Prevalence of HBs-Ag in schistosomiasis. (A) general aspects.

Nine hundred and sixteen schistosomal patient together with 97 non-schistosomal controls were examined for the presence of HBs-Ag and anti-HBs in their sera by counter-immunoelectrophoresis (CIEP). The results are reported and statistically analysed. HBs-Ag, anti-HBs and the exposure rate were found significantly higher in schistosomal patients than in controls. The frequency of HBs-Ag was not significantly different in the active and inactive schistosomal groups, while the anti-HBs was significantly higher in the inactive group. S. mansoni-infected cases showed significantly higher frequency of HBs-Ag and anti-HBs than cases with S. haematobium. The prevalence of HBs-Ag was highest between 20-39 years of age in the schistosomal group, while the anti-HBs was maximum at the age of 30-39 years. There were no sex differences in the prevalence of HBs-Ag and anti-HBs in both schistosomal and control groups. However, a significantly higher frequency of anti-HBs was found between male patients and male controls. The same was true for females. Patients with history of parenteral anti-bilharzial treatment and blood transfusions were accompanied with significantly higher percentage of HBs-Ag and anti-HBs. The importance and significance of the results are discussed.