Receptive Anal Intercourse and HIV Infection

Objective: Inform the public that receptive anal intercourse (RAI) is a key transmission route of the human immunodeficiency virus (HIV) epidemic in the United States. Method: The role of receptive anal intercourse (RAI) in this epidemic will be examined using the following approach: 1) Risk comparison of HIV transmission via RAI to the other major routes of transmission. 2) HIV transmission risks of RAI using some of the present risk reduction techniques. 3) HIV infection via anal intercourse among male youth. 4) HIV infection via anal intercourse among women. Results: Of the major transmission routes of HIV, receptive anal intercourse has the highest transmission risk for acquiring HIV infection. RAI is 2 times the risk of needle-sharing during injection drug use (IDU) and 17 times the risk of receptive vaginal intercourse. The estimated per act probability of acquiring HIV from an infected source by the exposure route of RAI is high in most circumstances: 1) Condoms alone only partially reduce the high risk of RAI. With the addition of pre-exposure prophylaxis (PrEP), the risk is further reduced. 2) When one or both partners are infected with a sexually transmitted disease (STD), even with condom use, the risks are very high. With the addition of PrEP the risks are reduced, but RAI still carries significant risks. 3) With exposure to acute HIV (high viral load) the risks of RAI are very high and remain significant even with condom use and PrEP. Anal intercourse often begins in adolescence; both genders are at risk. Conclusion: Public knowledge of the high transmission risks of receptive anal intercourse may likely result in a downward trend of new HIV infections and contribute to ending the epidemic.