Circulating anodic and cathodic antigen in serum and urine from Schistosoma haematobium-infected Cameroonian children receiving praziquantel: a longitudinal study.

A cohort of 148 Cameroonian children infected with Schistosoma haematobium was followed before praziquantel therapy and 1, 2, 3, 5, and 12 months thereafter. Egg output, the reagent strip index (RSI, a pathological marker), and circulating anodic antigen (CAA) and circulating cathodic antigen (CCA) in serum and urine were quantified. At enrollment, the median level of egg output was 365/10 mL of urine; 97% of children had a positive RSI; CAA was detected in serum from 76% of children and in urine from 64%; and CCA was detected in serum from 55% of children and in urine from 87%. Two months after chemotherapy, egg output and RSI had decreased significantly; reinfection later developed in parallel with increases in the serum and urine concentrations of CAA and the urine concentrations of CCA. The measurement of CAA and CCA is useful for diagnosis, evaluation of disease severity, and follow-up of chemotherapy in individuals infected with S. haematobium.