Helicobacter pylori is mainly transmitted through person-to-person contact, unclean diet can also lead to infection, as follows: 1. Person-to-person contact is the main cause of H. pylori infection, patients who already have H. pylori are particularly prone to spread the bacteria; contact with the saliva, urine, feces or other secretions of infected people, and inattention to hand washing before meals can lead to H. pylori infection. The use of unclean tableware during meals can also lead to infection. 2, for children resistance and immunity are poor, mouth-to-mouth feeding is highly contagious; in kindergartens or schools, close contact between students can lead to H. pylori infection. 3, like to eat cold food or seafood, barbecue food, easy to infect H. pylori, this is because many raw and cold animal meat are contain this germ.