New approaches to the measurement of morbidity in intestinal schistosomiasis.

New approaches for the assessment of morbidity due to schistosomiasis infection include the substitution of egg counts by quantitative assays for circulating schistosomal antigens, simple parameters for global immune responsiveness and functional hepatic alterations, and ultrasonography as an imaging technique. Quantification of circulating schistosome antigens in sera of S. mansoni, S. haematobium or S. intercalatum infected patients by sensitive immunoassays provides an exact measure for the individual worm burden. The effect of chemotherapy on immunomodulation was assessed by a panel of cutaneous recall antigens. Non-specific cell-mediated immune responses returned to subnormal pretreatment levels in the event of reinfection. Immunological morbidity can be monitored in this way. Pathophysiological alterations of the liver in S. mansoni infection can be assessed by the determination of unconjugated bile acids in the systematic circulation. The regression of intrahepatic vascular lesions in schistosomiasis with hepato(spleno)megaly can be detected earlier by this parameter than by ultrasonography. Ultrasonography provides characteristic, if not pathognomonic, images of Symmers fibrosis, and may be of value in the long-term evaluation of hepatic fibrosis.