Abstract: Introduction: The prevalence of malaria in Ethiopia has decreased somewhat in recent decades, but it is currently increasing as a result of the introduction of insecticide-resistant Anopheles mosquitoes. Therefore, this study was aimed to assess entomological factors related to malarial disease transmission in the study population.
Methods: Socio-demographic characteristics from 48 households were collected by using structured questionnaires. Anopheline immature stages of mosquito were collected by dipping methods and reared to adult in a laboratory to determine the species composition and drug susceptibility test. Using WHO papers and bioassay tubes, 150 adult female Anopheles mosquitoes, two to three days old, not fed blood, were exposed for one hour to varying dosages of 0.05% Deltamethrin, 0.45% Alpha-cymethrin, and 0.1% Propoxur. Logistic regression was used to identify local risk factors using SPSS version 25 for further analysis. Statistical significance was declared at p-value<0.05.
Results: The presence of Anopheles larvae was confirmed in all water-holding habitats. Insecticide susceptibility test was performed, 100 adult Anopheles mosquitoes were exposed to each insecticide as World Health Organization recommended (propoxur 0.1%, deltamethrin 0.05%, and alpha-cypermethrin 0.45%). The knockdown times (KDT), percentage knockdown, and percentage mortalities of the exposed mosquitoes were noted. Anopheles gambiae (S.L)., the species of mosquito that was identified, was resistant to propoxur (0.1%) and delthametrin (0.05%), but it was completely susceptible to alpha-cypermethrin (0.45%) across all study sites. Anopheles gambiae (S.L) prefer to breed in habitat which exposed to sun light, had stone substrate and had no canopy cover.
Conclusion: There is a need to employed integrated vector management approaches to malaria vector control.