A 46-year-old Texas woman tested HIV-positive while in a six-month monogamous relationship with a female sexual partner, 43, who had been previously diagnosed with HIV. The woman frequently supplemented her income by selling her plasma (similar but not the same as donating your whole blood) and she had tested negative for HIV in March 2012 when she made a plasma donation. However, 10 days later, she went to the emergency room with a fever, vomiting, frequent diarrhea, pain when swallowing, dry cough, muscle cramps, and other symptoms. Hospital staff treated her with azithromycin and discharged her after she tested negative once again (HIV-1/2 enzyme immunoassay (EIA) serology test), the Centers for Disease Control and Prevention (CDC) reported.

After 18 days passed, the woman attempted to sell plasma again, but this time she was refused when results were positive on both the EIA serology test and an HIV-1 Western blot test. About three months later on July 5, a health clinic repeated the two tests and confirmed her positive status.

In the CDC report released on Friday, the woman said she had no heterosexual sex in the previous 10 years, injection drug use, tattoos, or other recognized risk factors for HIV infection. The CDC noted that her partner had stopped receiving antiretroviral treatment in 2010. Analysis showed the two strains of virus to be virtually identical.

The couple described their unprotected sexual contact as rough to the point of bleeding at times, and routinely they shared sex toys. They also reported contact during menstruation. “The potential for HIV transmission by female-to-female sexual contact includes unprotected exposure to vaginal or other body fluids and to blood from menstruation, or to exposure to blood from trauma during rough sex,” wrote the authors of the CDC report.

In 2009, the authors of a paper published by the Women’s Institute for Gay Men’s Health Crisis wrote, “According to the CDC, there are no confirmed cases of HIV from female-to-female transmission.” It is commonly thought that women having sex with women have low rates of sexually-transmitted infections (STIs) or diseases. Usually, lesbians testing positive for HIV become infected due to intravenous drug use or heterosexual sex outside the relationship. In fact, one study of 18 WSW couples with one partner HIV-positive, the other HIV-negative, found no evidence of transmission over a three-to-six-month period. Publishing their report, the authors suggested that lesbian couples who were monogamous had no risk of HIV transmission.

One STI, bacterial vaginosis (BV), is more common in lesbian and bisexual women than in other women, though the reasons remain unknown. BV develops when the vagina, which normally has a balance of mostly "good" bacteria and fewer "harmful" bacteria, shows an imbalance with more harmful, less positive bacteria. Other STIs that may spread among lesbians, even when they exclusively sleep with other women, are chlamydia, herpes, trichomoniasis, and human papillomavirus (HPV).

Source: Chan SK, Thornton LR, Chronister KJ, Meyer J, Wolverton M, Johnson C, et al. Likely Female-to-Female Sexual Transmission of HIV — Texas, 2012. CDC Publication. 2014.