title: Slow decline of hepatitis B burden in general population: Results from a population-based survey and longitudinal follow-up study in Taiwan.
abstract: OBJECTIVE
  Hepatitis B virus (HBV) infection poses a global public health threat. HBV vaccination has proven highly effective in preventing the infection; however, its long-term impact on the general population has not been addressed. We conducted analysis to determine the total and changing burden of chronic HBV infection and evaluate the serological status between vaccinated and unvaccinated in Taiwan.
  
  
  METHODS
  Participants in "The Taiwanese Survey on Prevalence of Hyperglycemia, Hyperlipidemia and Hypertension" in 2002 (n=6602), and 4088 with follow-up survey in 2007 were included. HBsAg (including titers), anti-HBs, anti-HBc, HBeAg, anti-HBe, HBV genotypes and viral loads were assayed. Prevalence and evolving patterns of these seromarkers was compared between vaccinated and unvaccinated cohorts and predictors of persistent HBsAg positivity and negativity were examined.
  
  
  RESULTS
  The overall prevalence of chronic HBV infection was 13·7% (95% CI, 12.9% to 14.5%) and about two thirds had past exposure (anti-HBc: 68·46%) in 2002. The vaccinated cohort tended to have lower prevalence of HBsAg and anti-HBc, and a higher proportion of anti-HBs and HBeAg positivity, genotype C and high viral load. The majority (85·42%) were consistently HBsAg negative while 12·65% were consistently positive, and 8·98% achieved seroclearance in a five-year period. In the vaccinated cohort, no subjects had acquired new exposure and became HBsAg positive, and only one (0.54%) cleared HBsAg, demonstrating the durability of vaccination through teenage and young adulthood.
  
  
  CONCLUSIONS
  This comprehensive, population-representative-survey shows that 20 years after universal vaccination, the backlog still composed a substantial burden of chronic HBV infections in Taiwan.
authors: Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan; Graduate Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
authors: Chi-Ling
authors: CL
authors: Chen
authors: Centers for Disease Control, Taipei, Taiwan.
authors: Jyh-Yuan
authors: JY
authors: Yang
authors: Centers for Disease Control, Taipei, Taiwan.
authors: Szu-Fong
authors: SF
authors: Lin
authors: School of Public Health, Fu Jen Catholic University, New Taipei City, Taiwan.
authors: Chien-An
authors: CA
authors: Sun
authors: Department of Public Health, College of Public Health and Nutrition, Taipei Medical University, Taipei, Taiwan.
authors: Chyi-Huey
authors: CH
authors: Bai
authors: Genomics Research Center, Academia Sinica, Taipei, Taiwan.
authors: San-Lin
authors: SL
authors: You
authors: Graduate Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan; Genomics Research Center, Academia Sinica, Taipei, Taiwan.
authors: Chien-Jen
authors: CJ
authors: Chen
authors: Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan; Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan; Hepatitis Research Center, National Taiwan University Hospital, Taipei, Taiwan.
authors: Jia-Horng
authors: JH
authors: Kao
authors: Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan; Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan; Hepatitis Research Center, National Taiwan University Hospital, Taipei, Taiwan. Electronic address: peijerchen@ntu.edu.tw.
authors: Pei-Jer
authors: PJ
authors: Chen
authors: Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan; Genomics Research Center, Academia Sinica, Taipei, Taiwan; Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan; Hepatitis Research Center, National Taiwan University Hospital, Taipei, Taiwan. Electronic address: chends@ntu.edu.tw.
authors: Ding-Shinn
authors: DS
authors: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D004279:DNA, Viral / Q000235:genetics*; D005260:Female; D005500:Follow-Up Studies; D006509:Hepatitis B / Q000453:epidemiology* / Q000517:prevention & control / Q000821:virology; D017325:Hepatitis B Vaccines / Q000627:therapeutic use*; D006515:Hepatitis B virus / Q000235:genetics* / Q000276:immunology; D006801:Humans; D008297:Male; D011159:Population Surveillance; D015995:Prevalence; D012189:Retrospective Studies; D013624:Taiwan / Q000453:epidemiology; D014611:Vaccination / Q000379:methods*; D019562:Viral Load; D055815:Young Adult
chemical_list: D004279:DNA, Viral; D017325:Hepatitis B Vaccines
keywords: HBV vaccination; Hepatitis B virus infection prevalence; Longitudinal follow-up survey; Population-based survey