Sexually acquired syphilis: Historical aspects, microbiology, epidemiology, and clinical manifestations.

Syphilis is caused by infection with the spirochetal bacterium Treponema pallidum subsp. pallidum. It was first recognized in the late 15th century. Since 2000, the incidence of sexually acquired syphilis has increased substantially in the developed world, with men who have sex with men and persons living with HIV infection disproportionately affected. Clinical manifestations of syphilis are protean and often include mucocutaneous manifestations. The first article in this continuing medical education series reviews historical aspects, microbiology, epidemiology, and clinical manifestations of sexually acquired syphilis.