In 1983 before the discovery of Helicobacter pylori (Hp for short), some people found that gastric disease has a certain degree of contagious, but what is not clear, it is now clear that gastric disease – chronic gastritis, gastric, duodenal ulcer is caused by Hp, but some patients have some knowledge of Hp, daily life is very worried about Hp can be transmitted to each other. The following are some of the characteristics of H. pylori transmission, so that we can understand, the prevention of gastric disease. The source of infection and the route of infection Hp generally can only infect humans, parasitic in the human gastric mucosa, due to gastric-esophageal reflux so that Hp reaches the mouth, Hp can be transmitted through the oral-oral route; Hp may also be excreted from the stool through the fecal-oral route of transmission. Although there are few opportunities to culture Hp from stool or dental plaque, Hp can be detected in the stool or dental plaque of many infected patients by PCR, the most advanced and sensitive detection method, which indicates that the above two transmission methods of oral-oral and fecal-oral transmission may be the mode of Hp transmission. Mouth-to-mouth transmission requires direct person-to-person contact, mouth-to-mouth feeding during childhood, and sharing of utensils increases the chance of Hp transmission. Fecal-oral transmission depends on environmental contamination and survival time in the environment, generally under refrigerated conditions, in distilled water, salt water, and seawater can survive for several days, but recently it was found that Hp can change itself into a special form in water and prolong its survival time in water, which facilitates the transmission of Hp. Susceptibility and influencing factors Families with poor living conditions, poor hygiene and lack of nutrition are susceptible to Hp infection, especially in children, who generally start to be infected with Hp around the age of 5; on the contrary, families with high income, good living conditions, good hygiene and adequate nutrition are less susceptible to Hp infection, and are generally infected after adulthood. In kindergartens, nurseries and family groups, Hp infection occurs in clusters, and often several people in a family are infected with Hp and suffer from the same gastric disease. At present, from the characteristics of Hp causing gastric disease, gastric disease has some characteristics of an infectious disease, but as a whole, it is still considered to be an infectious disease. The vast majority of Hp infections in our country occur in adolescence, and later, if not treated, generally last a lifetime, and after Hp infection is eradicated by treatment, the infection rate is only 1.2% per year thereafter, so there is no need to be deeply afraid of the contagiousness of Hp.