Clonal analysis of hepatitis B viruses among blood donors from Joinville, Brazil: evidence of dual infections, intragenotype recombination and markers of risk for hepatocellular carcinoma.

Hepatitis B virus (HBV) is classified into seven major genotypes (A-H). Brazil, a country of continental proportions, has three prevailing lineages of HBV genotypes A, D, and F. Distinct HBV genotypes have been associated with differential risk of disease progression.