HIV is present in blood, semen, and vaginal secretions and can potentially be spread whenever there is direct contact with any of these body fluids.
Transmission can occur during all types of unprotected sex.
Anal sex is thought to pose the highest risk, followed by vaginal sex and then oral sex, but none of these is risk-free. The use of combination antiviral therapy, even if it is highly effective in an HIV-infected person, does not eliminate the risk of transmitting the virus to another. Several cases of HIV being spread by oral sex have been documented, but the precise risk is uncertain. The routine use of a barrier device will reduce, but not eliminate, the risk of contracting HIV infection from sexual activities. Howard Libman, M.D. .