Introduction Chronic hepatitis B virus (HBV) infection is a widely prevalent global health problem with estimate 350-400 million chronic HBV carriers worldwide. In China, Southeast Asia and sub-Saharan Africa, as many as 10-15% of the population are chronically infected with HBV. In North America and North Europe, HBV chronic carrier rates are much lower, usually below 1%. Intermediate HBV carrier rates of 1-7% are found in parts of Southern and Eastern Europe, Central America, the Middle East and parts of Japan (1-4).