This is an answer from the Centers for Disease Control and Prevention (CDC) to a question submitted by the CDC National AIDS Hotline concerning female-to-female sexual transmission of HIV.
Female-to-female sexual transmission -- e.g., how many cases have been reported and/or documented?
Demographic and other information is obtained on persons reported with AIDS for surveillance purposes. One of the most important sets of questions on the AIDS case report form concerns possible HIV risk exposures. Persons who report cases of AIDS in male and female adolescents and adults are asked if the patient had sexual contact with a male or with a female after 1977 and preceding the patient's diagnosis of HIV infection or AIDS. Therefore, information is routinely obtained on AIDS cases among women who are reported to have had sexual contact with other women.
There have been several reports in the medical literature indicating possible female-to-female sexual transmission of HIV. AIDS surveillance data indicate that women with AIDS who are reported to have had sexual contact only with other women have also been reported to have injected drugs or to have received blood transfusions or blood components. Although these risk factors do not preclude the possibility that the mode of transmission of HIV for these women was female-to-female sexual contact, the absence of cases in lesbian women without other established risk factors is striking. We interpret this observation to mean that these women most likely acquired their infection through injection drug use or receipt of blood transfusion or blood components.
Studies from HIV serosurveys among women attending sexually transmitted disease clinics and women's health clinics also suggest that HIV infection in lesbian and bisexual women is closely associated with injection drug use or to sexual contact with men at increased risk for HIV infection. These data do not exclude the possibility of female-to-female sexual transmission of HIV, but they do indicate that it is rare. However rare such transmission may be, women who have sexual contact with other women need to be aware of the potential for infection with HIV, including the risk behaviors of their sex partners. Lesbian women should know that vaginal and cervical secretions and menstrual blood are potentially infectious and that mucous membrane (e.g., oral, vaginal) contact with infected blood or secretions can lead to HIV transmission.
CDC will continue to examine behavioral and other risk factors for HIV infection among women.
Reference: Chu SY, Conti L, Schable BA, Diaz T. Female-to- female sexual contact and HIV transmission. [letter] JAMA 1994;272:433.