title: Helicobacter pylori infection occurs via close contact with infected individuals in early childhood.
abstract: BACKGROUND
  The manner in which Helicobacter pylori is transmitted is of fundamental importance when considering strategies for its control, yet, to date, the exact mode of transmission remains uncertain.
  
  
  METHODS
  The seroprevalence of H. pylori in a relatively isolated rural town in Japan (A-town) was examined to analyse the H. pylori infection route. The immunoglobulin G antibodies against H. pylori in 1684 subjects who had received public health examinations in A-town were determined with an enzyme-linked immunosorbent assay. The seroprevalence was compared in five areas according to the water source. The possibility and frequency of intrafamilial infection was analysed by comparing the seroprevalence among family members residing in the same home.
  
  
  RESULTS
  The seroprevalence of H. pylori did not differ significantly between the five areas examined. Seropositivity was significantly more common in the children whose mothers were seropositive (45.0%, 27/60) than in the children whose mothers were seronegative (10.0%, 2/20; odds ratio (OR) = 7.36, P = 0.0036, 95% confidence interval (CI) = 1.57-34.59). Seropositivity was significantly more common in the children whose older siblings were seropositive (55.0%, 22/40) than in the children whose older siblings were seronegative (23.5%, 20/85; OR = 3.97, P = 0.00051, 95% CI = 1.79-8.84). There was no significant relationship in seroprevalence between children and fathers, grandchildren and grandfathers, grandchildren and grandmothers, or within couples. Seropositivity was significantly more common in the adolescents who had attended a nursery school (44.4%, 20/45) than in the adolescents who had not attended a nursery school (25.6%, 109/426) (OR = 2.33, P = 0.0070, 95% CI = 1.24-4.36).
  
  
  CONCLUSIONS
  The acquisition of H. pylori infection occurs by close contact with infected individuals in early childhood, especially via contact with infected mothers and other infected children.
authors.affiliation: Second Department of Internal Medicine, Fukui Medical University, Yoshida-gun, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Miyaji
authors.forename: T
authors.initials: T
authors.lastname: Azuma
authors.forename: S
authors.initials: S
authors.lastname: Ito
authors.forename: Y
authors.initials: Y
authors.lastname: Abe
authors.forename: F
authors.initials: F
authors.lastname: Gejyo
authors.forename: N
authors.initials: N
authors.lastname: Hashimoto
authors.forename: H
authors.initials: H
authors.lastname: Sugimoto
authors.forename: H
authors.initials: H
authors.lastname: Suto
authors.forename: Y
authors.initials: Y
authors.lastname: Ito
authors.forename: Y
authors.initials: Y
authors.lastname: Yamazaki
authors.forename: Y
authors.initials: Y
authors.lastname: Kohli
authors.forename: M
authors.initials: M
authors.lastname: Kuriyama
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000907:Antibodies, Bacterial / Q000032:analysis*; D002391:Catchment Area, Health; D002648:Child; D018562:Disease Transmission, Infectious / Q000517:prevention & control; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D016481:Helicobacter Infections / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009679:Nuclear Family; D012189:Retrospective Studies; D012424:Rural Population; D016036:Seroepidemiologic Studies; D012923:Social Class
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G