Helicobacter pylori Recurrence after First- and Second-Line Eradication Therapy in Korea: The Problem of Recrudescence or Reinfection

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. Materials and 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 ¹³C-urea breath test. All patients were advised to undergo ¹³C-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.