Evaluation of reagent strips in urine tests for detection of Schistosoma haematobium infection: a comparative study in Ghana and Zambia

摘要

The presence of haematuria and proteinuria, detected by reagent strips, was compared with Schistosoma haematobium egg counts in the urines of human subjects from two epidemiologically distinct areas in Ghana and Zambia. In children and adults in both areas, the individual or combined semiquantitative levels of proteinuria and haematuria were related directly to increasing urinary egg counts. In both areas the presence of blood in the urine was highly specific (greater than 85%) and sensitive, being positive in 97% of urine specimens with more than 64 eggs per 5-ml sample of urine. The sensitivity of the protein indicator was also high, but its specificity was less than the blood indicator. The specificity of combined proteinuria and haematuria was higher than either alone; on the other hand, the sensitivity was lower than either alone. At each level of proteinuria and haematuria, the geometric mean urinary egg count was higher in Ghana than in Zambia. This study confirms the necessity to evaluate indirect diagnostic techniques in each endemic country, in order to establish criteria for their interpretation, before wide-scale use.