* More than 12 million Americans are infected with sexually transmitted diseases each year, 3 million of whom are teenagers.
* As many as 56 million Americans may be infected with an incurable STD other than HIV, including herpes and human papillomavirus (HPV).
* Chlamydia is the most common bacterial STD, with more than 4 million new cases in the U.S. reported each year.
* As many as 500,000 new cases of genital herpes occur in the United States each year, with 31 million people already infected.
* At least 24 million Americans are infected with HPV, the single most important risk factor for cervical cancer, and as many as 1 million new infections occur each year.
* At least 800,000 cases of gonorrhea occur each year.
* Syphilis affects an estimated 101,000 new people each year.
* Congenital syphilis (afflicting newborns) is diagnosed in an estimated 3,400 cases each year. Fetal or neonatal death occurs in up to 40% of babies whose mothers have untreated syphilis. As many as 40% of live-born infants of women with untreated early syphilis suffer irreversible health consequences, including blindness, bone deformities, mental retardation or death.
* HIV, the virus that causes AIDS, infects an estimated 40,000 to 80,000 people each year.
* All groups of people are potentially at risk for STDs, but women, teens and minorities are disproportionately affected by them. Women, for example, are biologically more susceptible than men to becoming infected if exposed to an STD. Once infected, women are more susceptible to reproductive cancers and infertility. Teens are at high risk for acquiring STDs because they are more likely to have multiple partners and may be more likely to have unprotected sex. Race and ethnicity often correlate with such determinants of health as poverty, limited access to health care, illicit drug use and living in communities with a high prevalence of STDs.
* In addition to the human costs, STDs add an estimated $17 billion to the nation's health care costs each year.
Sources: The Alan Guttmacher Institute, Kaiser Family Foundation, the Institute of Medicine, the National Center for HIV, STD & TB Prevention.