It sounds like a no-brainer, but the transmission of HIV from one woman to another is very uncommon, and so usually overlooked. But the recent case of two Texas women, reported yesterday by the CDC, "offers the strongest evidence to date that HIV transmission between women, although rare, is possible."
Above: An SEM microcraph of HIV-1 budding from cultured lymphocyte.
The woman who acquired HIV was aged 46 years and had a history of heterosexual intercourse, but not in the 10 years before HIV infection. She reported three female sexual partners in the preceding 5 years but said she had no IDU, receipt of tattoos, acupuncture, transfusions, transplants, or any other recognized HIV risk behavior. The woman supplemented her income by selling her plasma and had tested negative for HIV by HIV-1/2 enzyme immunoassay (EIA) serology screening after donating plasma in March 2012.
In April, 10 days after donating plasma, the woman went to an emergency department with a sore throat, fever, vomiting, decreased appetite, pain on swallowing, dry cough, frequent diarrhea, and muscle cramps. At that time, she was again tested for HIV by EIA serology screening, and the results were negative. She was treated with azithromycin for a presumed upper respiratory infection and discharged. Eighteen days later, the woman attempted to sell plasma but was refused because she tested positive for HIV by EIA serology screening followed by an HIV-1 Western blot test. On July 5, results of repeated EIA and Western blot tests conducted on the woman at a health clinic were positive for HIV infection.
The likely source of the patient's new HIV infection was her female sex partner aged 43 years who had tested positive for HIV in September 2008 when she had an HIV-1 viral load of 82,000 copies/mL and a CD4+ T-lymphocyte count of 372 cells/mm3(25%). The partner began antiretroviral treatment in February 2009 but stopped in November 2010. Although she had esophageal candidiasis and weight loss at the time of her HIV diagnosis, her HIV-1 viral load had decreased to 178 copies/mL, and her CD4+ T-lymphocyte count had increased to 554 cells/mm3 (44%) by January 2011, when she was lost to follow-up.
The couple reported routinely having unprotected (using no barrier precautions) oral and vaginal contact and using insertive sex toys that were shared between them but were not shared with any other persons. They described their sexual contact as at times rough to the point of inducing bleeding in either woman. They also reported having unprotected sexual contact during the menses of either partner. The recently infected woman reported that her partner was her only sexual contact during the 6 months before her seroconversion.