Sexual Transmission of HIV
Unprotected penile-anal intercourse (male-male or male-female)
Unprotected penile-anal intercourse, whether between two men or a man and a woman, exposes the anal and rectal mucous membranes of the receptive partner to semen, and exposes the penis (specifically, the mucous membrane in the opening of the penis) to anal mucus. Also, anal sex often causes tearing of the penis, anus, and rectum, so that both the receptive and the insertive partners may be exposed to blood. The anal and rectal tears, in turn, provide HIV with direct access to the bloodstream.
Unprotected penile- vaginal intercourse
penile-vaginal intercourse exposes the woman’s vaginal and cervical
mucous membranes to semen, and the man’s penis (specifically,
the mucous membrane at the penis’ opening) to vaginal secretions.
Moreover, if the sex is rough or dry, cuts and tears may expose the
man and woman to blood, and may open delicate vaginal and penile mucous
membranes for direct HIV transmission to the bloodstream.
Unprotected oral-genital sex
Unprotected oral-genital sex exposes HIV-infected semen or vaginal fluids to oral mucous membranes. While this is a biologically possible means of HIV transmission, the actual risk of it is unknown. The risk of oral-penile contact is thought to be low, and the risk of oral-vaginal contact is thought to be very low (1).
Factors That Increase the Risk of Sexual Transmission
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7. Editors. The most common opportunistic infections in women with HIV. HIV Newsline, 4 (4), 1998.
8. World Health Organization (WHO). Women and HIV/AIDS (Fact Sheet No. 242). Geneva: World Health Organization, 2000. Available online at: http://www.who.int/inf-fs/en/fact242.html
9. Laumann, E.O., Gagnon, J.H., Michael, R.T., Michaels, S. The Social Organization of Sexuality: Sexual Practices in the United States. Chicago, Illinois: The University of Chicago Press, 1994.
10. Zierler, S. & Krieger, N. Social Inequality and HIV Infection in Women. In The Emergence of AIDS: The Impact on Immunology, Microbiology, and Public Health, K.H. Mayer & H.F. Pizer (eds.). Washington, DC: American Public Health Association, 2000.
© Sociometrics Corporation, 2004