Parasites and Vectors (2010) 3 (83) - Culicidae diversity, malaria ...
Armel Djènontin, Sahabi Bio-Bangana, Nicolas Moiroux, Marie-Claire Henry, Olayidé Bousari, Joseph Chabi, Razaki Ossè, Sébastien Koudénoukpo, Vincent Corbel, Martin Akogbéto and Fabrice Chandre (2010)
Culicidae diversity, malaria transmission and insecticide resistance alleles in malaria vectors in Ouidah-Kpomasse-Tori district from Benin (West Africa): A pre-intervention study
Parasites and Vectors 3 (83)
Abstract: Background
To implement an Insecticide Resistance Management (IRM) strategy through a randomized controlled trial (phase III), 28 villages were selected in southern Benin. No recent entomological data being available in these villages, entomological surveys were performed between October 2007 and May 2008, before vector control strategies implementation, to establish baseline data.
Methods
Mosquitoes were sampled by human landing collection (16 person-nights per village per survey per village) during 5 surveys. Mosquitoes were identified morphologically and by molecular methods. The Plasmodium falciparum circumsporozoïte indexes were measured by ELISA, and the entomological inoculation rates (EIRs) were calculated. Molecular detection of pyrethroid knock down resistance (Kdr) and of insensitive acetylcholinesterase were performed.
Results
44,693 mosquitoes belonging to 28 different species were caught from October 2007 to May 2008. Among mosquitoes caught, 318 were An. gambiae s.s., 2 were An. nili, 568 were An. funestus s.s., and one individual was An. leesoni. EIR was 2.05 ± 1.28 infective bites per human per 100 nights on average, of which 0.67 ± 0.60 were from An. funestus and 1.38 ± 0.94 infective bites were from An. gambiae. Important variations were noted between villages considering mosquito density and malaria transmission indicating a spatial heterogeneity in the study area. The kdr allelic frequency was 28.86% in An. gambiae s.s. on average and significantly increases from October 2007 (10.26%) to May 2008 (33.87%) in M molecular form of An. gambiae s.s. Ace 1 mutation was found in S molecular of An. gambiae s.s at a low frequency (< 1%).
Conclusion
This study updates information on mosquito diversity and malaria risk in rural villages from south Benin. It showed a high spatial heterogeneity in mosquito distribution and malaria transmission and underlines the need of further investigations of biological, ecological, and behavioral traits of malaria vectors species and forms. This study is a necessary prerequisite to cartography malaria risk and to improve vector control operations in southern Benin.
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Full text of article
Database assignments for author(s): Nicolas Moiroux, Vincent Corbel, Fabrice Chandre, Razaki Ossè
Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution
pesticide resistance of pest
