Targeted text messages alert travelers to infectious disease threats

Young woman sitting using phone on the aircraft seat wearing face mask

You step off a plane into an airport terminal, and a text message buzzes your smartphone. It’s a CDC Travel Health Alert Notice (T-HAN) informing you about a new faster-spreading variant of COVID-19 in the country you just visited. The T-HAN recommends that you monitor yourself for symptoms and gives you recommendations on how to protect yourself and others.

NCEZID is working on a system that sends T-HANs like this one to international travelers when they enter the United States at designated locations. The location is determined by a geofence, an invisible border drawn by wireless technology. A geofence can encircle an airport or just a gate to send targeted messages to people coming from countries at risk for specific diseases. Currently, T-HANs are distributed in print, but a digital system could reach more people with tailored information. Updating digital alerts would be much faster and more effective than reprinting and distributing paper versions. Quickly updating T-HANs is particularly important in rapidly evolving outbreaks like COVID-19 when public health guidance can change frequently with growing knowledge and spread of the disease. CDC previously ran small tests of geofence-triggered alerts during the Zika response and early on in the COVID-19 pandemic.