Dengue fever
Dengue happens most around the equator. 2.5 billion people live in areas where dengue happens. 70% of these people live in Asia and the Pacific. In the United States, 2.9% to 8% of people who come back from traveling in areas where dengue happens, and have a fever, were infected while traveling.  In this group of people, dengue is the second most common infection to be diagnosed, after malaria.