Syphilis is a complex sexually transmitted disease that has a highly variable clinical course. Classification by a clinician with expertise in syphilis may take precedence over the following case definition developed for surveillance purposes.

CLINICAL DESCRIPTION

A stage of infection with Treponema pallidum in which organisms persist in the body of the infected person without causing symptoms or signs. Latent syphilis is subdivided in to early, late, and unknown categories based on the duration of infection.

• Early Latent: Initial infection occurred within the previous 12 months.
• Late Latent: Initial infection occurred more than 1 year previously.
• Of Unknown Duration: Initial date of infection cannot be established and patient's age and titer status meet criteria (below).

1. CONFIRMED

   • Not used.
2. PROBABLE
   

   • Latent: No clinical signs or symptoms of syphilis and the presence of one or more of the following:

     • No past diagnosis of syphilis, a reactive nontreponemal test (i.e. VDRL or RPR) and a reactive treponmenal test (i.e. FTA-ABS or MHA-TP)

     • A past history of syphilis therapy and a current nontreponemal test titer demonstrating fourfold or greater increase from the last nontreponemal test titer.

   • Early Latent: latent syphilis in a person who has evidence of having acquired the infection within the previous 12 months based on one or more of the following criteria:

     • Documented seroconversion or fourfold or greater increase in titer of a nontreponemal test during the previous 12 months.

     • A history of symptoms consistent with primary or secondary syphilis during the previous 12 months.

     • A history of sexual exposure to a partner who had confirmed or probable primary or secondary syphilis or probable early latent syphilis (documented independently as duration < 1 year).

     • Reactive nontreponemal and treponemal tests from a person whose only possible exposure occurred within the preceding 12 months.

   • Late Latent: latent syphilis in a patient who has no evidence of having acquired the disease within the preceding 12 months and whose age and titer do not meet the criteria specified for latent syhilis of unknown duration

   • Latent of Unknown Duration: latent syphilis that does not meet the criteria for early latent syphilis, and the patient is aged 13-35 years and has a nontreponemal titer ≥ 32.
     
3. POSSIBLE
   
   

   • Not used