GeoSentinel Sites participate in surveillance and monitoring of all travel related illnesses seen in their clinics.  Aggregation of this data across the network of 54 globally dispersed medicine clinics on all continents (17 in the United States and 37 in other countries) allows linking of final diagnoses in migrating populations with similar geographic exposures.  In addition to formal surveillance, GeoSentinel sites also participate in enhanced surveillance and networking with public health partners.

GeoSentinel Network Members are ISTM provider clinics that informally provide leads and contacts when they encounter any patient having a pre-defined alarming diagnosis or unusual event.  Network Members also participate in brief e-mail queries for enhanced surveillance and response in potential outbreak situations.  This program allows large numbers of individual members in many countries to be rapidly linked together to share clinical observations and facilitates direct interaction with health authorities.