Morbidity of schistosomiasis mansoni in rural Alexandria, Egypt.

A parasitological survey of stool and urine of 2577 from 3281 individuals living in Abis villages, Alexandria was undertaken in 1998 in order to investigate the prevalence of schistosomiasis in this area and risk factors for hepatic morbidity. A random sample of 1082 individuals was interviewed using a questionnaire regarding risk factors for liver morbidity. All interviewed adults (total: 728) were clinically examined for evidence of organomegally (hepatomegally and/or splenomegally). Individuals with clinically detected organomegally were referred for detailed investigations (total: 65). The criteria for severe hepatic morbidity were AST/ALT ratio higher than 1, prothrombin activity < 70%, and evidence of portal hypertension. The results revealed that prevalence of S. mansoni accounted for 20.5%, with low intensity of infection and increased with age to reach a maximum of 40-46.3% at 15-30 years of age. Intensity of infection followed the same pattern. All tested urine samples were negative for S. haemato-bium. The prevalence of clinically detected organomegally was 10.3% among adults (75/728). Significant risk factors for developing organomegally were age > or = 35 years (2.2 folds), farming occupation (1.7 fold), history of parenteral anti-schisto-somal treatment (PAT) with or without tablets (2.03 folds), and heavy water canal exposure (2.85 folds). Detailed morbidity study on 65 individuals with clinically detected organomegally showed that 52.3% reported heavy score for water canal exposure, 33.8% were positive for HCV antibodies, and 7.7% for HBV antibodies. Procollagen level was higher than 5.5 microg/l in 26.2% of this group. The results of Doppler ultrasonography showed that 33.3% recorded a portal vein diameter > or = 13 mm, 26.2% periportal fibrosis more than grade 2 (> 5 mm), 19% hepatofugal direction of portal blood flow, 30.2% collaterals, 28.6% splenomegaly, and 17.5% hepatofugal direction of splenic blood flow. The burden of severe hepatic morbidity was alarming among this group: 33.8% with portal hypertension, 24.6% with prothrombin activity < 70, and 13.8% with AST/ALT ratio > 1. There was a 4.44 and 3.7 fold increased risk for portal hypertension with elevated levels of PIIIP and positive serologic tests for HCV and/or HBV infections, respectively. Similarly, a 4.58 and 18.35 fold increased risk for AST/ALT more than one was attributed to these two factors, respectively. Elevated procollagen level was significantly associated with viral infection (HCV and/or HbsAG). Seropositivity for HCV antibodies was found strikingly high in adults above 35 years (positive HCV antibodies in 45.9% of individuals). This indicates a high level of endemicity in the study area which is also endemic for S. mansoni. So, a heavy burden of severe liver disease exist in rural Alexandria is attributed to combined infection of S. mansoni and hepatitis viruses. This emphasizes the need for intervenetion strategies targeting these two main liver offenders.