title: Long-term study of re-infection following successful eradication of Helicobacter pylori infection.
abstract: BACKGROUND
  'Re-infection' with Helicobacter pylori after eradication has been estimated to occur in 0-14% of patients, although most so-called 're-infections' occur within the first year following 'eradication' and many may actually be due to recrudescence of a temporarily suppressed infection.
  
  
  OBJECTIVE
  To study the true re-infection rate, we have studied re-infection rates after eradication therapy by excluding the first year's data, minimizing the possible confounding effect of recrudescence.
  
  
  METHODS
  All patients tested for H. pylori infection following eradication therapy between 1987 and 2004 were evaluated. Testing was carried out by urea breath test and gastric biopsy. Patients were included if they were found to be negative for H. pylori infection by testing at least 1 year following eradication and underwent at least one further test for H. pylori.
  
  
  RESULTS
  1162 patients met the inclusion criteria with median post-eradication follow-up of 3 years (1.5-14) including 4668 tests; 3319 years of follow-up were analysed. Thirteen cases of re-infection occurred (re-infection rate 0.4% per year).
  
  
  CONCLUSIONS
  This large study of H. pylori re-infection avoided cases of recrudescence by excluding the first post-eradication year. True re-infection is probably less common than previously thought.
authors.affiliation: Department of Gastroenterology, Ipswich Hospital, Ipswich, UK. camerone99@aol.com
authors.forename: E A B
authors.initials: EA
authors.lastname: Cameron
authors.forename: G D
authors.initials: GD
authors.lastname: Bell
authors.forename: L
authors.initials: L
authors.lastname: Baldwin
authors.forename: K U
authors.initials: KU
authors.lastname: Powell
authors.forename: S G J
authors.initials: SG
authors.lastname: Williams
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D005767:Gastrointestinal Diseases / Q000382:microbiology / Q000517:prevention & control*; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000188:drug therapy; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors
chemical_list: D000900:Anti-Bacterial Agents