Stool antigen detection versus 13C-urea breath test for non-invasive diagnosis of pediatric Helicobacter pylori infection in a limited resource setting

Introduction The prevalence of childhood infection with Helicobacter pylori is high, especially in developing countries. Non-invasive methods for detection of infection in children should be inexpensive, easy to perform, well tolerated and have a high diagnostic accuracy. We aimed to compare the reliability, specificity and sensitivity of the H. pylori stool antigen (HpSA) test with the 13C-urea breath test (13C-UBT) for the diagnosis of H. pylori infection in a limited resource setting. Material and methods The stool samples of 60 symptomatic and dyspeptic children with a mean age of 7.2 ±3.7 years (2-15 years) were evaluated using the rapid One step HpSA test by lateral flow immunoassay. The 13C-UBT was used as the gold standard method for the diagnosis of H. pylori infection. Results The HpSA test detected H. pylori antigen in 34 out of 38 positive patients with 4 false-negatives (sensitivity 89.5%, 95% confidence interval (CI): 75.2-97.1%), while 21 patients had true-negative results and one false-positive (specificity 95.5%, 95% CI: 77.2-99.9%), with a strong measure of agreement between the HpSA test and the 13C-UBT (κ = 0.83, 95% CI: 68-97%, p < 0.001). It had a positive predictive value of 97.1% (95% CI: 85.1-99.9%), a negative predictive value of 84% (95% CI: 63.9-95.5%) and an accuracy of 91.7%. Conclusions The rapid lateral flow HpSA test is a reliable method for the primary diagnosis of H. pylori infections in children, though not as accurate as the 13C-UBT. It is more affordable, simpler to perform and more tolerable, representing a viable alternative, especially in developing countries.