title: Age at acquisition of Helicobacter pylori infection: comparison of two areas with contrasting risk of gastric cancer.
abstract: BACKGROUND
  Helicobacter pylori infection is usually acquired during childhood and is a known risk factor for the development of gastric malignancies in adulthood. It has been reported that early age at first infection may determine a neoplastic outcome in adults. The purpose of this study was to determine the prevalence of Helicobacter pylori infection in children residing in areas with high (Pasto) and low risk (Tumaco) of gastric cancer in Colombia to evaluate whether differences in the age of acquisition of H. pylori infection were present in the two populations.
  
  
  METHODS
  The study sample was based on a census taken in 1999. Using the (13)C-urea breath test, we compared the prevalence of H. pylori infection among children aged 1-6 years.
  
  
  RESULTS
  Among 345 children in Pasto, 206 (59.7%) were H. pylori-positive, compared with 188 (58.6%) among 321 children in Tumaco. The two populations share a common pattern of very early age at infection and marked increase in prevalence during the first 4 years of life. No differences in any one year were observed when comparing the two groups.
  
  
  CONCLUSIONS
  The prevalence of infection was similarly high and increased with age in both populations. In these populations the age of acquisition of H. pylori after 1 year of age does not appear to be a primary factor responsible for the differences in the rates of gastric cancer incidence in adults. Previous findings in adults showed lower prevalence of the most virulent genotypes in Tumaco compared to Pasto, and bacterial virulence may play a key role in determining cancer outcome.
authors.affiliation: Department of Pathology, Louisiana State University Health Science Center, New Orleans 70112, USA.
authors.forename: M Constanza
authors.initials: MC
authors.lastname: Camargo
authors.forename: M Clara
authors.initials: MC
authors.lastname: Yepez
authors.forename: Cristina
authors.initials: C
authors.lastname: Ceron
authors.forename: Nancy
authors.initials: N
authors.lastname: Guerrero
authors.forename: Luis E
authors.initials: LE
authors.lastname: Bravo
authors.forename: Pelayo
authors.initials: P
authors.lastname: Correa
authors.forename: Elizabeth T H
authors.initials: ET
authors.lastname: Fontham
mesh_terms: D017668:Age of Onset; D000886:Anthropometry; D001944:Breath Tests; D002648:Child; D002675:Child, Preschool; D003105:Colombia / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D007223:Infant; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000175:diagnosis / Q000453:epidemiology*