title: Occult Hepatitis B (OBH) in Clinical Settings.
abstract: BACKGROUND
  Occult hepatitis B (OHB), or persistent HBV DNA in patients who are hepatitis B surface antigen (HBsAg) negative, is a recently recognized entity. In an attempt to summarize the issues, this review presents an overview of the current proposed hypothesis on the clinical relevance and also updates the knowledge on the classification of OHB in different clinical settings.
  
  
  METHODS
  OHB COULD BE FOUND IN DIFFERENT POPULATION AND CLINICAL BACKGROUNDS INCLUDING: viral co-infections (with either human immunodeficiency or hepatitis C viruses), HBV chronic carriers, dialysis patients, transplantation settings and certain clinical situations (named in here: special clinical settings) with no apparent distinguishable clinical parameters.
  
  
  RESULTS
  The exact magnitude, pathogenesis, and clinical relevance of OHB are unclear. Even the possible role exerted by this cryptic infection on liver disease outcome, and hepatocellular carcinoma development remains unknown.
  
  
  CONCLUSIONS
  Monitoring of Individuals with positive anti-HBc, mass immunization programs and improvement in diagnostic tools seem to be important to control the probability of transmission of HBV through cryptic HBV infection.
authors.affiliation: Baqiyatallah Research Center for Gastroenterology and Liver Disease, Baqiyatallah University of Medical Sciences, Tehran, IR Iran.
authors.forename: Seyed Moayed
authors.initials: SM
authors.lastname: Alavian
authors.forename: Seyed Mohammad
authors.initials: SM
authors.lastname: Miri
authors.forename: F Blaine
authors.initials: FB
authors.lastname: Hollinger
authors.forename: Seyed Mohammad
authors.initials: SM
authors.lastname: Jazayeri
keywords: Coinfection; Hepatitis B; Hepatitis B Surface Antigens