HEPATITIS-B AND HEPATITIS-C PREVALENCES AMONG BLOOD-DONORS IN THE SOUTH REGION OF BRAZIL

The prevalence of hepatitis B and C infection has been determined in a seroepidemiological survey among blood donors from the south of Brazil (Florianopolis, State of Santa Catarina). These markers has also been correlated with the levels of alanine aminotransferase (ALT), a surrogate marker to prevent post-transfusion hepatitis. Sera from 5000 donors were randomly collected in the period of April to November 1991. The prevalences of HBsAg, anti-HBs and anti-HBc were respectively 0.78%, 7.02% and 13.98%. The anti-HCV prevalence after confirmation testing with line immunoassay (LIA), was 1.14%. Normal values of ALT (< =32 U/ml) were found in 59.78%, values slightly above the mean (ALT between 32-70 U/ml) in 37.74% and high values of ALT (>=70 U/ml) in 2.48%. The positivity of anti-HCV antibodies increased with the elevation of ALT levels. This correlation was not observed in relation to HBsAg. There exists a diversity in the recognition of HCV epitopes among HCV positive donors. Via the confirmation test used, we could observe that 94.7% of donors recognize the structural core antigen. Besides that, we observed that 5.26% of the HCV reactive sera recognized only epitopes located in the NS4 and/or NS5 region, indicating the importance of these epitopes for the improvement of assays.