Comparison of diagnostic accuracy of non-invasive tests for Helicobacter pylori infection in children

Objective: To compare urea breath and stool antigen in children, with histological diagnosis for Helicobacter pylori (H.pylori) infection. Study Design: Cross-sectional study. Place and Duration of Study: From June 2005 to December 2005 carried out at KRL Hospital, Islamabad and Children Hospital, PIMS, Islamabad. Patients and Methods: Children between 3 and 15 years of age reporting in pediatric outpatient department with upper gastrointestinal symptoms were included. All the participating children underwent an upper gastrointestinal endoscopy and 3 tests namely: histopathological identification of H. pylori (the traditional gold standard), urea breath test and stool antigen test were carried out on each child. The sensitivity, specificity, and positive predictive values were calculated for each noninvasive test used in the study. Results: A total of 54 patients completed the study with a mean age of 8.2 years. On histological examination, 72% (39) were positive for H. pylori infection. On gross endoscopic examination, only 9 patients had signs of gastritis as compared to 39 histological positives. The sensitivity, specificity and positive predictive value of stool antigen test were: 77%, 73% and 89% respectively whereas the same for urea breath test were: 79%, 80% and 91% respectively. Conclusion: Both the noninvasive tests were found to be sensitive and specific as compared with histological identification, for the diagnosis of H.pylori in our pediatric population. The accuracy of urea breath test was better than the stool antigen test but later was easier to perform and could fulfill the criteria for a rapid bedside diagnostic test.