Helicobacter pylori infection in asymptomatic children: Comparison of diagnostic tests

Background. Childhood is known to be a major risk period for acquiring Heli cobacter pylori infection. Studies of the epidemiology of H. pylori infecti on depend on the validity of the diagnostic tools used to detect the infect ion in the pediatric setting. This study aims to conduct a combination of d iagnostic tests on the same children, evaluate the sensitivity and the spec ificity of IgG antibody testing compared with the C-13-urea breath test, an d examine the variability in the prevalence of H. pylori infection in asymp tomatic children based on the use of different diagnostic tests. Methods. C-13-urea breath test (C-13-UBT), whole blood FlexSure (systemic a ntibodies), and OraSure (salivary antibodies) tests were conducted on 287 a symptomatic children (151 boys, 136 girls; ages 2-18 years). The three test s were conducted on each child during the same day. The prevalence was calc ulated using each test independently. Results. H. pylori infection was detected in 32%, 22%, or 18% of the studie d children, based on UBT, OraSure, or FlexSure, respectively. A total of 10 3 children tested positive for any one test (92 on UBT, 8 on FlexSure, 3 on OraSure), giving a prevalence of 35% based on the "parallel" method. Only 39 children tested positive in all three tests, giving a prevalence of 14% based on the "serial" method. Using the UBT as the gold standard, the sensi tivity of FlexSure and OraSure were 48% and 65%, respectively, and the spec ificity of both tests was greater than 95%. When we applied the parallel me thod, the sensitivity and specificity of the combined antibody tests (FlexS ure + OraSure) compared to the UBT were 71% and 95%, respectively. Conclusions. Among asymptomatic children, there is a wide variation in the prevalence of H. pylori infection based on the diagnostic test used. The st udy shows that antibody assays are less suitable than the UBT. However, und er certain conditions, the IgG assays (combined systemic, salivary, or both ) are less expensive alternative tools to the UBT for epidemiological studi es in children.