[Epidemiologic and clinical aspects of Helicobacter pylori infection in children].

Worldwide, H. pylori prevalence in children ranges from under 10% to almost 80%. Prevalence is low in developed countries; whereas high prevalence is observed in most developing countries. Documented risk factors for infection include socioeconomic status, household crowding, ethnicity, migration from high prevalence regions, and infection status of family members. H. pylori infection is not associated with specific symptoms in children; although it is consistently associated with antral gastritis, which clinical significance is unclear. H. pylori associated duodenal ulcers are seldom seen in children under 10 years of age. The role of the infection in recurrent abdominal pain is highly controversial. H. pylori-infected children demonstrate a chronic inflammatory cell infiltrate, with a lack neutrophils, as compared with the response observed in adults. The importance of virulence determinants such as cagA and vacA, described as relevant for disease during H. pylori infection, has not been extensively studied in children. Sensitive and specific methods for the detection of H. pylori in children are needed, especially in infant populations where the colonization is in its early phases. Non-invasive, cheap, and simple methods are needed for epidemiologic studies. There is no consensus about criteria for the use of eradication treatment in H. pylori-infected children. Multicenter pediatric studies are needed to solve the many unanswered question on the natural history of H. pylori infection in children, including identification of risk factors for infection, identification of prognostic indicators for the development of gastroduodenal disease later in life, and the host response to infection.