Dengue is a disease caused by infection with dengue virus. In the U.S., most cases are travel-related, originating from visits to regions where dengue is common, such as the Caribbean and some continental U.S. states. The yellow fever and Asian tiger mosquitoes, found in many areas, transmit the virus. Travelers should check if dengue is prevalent in their destination and take precautions against mosquito bites. Infected individuals should avoid mosquito exposure to prevent local transmission.