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NOTE: A surveillance case definition is a set of uniform criteria used to define a disease for public health surveillance. Surveillance case definitions enable public health officials to classify and count cases consistently across reporting jurisdictions. Surveillance case definitions are not intended to be used by healthcare providers for making a clinical diagnosis or determining how to meet an individual patient’s health needs.

CSTE Position Statement(s)

  • 13-ID-04


  • Syphilis, primary
  • Syphilis, secondary
  • Syphilis, early latent
  • Syphilis, late latent
  • Syphilis, late with clinical manifestations (including late benign syphilis and cardiovascular syphilis)
  • Syphilitic stillbirth
  • Syphilis, congenital


Syphilis is a sexually transmitted disease (STD) caused by the bacterium Treponema pallidum. Syphilis is passed from person to person through direct contact with a syphilitic chancre. Chancres occur mainly on the external genitals, vagina, anus, or in the rectum but can also occur on the lips and in the mouth. Transmission of the organism occurs during vaginal, anal, or oral sex. Pregnant women with the disease can transmit it through the placenta to the fetus or at birth to the neonate. Many people infected with syphilis do not have any symptoms for years, yet remain at risk for late complications if they are not treated. Although transmission occurs from persons with chancres who are in the primary or secondary stage, many of these chancres are unrecognized. Thus, transmission may occur from persons who are unaware of their infection.

Syphilis is a complex sexually transmitted disease that has a highly variable clinical course. Adherence to the following surveillance case definitions will facilitate understanding the epidemiology of this disease across the U.S.

Subtype(s) Case Definition


Neurosyphilis can occur at any stage of syphilis. If the patient has neurologic manifestations of syphilis, the case should be reported with the appropriate stage of infection (as if neurologic manifestations were not present) and neurologic manifestations should be noted in the case report data. If no other stage is appropriate, the case should be staged as "late, with clinical manifestations".

Neurosyphilis can apply to all stages of infection of syphilis on this page, including: primary syphilis, secondary syphilis, early latent syphilis, late latent syphilis, and late syphilis with clinical manifestations.

Neurosyphilis Surveillance Case Definition:

Clinical description

Infection of the central nervous system with T. pallidum, as evidenced by manifestations including syphilitic meningitis, meningovascular syphilis, optical involvement including interstitial keratitis and uveitis1, general paresis, including dementia, and tabes dorsalis.

Laboratory criteria for diagnosis

  • A reactive VDRL in cerebrospinal fluid (CSF) AND either 1.) a reactive treponemal serologic test for syphilis (e.g., FTA-ABS, TP-PA, EIA, CIA, or equivalent serologic methods) OR 2.) a reactive nontreponemal serologic test for syphilis (VDRL, RPR, or equivalent serologic method).

Case classification


Syphilis of any stage with a negative VDRL test in CSF specimen and either 1) a reactive treponemal serologic test for syphilis (e.g., FTA-ABS, TP-PA, EIA, CIA, or equivalent serologic methods) OR 2) a reactive non-treponemal serologic test for syphilis (VDRL, RPR, or equivalent serologic method), AND both the following:

  • Elevated CSF protein† or leukocyte count† in the absence of other known causes of these abnormalities, AND
  • Clinical symptoms or signs consistent with neurosyphilis without other known causes for these clinical abnormalities


†CSF protein >50 mg/dL2, >5 white blood cells/cubic millimeter CSF3; in HIV-positive individuals, these parameters are less specific


Syphilis of any stage that meets the laboratory criteria for neurosyphilis.


  1. Doris JP, Saha K, Jones NP, Sukthankar A. Ocular syphilis: the new epidemic. Eye (Lond). 2006 Jun;20(6):703-5. Epub 2005 Jun 3.
  2. Sparling, PF, Swartz, MN, Musher, DM, Healy, BP. Clinical Manifestations of Syphilis. In Holmes, KK, Sparling, PF, Stamm, WE, Piot, P, Wasserheit, J, Corey, L, Cohen, MS, Watts, DH (eds). Sexually Transmitted Diseases (4th ed). McGraw Medical: New York City, NY (2008), pp. 661–684.
  3. Tramont, EC. Treponema pallidum (Syphilis). In Mandell, GL, Bennett, JE, Dolin, R (eds). Principles and Practice of Infectious Diseases (5th ed). Churchill Livingstone: Philadelphia, PA (2000), pp. 2474–2490.

Related Case Definition(s)