Investigation of Malaria Parasitemia among Asymptomatic Individuals in Designated Districts of Central and Muchinga Provinces of Zambia – A Cross Sectional Study

Abstract

Abstract. The aim of the study was to investigate asymptomatic malaria in health-conscious population across four selected districts. Malaria is a life-threatening disease caused by Plasmodium spp. transmitted through bites of infected female Anopheles mosquitoes. Asymptomatic malaria refers to the presence of malaria parasites in vivo without symptoms, which usually provides a reservoir for the disease transmission. Materials and methods. Blood collected in EDTA underwent testing through RDT (SD Bioline one-step malaria antigen P.f. (HRP-II) rapid test kits), while thin and thick blood smears Giemsa stained were microscopically examined. Results and discussion. Out of 385 individuals examined, 84 people (21.8 %) tested positive for malaria using RDT and 101/385 (26.2 %) – through microscopy. Microscopic examination further identified 27 individuals (7.0 %) with gametocytes and 74 (19.2 %) – with trophozoites. Intriguingly, 17 (4.4 %) samples showed negative results in RDT but exhibited trophozoites and gametocytes upon smear examination. District-wise analysis demonstrated the highest malaria positivity rate in Kanchibiya district, with 32 cases (8.3 %) detected by RDT and 35 (8.5 %) – through microscopy. Chitambo district followed closely: with RDT and microscopy values of 25 (6.5 %) and 33 (8.4 %), respectively; while Mpika and Serenje districts had 13 (3.4 %) and 14 (3.6 %) prevalence, respectively, with RDT and microscopy at 12 (3.1 %) in both districts [x2 =16.3, p-value=0.0118]. The study also revealed that 365/385 (95 %) of the participants demonstrated knowledge and positive attitudes toward malaria. Our findings accentuate the presence of asymptomatic malaria, encompassing trophozoites and gametocytes, among seemingly healthy individuals which poses a health risk to the community. Therefore, it is imperative to implement preventive chemotherapy and strengthen vector control efforts against malaria in order to reduce the infection rate.