The biologic risk of transmission through female-to-female sex is unknown, but case reports of female-to-female transmission of HIV and the well-documented risk of female-to-male transmission of HIV indicate that vaginal secretions and menstrual blood are potentially infectious and that mucous membrane (e.g. oral, vaginal) exposure to these secretions can potentially lead to HIV infection. Information from HIV/AIDS surveillance, however, suggests that female-to-female transmission of HIV is a rare occurrence.
HIV/AIDS among WSW: Surveillance Findings
--> Through December 1996, 85,500 women were reported with AIDS. Of these, 1,648 were reported to have had sex with women; however, the vast majority had other risks (such as injection drug use, sex with high-risk men, or receipt of blood or blood products). Of the 333 (out of 1,648) who were reported to have had sex only with women, 97% of these women also had another risk injection drug use in most cases. (Note: information on whether a woman had sex with women is missing in half of case reports, possibly because the physician did not elicit the information or the woman did not volunteer it.)
--> Women with AIDS whose only reported risk initially is sex with women are prioritized for follow up investigation. As of December 1996, none of these investigations had resulted in a confirmed AIDS case report of female-to-female transmission, either because other risks were subsequently identified or because, in a few cases, women declined to be interviewed.
--> A study of over 1 million female blood donors found no HIV-infected women whose only risk was sex with women.
--> These findings suggest that female-to-female transmission of HIV is uncommon. However, they do not negate the possibility because it could be masked by other behaviors.
Prevalence of Risk Behaviors among WSW
--> Surveys of risk behaviors have been conducted in groups of WSW. These surveys have generally been surveys of convenience samples of WSW that differ in sampling, location, and definition of WSW. As a result, their findings are not generalizable to all populations of WSW.
--> These surveys suggest that some groups of WSW have relatively high rates of high-risk behaviors, such as injection drug use and unprotected vaginal sex with gay/bisexual men and injection drug users.
Preventing Transmission among WSW
--> Although female-to-female transmission of HIV is apparently rare, female sexual contact should be considered a possible means of transmission among WSW. WSW need to be aware that mucous membrane especially nonintact exposure to vaginal secretions and menstrual blood are potentially infectious, particularly during early seroconversion and late-stage HIV infection when viral loads are expected to be highest.
--> Women should also be aware of the appropriate barrier methods they can use for different sexual activities to prevent transmission of HIV. Condoms should be used consistently and correctly each and every time for sexual contact with men or when using sex toys. Sex toys should not be shared. No barrier methods for use during oral sex have been evaluated as effective barriers or been approved by the FDA. However, women can use one of the following barriers to protect themselves from contact with body fluids during oral sex: dental dams, cut-open condoms, or plastic wrap.
--> WSW should know their own and their partner's HIV status. This knowledge can help uninfected women initiate and sustain behavioral changes that reduce their risk of becoming infected and can assist infected women in getting early treatment and avoiding infecting others.
--> Health care providers should understand that sexual identity does not necessarily predict behavior, and that women who identify as lesbian may be at risk for HIV through unprotected sex with men.
--> Prevention interventions targeting WSW must address behaviors that put WSW at risk for HIV infection, specifically injection drug use and unprotected vaginal-penile intercourse.
Chu SY, Buehler JW, Fleming PL, Berkelman RL. Epidemiology of reported cases of AIDS in lesbians: United States, 1980-89. Am J Pub Health 1990;80:1380-81.
Chu SY, Hammett TA, Buehler JW. Update: epidemiology of reported cases of AIDS in women who report only sex with other women, United States, 1980-91. AIDS 1992;6:518-19.
Kennedy, MB, Scarlett MI, Duerr AC, Chu SY. Assessing HIV risk among women who have sex with women: Scientific and Communication issues. J Am Med Wom Assoc 1995;50:103-107.
Lemp GF, Jones M, Kellog TA, et al. HIV seroprevalence and risk behaviors among lesbians and bisexual women in San Francisco and Berkeley, California. Am J Pub Health 1995;85:1549-52.
Petersen LR, Doll L, White C, Chu S, and the blood donor study group. J Acquir Immun Defic Synd 1992;5:853-855.
Other resources can be obtained by contacting:
The Centers for Disease Control and Prevention's Website: http://www.cdc.gov
CDC National AIDS Clearinghouse P.O. Box 6003 Rockville, MD 20849-6003 1-800-458-5231 firstname.lastname@example.org http://www.cdcnac.org
If you have questions concerning HIV infection, AIDS, or information in this update, please call:
CDC National AIDS Hotline 1-800-342-2437 1-800-344-7432 (Spanish) 1-800-243-7889 (Deaf)