Definitions and Nomenclature
Dengue is the accepted name of an acute infectious disease of man characterized by fever, aches and pains in various parts of the body which may range from mild to excruciatingly severe, generalized rash, lymphadenopathy and leukopenia. Its effects may be debilitating to the point of prostration, but uncomplicated classical (primary) dengue is rarely, if ever, fatal. It is caused by at least four antigenically distinct viruses constituting the dengue subgroup of group B togaviruses (see Section IV on Classification). By definition, they are transmitted to man by mosquitoes of the genus Aedes (Stegomyia). It follows that the occurrence of the disease (and the viruses) is restricted to those geographic areas in which suitable vector species are prevalent or in which, once imported, they can maintain themselves.