Schistosoma mansoni-related morbidity on Ukerewe Island, Tanzania: clinical, ultrasonographical and biochemical parameters

1695 people in three rural villages on Ukerewe Island Lake Victoria Tanzania were examined by clinical parasitological ultrasonographic and serological means in a study of Schistosoma mansoni-related morbidity at the community level. Villagers frequently complained of typical colitis symptoms including abdominal pain bloody stools and diarrhea. Hematemesis however was rare. 16.9% of the population had been given praziquantel previously. The overall prevalence of S. mansoni was 86.3% with a median and maximum egg output of 176 and 17984 eggs per gram respectively. Children and adolescents were infected more severely than adults men more severely than women. The pretreated individuals excreted significantly fewer ova. Hepatomegaly was present in 35% of the population splenomegaly in 80% and organomegaly was significantly related to egg output. Pretreated persons also had lower rates of splenomegaly and left lobe hepatomegaly. Low-degree periportal fibrosis was common severe grades of fibrosis were present among 6% approximately 10% had other abnormalities on liver sonography and passed significantly more ova than others and clear sonographic signs of portal hypertension were seen in 2.1%. Serum procollagen-IV-peptide and gamma-glutamyltransferase levels were increased in persons with severe periportal fibrosis irregular liver texture or portofugal collateral vessels.