Sharing cups of water may transmit diseases that are spread through the digestive tract and through close contact, such as influenza and hepatitis A. Sharing cups of water is a type of close contact that has the potential to spread disease, but the probability of this is usually not high. Common disease-causing bacteria and viruses, such as Helicobacter pylori, adenovirus, mumps virus, and hepatitis A virus, have a certain probability of being transmitted orally to contacts. The transmission of infectious diseases involves the source of infection, the means of transmission, and the susceptible population. Sharing a cup of water is a close contact or oral route of transmission. Transmission of the disease requires that the person who excreted the bacteria (toxin) had contact with the cup of water and there is a residual pathogen, and that the person who has contact with the cup of water is susceptible to the pathogen before transmission occurs. Not as long as there is contact will definitely be infected. In addition, usually should pay attention to personal hygiene, try to avoid sharing water cups with others.