title: Helicobacter pylori recurrence after first- and second-line eradication therapy in Korea: the problem of recrudescence or reinfection.
abstract: BACKGROUND
  Recurrence of Helicobacter pylori (H. pylori) infection is the result of either recrudescence or reinfection. Annual recurrence rates per patient-year of follow-up have been reported to vary across countries. The aim of this study was to analyze recurrence rates of H. pylori after first-line and second-line eradication therapies in Korea.
  
  
  METHODS
  From 2007 to 2010, 2691 patients with H. pylori infection received first-line therapy and 573 patients who failed to respond to first-line therapy received second-line therapy. H. pylori infection and the success of eradication were assessed by endoscopic biopsy and rapid urease test or (13) C-urea breath test. All patients were advised to undergo (13) C-urea breath test or esophagogastroduodenoscopy with biopsy or rapid urease test 6 months after eradication, with annual follow-up thereafter.
  
  
  RESULTS
  The eradication rate of the first-line therapy was 79.9% (1283/1605) and that of the second-line therapy was 90.4% (394/436) by per protocol analysis. Annual recurrence rates sharply declined after 2-year follow-up. Annual recurrence rates within and after 2-year follow-up were 9.3 and 2.0% after first-line therapy and those of second-line therapy were 4.5 and 2.9%, respectively.
  
  
  CONCLUSIONS
  Annual recurrence rates of H. pylori showed a sharp decline after 2-year follow-up after eradication in Korean adults, which is not higher than that of Western countries. Enough time interval after treatment (i.e., 2 years) is necessary to confirm eradication, and it would not be easy to distinguish between recurrence and recrudescence before 2 years without identifying H. pylori strains.
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Seung Young
authors.initials: SY
authors.lastname: Kim
authors.forename: Jong Jin
authors.initials: JJ
authors.lastname: Hyun
authors.forename: Sung Woo
authors.initials: SW
authors.lastname: Jung
authors.forename: Ja Seol
authors.initials: JS
authors.lastname: Koo
authors.forename: Hyung Joon
authors.initials: HJ
authors.lastname: Yim
authors.forename: Sang Woo
authors.initials: SW
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001706:Biopsy; D001944:Breath Tests; D004359:Drug Therapy, Combination / Q000379:methods; D016145:Endoscopy, Digestive System; D016481:Helicobacter Infections / Q000188:drug therapy* / Q000453:epidemiology* / Q000382:microbiology; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D007723:Korea / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D014510:Urease / Q000032:analysis; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D014510:Urease
keywords: Helicobacter pylori; eradication; recurrence