[Helicobacter pylori update].

Helicobacter pylori (Hp) infection is one of the most common chronic bacterial infections worldwide. The pathogenic properties of Hp are due to its ability to survive in the gastric juice, to escape the gastric acidity and to colonise the crypts of the gastric mucosa. Eradication of Hp is needed for patients with a gastroduodenal ulcer associated with Hp gastritis. Eradication modifies the natural history of the disease and greatly reduces the risk of recidive and the consequences of the discovery of Hp have been spectacular, in particular in duodenal ulcer disease. A tritherapy regimen given for 7 days combining a double-dosed proton pump inhibitor, amoxicillin (2 g/d) and clarithromycin (0.5 g bid) is used. Persistent infection may lead to a progression toward atrophy, intestinal metaplasia, dysplasia and eventually cancer. However, systematic eradication in order to reduce the incidence of gastric adenocarcinoma is not recommended. Acquisition of mucosa-associated lymphoid tissue (malt) lymphoma is related to gastritis induced by Hp infection and is commonly postulated as the initial stage in the development of malt lymphoma. Eradication is also indicated for patients with lymphoma with a low degree of malignancy.