ABSTRACT

 Anopheles gambiae s.l. is the primary vector of malaria, a debilitating disease responsible for substantial mortality and morbidity in Sub-saharan Africa. This study was conducted between June 2021 and October 2022 to evaluate the prevalence of L1014F kdr type mutation in Anopheles gambiae s.l., and assess malaria vector control practices in Abia state, Nigeria. Immature stages of An..gambiae (s.l.) were collected from Umudike, Agalaba, and Ebem communities and reared to adulthood; whereas 510 structured questionnaires were used to elicit information on malaria vector control practices. Batches of twenty five sugar fed female mosquitoes, aged 3-5 days, were exposed to four types of WHO insecticide impregnated papers ■ i.e., 4% DDT, 0.75% Permethrin, 0.1% bendiocarb, and 5% Malathion procured from Universiti Sain Malaysia, following' the WHO recommended standard procedure. Mosquitoes were also subjected to molecular diagnosis for speciation, and genotyped for kdr type gene mutation L1014F. Anopheles gambiae (s.l.) was highly resistant to permethrin (Umudike-18.76% mortality, Agalaba-17.51%, Ebem- 49.01%) and DDT (0%) in the three locations. Conversely, all the locations recorded complete susceptibility to malathion (100%). Although complete susceptibility to bendiocarb was reported from Umudike (100%) and Ebem (100%), some resistance was reported from Agalaba (87.5%). PCR analyses showed that An. gambiae (s.l.) were predominantly An. gambiae s.s. at Umudike (90%), Agalaba (67.5%) and Ebem (67.5%), whereas the rest were An. coluzzii. Very high frequencies of the L1014F kdr mutation was observed in all locations [Umudike (1.00), Agalaba (0.98), and Ebem-ohafia (0.95)]. Use of insecticides was the predominant malaria vector control practice (325; 63.7%) in Abia State, although respondents used a combination of different control methods. Level of education, type ■of dwelling structure, household size and Local' Government Area (L.G.A.) had significant relationship with most of the vector control practices (P > 0.05), whereas effectiveness was the resonating reason for the use of malaria vector control methods. Unfortunately, majority (386; 75.7%) of the respondents attested to non-involvement of Government and NGO’s in malaria. vector control within the state. The worrisome resistance to bendiocarb in Agalaba suggests existence of metabolic and/or GS119 target site resistance that needs to be investigated. High occurrence (Fixation) of L1014F kdr resistance mutation in populations calls for urgent implementation of integrated vector control strategies in Abia State. Furthermore, malaria vector control programs should consider level of education, type of dwelling structure, household size and L.G.A., during the design and deployment of vector control strategies, as they scale-up campaigns towards discouraging abusive use ofinsecticides in the State.