AIDS is not usually transmitted through saliva. It is now clear that there are three ways of transmission of AIDS. The first is through sexual transmission, the second is through blood transmission, and the third is through mother-to-child transmission. However, people with AIDS and asymptomatic HIV carriers are the source of infection for the disease. The virus is in blood, body fluids (semen, vaginal secretions, saliva, tears, breast milk and wound exudate, etc.) organ tissues. When there is damage to mucous membranes, or exudate from inflammatory ulcers, it contains a large amount of HIV, which is relatively infectious, so it can also be transmitted through saliva. In general life, eating together, shaking hands, hugging, and being in the same workplace, etc. are not infectious.