New app tracks travel-related illnesses

Travelers sometimes take more than just souvenirs when they go abroad. Unfortunately, they can also experience health problems caused by pathogens. Data collected by a new travel app developed by UZH researchers in cooperation with the World Health Organization (WHO) now shows that this happens remarkably often.

The app is not only useful for travelers, but can also help track outbreaks and the spread of infectious diseases such as dengue or new flu viruses. The results are published in the journal BMJ open.

“Travelers are a great reflection of what is happening in the world,” says Patricia Schlagenhauf, head of the study from the Institute of Epidemiology, Biostatistics and Prevention at UZH. “They also often play a role in introducing pathogens to different regions of the world.” As an example, she cites the recent case of mpox in Sweden, imported by a traveler returning from Africa.

Track the spread of infections

The Illness Tracking in Travelers (ITIT) app allows people on the move to report their daily symptoms by completing a short, user-friendly questionnaire. This information is then linked to location data as well as climate and air quality information.

The research team has now analyzed data collected via the app between April 2022 and July 2023. The analysis covered 470 trips recorded by 609 people across all continents. Travelers get sick surprisingly often during their trips, with health problems occurring in more than a third of trips.

Gastrointestinal symptoms top the list

The most common health concerns were gastrointestinal symptoms, reported in 19% of trips and most commonly among travelers to Asia. On the other hand, these symptoms are less common among people traveling to Africa.

Significantly more women than men reported symptoms of diarrhea. It is possible that women are more sensitive to diarrhea or are more conscientious when recording symptom information in the app.

In contrast, respiratory illnesses (17%) such as colds were most common among travelers to Europe. “Remember that you should carry a first aid kit even when traveling to supposedly low-risk countries like France or Greece,” says Schlagenhauf.

She recommends travelers bring medicine to treat diarrhea, nausea, headache and fever, because these are the health conditions that limit people the most when traveling, according to the study.

Healthy and safe travel

The research team now wants to invite even more people to use the app. Larger datasets would allow researchers to carry out automated analyzes using artificial intelligence, which could, for example, be used to detect dengue or mpox outbreaks at an early stage.

“This bottom-up, real-time approach is much faster than top-down reporting systems,” says Schlagenhauf. Even in well-organized government agencies like the Federal Office of Public Health, it often takes months for case figures to become available.

“Mobile technologies offer a revolutionary solution for tracking travel-related illnesses. This will make our travels safer and healthier.”