Influence of Vector Control and Chemotherapy Interventions on Treatment Outcomes and Parasite Incidence in Artemether Combined Therapies Treated Populations of Kisii County, Kenya

Introduction: Malaria remains the major vector borne disease in the world. Currently Kenya the ministry of health has scaled up interventions with chemotherapy and vector control standing out as a major strategy. Therefore, this study examined the influence of vector control and chemotherapy interventions on the treatment outcomes in Kisii County. Methods: Multi-stage random sampling was used for this study. The study was conducted from February 2021 to June 2021. Malaria-positive 275 participants were recruited into the study, treated with ACTs and followed for a period of 28 days at specified follow up days for parasite diagnosis. Occurrence of malaria clinical symptoms on the patients was also conducted. Molecular analysis was done by characterizing Merozoite proteins (MSP2) on the samples showing parasite recurrence. A Questionnaire was administered to determine the utilization of drugs for malaria treatment prior to this study and the usage of vector control after patient treatment with ACTs. Meanwhile, emphasis was laid on intervention strategies such as the use the usage of insecticide-treated nets (ITNs), Indoor residual spraying and chemotherapeutic practices as recommended by the World Health Organization (WHO). Results: Early treatment failure was reported among 27(12%) respondents, late clinical failures 20(8%), late parasitological failures 11(5%), and adequate clinical and parasitological outcomes 173(75%).Chemotherapeutic practices influencing treatment outcomes included; previous self-medication (OR=0.417; 95% CI: 0.153-1.385; p=0.035), ability of previously finishing doses (OR=0.328; 95% CI: 0.168-0.941; p=0.003,) and Frequency of previous antimalarial usage (OR=3.259; 95% CI: 1.054-4.721; p=0.004). While vector control interventions influencing treatment outcomes included; usage of indoor residual spraying (OR=0.408; 95% CI: 0.132-0.682; p=0.002), sleeping under the mosquito net (OR=0.218; 95% CI: 0.119-0.909; p=0.025,) and mosquito net treatment (OR=0.262; 95% CI: 0.092-0.823; p=0.003).With the molecular analysis detecting 10 samples with parasite recrudescence. Conclusions: Based on these findings, Antimalarial usage practices prior to current usage of ACTs and vector control after treatment remain important predictor factors for treatment outcomes.