Helicobacter pylori and gastrointestinal disease.

Helicobacter pylori infection is quite common. In the United States, prevalence varies considerably with race, nationality, socio-economic status and location of residence. In Western countries, the prevalence of the infection has shown a steady increase with increasing age. H. pylori has been shown to cause chronic gastritis. Most patients infected with H. pylori are asymptomatic and require no therapy. The precise role of the infection in the pathogenesis of peptic ulcer disease is unknown. However, H. pylori infection is associated with a high recurrence rate of both gastric and duodenal ulcers. Eradication of the infection reduces the recurrence rate. Once H. pylori infection is acquired, it usually persists for years, possibly for the patient's lifetime. Although a causative role in gastric cancer has not been proved, evidence suggests an association between H. pylori infection and well-differentiated gastric adenocarcinoma and gastric lymphoma.