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University Gazette

The University of North Carolina at Chapel Hill

Allison Aiello discusses her research on how the flu spreads

Focus Carolina is an exclusive program on WCHL where faculty members talk about their research and how it serves our community and the state, nation and world. The following transcript is from a recent Focus Carolina interview that aired on WCHL. To hear more interviews with Carolina faculty, visit

Flu season is here. Dr. Allison Aiello’s research helps us understand how the flu spreads and what social factors determine who gets the flu. Her research at the Gillings School of Global Public Health includes the use of smartphone apps and Bluetooth beacons to track interactions among colleagues in workplaces or among students at college. This information can then be used to make health recommendations.

Allison Aiello

We had a randomized intervention study where we asked individuals to, as soon as we saw the first case of influenza on campus at University of Michigan, to wear a mask and use hand sanitizer. The people who were wearing the mask and using hand sanitizer over the flu season had a significant reduction in their influenza-like illness symptoms, up to 50 percent. We were randomizing people to staying home when they were sick. As soon as an individual said that they had any influenza-like symptoms, whether they were feverish or coughing, we asked them to stay home from classes. And we asked them about all of the individuals that they contacted, who they interacted with before they became sick. And then who they interacted with when they were sick, so that we could see whether pulling them out of their social networks reduced the transmission of flu to their friends. 

Historically, this kind of research is usually collected by giving individuals a survey and asking them: how many people do you contact in the past day or the past week? And it’s notoriously difficult for people to remember that information.

We met with a colleague at the University of Saskatchewan, a computer scientist. I told him about our social network study, and he mentioned this neat app that they had developed to track individuals using smartphones. We got together with their computer science group and they helped us develop the app for our own application to track interactions between individuals. So when individuals have their smartphones and they came in contact with each other, their smartphones, running this app, would tell us whether they interacted. 

At that moment of interaction, the smartphone would provide a survey that asked about the context of that interaction: are you in the same room with your friend? And it would name your friend because apps were running and knew who was coming in contact with each other. Those kinds of questions could get at the context of those interactions. 

When we started to look at this smartphone app data and all of these interactions that we had between individuals, we were able to really visualize the extent of missing information we have on interactions, much more often than they are able to report on a survey. That was really important information for us, because if we really want to cut down on influenza in the community setting, then we need to truly understand the extent of interactions that people have in the community setting. I think the only real objective way to do this is through technology to gather that information that we can’t gather by asking someone to fill out
a form.

The study is valuable in providing information on other conditions as well, which led Dr. Aiello to Carolina. 

I had been fascinated by infectious diseases. I did an internship at Yale New Haven Hospital on a floor looking at vancomycin resistant and enterococcus infection among individuals with HIV in the clinical setting and how that was kind of moving through the hospital setting. And so I came to UNC to continue to study infectious diseases in the environmental setting, and I worked on laboratory methods for detecting certain types of parasites that people were infected with due to foodborne outbreaks and other waterborne outbreaks.

Dr. Aiello says it’s a struggle to get people to practice good hygiene, despite the preponderance of evidence to its benefits, sometimes
even at home.

I thought I’d be a lot more effective as a mom who studies hand hygiene at getting my children to do it, but it’s a daily struggle anyway.

Every day, Carolina faculty members engage in groundbreaking research, innovative teaching and public service that impacts in our community and the state, nation and the world.

Tune in to Focus Carolina during morning, noon and evening drive times and on the weekends to hear their stories and find out what ignites their passion for their work. You can listen to WCHL at 97.9 FM or 1360 AM. The interviews will also be available anytime online at under the Focus Carolina tab.

Focus Carolina is an exclusive program on WCHL, sponsored by the University.


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