The low probability of sexual transmission of HIV (human immunodeficiency virus) is due to the use of condoms and the conditions required for their transmission. Sexual transmission is the main mode of HIV transmission, followed by blood transmission and mother-to-child transmission. A single act of sexual intercourse does not necessarily result in HIV infection, and the chances of infection are greatly reduced by the use of condoms. Most people with HIV have a history of prolonged sexual misconduct, multiple sexual partners, homosexuality, or drug use. HIV transmission requires contact with body fluids or blood containing the virus, which can enter the body through broken skin or mucous membranes and cause infection. Although sexual contact does not necessarily lead to HIV infection, most people with HIV are infected by sexually transmitted infections, and therefore should avoid sexual misconduct. If you have a history of high-risk contact, you should consult a regular hospital in a timely manner.