title: Declining hepatitis A seroprevalence in adults in Catalonia (Spain): a population-based study.
abstract: BACKGROUND
  One of the main uses of seroprevalence studies it to evaluate vaccination programmes. In 1998, a programme of universal vaccination of preadolescents in schools with the hepatitis A vaccine was begun in Catalonia. The objective of this study was to investigate the prevalence and risk factors of hepatitis A virus infection (HAV) in a sample of the adult population of Catalonia in 2002 and to evaluate the changes with respect to a survey carried out in 1996.
  
  
  METHODS
  The prevalence of HAV antibodies was determined by a third generation competitive immunometric assay in a representative sample of 1292 people aged >15 years. The association between the prevalence and different sociodemographic variables was determined by multiple logistic regression analysis.
  
  
  RESULTS
  The standardized global prevalence of HAV antibodies in 2002 was 68.2%, increased with age (p < 0.0001) and was associated with being born outside Catalonia (OR: 1.75; 95% CI 1.11-2.76) and lower social class (OR: 1.14; 95% CI 1.05-1.25). Compared with the last survey carried out in 1996 the standardized global prevalence was lower (68.2% vs 77.8%; p < 0.0001) as was the prevalence in people under 45 years.
  
  
  CONCLUSIONS
  The prevalence of the hepatitis A virus is decreasing in the adult population of Catalonia, especially in the younger age groups. The programme of vaccination of adolescents begun in 1998 to control the disease can provide indirect protection to the unvaccinated population.
authors.affiliation: Directorate of Public Health, Generalitat of Catalonia, Travessera de les Corts, Barcelona, Spain. angela.dominguez@ub.edu
authors.forename: Angela
authors.initials: A
authors.lastname: Domínguez
authors.forename: Miquel
authors.initials: M
authors.lastname: Bruguera
authors.forename: Pere
authors.initials: P
authors.lastname: Plans
authors.forename: Jordi
authors.initials: J
authors.lastname: Espuñes
authors.forename: Josep
authors.initials: J
authors.lastname: Costa
authors.forename: Antoni
authors.initials: A
authors.lastname: Plasencia
authors.forename: Lluis
authors.initials: L
authors.lastname: Salleras
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D005260:Female; D006506:Hepatitis A / Q000097:blood* / Q000453:epidemiology* / Q000517:prevention & control; D035922:Hepatitis A Antibodies / Q000097:blood*; D022362:Hepatitis A Vaccines / Q000008:administration & dosage / Q000276:immunology; D030041:Hepatitis A virus / Q000276:immunology; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D016036:Seroepidemiologic Studies; D013030:Spain / Q000453:epidemiology
chemical_list: D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines