Malaria parasite species prevalence and transmission dynamics at selected sites in the Western highlands of Kenya

Background: Malaria in the Western Kenya highlands is unpredictable sometimes leading to epidemics that result in dramatic emergencies in terms of severe morbidity and mortality. This places enormous strain on health facilities disrupting fragile health care services culminating into crises. This underlies the need for a better understanding of the disease dynamics and determinants to formulate specific and focused intervention strategies. Aim: One year study was undertaken in Kipsamoite and Kapsisiywa in Nandi County to evaluate Plasmodium species prevalence and transmission risk in the general population and specific age groups. Subjects and Methods: Positive blood smears were used to determine monthly malaria prevalence, age-group prevalence. Malaria risk in population was worked out using adult to child ratio (ACR). Results: ACR results indicated a less immune population in which all age groups and sexes were equally susceptible to malaria. Plasmodium falciparum was most prevalent (90%, n = 264) while Plasmodium malariae (10%, n = 30). There was significant difference in the malaria parasite species prevalence (χ2,P < 0.05), but there was no significant difference in parasite species prevalence between the study sites (χ2, P > 0.05). Conclusions: Malaria transmission dynamics were similar in both sites, largely driven by seasonality, had an even age distribution implying that the threat of epidemics was real should all age-groups become exposed to parasites and conditions of disease transmission become favorable