Article

Viewpoint: High susceptibility to Chikungunya virus of Aedes aegypti from the French West Indies and French Guiana

Unité d'entomologie médicale, Institut Pasteur de Guyane, Cayenne, Guyane française.
Tropical Medicine & International Health (Impact Factor: 2.33). 01/2011; 16(1):134-9. DOI: 10.1111/j.1365-3156.2010.02613.x
Source: PubMed

ABSTRACT

To estimate the vector competence of Aedes aegypti populations sampled from distinct anthropogenic environments in French Guiana, Guadeloupe and Martinique for the strain CHIKV 06.21.
F(1)/F(2) females were orally infected at titres of 10(6) and 10(7.5) pfu/ml in blood-meals. Disseminated infection rates (DIR) of mosquitoes were estimated using indirect fluorescent antibody assay on heads' squashes, 7 or 14 days post-infection (pi).
At a titre of 10(7.5) pfu/ml, DIR ranged from 88.9% to 100.0% and were not significantly different whether assessed at day 7 or 14 pi. At a titre of 10(6) pfu/ml, DIR observed 7 days pi ranged from 37.6 to 62.0%.
Ae. aegypti from French Guiana and French West Indies are highly competent to transmit CHIKV. An evaluation of DIR 7 days rather than 14 days pi is adequate to estimate vector competence. The titre of 10(6) pfu/ml allows us to distinguish Ae. aegypti populations originating from distinct environments (dense or diffuse housing) by their vector competence. This assessment is a prerequisite to better evaluate the potential risk of Chikungunya outbreaks once the virus is introduced from endemic regions.

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