Sexually transmitted diseases (STDs) affect approximately 15 million new people annually in the United States, but most people remain unaware of the risks and consequences of all but the most prominent STD-HIV. Most prevalent among teenagers and young adults, many STDs are asymptomatic, especially in women. Due to the lack of noticeable symptoms, STDs are often not diagnosed, and even when they are, the diagnoses are underreported. Even when asymptomatic, STDs are infectious to sex partners, which is why periodic screening for all persons who have had multiple partners is recommended. The regular use of condoms decreases the transmission of most STDs.
Center for Disease Control and Prevention's Division of Sexually Transmitted Disease Prevention The Massachusetts Department of Public Health's Division of STD Prevention includes data on local prevalence, disease surveillance and fact sheets.