title: Association of hepatitis A virus infection with allergic sensitization in a population with high prevalence of hepatitis A virus exposure.
abstract: BACKGROUND
  An inverse association between allergic sensitization and markers of exposure to food-borne and orofecal infections (particularly hepatitis A virus, HAV) has been reported. The prevalence of HAV exposure and allergic sensitization vary widely in different areas, and vary along with age within a given area.
  
  
  OBJECTIVE
  To investigate the association between HAV exposure and allergic sensitization in adults from a mostly rural area of Spain.
  
  
  METHODS
  An age-stratified random sample of 720 subjects was drawn from the population older than 18 years of A-Estrada, Spain. From 697 eligible subjects, 469 (67.2%, median age 54 years, range: 18-92) participated in the study. Positive skin prick tests to a panel of aeroallergens defined allergic sensitization. Positive serum HAV antibodies (assayed in 465 subjects) defined HAV exposure.
  
  
  RESULTS
  The prevalence of HAV exposure was 83.6% (95% CI: 80.7-86.5). The prevalence of allergic sensitization was lower in subjects with HAV exposure than in patients without it (25.0%vs 40.0%, OR 0.44, 95% CI: 0.25-0.77, P=0.004), but this association became substantially altered after adjusting for age, which was closely linked to both allergic sensitization and HAV exposure (adjusted OR 1.15, 95% CI: 0.60-2.19, P=0.66).
  
  
  CONCLUSIONS
  In a population with high prevalence of HAV exposure, no significant association between HAV exposure and allergic sensitization is observed after controlling for the confounding effect of age.
authors.affiliation: Department of Internal Medicine, Complejo Hospitalario Universitario de Santiago, Santiago, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Gonzalez-Quintela
authors.forename: F
authors.initials: F
authors.lastname: Gude
authors.forename: O
authors.initials: O
authors.lastname: Boquete
authors.forename: A
authors.initials: A
authors.lastname: Aguilera
authors.forename: J
authors.initials: J
authors.lastname: Rey
authors.forename: L M
authors.initials: LM
authors.lastname: Meijide
authors.forename: M C
authors.initials: MC
authors.lastname: Fernandez-Merino
authors.forename: C
authors.initials: C
authors.lastname: Vidal
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood*; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D006506:Hepatitis A / Q000150:complications*; D030041:Hepatitis A virus / Q000276:immunology*; D006801:Humans; D006967:Hypersensitivity / Q000150:complications* / Q000453:epidemiology; D008875:Middle Aged; D015995:Prevalence; D012424:Rural Population / Q000706:statistics & numerical data; D013030:Spain / Q000453:epidemiology
chemical_list: D000914:Antibodies, Viral