Imported cases of dengue fever diagnosed in metropolitan France, from January 2001 to December 2006

Dengue fever is the main emerging vector-borne disease worldwide. It was estimated that 40% of the world population is at risk. A potential vector (Aedes albopictus) is present in four French departments of the southeast area of metropolitan France. The authors tried to document the number of imported cases of dengue diagnosed from 2001 to 2006, inclusive, as well as their main features. Between 12 and 28 cases of imported dengue were diagnosed every month during that period (eight to 18 cases per month except for years 2001-2002 during which an important dengue epidemic was documented in the French West Indies). Nearly 40% of the cases were imported between June and September during which the vector is active in the metropolitan area. This data underlines the strong and close link between the endemic zones of the French territory (French West Indies and Guyana) and the risk of imported cases to metropolitan France. The identification of this "importation track" entails strengthening the system for detecting and managing imported dengue cases in metropolitan France when a dengue epidemic is detected in the French West Indies.