Awide variety of infectious agents are sexually transmitted (see table 6.1), causing an array of disease manifestations that are frequently not confined to the genital tract. According to the most recent Centers for Disease Control (CDC) surveillance data from 2009, the most common reportable sexually transmitted diseases (STDs) in the United States are chlamydia, gonorrhea, and primary and secondary syphilis, respectively, and the annual incidence of chlamydia and early syphilis is still increasing. Case reporting for more common STDs, such as genital herpes simplex virus (HSV), trichomonas, and human papilloma virus (HPV) infections is not required. In this chapter several of the most common ulcerative and nonulcerative STDs are discussed. The viral hepatitides (A, B, and C) and HIV merit individual attention and are not addressed in this chapter. Vaginitis and HPV are also not discussed here.