【原文】Helicobacter pylori infection is a common, usually lifelong, infection that is found worldwide. Testing for H. pylori is recommended in patients with peptic ulcer disease, gastric cancer, or gastric mucosa-associated lymphoid tissue lymphoma (MALToma). Other recommended indications for testing include dyspepsia, prolonged use of nonsteroidal antiinflammatory drugs or aspirin, unexplained iron-deficiency anemia, and immune thrombocytopenia. Testing for H. pylori can be performed directly on biopsy specimens obtained during endoscopy or performed by means of the stool antigen test or urea breath test. Proton-pump inhibitors interfere with the detection of bacteria and must be discontinued before any testing is performed. Several regimens are considered to be acceptable for initial treatment. The presence of an allergy to penicillin, previous exposure to macrolides, and high levels of macrolide resistance where the patient lives or has lived (if information is known) are relevant in choosing a regimen. After treatment, it is essential to document clearance of the infection, typically by means of a stool antigen test or urea breath test performed 1 month after the completion of antibiotic therapy(again, while the patient is not taking a Proton-pump inhibitors). Should retreatment be indicated, a different regimen that avoids repetitive use of the same antibiotic agents is recommended.