Sexual identity and sexual practice

When considering the issue of woman–to–woman transmission it is important to draw a distinction between the risk of transmission by this route and diagnoses of HIV infection and AIDS in women who identify as lesbians. There have been only five reported cases of woman–to–woman transmission, and these reports need to be viewed with the same caution as any other above–mentioned reports of oral transmission.

The most thoroughly investigated report concerns a woman who had a monogamous sexual relationship lasting nearly two years with a woman who died of AIDS in 1989. Sexual activity consisted of mutual fingering and oral sex and use of a shared vibrator. Her partner had ceased menstruating and the woman could recall no instance when sexual activity resulted in a visible laceration or haemorrhage. In 1987 the patient developed vaginal herpes; her partner was not suffering from herpes. In April 1988 the woman developed what appears to have been a seroconversion illness. Upon the death of her partner in 1989 the woman tested HIV–positive. She had a relatively high CD4 count, suggesting that she had been infected recently. The woman denied any activity which could have put her at risk for HIV infection apart from sexual contact with her deceased partner (Rich).

It is sometimes argued that no large-scale epidemiological investigation of HIV prevalence amongst lesbians has taken place. However, three studies of the source of infection of all women with AIDS in the US have failed to identify any cases of woman–to–woman transmission (Chu; McCombs; Petersen). A 1992 follow–up of all 144 women identified as HIV–positive through the blood donation services in the US interviewed 106 women, and identified only three who had had sex with women. All of these women had other risk factors: either injecting drugs or intercourse with men. Of those who remained uninterviewed by the researchers, almost half had identified other risk factors in previous interviews following their diagnosis (Chu 1992).

These studies suggest that whilst lesbians may be infected with HIV through sexual intercourse with men or through shared injecting equipment, there is very little risk that they will transmit the virus to other women during sexual intercourse.

Petersen's study may have underestimated the number of lesbian or bisexual women who were infected with HIV because it was drawn from blood donors, who are asked not to donate blood if they are at risk for HIV infection.

An Italian study of 18 HIV–discordant lesbian couples who had been monogamous partners for at least three months prior to recruitment and who were followed for six months found no seroconversions occurred during this period. Three-quarters of the couples reported sharing sex toys and virtually all couples reported oral sex (Raiteri).

In January 2003 a case report of female-to-female sexual HIV transmission was reported in the journal Clinical Infectious Diseases. Doctors suggest the woman may have been infected through sharing sex toys after drug resistance tests found striking similarities between the genotypes of the woman and her female HIV-positive partner.

The case concerns a 20 year-old woman, from Philadelphia, who presented with HIV infection having had a negative HIV test result six months earlier. The woman had been in a monogamous lesbian relationship for the past two years, and denied having had any other sexual partners, male or female. She had never injected drugs or received blood products, and had no tattoos or body piercings.

The couple’s sexual practices included the sharing of sex toys, and oral sex. These activities did not occur during menstruation, but sex toys had occasionally been used vigorously enough to draw blood.

A medical examination established that the woman was in good health with no evidence of injecting drug use, or nasal damage from cocaine snorting. The woman also had good oral health, which physicians took to mean that oral transmission could be ruled out.

Her bisexual partner was known to be HIV-positive, and is believed to be the source of infection because of similarities observed when the two women underwent genotypic drug resistance tests. The 20 year-old woman was infected with multi-drug resistant HIV, which carried the following mutations: T215Y (associated with resistance to AZT, d4T and abacavir), D30N (associated with resistance to nelfinavir), K103N (associated with resistance to NNRTIs), L63P (a polymorphism), V77I (also a polymorphism), and M41L (associated with resistance to AZT and d4T, and with resistance to other NRTIs in the presence of T215Y). Her partner’s genotype carried mutations at each of these points, plus M184V (associated with resistance to 3TC).

The investigators note that this is the "first reported case of female-to-female sexual transmission of HIV supported by identification of similar HIV genotypes in the source patient and the recipient."

They conclude that whilst reports of woman-to-woman sexual transmission of HIV are scarce, lesbians in HIV-discordant relationships should be advised regarding safer sexual practices.

Risk factors which have been suggested in sex between women include:

• Oral sex (see above).
• Sharing of sex toys: although no cases have been reported, this cannot be ruled out.
• Fisting, particularly if blood is drawn (see next section).

References

Chu SY et al: Update: epidemiology of reported cases of AIDS in women who report sex only with other women, United States 1980–1991, AIDS 6: 516–519, 1992.

Chu SY et al: Epidemiology of reported cases of AIDS in lesbians, United States 1980–1989, AJPH 80: 1380–1381, 1990.

Kwakwa HA et al. Female-to-female transmission of human immunodeficiency virus. Clinical Infectious Diseases, 36, 1 February 2003.

Marmor M et al: Possible female to female transmission of HIV, AIM 105: 969, 1986.

McCombs SB et al: Epidemiology of HIV–1 Infection in Bisexual Women, AIDS 5: 850–852, 1992.

Monzon O and Capellan J B M: Female–to–female transmission of HIV, Lancet ii: 0–41, 1987.

Petersen L et al: No evidence for female–to–female HIV transmission among 960,000 female blood donors, JAIDS 5(9): 853–855, 1992.

Raiteri R et al: No HIV–1 transmission through lesbian sex, Lancet 344: 270, 1994.

Rich JD et al: Transmission of human immunodeficiency virus infection presumed to have occurred via female homosexual contact, J Clin Inf Diseases 17: 1003–1005, 1993.

Ross MW et al: Sexually Transmissible Diseases, Injecting Drug Users, Genitourinary Medicine 67: 32–36, 1991.

Sabatini MT et al: Kaposi's sarcoma and T–cell lymphoma in an immunodeficient woman: a case report, AIDS Research 1(2): 135–157 (1983/84) The case of a 37 year-old lesbian who died of an AIDS related illness; both she and her female partner denied sexual contact with men or intravenous drug use; no explanation has been discovered for how either partner acquired HIV infection, but the means of transmission from one partner to another is assumed to have been orogenital contact.