Abdominal ultrasonography for assessing morbidity from schistosomiasis. 1. Community studies.

Portable abdominal ultrasonography has been used to measure community morbidity from schistosomiasis in schoolchildren and cross-sectional population samples and to assess efficacy of chemotherapy. Periportal fibrosis and hepatosplenomegaly have been common findings, usually associated with each other and with prevalence and intensity of infection as measured by faecal Schistosoma mansoni ova excretion. Similar, less severe, lesions have been noted in subjects infected with S. haematobium. Inhabitants of villages where praziquantel therapy was systematically provided had less periportal fibrosis and hepatosplenomegaly than those living in nearby villages where treatment was not available. Community-based screening in S. haematobium endemic areas has shown high prevalence of bladder wall thickening, irregularities, and polyps which were usually more frequent and severe in children and in those excreting most ova. Obstructive uropathy was frequent in most studies. Chemotherapy usually rapidly resolved the bladder wall abnormalities. In some studies hydronephrosis and hydroureter were more persistent. Reversibility of chronic, stable lesions in adults remains unproven.