AIDS is an infectious disease caused by infection with the HIV virus that is mainly transmitted sexually, through blood, and from mother to child. Sleeping once usually refers to a single act. If you have unprotected sex with a person with HIV, you have a higher chance of infection even if it is only once. If there is protection, such as using condoms during sex, and no direct contact occurs, the chances of contracting HIV in this case are lower. The source of HIV infection is the HIV-infected person, whose blood, semen, vaginal secretions, saliva, tears, breast milk and other body fluids contain the HIV virus. Sexual contact is the main way of HIV transmission. HIV virus can invade the body through the slightest breakage caused by friction in sexual contact, which can cause the disease. There is a long incubation period after HIV infection, and there is no obvious performance in the early stage, so it is not possible to tell whether a person is infected by symptoms alone. It is recommended to take precautions in daily life, such as maintaining a healthy sex life, avoiding too many sexual partners or having sex with strangers, and paying attention to the use of condoms and other tools to protect oneself.