Characterization of hepatitis B virus in Turkish blood donors, and the prevalence of the SP1 splice variant.

Hepatitis B is a disease of the liver that can manifest acutely, or persist chronically as a result of infection with the hepatitis B virus (HBV). Turkey has a moderate endemicity level of HBV infection, and all data published to date has shown this to be of genotype D, predominantly of subgenotype D1. However the sequences of very few full genomes have been published. The aim of this study was to characterize the molecular profile of hepatitis B virus in asymptomatic, first-time Turkish blood donors. The results confirm that genotype D, subgenotype D1 is the most prevalent HBV strain in Turkey, accounting for 94% of cases. Subgenotypes D2 and D3 were present as minority strains (4% and 2%, respectively). A singly spliced HBV variant that is capable of forming defective HBV particles and has been associated with apoptosis and activation of T-cell responses was also detected in 52.5% of samples screened, co-circulating with wild type genomes.