Prevalence and Intensity of Schistosomiasis in Adjacent Human Communities along the River Kochi, West Nile Region of Uganda

Aim: To assess the prevalence of Schistosomiasis in adjacent human communities along the River Kochi, West Nile region of Uganda in relation to the presence of infected Biomphalaria snails
Study Design: A combination of cross sectional field survey and laboratory analysis
Place and Duration of Study: This study was conducted between October 2007 and March 2008 along the River Kochi in the West Nile Region, Uganda.
Methodology: Five sites along this river that were approximately 20km apart were selected. Stool samples were collected from 40 randomly selected families, 20 living within 3km from the river banks and 20 beyond 3km. Four hundred and eighty nine stool samples (157 from children, 159 from adolescents and 173 from adults) were analysed and examined using standard methods for the presence of Schistosoma Mansoni cercariae on a monthly for a period of six months. Biomphalaria species snails living in the river were collected using a sweep net and screened for the presence of S. mansoni cercariae. A generalised Linear Model was used to establish associations between human parasitic infections with age and gender. Spearman’s rank correlations coefficient was used to explore the relationship between infected Biomphalaria snail numbers and infection incidence in humans.
Results: Percentage infection of 24.1% (118/459) was recorded. Prevalence of Schistosomiasis was lower in children than in adolescents (P=.001) and adults (P=.013), and was overall slightly higher in males than females (P=.014). A Spearman’s rank correlations coefficient of (rs=.710) revealed that there was a link between infected Biomphalaria snail numbers and infection incidence in humans.
Conclusion: From the results it appears that Schistosomiasis is still present in West Nile region and is associated with the presence of infected Biomphalaria snail species. Male adolescents and adults are more prone to infection than the females. There is need for regular surveys and continuous Schistosomiasis education to the communities.