Descriptive epidemiology of chronic hepatitis B by using data from a hepatitis registry in Central Greece.

Background: In Greece, there are few data on the epidemiological characteristics of HBV. Our aim was to study the epidemiological patterns of HBV in Central Greece and identify the possible differences in HBV prevalence (clusters) among areas inside this region using data from the hepatitis registry.
Methods: The study was performed in Thessaly, one out of the thirteen regions of Greece and covers most of the part of Central Greece. A total of 921 HBV patients were registered in the hepatitis registry during the period 1999-2004 while 303 were randomly selected to be studied further using a detailed questionnaire on several epidemiological factors.
Results: 187/303 patients (61.7%) classified as chronic inactive HBV carriers, 78/303 (25.7%) had chronic hepatitis B, 29/303 (9.6%) had HBV-related cirrhosis and 9/303 (3%) HBV-related hepatocellular carcinoma (HCC). The route of HBV transmission was vertical in 103 (34%), sexual in 46 (15.1%) and intrafamilial in 98 (32.4%). Folk remedies were identified as the predisposing risk factor for contracting HBV infection in 38 (12.5%), previous transfusion in 9 (3%) and unknown mode of transmission in 9 patients (3%). Alcohol abuse was the only independent factor (OR: 2.5; p=0.01) associated with the progression to cirrhosis-HCC. There were specific areas (clusters) inside Thessaly region with increased ratio of HBV infection; Vertical and sexual modes of transmission were more prominent in some of these areas.
Conclusions: Vertical, intrafamilial and sexual modes of HBV transmission identified as the major routes of HBV infection in our study. We also identified cluster areas of HBV infection in Central Greece. Alcohol abuse is frequent among HBV patients and is acting as an effect modificator risk factor for the development of HBV-related cirrhosis and HCC. Extended population studies in Greece are needed to assess in detail the epidemiological patterns of HBV and evaluate control programmes.