HIV cannot be transmitted through saliva, because even though HIV patients do not undergo any antiretroviral treatment and have a large amount of HIV in their blood or other body fluids, the amount of HIV in saliva is very small, so small that it cannot be transmitted through saliva. From the relevant information, it is likely that there is less than one HIV particle in one milliliter of saliva. With such a small amount of HIV, no specific examples of transmission through saliva have been seen in real life, so it is believed that HIV cannot be transmitted to other people through saliva. If a person with AIDS does not take antiretroviral treatment, in addition to the high HIV content in the blood, there can also be a relatively high level of HIV in other body fluids, such as semen, vaginal secretions, pleural fluid, ascites, cerebrospinal fluid, amniotic fluid and breast milk, so it is possible to transmit HIV through these. In addition, if there is chronic inflammation or bleeding in the mouth, there may be more HIV in the saliva, and if the other person also has active bleeding in the mouth, it will cause transmission, but this is rare.