To date, there are no confirmed cases of female-to-female sexual transmission of HIV in the United States database (K. McDavid, CDC, oral communication, March 2005). However, case reports of female-to-female transmission of HIV and the well-documented risk of female-to-male transmission1 indicate that vaginal secretions and menstrual blood are potentially infectious and that mucous membrane (for example, oral, vaginal) exposure to these secretions has the potential to lead to HIV infection.
The following information comes from CDC unpublished data.
- Through December 2004, a total of 246,461 women were reported as HIV infected. Of these, 7,381 were reported to have had sex with women; however, most had other risk factors (such as injection drug use, sex with men who are infected or who have risk factors for infection, or, more rarely, receipt of blood or blood products).
- Of the 534 (of 7,381) women who were reported to have had sex only with women, 91% also had another risk factor -- typically, injection drug use.
- HIV-infected women whose only initially reported risk factor is sex with women are given high priority for follow-up investigation. As of December 2004, none of these investigations had confirmed female-to-female HIV transmission, either because other risk factors were later identified or because some women declined to be interviewed.
- A study of more than 1 million female blood donors found no HIV-infected women whose only risk factor was sex with women. Despite the absence of confirmed cases of female-to-female transmission of HIV, the findings do not negate the possibility. Information on whether a woman had sex with women is missing in more than 60% of the 246,461 case reports -- possibly because the physician did not ask or the woman did not volunteer the information.
Risk Factors and Barriers to Prevention
Surveys of behavioral risk factors have been conducted in groups of women who have sex with women (WSW). These surveys generally have been of WSW samples that differ in criteria for participation, location for recruitment, and definition of WSW. As a result, the findings of these surveys cannot be generalized to all WSW. The findings have, however, suggested that some WSW have other behavioral risk factors, such as injection drug use and unprotected vaginal sex with men who have sex with men (MSM) or men who inject drugs.
Although there are no confirmed cases of female-to-female transmission of HIV, female sexual contact should be considered a possible means of transmission among WSW. These women need to know
- their own and their partner's HIV serostatus. This knowledge can help women who are not infected to change their behaviors and thus reduce their risk of becoming infected. For women who are infected, this knowledge can help them get early treatment and avoid infecting others.
- the risk for exposure through a mucous membrane. Potentially, HIV can be transmitted through the exposure of a mucous membrane (in the mouth, for example), especially if the tissue is cut or torn, to vaginal secretions and menstrual blood. The potential for transmission is greater during early and late-stage HIV infection, when the amount of virus in the blood is expected to be highest.
- the potential benefits of using condoms. Condoms should be used consistently and correctly during every 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 by the Food and Drug Administration. However, natural rubber latex sheets, dental dams, condoms that have been cut and spread open, or plastic wrap may offer some protection from contact with body fluids during oral sex and thus may reduce the possibility of HIV transmission.
Health care providers need to remember that sexual identity does not necessarily predict behavior and that some women who identify themselves as WSW or lesbian may be at risk for HIV infection through unprotected sex with men.
- CDC. HIV and AIDS: Are You at Risk?