them or onto surfaces, how building ventilation and air quality influences contagiousness or if stress and health habits play a role in illness susceptibility, we can make recommendations to limit the spread of disease. This could be in the form of better ventilation and filtration technology for dorms, offices and other confined spaces (transportation for example) so that we don’t transmit influenza or other viruses."

Mary Jo DiLonardo writes about everything from health to parenting — and anything that helps explain why her dog does what he does.

The Gesundheit machine wants your flu germs
Dr. Don Milton's Gesundheit machine collects the breath exhaled by a sick person so researchers can study how viruses are spread.