Epidemiology and genotyping of patients with chronic hepatitis B: genotype shifting observed in patients from Central Europe

Background: Knowledge on HBV prevalence and genotype distribution in Europe still is hampered by lack of coherent data sampling, small numbers of patients studied so far, and also modern times migration which influences both parameters in a quite dynamic manner. To find out whether HBV prevalence and genotype distribution has undergone any significant changes over the past decades, we have analyzed our cohort of HBV patients. Methods: Retrospective analysis of virological data and correlation with the epidemiological backgrounds of 408 chronically HBV-infected patients, followed in the year 2009 at Tübingen Virus Hepatitis Center, Germany. Results: A background of migration was found in more than 80% of our HBV patients, displaying an origin from 41 different countries. Analysis of the genotypes revealed that genotype A predominated only among patients from Central Europe with 55.8% while genotype D, known to be most common worldwide, was most prevalent in patients born in Eastern and Southern Europe, Central Asia and Middle East, exhibiting a range from 81% to 94%. In Central Europe, genotype A was particularly seen in older patients as compared to genotype D that predominated in the younger patients. Conclusions: These data suggest that Central Europe is straight on its way to switch from genotype A to genotype D. One reason for this significant shift may be related to the ongoing European and global migration flow.