The modes of transmission of infectious diseases include horizontal transmission as well as vertical transmission. Vertical transmission mainly refers to mother-to-child transmission, and horizontal transmission has more modes of transmission, including respiratory transmission, gastrointestinal transmission, and blood transmission, as follows: 1. Gastrointestinal transmission mainly refers to fecal-oral transmission, mainly through the consumption of contaminated water and food, including bacterial dysentery, viral hepatitis, typhoid, paratyphoid, etc. 2, Respiratory transmission is numerous, and it is mainly spread by droplets or airborne transmission. The patient sneezes and coughs, spewing out the droplets of the pathogens carried, and is infected by contact with susceptible people for a short period of time.3. Contact transmission is when an infectious person carrying a pathogen transmits the virus to an object by touching it, and then transmits it to another person by hand.4. Blood transmission, which mainly refers to infection by contact with other secretions such as the blood of the transmitter.