AIDS is generally not transmitted through saliva. The main ways of HIV transmission are sexual transmission, blood transmission, and mother-to-child transmission. This is because HIV is mainly found in the blood, semen, vaginal secretions, cerebrospinal fluid and other body fluids of the infectious agent. The viral load in saliva is very low and cannot constitute transmission. 1. Sexual contact transmission: There is a large amount of virus in the semen or vaginal secretions of HIV-infected people. When both parties have unprotected sex, due to the friction of the organs of sexual intercourse, resulting in damage to the genital mucosa, the virus can enter the blood of the uninfected person from the skin and mucous membrane rupture, thus causing transmission. 2. Blood and blood products: HIV-infected needles or other sharp instruments piercing the skin; sharing needles, syringes, cotton pads, etc. for injection; using contaminated blood products; and unstandardized medical operation, all of the above situations can cause HIV infection. 3. Mother-to-child transmission: This mainly includes intrauterine infection, delivery and breastfeeding. Patients who are suspected to be infected with HIV should go to the hospital in time for interruption of treatment.