Preliminary Evaluation of Village-Scale Insecticide-Treated Durable Wall Lining Against Anopheles gambiae s.l in Akorede, Kwara State, Nigeria
A. Obembe, K. Popoola, A. Oduola, M. Tola, A. Adeogun, T. Oyeniyi, and S. Awolola (pp. 1-9)
Abstract
Insecticide-treated durable wall lining (DL) was designed for user-independent and longer-lasting malaria vector control lacking in insecticide-treated bed nets and indoor residual spraying, respectively. Field efficacy studies involving pyrethroid-treated DL in Africa have been limited to experimental huts and mobile population settings. This study reports a preliminary assessment of village-scale DL installation against An. gambiae s.l in Akorede, Kwara State, Nigeria. Two similar villages were selected as DL intervention and control sites. Subsamples of installed DL were assessed for bio-efficacy every six months while window exit trap and monthly pyrethrum spray mosquito collections were conducted in both sites. Anopheles gambiae s.l collected were identified with PCR and tested for human blood and Plasmodium falciparum sporozoite using ELISA. Compared to baseline, the number of mosquitoes reduced significantly (p = 0.008) with 0% sporozoite rate in the intervention village but remained the same or increased significantly (p = 0.003) with 2.59% post-baseline sporozoite rate in the control. Bio-efficacy of DL remained 100% (mortality) with significantly (p = 0.04) increased mortality (53%) of free-flying indoor and exiting mosquitoes in the intervention village compared to control (1.8%). The results provide preliminary evidence to justify the need for randomized controlled trials in rural communities with pyrethroid-susceptible mosquitoes. Recent reports of widespread pyrethroid resistance in the Anopheles gambiae s.l also call for development and assessments of non-pyrethroid insecticide incorporated control tools.