Distribution of HCV genotypes among different exposure categories in Brazil

Hepatitis C virus (HCV) infection is widespread and responsible for more th an 60% of chromic hepatitis cases. HCV presents a genetic variability which has led to viral classification into at least 6 genotypes and a series of subtypes. These variants present characteristic geographical distribution, but their association with different responses to treatment with interferon and severity of disease still remains controversial. The aim of this study was to investigate the patterns of distribution of HCV genotypes among dif ferent exposure categories in Brazil. Two hundred and fifty anti-HCV positi ve samples were submitted to HCV-RNA detection by RT-PCR and their genotype was determined by restriction fragment length polymorphism (RFLP) analysis . In addition, the genotype/subtype of 60 samples was also determined by a reverse hybridization assay. HCV 1 was the most prevalent (72.0%), followed by type 3 (25.3%), HCV 2 (2.0%) rind HCV 4 (0.7%). The HCV genotype distri bution varied among the different exposure categories, with HCV 1 being mor e frequent among blood donors, hemophiliacs and hemodialysis patients. A hi gh frequency of HCV 3 was observed in cirrhotic patients, blood donors from the South of Brazil and injecting drug users (IDUs). The general distribut ion of the HCV genotype in Brazil is similar to that in other regions of th e world.