Background Adventure travel necessarily places travelers at risk of environmental hazards. We assessed the burden of “environmental” hazards among a cohort of travelers and expatriates presenting to a large travel clinic in Nepal.

Methods Data on travelers and expatriates seen at the Canadian International Water and Energy Consultants (CIWEC) clinic in Kathmandu were prospectively collected and entered into the GeoSentinel Surveillance Network database. Data on individuals receiving predefined diagnoses related to environmental hazards were extracted and analyzed.

Results Of 10,499 travelers and 4,854 expatriates in the database, 2,160 were diagnosed with 2,533 environment-related illnesses. Injuries were common among both travelers and expatriates [N= 788 (6.1%) and 328 (4.9%), respectively], while altitude illness was seen almost exclusively in travelers [N= 611 (4.7%) vs N= 8 (0.1%)]. Factors independently associated with environmental diagnoses include male gender (p < 0.001), traveling for tourism (p < 0.001), and lack of pre-travel advice (p= 0.043). Three percent of travelers and 2% of expatriates presenting to CIWEC sustained a bite wound or required rabies postexposure prophylaxis. Injured travelers were less likely than others to have obtained pre-travel advice (p= 0.003), while those who sustained bite wounds were more likely to have received pre-travel advice (p < 0.001).

Conclusions Environmental hazards are important causes of morbidity and potential mortality among adventure travelers and expatriates. Current pre-travel interventions are missing certain risk groups entirely and failing to have the desired educational impact in others.