Sexually transmitted disease (STD) is a term used to describe more than 20 different infections that are transmitted through exchange of semen, blood, and other body fluids; or by direct contact with the affected body areas of people with STDs. Sexually transmitted diseases are also called venereal diseases.

Once called venereal diseases, STDs are some of the most commonly reported infections and the incidence has been rising over the past 20 years, despite improved methods of diagnosis and treatment. The Centers for Disease Control and Prevention has reported that 85% of the most prevalent infectious diseases in the United States are sexually transmitted. The rate of STDs in this country is 50-100 times higher than that of any other industrialized nation; in fact, one in four sexually active Americans will be affected by an STD at some point. About 13 million new infections occur in the United States...