The morbidity of schistosomiasis mansoni in the Rusizi Plain (Burundi).

A cross-sectional study was made of the morbidity due to Schistosoma mansoni infection in the Rusizi plain, Burundi. An evenly distributed 5% population sample (n = 6203) was examined; each subject was submitted to a standardized medical history and abdominal palpation. The prevalence of infection was 33% and most infections were light. Diarrhoea was complained of by 26% of those infected and 21% of those not infected; "bloody diarrhoea" by 13% and 4%, respectively. The association with schistosomiasis was significant in all age groups. "Abdominal pain" was a very common complaint, "tiredness" an infrequent one; neither was associated with the infection. Left lobe hepatomegaly was found in 26% of those infected, and in 10% of those not infected; right lobe hepatomegaly in 7% and 5%, and splenomegaly in 30% and 24%, respectively. The frequency of organomegaly and its association with schistosomiasis was maximal in children, decreased in adolescents and young adults, and increased again in older adults; its intensity was generally mild. Ascites or histories of haematemesis were not recorded, though several cases of decompensated portal hypertension due to schistosomiasis have been documented at the central hospital of Bujumbura. The relation of morbidity to intensity of infection was limited to a correlation between hepatomegaly and egg load in those over 40 years old. It is concluded that, in this situation, selective mass treatment is a better strategy than targeted or selected group chemotherapy.