title: Seropositivity to Helicobacter pylori and CagA protein in schoolchildren of different ages living in urban and rural areas in southern Estonia.
abstract: OBJECTIVE
  To evaluate Helicobacter pylori and CagA seropositivity in a non-selected group of schoolchildren in southern Estonia, with reference to previous studies where high seroprevalence to H. pylori (87%) and anti-CagA positivity (63%) in an adult population from the same region were found.
  
  
  METHODS
  A total of 421 schoolchildren selected haphazardly from a random population (n = 1018, ages 9, 12 or 15 years) and living in urban or rural areas.
  
  
  METHODS
  H. pylori status was determined by evaluation of IgG antibodies against cell surface proteins of H. pylori, strain CCUG 17874, using standard ELISA. Anti-CagA IgGs were determined by ELISA using a recombinant fragment of CagA (CCUG 17874) as solid-phase antigen. Absorbance values > 0.3 (405 nm) were taken as a CagA-positive result based on a study of 25 sera from H. pylori-negative children.
  
  
  RESULTS
  Of the 421 subjects, 235 (56%) were H. pylori-ELISA positive, and 109 out of the 235 (46%) were anti-CagA positive. Neither H. pylori nor CagA positivity were significantly different in girls and boys, or in children aged 9, 12 or 15 years. The H. pylori prevalence rate (118/181, 65%) as well as CagA positivity (64/181, 35%) in rural areas were higher compared with those in towns (117/240, 49% and 54/240, 22%, respectively; P = 0.001 and P = 0.005).
  
  
  CONCLUSIONS
  Of schoolchildren living in southern Estonia, 56% were seropositive to H. pylori. Half of them had anti-CagA antibodies. Schoolchildren living in rural areas were infected significantly more often with CagA-seropositive strains compared with those living in towns.
authors.affiliation: Department of Immunology, University of Tartu, Estonia. tamara@imlab.ut.ee
authors.forename: T
authors.initials: T
authors.lastname: Vorobjova
authors.forename: H
authors.initials: H
authors.lastname: Grünberg
authors.forename: M
authors.initials: M
authors.lastname: Oona
authors.forename: H I
authors.initials: HI
authors.lastname: Maaroos
authors.forename: I
authors.initials: I
authors.lastname: Nilsson
authors.forename: T
authors.initials: T
authors.lastname: Wadström
authors.forename: A
authors.initials: A
authors.lastname: Covacci
authors.forename: R
authors.initials: R
authors.lastname: Uibo
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology*; D001426:Bacterial Proteins / Q000097:blood / Q000276:immunology*; D002648:Child; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D004957:Estonia / Q000453:epidemiology; D005260:Female; D016481:Helicobacter Infections / Q000097:blood / Q000453:epidemiology* / Q000276:immunology; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D008297:Male; D012424:Rural Population; D016036:Seroepidemiologic Studies; D014505:Urban Population
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori