Travel Healthy, a mobile app for participatory surveillance among U.S. international travelers

Global travel plays a role in the spread of infectious diseases. Existing travel surveillance programs collect data before and after trips, resulting in data incompleteness and recall bias. We developed the Travel Healthy mobile app to address these gaps, by enabling U.S. travelers to report daily symptom surveys including GPS location. The app offers traveler tools, including outbreak notices, a travel wallet, and a malaria medication reminder.

We developed Travel Healthy following a user-centric approach. We recruited study participants through an online platform and at the Travelers' Advice and Immunization Center at Massachusetts General Hospital, between July 2023 and August 2024. We analyzed demographic, GPS, and self-reported symptom data from the first 50 participants. Data were collected starting one day before the trip and ending three days after. A post-travel feedback survey was performed.

Participants visited 204 locations in Asia, Africa, the Americas, and Europe. Mean age was 33 years and 66 % were female. The most common purposes of travel were leisure and/or business, with 46 (92 %) of participants listing these as traveling reasons. A total of 755 daily symptom surveys were entered, with 105 reporting symptoms, corresponding to 29 of the 50 (58 %) participants. Among all symptoms with GPS data, 58 % were upper respiratory symptoms, 25 % were gastrointestinal (clustered in South Asia), and 17 % were other. Post-travel questionnaires showed that participants found the application easy to use.

This pilot study underscores the potential of participatory surveillance tools to complement traditional public health surveillance methods for travel-related illness.