Since the successful isolation and culture of H. pylori from human gastric mucosa by Australian scholars warren and marshall in 1982, a large number of studies have confirmed that pediatric HP infection is widespread and closely related to the occurrence, development and recurrence of chronic gastritis and peptic ulcer disease. I. Pathogenesis It is currently believed that the pathogenesis of HP includes HP motility, colonization and mucosal damage caused by toxins, host immune response-mediated mucosal damage and abnormal gastric acid secretion caused by HP infection. Colonization is the primary condition for HP infection, and whether it can cause disease depends on the characteristics of HP itself such as vacuolar toxin and toxin-associated protein. Diagnosis 1. Symptoms: Clinical symptoms of pediatric Hp infection are non-specific, including recurrent abdominal pain, nausea and vomiting, gastrointestinal bleeding and anorexia, anemia and other symptoms. 2. Signs: Most of the children have no special positive signs, some of them have mild pressure pain under the saber or around the umbilicus, weakness, bad taste in the mouth, anemia, weight loss or growth retardation, etc. Laboratory tests: Laboratory techniques for the diagnosis of Hp infection include two major categories: (1) invasive tests: rapid urease test by gastroscopy of the mucosal tissue of the gastric sinus, microscopic examination of tissue sections with silverophilic staining (Warthin-Starry) or modified Giemsa staining, and bacterial culture, etc. (2) Non-invasive tests: urea breath test and serum anti-Hp antibody assay, stool Hp antigen test. (3) Treatment The drugs used for the treatment of HP infection in children are: clarithromycin, metronidazole, amoxicillin, bismuth complex (mainly bismuth potassium subcitrate), proton pump inhibitor (PPI) or H2 receptor antagonist (H2RI). Many second-line drugs (e.g., tetracycline, rifabutin, ciprofloxacin) are contraindicated or have not been approved for use in children. Combination of drugs is required. A triple therapy of PPI plus 2 antibiotics for 7-14 d is the best treatment available. Commonly used drug doses: hydroxybenzyl penicillin 30-50mg/kg daily, metronidazole 15-20mg/kg daily, clarithromycin 15-20mg/kg daily, furazolidone 3-5mg/kg daily, colloidal bismuth subcitrate (CBS) 6-8mg/kg daily. Commonly used combination drug regimens: (1) CBS + one of the above antibiotics; (2) CBS + the above two antibiotics; (3) PPI + the above two antibiotics; (4) H2RA + the above two antibiotics, forming a duplex or triple therapy containing inhibition of gastric acid secretion or containing bismuth. Prevention Develop good living rules and hygiene habits to prevent the disease from entering by mouth; recommend meal sharing, or communal chopsticks system for dining, and strengthen the disinfection of eating utensils; other family members with Hp infection should be eradicated and treated to prevent cross-infection.