Sharing cups of water may be infected with hepatitis B under certain circumstances. If one has hepatitis B surface antibody formation in both half pairs, and the antibody number is high, which suggests that one has good immunity against hepatitis B, the risk of hepatitis B infection from sharing cups of water is extremely small. If you have not produced hepatitis B antibodies or the number of antibodies is very low, hepatitis B carriers who share water cups have a high viral replication, and recently there are ulcers in the oral cavity or mucous membrane of the digestive tract, such as gastric ulcers, duodenal bulbous ulcers, and gastric mucous membrane erosion, hemorrhage, etc., the hepatitis B virus may enter into the body through the broken mucous membrane of the digestive tract, and you may get infected with the hepatitis B virus.