Changes in Anopheles funestus Biting Behavior Following Universal Coverage of Long-Lasting Insecticidal Nets in Benin.

Nicolas Moiroux (1, 2) , Marinely B Gomez (2) , Cédric Pennetier (1, 2) , Emmanuel Elanga (3, 2) , Armel Djènontin (3, 2) , Fabrice Chandre (1, 4) , Innocent Djègbé (3, 2) , Hélène Guis (5) , Vincent Corbel (3, 2)

1 MIVEGEC-VCG - Vector Control Group
2 CREC - Centre de Recherche Entomologique de Cotonou
3 MIVEGEC - Maladies infectieuses et vecteurs : écologie, génétique, évolution et contrôle
4 Laboratoire de Lutte contre les Insectes Nuisibles
5 UMR CMAEE - Contrôle des maladies animales exotiques et émergentes

Background. Behavioral modification of malaria vectors in response to vector control methods is of great concern. We investigated whether full coverage of long-lasting insecticide-treated mosquito nets (LLINs) may induce a switch in biting behavior in Anopheles funestus, a major malaria vector in Africa.Methods. Human-landing collections were conducted indoor and outdoor in 2 villages (Lokohouè and Tokoli) in Benin before and 1 year and 3 years after implementation of universal LLIN coverage. Proportion of outdoor biting (POB) and median catching times (MCT) were compared. The resistance of A. funestus to deltamethrin was monitored using bioassays.Results. MCT of A. funestus switched from 2 am in Lokohoué and 3 am in Tokoli to 5 am after 3 years (Mann-Whitney U test, P < .0001). In Tokoli, POB increased from 45% to 68.1% (odds ratio = 2.55; 95 confidence interval = 1.72-3.78; P < .0001) 1 year after the universal coverage, whereas POB was unchanged in Lokohoué. In Lokohoué, however, the proportion of A. funestus that bites after 6 am was 26%. Bioassays showed no resistance to deltamethrin.Conclusions. This study provides evidence for a switch in malaria vectors' biting behavior after the implementation of LLIN at universal coverage. These findings might have direct consequences for malaria control in Africa and highlighted the need for alternative strategies for better targeting malaria vectors.

Domaines: Ecologie, Environnement; Maladies infectieuses

Nicolas Moiroux, Marinely B Gomez, Cédric Pennetier, Emmanuel Elanga, Armel Djènontin, et al.. Changes in Anopheles funestus Biting Behavior Following Universal Coverage of Long-Lasting Insecticidal Nets in Benin.. Journal of Infectious Diseases, 2012, 206 (10), epub ahead of print. ⟨10.1093/infdis/jis565⟩. ⟨hal-00742218⟩