Autor(es): Owino Eunice A, Sang Rosemary, Sole Catherine L, Pirk Christian, Mbogo Charles, Torto Baldwyn

Resumo: Effective surveillance - estimation of the biting fraction of Aedes aegypti is critical for accurate determination of the extent of virus transmission during outbreaks - inter-epidemic periods of dengue - chikungunya fever. Here, we describe the development - use of synthetic human odor baits for improved sampling of adult Ae. aegypti, in two dengue - chikungunya fevers endemic areas in Kenya; Kilifi - Busia counties. We collected volatiles from the feet - trunks of two female - two male volunteers aged between 25 - 45 years. We used coupled gas chromatography- electroantennographic detection (GC/EAD) analysis to screen for antennally-active components from the volatiles - coupled GC-mass spectrometry (GC/MS) to identify the EAD-active components. Using r-omized replicated designs, we compared the efficacies of Biogents (BG) sentinel traps baited with carbon dioxide plus either single or blends of the identified compounds against the BG sentinel trap baited with carbon dioxide plus the BG commercial lure in trapping Ae. aegypti. The daily mosquito counts in the different traps were subjected to negative binomial regression following the generalized linear models procedures. A total of ten major EAD-active components identified by GC/MS as mainly aldehydes - carboxylic acids, were consistently isolated from the human feet - trunk volatiles from at least two volunteers. Field assays with synthetic chemicals of the shared EAD-active components identified from the feet - trunk gave varying results. Ae. aegypti were more attracted to carbon dioxide baited BG sentinel traps combined with blends of aldehydes than to similar traps combined with blends of carboxylic acids. When we assessed the efficacy of hexanoic acid detected in odors of the BG commercial lure - volunteers plus carbon dioxide, trap captures of Ae. aegypti doubled over the trap baited with the commercial BG lure. However, dispensing aldehydes - carboxylic acids together in blends, reduced trap captures of Ae. aegypti by ~45%-50%. Our results provide evidence for roles of carboxylic acids - aldehydes in Ae. aegypti host attraction - also show that of the carboxylic acids, hexanoic acid is a more effective lure for the vector than the BG commercial lure.

Palavras-Chave: Aedes aegypti; Dengue; Chikungunya; Attractant; Electrophysiology; Mosquito; Traps

Imprenta: Parasites & Vectors, v. 8, p. 253, 2015

Identificador do objeto digital: 10.1186/s13071-015-0866-6

Descritores: Chikungunya virus - Flaviviridae ; Chikungunya virus - Pathogenesis ; Chikungunya virus - Viral infections ; Chikungunya Virus - Virus ; Chikungunya virus - Transmission ; Chikungunya virus - Chikungunya fever ; Chikungunya virus - Dengue ; Chikungunya virus - Epidemic ; Chikungunya virus - Epidemiology ; Chikungunya virus - Public health

Data de publicação: 2015