HELICOBACTER-PYLORI INFECTION IN CHILDREN

Helicobacter pylori colonizes the human stomach, especially during chi ldhood. However, a variety of H. pylori strains exists, with major dif ferences in virulence characteristics which probably account for diffe rent clinical symptoms, and the majority of infected subjects remains asymptomatic. Helicobacter pylori infection is correlated with socioec onomic conditions and hygienic circumstances, resulting in an extremel y high prevalence in children in developing countries. Commercial scre ening tests are not capable of separating the more virulent strains (t ype I with vacuolating toxin VacA and CagA protein) from the less viru lent strains (type II, VacA and CagA negative). Type I strains, but no t type II, are associated with an increased risk for duodenal ulcer an d gastric cancer. Therefore, future screening tests and vaccinations s hould focus on the type I strains.