Description

• A chronic, systemic infectious disease caused by the spirochete Treponema pallidum
• Transmitted sexually by direct contact with an active lesion; also transmitted vertically (maternal–fetal) and via blood transfusions
• Untreated disease includes four overlapping stages.
  • Primary: single (usually) painless chancre at point of entry; appears in 10 to 90 days; chancre heals without treatment in 3 to 6 weeks.
  • Secondary: appears 2 to 8 weeks after primary chancre; nonpruritic rash on palms or soles of feet, mucous membrane lesions, headache, fever, lymphadenopathy, and alopecia
  • Latent: seroreactive without evidence of disease
    • Early latent: acquired within the last year
    • Late latent: exposure >12 months prior to diagnosis
  • Tertiary (late): Serology may be negative (fluorescent treponemal antibody absorption [FTA-ABS] test typically positive).
    • Gumma, cardiovascular, and late neurosyphilis; may be fatal
  • Neurosyphilis: any type of CNS involvement; can occur at any stage
    • Psychosis, delirium, dementia

Pediatric Considerations
In noncongenital cases, consider child abuse.

Pregnancy Considerations

• Screen all patients who are pregnant with venereal disease research laboratory (VDRL) test or rapid plasma reagin (RPR) test early in pregnancy, (i.e., first prenatal visit); if high risk, repeat at 28 weeks and at delivery (1)[A].
• Use the same nontreponemal test for initial screening and for follow-up (1)[A].

Epidemiology

Incidence

• Syphilis rates decreased through 2000 and have since increased (primarily in men who have sex with men [MSM]) (2).
  • All stages: 53 per 100,000
• Congenital: 78/100,000 live births (2)

Prevalence

• Predominant sex for primary and secondary syphilis: male (78%) > female (22%) (2)
• Highest prevalence in MSM (2)

Etiology and Pathophysiology

T. pallidum enters through intact mucous membranes or breaks in skin. The organism quickly enters the lymphatics to cause systemic disease; highly infectious; exposure to as few as 60 spirochetes is associated with ~50% chance of infection.

Risk Factors

MSM, multiple sexual partners, exposure to infected body fluids, injection drug use, transplacental transmission, adult individuals in custody, high-risk sexual behavior, people living with HIV (PLWH)

General Prevention

Commonly Associated Conditions

HIV infection, hepatitis B, and other sexually transmitted infections (STIs)