Saliva does not transmit AIDS, because saliva does not contain HIV, and even if it does, the amount is very low and cannot cause the transmission of AIDS, so saliva does not transmit AIDS, so do not worry too much. Only the blood, prostate fluid, semen, vaginal secretions, cervical secretions, cerebrospinal fluid, breast milk, pleural fluid and ascites of AIDS patients can transmit AIDS. These blood and body fluids contain high HIV load and are highly contagious, and may cause infection if they enter the circulatory system of normal people or come into contact with wounds of normal people. Therefore, to prevent AIDS, we should avoid contact with the blood and body fluids of AIDS patients.