Sexually transmitted diseases (STDs) are infections that spread from person to person through sexual contact, including anal, vaginal, or oral sex. HIV is an STD. Chlamydia, gonorrhea, human papillomavirus (HPV) infection, and syphilis are examples of other STDs. While sexual transmission of Hepatitis C (Hep C) is relatively rare, being HIV positive appears to increase the risk for acquiring Hep C sexually. During the past decade, outbreaks of sexually transmitted Hep C have been reported among HIV-positive gay, bisexual, and other men who have sex with men (MSM).