title: Recent trends in hepatitis B virus infection in the general Korean population.
abstract: OBJECTIVE
  Hepatitis B virus (HBV) is the major cause of chronic liver disease in Korea, but viral prevalence has decreased because of hepatitis B vaccination programs. In this study, we investigated longitudinal changes in HBV in fection in the general Korean population.
  
  
  METHODS
  HBV surface antigen (hepatitis B surface antigen, HBsAg) seropositivity was assessed from the Korea National Health and Nutrition Examination Survey (I to V). In total, 50,140 subjects were tested for serum HBsAg positivity over a period of 12 years (1998 to 2010).
  
  
  RESULTS
  The prevalence of HBsAg seropositivity decreased over the study period. The rates of HBsAg carriers were 4.61% in 1998, 4.60% in 2001, 3.69% in 2005, 3.01% in 2008, and 2.98% in 2010 (p < 0.0001). The reduction in HBV infection rates was more prominent in younger age groups. Among teenagers (10 to 19 years), the percentage of HBsAg carriers decreased from 2.2% in 1998 to 0.12% in 2010 (p < 0.0001). Among those aged 10 to 39 years, the percentage of HBV infection decreased from 4.72% in 1998 to 2.29% in 2010 (p < 0.0001). However, no decreasing trend in HBsAg positivity was observed among those aged 50 or older (p > 0.05). Neither gender nor socioeconomic status were associated with the decreased prevalence of HBsAg carriers.
  
  
  CONCLUSIONS
  HBV infection has decreased in the Korean population since the advent of vaccination programs. However, the decrease is limited to the younger population, and viral persistence remains in the middle-aged and older population.
authors.affiliation: Department of Internal Medicine, Kyung Hee University Medical Center, Seoul, Korea.
authors.forename: Hyuck
authors.initials: H
authors.lastname: Kim
authors.forename: A Ri
authors.initials: AR
authors.lastname: Shin
authors.forename: Hoe Hoon
authors.initials: HH
authors.lastname: Chung
authors.forename: Min Kyoung
authors.initials: MK
authors.lastname: Kim
authors.forename: Ji Sung
authors.initials: JS
authors.lastname: Lee
authors.forename: Jae-Jun
authors.initials: JJ
authors.lastname: Shim
authors.forename: Byung-Ho
authors.initials: BH
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D015415:Biomarkers / Q000097:blood; D016009:Chi-Square Distribution; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006306:Health Surveys; D006509:Hepatitis B / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control; D006514:Hepatitis B Surface Antigens / Q000097:blood; D017325:Hepatitis B Vaccines / Q000627:therapeutic use; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D056910:Republic of Korea / Q000453:epidemiology; D016036:Seroepidemiologic Studies; D012959:Socioeconomic Factors; D013997:Time Factors; D055815:Young Adult
chemical_list: D015415:Biomarkers; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines
keywords: Age groups; Hepatitis B surface antigens; Hepatitis B virus; Korea; Prevalence