A 46-year-old woman in Houston, Texas has contracted HIV, the virus that causes AIDS, from her long-term lesbian lover.

According to the Houston Department of Health and Human Services, the case is the first to be recorded among gay women.

“In 34 years of investigating HIV infection, this is the first time anybody has ever identified sexual transmission between two women,” Barton told Click2Houston.com. “This is a very unique case in that the newly infected person was a regular blood donor. So we had a long history of her negative status for many years.”

The unidentified woman's status changed in the summer of 2012, which led to a nearly two year investigation in which other forms of transmission were ruled out.

According to a report released Friday by the Centers for Disease Control and Prevention (CDC), the woman's HIV-positive girlfriend stopped antiretroviral therapy in 2010.

“Women think if they're only having sex with other women, that they're safe from sexually transmitted diseases. But they're not safe,” said Dr. Robin Hardwicke of the University of Texas Health Medical School.

Lesbian blog The Fab Femme called the news “a big wake up call for the lesbian community.”