Saliva does not transmit HIV. HIV is a clinically common sexually transmitted disease caused by HIV infection. The HIV virus is found in the blood, semen, vaginal secretions, chest and abdominal fluids, breast milk and cerebrospinal fluid of HIV-infected patients and people with HIV. Saliva does not contain HIV, and it has been clinically found that eating with HIV patients does not cause HIV transmission, so saliva does not cause HIV transmission. There are three main clinical modes of HIV transmission: 1) through sexual intercourse; 2) through blood transmission; and 3) through vertical transmission from mother to child.