Trends in insecticide resistance among Anopheles gambiae s.l. mosquitoes in Ondo and Anambra states in southern Nigeria

Authors: Chukwuebuka Ezihe, Azuka Iwegbu, Saliu Ogunmola, Udoka Nwangwu, Peter Okeke, Jafar Braimah, David Nwele, Okechukwu Ezeike, Bosede Adu, Estelle McLean, Abiola Oluwagbemiga, Tarekegn A Abeku

Changing insecticide resistance patterns across locations and over time highlight an important need for adaptive data-driven vector control strategies to sustain malaria control.

Insecticide resistance poses a major challenge to malaria elimination by reducing the effectiveness of vector control interventions. Insufficient local data further constrain malaria control strategies and increase the risk of deploying ineffective tools. To address this gap, entomological studies were conducted to assess changes in insecticide resistance among Anopheles gambiae complex (s.l.) mosquitoes in Ondo and Anambra states, Nigeria, following insecticide-treated net (ITN) distribution campaigns. ITNs containing the insecticide alpha-cypermethrin and a synergist, piperonyl butoxide (PBO), were distributed during campaigns in December 2021 in Ondo state and August 2022 in Anambra state, respectively. The study evaluated trends in resistance levels against different insecticides following the campaigns.

This poster was presented at the 2025 Annual Meeting of the American Society of Tropical Medicine and Hygiene, held on 9-13 November in Toronto, Canada.