[Travelers with underlying medical conditions]

Travelers with pre-existing medical disease are at risk of exacerbation of their underlying disease during their journey but are also more susceptible to various infectious agents, which consequences could be much more severe than in healthy subjects. Prevention and education are primordial in order to optimize the trip. Each new prescription should be checked for potential drug/drug interactions. Malaria chemoprophylaxis should be considered if concerned, as well as mechanical protection against insect-bites. Vaccinations should be recommended after weighting risks and benefits, keeping in mind that live-attenuated vaccines are not recommended in case of cellular immune suppression. Prevention of travel-related diarrhea by general hygiene measures is of particular interest in this population. Thereafter, we are discussing specific preventive measure according to different medical conditions.