Diagnostic performance of screening methods for urinary schistosomiasis in a school-based control programme, in Ibadan, Nigeria

Abstract

Background: Indirect diagnostic methods in urinary schistosomiasis are widely used for screening high-risk populations in endemic areas. Their diagnostic performances, however, vary. The objective of this study was to assess their usefulness in the context of a school-based control programme Methods: An assessment of screening methods of urinary schistosomiasis was carried out among junior students in a secondary school. Interview technique (unqualified haematuria, terminal haematuria and dysuria), visual examination of urine and chemical reagent technique were each compared with microscopic examination of urine for schistosome ova. Results: Chemical reagent strip technique was the most sensitive of all indirect methods assessed with sensitivity of 68.3%, followed by unqualified haematuria (41.7%), terminal haematuria (38.2%), dysuria (25.0%) and visual urine examination (16.7%). In terms of specificity, terminal haematuria and visual examination were the most specific with values of 96.1 and 96.0% respectively. Conclusion: The validity of screening methods agreed with previous observations. Their use, however, depends on the endemicity of schistosomiasis in a given area. There is therefore a need to evaluate screening methods on a sample of the target population before being used to estimate prevalence of disease