title: Age at acquisition of Helicobacter pylori infection: a follow-up study from infancy to adulthood.
abstract: BACKGROUND
  Helicobacter pylori infection is common worldwide, but the time of acquisition is unclear. We investigated this issue in a cohort of children selected retrospectively from a population followed up for 21 years.
  
  
  METHODS
  We monitored 224 children (99 black, 125 white; 110 male, 114 female) from 1975-76 (ages 1-3 years) to 1995-96. H pylori status was assessed by presence of serum IgG antibodies.
  
  
  RESULTS
  18 (8.0%) children at age 1-3 years had H pylori antibodies (13% black vs 4% white children, p=0.008). By age 18-23 years, the prevalence of the infection was 24.5% (43% black vs 8% white participants, p< 0.0001). Of the 206 children not infected at baseline, 40 (19%) became infected by age 21-23. The crude incidence rate per year was 1.4% for the whole cohort, ranging from 2.1% at 4-5 years and 1.5% at age 7-9 years to 0.3% at 21-23 years. The seroconversion rate was higher among black than among white children (relative risk 3.3, 95% CI 1.8-6.2, p=0.001). The median age for seroconversion was 7.5 years for both races. Nine of the 58 seropositive children cleared the infection during follow-up. The rate of seroreversion per year was 1.1%; it was highest among children at age 4-5 years (2.2% vs 0.2% at ages 18-19).
  
  
  CONCLUSIONS
  Most newly acquired H pylori infections happened before age 10 years. Treatment and preventive strategies should be aimed at children in this age-group.
authors.affiliation: Department of Medicine, Veterans Affairs Medical Center and Baylor College of Medicine, Houston, TX 77030, USA. hmalaty@bcm.tmc.edu
authors.forename: Hoda M
authors.initials: HM
authors.lastname: Malaty
authors.forename: Abdalla
authors.initials: A
authors.lastname: El-Kasabany
authors.forename: David Y
authors.initials: DY
authors.lastname: Graham
authors.forename: Charles C
authors.initials: CC
authors.lastname: Miller
authors.forename: Sidd G
authors.initials: SG
authors.lastname: Reddy
authors.forename: Sathanur R
authors.initials: SR
authors.lastname: Srinivasan
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Yamaoka
authors.forename: Gerald S
authors.initials: GS
authors.lastname: Berenson
mesh_terms: D000328:Adult; D017677:Age Distribution; D000907:Antibodies, Bacterial / Q000097:blood*; D044383:Black People; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D016481:Helicobacter Infections / Q000453:epidemiology*; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D007223:Infant; D008145:Louisiana / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D017678:Sex Distribution; D044465:White People; D001741:Black or African American
chemical_list: D000907:Antibodies, Bacterial