Background. H. pylori can cause several gastroduodenal diseases. Because H. pylori infection is usually acquired in childhood, accurate diagnosis of the infection in the pediatric population is important. Tests for the diagnosis of H. pylori infection can be divided into invasive and noninvasive. The aim of our study was to compare invasive tests (endoscopy, gastric mucosal biopsy, histology) and the noninvasive, newly developed stool antigen test to diagnose H. pylori infection. Methods and Results. 91 children (40 boys, 51 girls, mean age 12,6±3,5 years) with dyspeptic symptoms were tested for H. pylori infection using endoscopy and gastric biopsy and a new antigen test in stool samples (immunoassay). Thirty-one of the children (34,1 %) with dyspepsia were found positive for H. pylori according to histologic examination and rapid urease test. In 28 of the 31 patients, H. pylori stool antigen could be detected (senzitivity 90.3 %). Of the 60 patients with negative direct histologic examination and rapid urease test, 60 were H. pylori – negative in stool antigen test (specificity 100 %). Positive predictive value of stool antigen test is 100 % and negative predictive value is 95.2 %. Conclusions. The stool antigen test is highly sensitive and specific. It will be potentially very helpful in the diagnosis of H. pylori infection and can replace endoscopy for detection of H. pylori infection in children with comparable accuracy and reliability.

        Key words: Helicobacter pylori, endoscopy, histologic examination, stool antigen test.