On Thursday this week, it was confirmed that an H.I.V.-positive woman transmitted the virus to another female sex partner in what is the first reported case of the virus being transmitted between female partners. Health officials claim it is "exceedingly rare" but advise that precautions should be taken nonetheless.

The CDC stated in their Morbidity and Mortality Weekly Report that "the case was investigated, and laboratory testing confirmed that the woman with newly diagnosed H.I.V. infection had a virus virtually identical to that of her female partner, who was diagnosed previously with H.I.V. and who had stopped receiving antiretroviral treatment in 2010."

The women reported "having sex during their periods and using insertive sex toys, sometimes so roughly that bleeding occurred." In order to prevent transmission, the CDC urges the continued use of antiretroviral drugs.

In an editorial, C.D.C. officials advised that all infected people having sex with uninfected people stay on daily antiretroviral drugs, which can reduce virus levels in blood and bodily fluids so much that transmission is highly unlikely.

Though other cases of gay women contracting H.I.V. have been reported, this is the first where both women had no prior sexual history with men or intravenous drug use.

[Image via Huffington Post]