Travelers as a sentinel population: use of sentinel networks to inform pretravel and posttravel evaluation.

The establishment of collaborative sentinel surveillance networks specifically to monitor disease trends among travelers offers new options for evaluating travel health issues. These networks can inform pre- and posttravel patient management by providing complementary surveillance information, facilitating communication and collaboration between participating network sites, and enabling new analytical options for travel-related research. The two major multinational sentinel networks are TropNetEurop and GeoSentinel. Practical examples demonstrating their significant contributions to improved travel health information are discussed. Data obtained from studying health problems among travelers may also have significant benefits for local populations in resource-limited countries. However, there are limitations of data collected by sentinel networks, so they should be considered as complementary tools and not relied on as an exclusive basis for evaluating health risks among travelers.