Transmission of human immunodeficiency virus infection presumed to have occurred via female homosexual contact.

We describe a 24-year-old woman infected with the human immunodeficiency virus (HIV) whose sole risk behavior was prior sexual contact with an HIV-infected woman. Our patient's clinical course suggests that viral transmission occurred during the beginning of their sexual relationship. Our case, combined with those previously reported, provides evidence that female homosexual activity can be a risk behavior for acquisition of HIV infection. Seroprevalence studies, however, have not provided evidence for transmission of HIV by this behavior. These studies, combined with the sparse number of individual case reports, suggest that female homosexual activity is an inefficient mechanism of HIV transmission.