Distribution of hepatitis B virus genotypes in Europe and clinical implications: a review

: With an estimated 15 million infected persons in Europe, hepatitis B virus (HBV) infection is still one of the leading causes of chronic liver disease and associated mortality. The HBV infection prevalence in the general population depends on the region and ranges from 0.01% in Scandinavia to 10.3% in Kyrgyzstan. The prevalence of the 10 HBV genotypes (A-J) varies among different parts of the world, with genotypes A and D being most prevalent in Europe. Other HBV genotypes are mainly imported into Europe from other parts of the world and are rarely detected. HBV genotypes influence the clinical outcome of HBV infection, HBeAg seroconversion rates, and the frequency of mutations in the pre-core and core promoter regions. In addition, response rates to treatment with pegylated interferon alpha vary among HBV genotypes, whereas there is no influence of HBV genotypes on treatment response when using nucleoside/nucleotide analogues. Due to recent large-scale immigration to Europe, a change in HBV genotype distribution and the consequent clinical outcome of chronic hepatitis B may be expected in the near future.