Oral receptivity of Aedes aegypti formosus from Franceville (Gabon, Central Africa) for dengue type 2 virus.

Dengue is widely distributed in the tropics but epidemic activity was rarel y reported in Africa before the 1980's. in he past 15 years, increased epid emic dengue fever has been reported both in East and West Africa, raising c oncern about the ability of local populations of Aedes aegypti to transmit dengue viruses. Ae. aegypti is present in two forms in Africa. Ae. aegypti aegypti and Ae. aegypti formosus. This latter form, much darker, was not or iginally a local species but is now colonizing artificial breeding sites wi thin cities. We have been able to demonstrate the oral susceptibility for d engue type 2 virus of Ae. aegypti formosus collected in Franceville, Gabon (Central Africa). However these mosquitoes sampled exhibited lower infectio n rates than those of a control colony of Ae. aegypti aegypti originating f rom French Polynesia.