[Helicobacter pylori: new answers to old questions].

Infection with Helicobacter pylori affects 20-40% of the adult population in advanced countries. A causal relationship between Helicobacter pylori and gastritis type B was proved. There is some indirect conclusive evidence of an aetiological association with peptic gastroduodenal ulceration. Attention is drawn to possible associations with gastric malignities. The author reviews aetiopathogenetic relations between Helicobacter pylori infection and these diseases.