<unk>  is caused by the spirochete Treponema pallidum. 
Usually sexually transmitted
Causes a wide range of<unk> stemic manifestations that are characterized by episodes of active disease interrupted by periods of latency
Approximately 30% of asymptomatic contacts examined within 30 days of exposure have infection
Spirochetes penetrate intact mucous membranes or microscopic dermal abrasions.
Transmission through sexual contact with infectious lesions, infection in utero, blood transfusion, and organ transplantation
Blood from a patient with incubating or early<unk>  is infectious.
Characterized by multiple stages separated by periods of latency: primary, secondary, latent and tertiary
Syphilis
Ulcerative STDs
Smallpox
Proctitis
Leprosy
Genital Herpes
Rubella
Chancroid