Imported dengue--United States, 1997 and 1998.

Dengue is a mosquito-transmitted acute viral disease caused by one of four dengue virus serotypes (DEN-1, DEN-2, DEN-3, and DEN-4). Dengue is endemic in most tropical areas of the world and has occurred in U.S. residents returning from travel to such areas. CDC maintains a laboratory-based passive surveillance system for imported dengue among U.S. residents. The system relies principally on reports by clinicians to state health departments, which forward patient specimens to CDC for diagnostic testing. This report summarizes information about imported dengue cases among U.S. residents for 1997 and 1998, which indicates that most persons with a known travel history probably acquired infection in the Caribbean islands or Asia.