Malaria among rice farming communities in Kilangali village, Kilosa district, Central Tanzania: prevalence, intensity and associated factors

Background Malaria remains the most important cause of morbidity and mortality in Tanzania. However, its prevalence varies from area to area depending on various ecological, socio-economic and health system factors. This study was carried out to determine malaria prevalence and associated factors among rice farming communities in the Kilangali village of Kilosa District in Central Tanzania. Methods A cross-sectional study was conducted in May 2015, involving randomly selected persons living in the six sub-villages of the Kilangali village, namely Mlegeni, Kisiwani, Makuruwili, Kwamtunga, Upogoroni and Chamwino. A finger prick blood sample was obtained for diagnosis of malaria infection using Giemsa-stained thick smears and a rapid malaria diagnostic test. Study participants were also screened for haemoglobin levels and a total of 570 children aged ≤ 12 years of age were examined for spleen enlargement using the palpation method. Results A total of 1154 persons were examined for malaria infection with mean age of 21.9 ± 19.69 years. The overall malaria prevalence was 14.2% and 17.5% based on microscopic examination and rapid diagnostic test, respectively. Plasmodium falciparum accounted for the majority (89%) of the malaria infections. The overall geometrical mean parasite density was 20.5 parasites/μL (95% CI : 14.6–28.8). Malaria prevalence and parasitaemia was highest among individuals living in the Mlegeni (23.9%) and Makuruwili (24.4%) sub-villages. Among the children examined for splenomegaly, 2.98% (17/570) had it. The overall prevalence of anaemia was 34.6%. Malaria infection was associated with the age groups of 1–10 years (a OR = 4.41, 95% CI : 1.96–9.93, P < 0.001) and 11–20 years (a OR = 6.68, 95% CI : 2.91–15.37, P < 0.001); and mild anaemia (a OR = 1.71, 95% CI : 1.11–2.62, P < 0.014) and moderate anaemia (a OR = 1.55, 95% CI : 1.01–2.39, P < 0.045). Conclusions Malaria was found at the study setting and its prevalence varied according to the demographic characteristics of the study participants and between sub-villages that are closely located. Electronic supplementary material The online version of this article (doi:10.1186/s40249-017-0315-1) contains supplementary material, which is available to authorized users.