GeoSentinel is a network of travel/tropical medicine clinics initiated in 1995 by the International Society of Travel Medicine (ISTM) and the Centers for Disease Control (CDC).  Surveillance of morbidity and mortality in travelers serves a number of purposes.  Firstly, it provides information to assist in the prevention of morbidity in travelers.  Secondly travelers can serve as sentinels for changes that affect the morbidity and mortality of local populations.  Thirdly, travelers can be a factor in the spread of diseases in their countries of origin.  GeoSentinel is based on the concept that these clinics are ideally situated to effectively detect geographic and temporal trends in morbidity among travelers, immigrants and refugees.  Clinics can be affiliated with GeoSentinel in one of two ways, as a GeoSentinel Site, or in a more informal manner as a GeoSentinel Network Member.

Objectives of GeoSentinel:

	Maintain an international communications and data collection network of travel medicine clinics on all continents (except Antarctica), including real-time web-conferencing capability.
	Track geographic and temporal trends in infectious diseases among travelers, immigrants, and refugees.
	Conduct syndromic surveillance that may herald pandemic influenza, return of SARS, or bio-terrorist events.
	Identify yet to be described emerging infectious diseases among international travelers.
	Response - Disseminate relevant information and suggested response options for new or acutely emerging infections, including potential bio-terrorism threats to the network of GeoSentinel providers, the larger network of ISTM providers, and to collaborating networks.

Current activities include:

	Surveillance: A two-tiered approach to surveillance is used.  Through GeoSentinel Sites, surveillance involves ongoing monitoring of sentinel data from globally dispersed sites that allows linking of travel-related infections with geographic destinations.  Through GeoSentinel Network Members, surveillance involves informal communication from participating clinics about unusual cases.
	Response Capabilities: These include urgent requests for enhanced surveillance and notification in outbreak situations as well as electronic dissemination of alerts using the network to assist in connections with appropriate local or national public health or health care groups.  Responses can involve GeoSentinel Sites, the larger number of GeoSentinel Network Members, 500 medical providers on the ISTM listserv (TravelMed), or 2000 ISTM providers in 65 countries.
	Development Of Partnerships: A major achievement of GeoSentinel has been the development of a continually expanding partnership among ISTM and the Centers for Disease Control and Prevention and health-care providers around the world.