title: Hepatitis A virus infection in Taipei in 1999.
abstract: OBJECTIVE
  Hepatitis A is a disease that is heavily affected by sanitation status. Hepatitis A is much less prevalent compared with decades ago in Taiwan, as in many rapidly developing regions. Hepatitis A vaccine is still self-paid under the National Health Insurance program and is still not widely utilized by the general public in Taiwan. This seroepidemiologic study evaluated the prevalence of antihepatitis A virus (anti-HAV) seropositivity in Taipei in 1999.
  
  
  METHODS
  A total of 1017 serum samples from healthy inhabitants in Taipei were examined for anti-HAV antibody by qualitative enzyme immunoassay.
  
  
  RESULTS
  The overall seroprevalence rate was 25.2% (255/1013) in the nonvaccinated population. The seropositivity rate for anti-HAV antibody among children younger than 12 months old was 23.3%. The rates dropped to between 1% and 4.8% among subjects between 1 and 20 years of age. A markedly higher rate of 40% was observed in subjects aged between 20 and 30 years. The seropositivity rate in subjects aged 31 to 50 was 80%. More than 90% of subjects older than 50 years were seropositive. The vaccination rate was low (0.5%).
  
  
  CONCLUSIONS
  Our findings indicate that Taipei is an area of intermediate endemicity for hepatitis A virus. To achieve better herd immunity, a more active approach to the adoption of hepatitis A vaccine is warranted.
authors.affiliation: Department of Pediatrics, National Taiwan University Hospital, 7 Chung-Shan South Road, Taipei, Taiwan.
authors.forename: H Y
authors.initials: HY
authors.lastname: Tseng
authors.forename: C Y
authors.initials: CY
authors.lastname: Lu
authors.forename: C Y
authors.initials: CY
authors.lastname: Lee
authors.forename: C C
authors.initials: CC
authors.lastname: Yeh
authors.forename: S C
authors.initials: SC
authors.lastname: Lin
authors.forename: W Y
authors.initials: WY
authors.lastname: Shih
authors.forename: S Y
authors.initials: SY
authors.lastname: Wu
authors.forename: M H
authors.initials: MH
authors.lastname: Chang
authors.forename: L M
authors.initials: LM
authors.lastname: Huang
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D006506:Hepatitis A / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D022362:Hepatitis A Vaccines / Q000276:immunology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D016036:Seroepidemiologic Studies; D013624:Taiwan / Q000453:epidemiology; D013997:Time Factors; D014195:Travel; D014611:Vaccination
chemical_list: D022362:Hepatitis A Vaccines