title: Helicobacter pylori infection in children in Estonia: decreasing seroprevalence during the 11-year period of profound socioeconomic changes.
abstract: BACKGROUND
  The prevalence of Helicobacter pylori infection is inversely associated with socioeconomic conditions in childhood. In Estonia, a high prevalence of H. pylori infection has been observed among children born in 1987 and earlier. Since 1991, after the dissolution of the USSR, profound social and economic changes have taken place in the country. The aim of the study was to evaluate changes in the seroprevalence of H. pylori infection among children in the period 1991-2002.
  
  
  METHODS
  The hospital-based study population consisted of two groups of children enrolled in 1991 (n = 425) and 2002 (n = 296) according to the same inclusion criteria. The immunoglobulin G antibodies to the cell surface proteins of H. pylori were determined by enzyme-linked immunosorbent assay, and the sera with the borderline results were analyzed by immunoblot analysis. Multiple regression analysis was used to determine the associations between H. pylori seropositivity and different variables such as demographic characteristics, diagnoses and year of enrollment.
  
  
  RESULTS
  The only two variables linked independently to H. pylori serostatus were age and year of enrollment: the adjusted odds of being H. pylori seropositive were 1.92 [95% confidence interval (CI) 1.33-2.76] times higher for the children enrolled in 1991 compared with the children enrolled in 2002. The age-standardized seroprevalence rate was 42.2% (95% CI 37.4-47.0%) for the group of 1991 and 28.1% (95% CI 23.1-33.6%) for the group of 2002.
  
  
  CONCLUSIONS
  The prevalence of H. pylori infection among children has significantly decreased during the 11-year period of profound socioeconomic changes in Estonia.
authors.affiliation: Department of Polyclinic and Family Medicine, University of Tartu, Estonia. marje.oona@ut.ee
authors.forename: Marje
authors.initials: M
authors.lastname: Oona
authors.forename: Meeme
authors.initials: M
authors.lastname: Utt
authors.forename: Ingrid
authors.initials: I
authors.lastname: Nilsson
authors.forename: Oivi
authors.initials: O
authors.lastname: Uibo
authors.forename: Tamara
authors.initials: T
authors.lastname: Vorobjova
authors.forename: Heidi-Ingrid
authors.initials: HI
authors.lastname: Maaroos
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D000907:Antibodies, Bacterial / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D004957:Estonia / Q000453:epidemiology; D005260:Female; D016481:Helicobacter Infections / Q000453:epidemiology* / Q000382:microbiology; D016480:Helicobacter pylori / Q000276:immunology*; D006760:Hospitalization; D006801:Humans; D007223:Infant; D008297:Male; D016036:Seroepidemiologic Studies; D012959:Socioeconomic Factors
chemical_list: D000907:Antibodies, Bacterial