[Helicobacter pylori: When to look for an infection and treat it in adults?].

Helicobacter pylori infection is acquired during childhood mainly within the family. It causes active chronic gastritis associated with the development of many digestive and extra digestive diseases. Its expression results from interactions between the bacteria, the host and environmental factors modulating the evolution of gastritis and acid secretion. The French recommendations for research and treatment for curative or preventive purposes were updated in 2017. These are indications with a high level of evidence for association and efficacy of the eradication treatment: peptic ulcer, taking non-steroidal anti-inflammatory drugs or aspirin with an ulcer history, gastric MALT lymphoma, and localized resection of gastric cancer. The recommendations relate to other diseases with a lower level of evidence: functional dyspepsia, risk factors for gastric adenocarcinoma (family history of gastric cancer, Lynch syndrome, pre-neoplastic lesions: atrophy, intestinal metaplasia, dysplasia), unexplained iron deficiency anemia and vitamin B12 deficiency, immunological thrombocytopenic purpura, bariatric surgery isolating part of the stomach. The diagnosis is made by examining gastric biopsies or by non-invasive test depending on the clinical situation. The 10-day triple therapies guided by the study of antibiotic sensitivity (proton pump inhibitors (PPI), amoxicillin, clarithromycin or levofloxacin) are recommended as first-line treatment because of the increase in resistance, allowing the reduction of the duration of treatment, the number of antibiotics and side effects. By default, probabilistic quadruple therapies of 14 days are possible and interchangeable (PPI with amoxicillin, clarithromycin, metronidazole, or a combination of bismuth salt, tetracycline and metronidazole). Eradication control is necessary.