Diagnosis of Helicobacter pylori infection in children based on stool antigen test

Background: During infancy, preventive, diagnostic and therapeutic efforts for Helicobacter pylori infection should be made. Aim: To evaluate noninvasive diagnostic methods such as stool antigen test (HpSA) and serum anti-H pylori antibody detection (IgG a IgA), compared to endoscopy-based invasive methods (histology and urease test) for the diagnosis of Helicobacter pylori infection. Patients and Methods: Thirty nine children (aged 3 to 14 years, 20 males) referred for upper gastrointestinal endoscopy, were studied. The gold standard to diagnose Helicobacter pylori infection was defined as a positive invasive diagnostic test (histology and/or urease test). Sensitivity (S), specificity (E) and positive (PPV) and negative (NPV) predictive values were obtained for HpSA and serum antibodies. Results: Ten children (26%) were infected with H pylori. S, E, PPV and NPV for HpSA were 90, 100, 100 and 97%, respectively. The figures for serum IgG were 81, 97, 89 and 93%, respectively and for IgA, 90, 76, 36 and 96%, respectively. Conclusions: HpSA was sensitive and specific as a clinical and epidemiological tool to evaluate H pylori infection in children. Serology was not as accurate, but IgG had a better performance than IgA.