URINARY-TRACT MORBIDITY DUE TO SCHISTOSOMA-HAEMATOBIUM INFECTION IN MALI

A total of 824 Malian villagers in a region endemic for Schistosoma (S .) haematobium were examined clinically, parasitologically and by abdo minal ultrasound. Systematic schistosomicidal treatment had never been applied to this population. Prevalence of S. haematobium infection ra nged from 77% in adolescents to 51% in adults older than 40 years. Int ensity of infection was generally mild 91% of all patients excreting l ess than 100 ova/10 ml urine. Bladder wall enlargement and irregularit ies, bladder masses, pseudopolyps and dilation of the upper urinary tr act were found ultrasonographically in about one third of infected ind ividuals. Bladder lesions were more frequent in children than in adult s and correlated with the intensity of infection in younger age groups only. Hydronephrosis was rear (7 of 824) and never seen in uninfected individuals. Prevalence of urinary tract pathology dropped significan tly with age (P < 0.001) and was lowest in patients older than 40 year s. Logistical regression identified age and infection as independent p arameters affecting the prevalence of urinary tract pathology (P < 0.0 01). We conclude that Schistosoma haematobium infection causes substan tial morbidity in children and younger adults. The reduction of urinar y tract morbidity in children and younger adults. The reduction of uri nary tract morbidity with age despite a considerable prevalence of inf ection in older age groups suggests spontaneous resolution during adul thood in most cases.