Heterosexual anal intercourse: Prevalence, cultural factors, and HIV infection and other health risks, Part I

Studies of heterosexual HIV transmission have consistently found anal inter course to be a highly predictive risk factor for seroconversion. Yet most A IDS prevention messages targeted at heterosexuals, presumably influenced by cultural taboos against acknowledging this sexual practice, continue to em phasize vaginal and, increasingly, oral sex transmission. The health risks of anal sex appear to be severely underestimated by a substantial proportio n of sexually active women and men in North and Latin America as well as pa rts of South Asia, Africa, and other regions. Among heterosexuals reported rates of condom use are nearly universally lower for anal than for vaginal intercourse. This review examines anal sex among the general population, in cluding its prevalence in various world regions, related sociocultural fact ors, and other associated health problems including anorectal STDs, Hepatit is B infection, and HPV-related anal cancer in women. U.S. survey and other data suggest that, in terms of absolute numbers, approximately seven times more women than homosexual men engage in unprotected receptive anal interc ourse. Research among higher risk subpopulations, including bisexual men, i njecting drug users, female sex workers, inner-city adolescents, and serodi scordant heterosexual couples, indicates that persons particularly at risk of being infected by or transmitting HIV are also more likely to practice a nal sex. Considering this finding, along with the much greater efficiency f or HIV infection as well as lower rates of condom usage, a significant prop ortion of heterosexual transmission in some populations is due to anal inte rcourse. This typically stigmatized and hidden sexual practice must be give n greater emphasis in AIDS/STD prevention, women's care, and other health p romotion programs.