Syphilis in the modern era: an update for physicians.

Syphilis is a complex, systemic disease caused by the spirochete Treponema pallidum. Syphilis is most commonly transmitted sexually or congenitally and can involve nearly every organ system. Its clinical progression involves several well-characterized stages: an incubation period, a primary stage, a secondary stage, a latent stage, and a late or tertiary stage. Syphilis during pregnancy is a leading cause of perinatal mortality in sub-Saharan Africa and can cause spontaneous abortion, stillbirth, prematurity, low birth weight, or congenital syphilis. Penicillin is highly effective against syphilis and remains the treatment of choice. This article reviews the epidemiology, clinical features, diagnostic approach, treatment, and prevention of syphilis.