Shirley K. Chan, Lupita R. Thornton, Karen J. Chronister, Dr. Jeffrey Meyer, Marcia Wolverton, Cynthia K. Johnson, Dr. Raouf R. Arafat, all of the Houston Department of Health and Human Services; and Dr. M. Patricia Joyce, William M. Switzer, Walid Heneine, Anupama Shankar, Timothy Granade, S. Michele Owen, Patrick Sprinkle, Vickie Sullivan all of the National Center for HIV at the Centers for Disease Control and Prevention, investigated the case.
Laboratory testing confirmed the woman with newly diagnosed HIV infection had a virus virtually identical to that of her female partner, who was diagnosed previously with HIV and who had stopped receiving anti-retroviral treatment in 2010, the CDC's Morbidity and Mortality Weekly Report said.
The woman with the newly acquired infection did not report any other recognized risk factors for HIV infection, and the viruses infecting the two women had more than 98 percent sequence identity in three genes.
The couple had not received any preventive counseling before acquisition of the virus by the woman who had tested negative for HIV.
HIV-discordant couples -- one negative and one positive -- should receive counseling regarding safer sex practices, and HIV-infected partners should be linked to and retained in medical care, the CDC said.
Transmission of HIV between women who have sex with women has been reported rarely and is difficult to ascertain, the CDC said.
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 sex.
Other potential exposures associated with HIV transmission in women having sex with women must be ruled out include injection drug use, heterosexual sex, tattooing, acupuncture, piercing, use of shared sex toys between the partners and other persons, exposure to body fluids of others and receipt of transplants or transfusion, the CDC officials said.