The Centers for Disease Control and Prevention (CDC) has a great deal of information for travelers. Please see links below.
Adventure TravelAnimal SafetyBlood ClotsBug BitesBusiness TravelCold ClimatesCounterfeit DrugsCruise Ship TravelFamilies with ChildrenFish Poisoning in TravelersFood and Water Safety
Getting Health Care AbroadGetting Sick After TravelHigh AltitudesHot ClimatesHumanitarian Aid WorkersInsuranceInternational AdoptionJet LagList-Minute TravelLong-Term TravelMass GatheringsMedical Tourism
Mental HealthMotion SicknessNatural DisastersPregnant TravelersRoad SafetySenior CitizensSex TourismSTDsSun ExposureSwimming and DivingStudy AbroadTick Bites
Travelers' DiarrheaTravelers with Chronic IllnessesTravelers with DisabilityTravelers with Weakened Immune SystemsTraveling with Your PetVisiting Friends or RelativesWater DisinfectionInfographics for TravelersTraveler Survival Guide