title: Occult hepatitis B virus and the risk for chronic liver disease: a meta-analysis.
abstract: BACKGROUND
  The role of occult hepatitis B virus infection as a cause of liver disease is still debated although many studies found a higher prevalence of this condition in subjects than those without liver disease compared. A recent meta-analysis showed an increased risk of hepatocellular carcinoma for occult hepatitis B virus infection.
  
  
  OBJECTIVE
  We carried out a meta-analysis of observational studies to summarize the existing evidence and assess quantitatively the association between occult hepatitis B virus infection and chronic liver disease.
  
  
  METHODS
  We searched the available literature on this issue published up to May 2012 using PubMed and EMBASE. All articles that provided enough information to estimate the chronic liver disease risk associated with occult hepatitis B virus infection were selected. Fourteen studies were retrieved.
  
  
  RESULTS
  A total of 1503 subjects with (cases) and 2052 without chronic liver disease (controls) were included. The summary odds ratio for chronic liver disease from all studies was 8.9 (95% confidence interval: 4.1-19.5). The meta-analysis restricted to 7 studies with more precise effect estimate (wt%>8%) provided a lower odds ratio estimate (odds ratio=3.9; 95% confidence interval: 1.7-9.0).
  
  
  CONCLUSIONS
  These findings suggest a relevant association between occult hepatitis B virus infection and chronic liver disease, confirming the hypothesis that hepatitis B virus may play a pathogenic role even in the "occult" status.
authors.affiliation: Institute of Hygiene, Epidemiology and Public Health, University of Brescia, Brescia, Italy. covolo@med.unibs.it
authors.forename: Loredana
authors.initials: L
authors.lastname: Covolo
authors.forename: Teresa
authors.initials: T
authors.lastname: Pollicino
authors.forename: Giovanni
authors.initials: G
authors.lastname: Raimondo
authors.forename: Francesco
authors.initials: F
authors.lastname: Donato
mesh_terms: D004279:DNA, Viral / Q000302:isolation & purification*; D006515:Hepatitis B virus / Q000235:genetics; D019694:Hepatitis B, Chronic / Q000150:complications*; D006521:Hepatitis, Chronic / Q000821:virology*; D006801:Humans; D008103:Liver Cirrhosis / Q000821:virology*; D008107:Liver Diseases / Q000821:virology; D016017:Odds Ratio
chemical_list: D004279:DNA, Viral