Evaluation of Helicobacter pylori re-infection rate – an interim analysis

Abstract

Aim: To determine the re-infection rate of Helicobacter pylori (HP) in a large cohort of patients who previously underwent a successful eradication therapy. Patients and methods: The histologic results of 1726 patients were reviewed retrospectively in order to evaluate their HP status. The upper GI endoscopies were performed between 1994 and 2006, the samples were taken from the antrum and the corpus, HP status was determined with hematoxylin eosin and confirmed with Giemsa staining. Results: The HP positivity rate was 666/1726 (39%). Out of these 666 HP positive patients, 149 patients had at least one negative control biopsy after eradication; 13 patients from this subgroup developed HP positivity (re-infection). The remaining 136 patients were tested using the urea breath test (C13-UBT); 3 of the 35 participating patients proved to have acquired HP re-infection. Taken together, 16/149 patients showed re-infection, 32/149 patients were treated successfully, and due to lack of co-operation the HP status could not be determined in 101/149 patients. Conclusion: We experienced a minimum rate of HP re-infection of 10%. One of the biases of the study is the high number of patients refusing to take the non-invasive control C13-UBT with potentially further HP re-infection cases remaining undiagnosed. The other limitation is the absence of confirmation of previous biopsy results by another reliable method (e.g. C13-UBT) with high sensitivity and specificity. Finally, even with these biases, the 10% re-infection rate is high therefore we plan to reinvite the non-cooperating patients and process the data of patients with previous UBT results.