Hp-infected symptomatic endoscopy cases at the investigators' established 3 clinical centers of high, moderate and low Hp prevalence will be compared with age-matched Hp-infected asymptomatic and uninfected symptomatic controls. Two geographically and demographically distinct centers have been added to provide additional geographic and subject representativeness to the patient cohort. The updated Sydney system will be employed to assess gastric histopathology severity and phenotype in newly enrolled cases in specific age, gender and demographic strata and follow-up of the two "novel" cohorts established in the past 5 years: a) atrophic gastritis; and b) esophageal and gastric disease groups enabling a comprehensive, multivariate evaluation of the natural history of Hp-infected children in two distinct disease paradigms.