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Chapter 1 Introduction

Travel Medicine Data Collection: GeoSentinel & Global TravEpiNet

Regina C. LaRocque, David O. Freedman, Mark J. Sotir

During the past 2 decades, the knowledge base of travel medicine has been enhanced by medical provider networks designed to systematically collect data about travelers. This chapter discusses 2 of these networks, GeoSentinel Surveillance Network and Global TravEpiNet, both of which involve active participation of travel and tropical medicine clinics. Whereas GeoSentinel collects data from ill patients seen at clinics primarily during and after travel, Global TravEpiNet focuses on optimizing medical advice and care before travel.


GeoSentinel, a global surveillance system of travelers and migrants, operates under a cooperative agreement between the International Society of Travel Medicine and CDC and receives data from 54 travel and tropical medicine clinics on 6 continents. GeoSentinel conducts provider-based surveillance of travel-related illnesses and injuries to detect and respond to sentinel events, document ongoing disease trends, and provide a repository of data for analyses to improve epidemiologic expertise in the field of travel medicine. In addition, to facilitate communication and reporting of atypical and noteworthy events within the travel medicine community, GeoSentinel maintains a network membership of >200 travel medicine practitioners worldwide.

GeoSentinel clinics use a standard online data collection template to relate a specific diagnosis to a place and time of exposure. Exposure, if determined, can be at the country level or locally if ascertainable. Ancillary information submitted in real time to the central database includes country of residence, history of recent and previous travel, reason for travel, presenting signs and symptoms, pre-travel medical consult, and whether the patient is a classic traveler, an immigrant, or an expatriate. Records are segregated by clinical setting, which includes during or after travel and inpatient or outpatient. Specific diagnosis codes are used, and several codes are designated as “alarming diagnoses” to prompt more immediate attention.

GeoSentinel initiated data collection in 1997, and by the end of 2011 had generated >160,000 records on travelers seen at GeoSentinel site clinics. Of the patients with travel-related conditions reported by GeoSentinel clinics through the end of 2011, approximately 50% were seen after travel, 31% during travel, and 14% for illnesses related to their initial immigration travel. Among those seen after travel, 57% were leisure travelers; 14% were business travelers; 14% were missionaries, volunteer researchers, or aid workers; 12% were people visiting friends and relatives (VFR); and 2% were students. The most common destinations of returned travelers seen at GeoSentinel clinics were Mexico, Brazil, Egypt, Kenya, India, Thailand, and Indonesia.

GeoSentinel surveillance data have been used to report the spectrum of disease, document longitudinal disease trends, and detect sentinel events among traveling populations. Numerous reports using GeoSentinel data have been published; a list of publications, presentations, and citations can be found on the GeoSentinel website at In 2006, a report was published describing spectrum of disease in 17,353 returning travelers from developing countries seen at GeoSentinel clinics and documenting both overall disease trends and regional disease occurrences. Additional studies using GeoSentinel data have been published, including reports focused on specific diseases such as dengue and malaria, animal-associated injuries, specific populations such as VFR travelers, destination-specific reports including the 2010 World Cup in South Africa and response to the 2010 Haiti earthquake, and outbreaks of leptospirosis and suspected sarcocystosis.

A continued focus of GeoSentinel will be to maintain systematic and timely data collection from sites, document trends and changes of illness patterns in travelers, and report new and unusual events in traveling populations. GeoSentinel will also seek to add new sites and expand its network membership. Further information on GeoSentinel can be found at


Global TravEpiNet was formed in 2009 to advance the pre-travel health care of US international travelers, particularly those at higher risk of travel-associated illness because of itinerary, purpose of travel, or existing medical conditions. Global TravEpiNet performs this work by systematically evaluating the health characteristics and pre-travel health care of travelers, developing evidence-based web tools for travelers and practitioners, and assessing the effect of pre-travel health interventions. As of September 2012, the Global TravEpiNet Consortium was composed of a network of 25 clinical sites across the United States, including primary care clinics, academic travel medicine practices, pharmacy-based practices, public health clinics, and occupational health clinics; many are registered to administer yellow fever vaccine.

Clinicians at Global TravEpiNet sites use a web tool to systematically collect data about the pre-travel health consultation. Data collected from the pre-travel consultation include demographics, travel itinerary, travel purpose, immunization history, vaccines administered, medication provided, and reasons for not administering a recommended vaccine. Data on >33,000 pre-travel consultations have been collected as of June 2012. More than 80% of travelers seen at Global TravEpiNet sites are visiting resource-poor destination countries. Africa is the most commonly visited region, and nearly a third of travelers visit multiple countries. Leisure (49%) is the most commonly reported purpose of travel, but business (15%), service work (15%), and VFR travelers (11%) are also common. Fifty-nine percent of travelers report an existing health condition before departure; 3% have an immune-suppressing condition of some type.

Patients declining recommended vaccines during the pre-travel consultation, particularly the influenza and rabies vaccines, have been identified as an area of concern within Global TravEpiNet. In particular, being a VFR traveler is an independent predictor of declining any recommended vaccine (OR, 1.45; 95% CI, 1.31–1.60). Global TravEpiNet is exploring the reasons that lead travelers to decline vaccines. Other areas of active research include determining the cost-effectiveness of the pre-travel consultation, evaluating specific traveling populations (such as VFR, pediatric, and immunocompromised travelers), and assessing the use of specific pre-travel interventions (such as yellow fever, Japanese encephalitis, and rabies vaccines).

Global TravEpiNet has identified that VFR travelers are less likely to seek timely pre-travel medical care and are more likely to decline recommended vaccines, even when they have sought medical advice. Because the Internet and primary care providers are common sources of health information for international travelers, especially VFR travelers, Global TravEpiNet has developed a number of web-based tools to optimize pre-travel health care for high-risk international travelers (Box 1-02). These publicly available web tools link directly to up-to-date recommendations from CDC. The Global TravEpiNet Consortium is also actively recruiting primary care and public health clinical sites that provide care to VFR and other high-risk travelers. More information on Global TravEpiNet, its web tools, and its membership can be found at

Box 1-02. Publicly available travel resources from Global TravEpiNet

  • All resources are free, do not require registration, and can be accessed at
  • The Travelers’ Health Tool encourages international travelers to seek pre-travel health advice and provides quick, itinerary-specific recommendations based on CDC guidelines.
  • The Healthcare Providers’ Tool guides clinicians through preparing a person for international travel and is up-to-date with CDC recommendations.


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