The usefulness of urinalysis reagent strips in selecting Schistosoma haematobium egg positives before and after treatment with praziquantel

The effectiveness of urinalysis reagent strips for haematuria and proteinuria in selecting Schistosoma haematobium egg-positive persons was studied on 426 subjects of all ages in a Kenyan community before and 3 months after treatment with praziquantel. Before and after treatment, the degree of urinary blood or protein and prevalence of egg positives were closely associated. Haematuria and proteinuria were positively correlated with urinary egg counts. For selecting egg-positive persons with reagent strips, a combined criterion 'haematuria trace up or proteinuria 1+ up' was considered the best in this area. With this criterion, sensitivity and specificity before treatment were 69.6 and 84.4 respectively. These values remained at the same level (70.7 and 81.2%) even after treatment with praziquantel reduced prevalence from 59.4 to 13.6% (77% reduction) and intensity of infection from 57.2 to 11.3 eggs 10 ml-1 of urine (80% reduction). Although the sensitivity was not very high, heavy infections were not missed. If all those selected with reagent strips were treated and cured, a 98% reduction in total egg excretion by the community would be expected in both our first and second urine examinations.