Residual efficacy of Clothianidin (SumiShield 50WG) used in experimental huts conditions and then in Indoor Residual Spraying campaign in Senegal

Background: In Senegal, the main vector control strategies include implementing indoor residual spraying (IRS) and distribution of long-lasting insecticides insecticidal nets (LLINs). Drugs resistance and insecticides resistance use on public health were appearing affected to combatted malaria transmission. In the country vectors became resistant to pyrethroids, the insecticides class that nets are impregnate. As they affected strategies for vector control, new formulation belonging on neonicotinoid class, clothianidin was developed and used for malaria vector control through IRS of insecticide. Methods Residual efficacy of clothianidin treated walls was assessed monthly using cone bioassays following WHO method. Five houses in each of the two villages sprayed were assessed and one unsprayed house served as the control. In trial huts experimental, six huts in total, including three in banco and three others in cement treated were assessed monthly. Three cones were installed on three walls in each of the sprayed houses at 0.5 m, 1m and 1.5m above the floor, and three cones at the control house. About 10 females, 2–5 -days old from the laboratory susceptible strain of An. coluzzii were exposed in each cone for 30 mins and then transferred to holding cups and mortality rate was recorded to four days post exposure. Results The results show good efficacy of SumiShield 50WG on banco and cement substrates after twelve month in experimental huts and eight months on the field area. In Bandaffassi and Tomboronkoto, mortality rate of susceptible strain was always more than 80% after eight months. Conclusion The use of this new formulation of clothianidin belonging the neonicotinoid class does not yet show resistance on malaria vectors countries in Africa