Abstract:
This study was carried in order to evaluate the emergence of resistant Anopheles and Culex Mosquitoes against PermaNet 3.0, Long Lasting Insecticidal Net, In Some selected districts of Jimma zone, South West Ethiopia. Taxonomically, mosquitoes belong to kingdom Animalia, phylum Arthropoda, class Insecta, order Diptera and family Culicidae. Many members of the genus Anopheles have the ability to transmit human malaria. Long-lasting insecticidal nets (LLINs), indoor residual spraying (IRS) and environmental management are the most widely used tools for malaria vector control. Thus the objective of this study was to evaluate the Bio-Efficacy and wash resistance of PermaNet 3.0 LLIN using Anopheles gambiae and Culex quinquefasciatus mosquitoes in selected districts of Jimma zone, south west Ethiopia. This study was conducted from March, 2015 to August 2015.A community based survey was conducted using structured, questionnaire interview. In line with administration of interview, 150 old PermaNet 3.0 samples were collected by replacing with new PermaNet 3.0 on spot and the nets hole was measured. Anopheles and Culex mosquito larvae were collected from the outskirts of Jimma town and reared understandard conditions. Susceptible Anopheles arabiensis mosquitoes were obtained from Sekoru Vector biology and insectary unit, Jimma University. Vector mosquitoes were exposed to 30 cm x 30 cm pieces of impregnated bed nets for 3 min, Knockdown was measured after 60 minutes and the mortality was measured after 24 h recovery period. Among the socio-characteristic factors the association between Physical condition of the net and misuse of the net by children was highly significant (Df 1, P=0.000) whereas no significant relation was observed between factors net washing habit, soaking time, housing type and source of light. Reduced susceptibility of both Anopheles gambiae s.l. (79%) and Culex quinquefasciatus (85%) was recorded using unwashed PermaNet 3.0 samples. Comparison of mean percent mortalities and knockdown effects among different wash status of PermaNet 3.0 has shown significant variation (P=0.000) among different washes. The unwashed PBO-deltamethrin top netting induced mortality in Cx. Quinquefasciatus (100%) and An. gambiae s.l(97%) in both above WHO reference line indicating that PBO was synergizing the pyrethroid resistanceMean percent mortality of mosquito at the top panel of PermaNet 3.0 significantly higher than that of mosquito at the side part of the LLN(P<0.05).
