Diagnostic accuracy of a new non-invasive enzyme immunoassay for detectingHelicobacter pylori in stools after eradication therapy

Background: Helicobacter pylori eradication therapy has been commonly perfo rmed for patients with peptic ulcer. An inexpensive, reliable, non-invasive test would be useful for evaluation of the effectiveness of eradication th erapy. Aim: To evaluate the diagnostic potential of a new non-invasive enzyme immu noassay (HpSA) for H. pylori antigen in stools. Methods: A total of 112 peptic ulcer patients with H. pylori infection (82 male, 30 female; age range 22-81 years, mean 54 years) received a course of eradication therapy. Four weeks after the end of the therapy, stool sample s were collected from all patients and tested using the HpSA. The diagnosti c accuracy of the HpSA EIA was evaluated in comparison with the results of a C-13-urea breath test. Results: The diagnostic sensitivity of HpSA EIA after eradication therapy w as 90%, the specificity 98%, the positive predictive value 82% and the nega tive predictive value 99%. Conclusion: The HpSA stool test is potentially useful for the diagnosis of H. pylori infection 4 weeks after the end of eradication therapy.