title: Prevalence of occult hepatitis B virus infection in a general adult population in Korea.
abstract: OBJECTIVE
  We investigated the prevalence of hepatitis B virus (HBV) markers and occult HBV infection in a general adult population in Korea.
  
  
  METHODS
  HBsAg, anti-HBs and anti-HBc were analyzed on 1,091 samples of routine medical check-up examinees by chemiluminescence immunoassay. Nucleic acid amplification test (NAT) was performed on 1,047 HBsAg-negative samples by multiplex real-time polymerase chain reaction (PCR) kit for simultaneous detection of HBV, hepatitis C virus, and human immunodeficiency virus (Cobas Taqscreen MPX) in pools of six and reactive pools were resolved to individual samples, and further discriminated by PCR-based assay for HBV (Cobas Ampliscreen HBV).
  
  
  RESULTS
  The prevalences of HBsAg, anti-HBc, and anti-HBs were 4.0, 39.3, and 75.4%, respectively. The prevalence of anti-HBc significantly decreased with decreasing age (p< 0.001). Occult HBV infection was found in 7 (0.7%) of 1,047 HBsAg-negative subjects, and 5 of them were anti-HBc-negative. Sequencing of HBV S gene in 3 cases revealed one wild-type and two mutant strains (W74S, F85Y; T63I, W74S, T131N substitutions).
  
  
  CONCLUSIONS
  This study helps to understand the current status of hepatitis B infection and the prevalence of occult HBV infection in a general adult population in Korea.
authors.affiliation: Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Song
authors.forename: Yeo Min
authors.initials: YM
authors.lastname: Yun
authors.forename: Myoung Hee
authors.initials: MH
authors.lastname: Park
authors.forename: Dong Hee
authors.initials: DH
authors.lastname: Seo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004279:DNA, Viral / Q000302:isolation & purification*; D005260:Female; D006678:HIV / Q000235:genetics / Q000302:isolation & purification; D016174:Hepacivirus / Q000235:genetics / Q000302:isolation & purification; D006509:Hepatitis B / Q000453:epidemiology*; D006510:Hepatitis B Antibodies / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000097:blood; D006515:Hepatitis B virus / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D007723:Korea / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D020125:Mutation, Missense; D016133:Polymerase Chain Reaction / Q000379:methods; D015995:Prevalence; D017422:Sequence Analysis, DNA; D014759:Viral Envelope Proteins / Q000235:genetics; D055815:Young Adult
chemical_list: D004279:DNA, Viral; D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; C118669:S envelope protein, hepatitis B virus; D014759:Viral Envelope Proteins