Assessment, Mapping and Prediction of the Spatial Distribution of Intestinal Parasitic Infections in Rivers State, Nigeria

Abstract

This study assessed the prevalence of intestinal parasitic infections among school-aged children in Rivers state, Nigeria using Geographical Information System (GIS). A total of 3,828 stool samples were collected from school children from thirty six primary schools in thirteen local government areas of the state. The samples were analyzed using wet saline/iodine and formal ether concentration methods. The parasites found were identified. The location of the schools was linked to prevalence data and environmental data using unique schools identifier. Separate layers were created for school location, infection data and environmental data and which were used for map production. Infection prevalence for school was classified into five groups using WHO prevalence classification system, viz: (1) No infection, (2) Light infection 0.1-9.99%, (3) Moderate infection 10-24.9% (4) Heavy infection 25-49.9% and (5) Very heavy infection 50% and above for display in GIS. The spatial analysis was performed using Arc view. The estimated population of school-aged children at risk was calculated by over laying the predictive maps of infection prevalence on a population density map and total extracted. Parasites identified in the study were Ascaris lumbricoides (51.78%), hookworm (25.0%), Trichuris trichiura (15.18%), Strongyloides stercoralis (7.14%), Taenia sp. (0.89%), Enterobis vermicularis (0.01%). Current study estimated number of school-aged children (5-14years) at risk of intestinal parasitic infections in Rivers State to be 655,061 (0.65million). This estimate represented the school-aged populations living in areas where the environmental factors, when combined with host/parasite are suitable for the intestinal parasitic infections. The rate of infection showed that Emohua and Ahoada East and their environment need intervention. This study provided for the first time, the rate of infection, risk and prediction maps of prevalence of intestinal parasitic infections in Rivers State. It is hope that the map produced would help policy makers in the deployment of scarce available resources in the management of these diseases.