EKOKO WOLFGANG E.*1,2, DOUMBE-BELISSE P.L.2, MANDENG S.E. 2,3, TOTO J.C.2, BAHEBEGUE SAMUEL2 and AWONO-AMBENE H.P.2
1 Higher Teacher Training College, Department of Biology, University of Bamenda, P.O. Box 39, Bambili, Cameroon
2 Institut de Recherche de Yaoundé (IRY), Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), P.O Box 288 Yaoundé, Cameroun
3 Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
* Corresponding author: ewolfgang388@gmail.com
Received: 21 Jan 2025, Reviewed: 15 Mar 2025, Revised: 09 Apr 2025, Accepted: 14 Apr 2025, Published: 08 May 2025
https://doi.org/10.63342/cjbbs2025.33.02
ABSTRACT
Communities living in the tropics use insecticide products to prevent or control mosquito nuisance in general. In Cameroon, these products are used at home without evidence of their efficacy against targeted mosquito populations. In this paper, we present a sample of anti-mosquito tools used by households in the city of Kribi, and their efficacy versus local Anopheles and Culex mosquitoes. The study protocol included: i) a survey in 500 randomly selected households using a questionnaire; ii) mosquito larvae and pupae collections in breeding sites and rearing; iii) WHO cone and susceptibility bioassays were conducted, respectively, using reared An. gambiae s.l. and Culex mosquitoes; and iv) molecular identification of members of the An. gambiae complex via PCR. The household survey revealed that long-lasting insecticidal nets (LLINs) (89%), insecticide aerosols (51.5%), or insecticide coils (35.3%) were the most used, as anti-mosquito tools. The aerosols provided optimal efficacy against An. gambiae s.l. and Culex mosquitoes with 98.6% and 100% mortality, respectively. Coils showed minimal efficacy (78.7%) to no efficacy (27.1%), respectively, against Anopheles and Culex mosquitoes, and LLINs showed no efficacy (25.6%) against Anopheles mosquitoes (P˂˂0,005). An. gambiae and Culex mosquitoes equally showed resistance to deltamethrin (81.7% and 78.5%, respectively) and permethrin (34.3% and 27.1 respectively). Bioassays conducted with the insecticide bendiocarb demonstrated that An. gambiae s.l. was fully susceptible, achieving a mortality rate of 100%. These findings highlight the challenges of individual anti-mosquito control measures in Kribi thus, there is a need for an integrated mosquito control approach involving effective household anti-mosquito tools to complement the use of LLINs, in the context of increasing insecticide resistance in natural mosquito populations.
Key words: Efficacy, anti-mosquito tools, insecticide resistance, mosquitoes, Kribi.
RÉSUMÉ
Les communautés vivant sous les tropiques utilisent des produits insecticides pour prévenir ou contrôler la nuisance des moustiques en général. Au Cameroun, ces produits sont utilisés à domicile sans que leur efficacité contre les populations de moustiques ciblées ne soit démontrée. Dans cet article, nous présentons un échantillon d’outils anti-moustiques utilisés par les ménages dans la ville de Kribi, et leur efficacité contre les moustiques locaux Anopheles et Culex. Le protocole de l’étude comprenait : i) une enquête dans 500 ménages sélectionnés au hasard à l’aide d’un questionnaire ; ii) des collectes de larves et de nymphes de moustiques dans des sites de reproduction et d’élevage ; iii) des essais biologiques de cône et de sensibilité de l’OMS ont été menés, respectivement, en utilisant des moustiques An. gambiae s.l. et Culex élevés ; et iv) l’identification moléculaire des membres du complexe An. gambiae via la PCR. L’enquête auprès des ménages a révélé que les moustiquaires imprégnées d’insecticide de longue durée (MIILD) (89%), les aérosols d’insecticide (51,5%) ou les serpentins d’insecticide (35,3%) étaient les outils anti-moustiques les plus utilisés. Les aérosols ont fourni une efficacité optimale contre An. gambiae s.l. et les moustiques Culex avec 98.6% et 100% de mortalité respectivement. Les serpentins ont montré une efficacité minimale (78,7 %) à nulle (27,1 %), respectivement, contre les moustiques Anopheles et Culex, et les MILD n’ont montré aucune efficacité (25,6 %) contre les moustiques Anopheles (P˂˂0,005). Les moustiques An. gambiae et Culex ont également montré une résistance à la deltaméthrine (81,7 % et 78,5 %, respectivement) et à la perméthrine (34,3 % et 27,1 respectivement). Les bioessais réalisés avec l’insecticide bendiocarbe ont montré qu’An. gambiae s.l. était totalement sensible, atteignant un taux de mortalité de 100 %. Ces résultats soulignent les défis des mesures individuelles de lutte contre les moustiques à Kribi. Ainsi, il y a un besoin pour une approche intégrée de lutte contre les moustiques impliquant des outils efficaces de lutte contre les moustiques dans les ménages pour compléter l’utilisation des MILD, dans le contexte d’une résistance croissante aux insecticides dans les populations naturelles de moustiques.
Mots clés : Efficacité, outils anti-moustiques, résistance aux insecticides, moustiques, Kribi.
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