[Aedes aegypti in French Guiana. Some aspects of history, general ecology and vertical transmission of the dengue virus]

Abstract

Aedes aegypti is suspected to be present in the country since the late 18th century, and was responsible of urban yellow fever epidemics in the last century. This mosquito was identified for the first time in French Guiana in 1902. More recently, in 1940, an eradication campaign started and Aedes aegypti was eradicated between 1950 and 1963, date of the reinfestation. During the past 30 years, some dengue outbreaks occurred every 2 to 6 years, and the first dengue haemorrhagic fever epidemic spread over the country in 1992. Actually, Ae. aegypti is distributed almost all inhabited areas of French Guiana: in the towns, villages, smaller human settlements, and was also found in a wild area. The most frequent Ae. aegypti breeding-sources are the outside discarded small containers, other less frequent breeding-sites are the outside flower pots and the outside big containers. The type of breeding-source significantly influences the duration of larval and pupal development. In French Guiana, Ae. aegypti is the only vector of dengue. The vertical transmission of dengue viruses under field conditions was demonstrated. Dengue is thus endemic in the country and has almost the same distribution as Ae. aegypti, with most probably the same possibilities of extension. Ae. aegypti can be considered not only as vector and an amplificator of dengue in French Guiana, but also as a reservoir, even if occasional.