In five settlements on Lake Volta, Ghana, 230 persons infected with S. haematobium were treated with either 30 or 40 mg/kg of praziquantel. Both treatment regimes gave similar overall cure rates (60%) and reduction in geometric mean egg counts (92%) at a six-month follow-up. In this highly endemic area, 32% of the initial urine specimens were visibly bloody and only 4% remained bloody after treatment. Geometric mean egg counts of visibly bloody urine specimens were two to six times higher than normal appearing urine specimens.
In children under 15 years of age, gross hematuria was reduced by 91% and hematuria as detected by reagent strips was reduced by 77% after treatment with praziquantel. Among adults, gross hematuria was reduced by 76% and hematuria as detected by reagent strips was reduced by 68%. Reduction was observed in 74% of all persons with 100 mg of protein/100 ml of urine or more prior to treatment.
The cure rate with praziquantel was only 36.1% in children who had visibly bloody urine specimens associated with high geometric mean egg counts prior to treatment. The lowest cure rate (15.4%) was observed in persons with persistent hematuria and proteinuria after treatment although the geometric mean urinary egg count was reduced 84%. In infected individuals without hematuria or proteinuria prior to treatment, the cure rate was 96%.
This study demonstrated that praziquantel reduced clinical signs due to S. haematobium infection as well as achieved a high cure rate and/or reduction of egg excretion. Conversely, individuals with clinical signs of hematuria and proteinuria had a lower cure rate with praziquantel than individuals without clinical signs.