Evaluation of the reagent strip test for haematuria in the control of Schistosoma haematobium infection in schoolchildren

Several recent reports have indicated the potential of the reagent strip test for haematuria in the diagnosis of Schistosoma haematobium infection. Approximately 15 000 schoolchildren from a population of 40 000 people were examined for reagent strip microhaematuria on three occasions between 1986 and 1987 and treated with praziquantel 40 mg/kg if positive. The reagent strip was evaluated against a single filtration of 10 ml urine for S. haematobium eggs. Initially 65.9% of children were treated followed by 37.5% at the second examination 6 months later and 44.5% at the third examination a further 12 months later. Reagent strip sensitivity was shown to be related to the intensity of infection. The reagent strip specificity improved significantly with successive treatments indicating that haematuria was more sensitive than parasitology for light infections. The amount of S. haematobium reinfection was highest in the 7–9 year olds decreasing to the 16–20 year age group which suggested an impact of protective immunity. It was concluded that microhaematuria is a valuable indicator for the diagnosis of S. haematobium in national control programmes and can be substituted for parasitological examination with advantage but sensitivity and specificity should continue to be evaluated throughout the programme.