Published online Dec 27, 2014. doi: 10.4254/wjh.v6.i12.860
Revised: September 23, 2014
Accepted: October 28, 2014
Published online: December 27, 2014
Core tip: Occult hepatitis B virus infection (OBI) is defined by the presence of hepatitis B virus (HBV) DNA without detectable hepatitis B surface antigen. The prevalence of OBI varies according to the different endemicity of HBV infection, cohort characteristics, and detection methods. Increasing research on OBI has been conducted with respect to the following: (1) transmission through transfusion, organ transplantation, or hemodialysis; (2) reactivation in an immunosuppression state; (3) contribution to the progression of chronic liver disease; and (4) increased risk for hepatocellular carcinoma. Further studies are needed to establish its clinical significance and management.