title: Reinfection rate following effective therapy against Helicobacter pylori infection in Japan.
abstract: OBJECTIVE
  In developed countries, reinfection of Helicobacter pylori (H. pylori) after eradication of the bacterium is unusual, while the reinfection rate in developing countries is variable. In this study, we determined the reinfection rate after successful H. pylori eradication in Japan, a country with a high prevalence of H. pylori infection.
  
  
  METHODS
  After successful eradication, 377 patients were followed up by endoscopy and urea breath test annually. In reinfected patients, H. pylori strains isolated initially and after reinfection were compared by using random amplification of polymorphic DNA fingerprinting.
  
  
  RESULTS
  H. pylori became positive in four of 337 patients (1.2) 1 year after eradication and in two of 133 patients (1.5) 2 years after eradication. One patient experienced an ulcer relapse 2 years after eradication therapy. Random amplification of polymorphic DNA fingerprinting of the isolated strains from four of the six patients showed two had identical strains (at 1 year) while the other two had different strains (one at 1 year and one at 2 years). When infection in the two patients reinfected with identical strains is considered a recrudescence, the true reinfection rate is < 0.8 per patient year.
  
  
  CONCLUSIONS
  The reinfection rate after eradication of H. pylori is low in Japan despite the country's high prevalence of H. pylori infection.
authors: Department of Medicine and Medical Science, Okayama University Graduate School of Medicine and Dentistry, Japan.
authors: Masayasu
authors: M
authors: Adachi
authors: Motowo
authors: M
authors: Mizuno
authors: Kenji
authors: K
authors: Yokota
authors: Masatsugu
authors: M
authors: Miyoshi
authors: Yasuhiro
authors: Y
authors: Nagahara
authors: Toshirou
authors: T
authors: Maga
authors: Kunihara
authors: K
authors: Ishiki
authors: Tomoki
authors: T
authors: Inaba
authors: Hioyuki
authors: H
authors: Okada
authors: Keiji
authors: K
authors: Oguma
authors: Takao
authors: T
authors: Tsuji
mesh_terms: D000328:Adult; D000368:Aged; D001944:Breath Tests; D016172:DNA Fingerprinting / Q000379:methods; D004381:Duodenal Ulcer / Q000382:microbiology; D016099:Endoscopy, Gastrointestinal; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D016480:Helicobacter pylori / Q000145:classification / Q000302:isolation & purification; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D015995:Prevalence; D012008:Recurrence; D013276:Stomach Ulcer / Q000382:microbiology; D014510:Urease / Q000032:analysis
chemical_list: D014510:Urease