Is H. pylori contagious? Yes, it is contagious, and there are two main ways: first, oral-oral transmission. China has a high rate of H. pylori infection in the world, which is related to the traditional habit of sharing eating utensils that leads to the oral-oral transmission of H. pylori. The oral cavity is the reservoir of H. pylori, and saliva becomes the vector of H. pylori transmission. In addition, it can also be transmitted through contaminated water and food into the mouth. Second, close contact. H. pylori shows a clear family aggregation phenomenon. Close contact can increase the chance of infection. If parents are positive for H. pylori, the infection rate of their children increases, and if one spouse is positive for H. pylori, the infection rate of the other spouse also increases.