Lesbian contracted HIV from her partner while in a monogamous relationshipCDC

A rare case of HIV being transmitted between two women has been reported in the US.

The Centres for Disease Control and Prevention has said a case of female-to-female transmission of HIV has taken place in Houston.

The Houston Department of Health contacted the CDC about the case and it was investigated, with laboratory findings confirming a woman, 46, with newly diagnosed HIV had a virus almost identical to that of her female partner, 43.

The case was first reported in August 2012, two years after the first woman with HIV has stopped receiving antiretroviral treatment.

According to the CDC, the infection to her partner took place during a six-month monogamous relationship.

The CDC report said: "Transmission of HIV between women who have sex with women (WSW) has been reported rarely and is difficult to ascertain. 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.

"Other potential exposures associated with HIV transmission in WSW that 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."

"They described their sexual contact as at times rough to the point of inducing bleeding in either woman."

CDC report

The woman who contracted HIV from her partner had not used drug intravenously and had no tattoos, nor had she had acupuncture, transfusions or transplants.

She was diagnosed with HIV in April 2012 after getting a sore throat, fever, vomiting, lack of appetite, pain on swallowing, a cough, muscle cramps and diarrhoea.

At first she tested negative for HIV, but 18 days later, when she attempted to sell plasma – which she had done regularly beforehand – she was refused because of a positive HIV result.

"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 ... The partner began antiretroviral treatment in February 2009 but stopped in November 2010" the CDC said.

"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 six months before her seroconversion."

The CDC notes that female-to-female transmission of HIV is rare, with just a handful of cases confirmed. Most often, WSW HIV infections take place through concomitant heterosexual sex or intravenous drug use.