Dengue fever is a viral illness spread by certain types of mosquitoes.
The disease occurs mainly in tropical Asia, Africa, and the Caribbean. It is most common during the rainy season in areas infested with infected mosquitoes. Occasionally, persons arriving from other countries may enter the United States with dengue fever. There has been no transmission of dengue fever in Hawaii for several decades. The dengue virus is transmitted to people as a result of being bitten by infected Aedes mosquitoes.