Definitions Syphilis Syphilis is a complex, sexually transmitted disease with a highly variable clinical course. Classification by a clinician with expertise in syphilis may take precedence over the following case definitions developed for surveillance purposes. The characteristic lesion of primary syphilis is the chancre, but atypical primary lesions may occur. A stage of infection due to Treponema pallidum, characterized by localized or diffuse mucocutaneous lesions and generalized lymphadenopathy.
Constitutional symptoms are common, and clinical manifestations are protean.
The primary chancre may still be present. A stage of infection due to Treponema pallidum in which organisms persist in the body of the infected person without causing symptoms or signs. Latent syphilis is subdivided into early, late, and unknown syphilis categories based upon the length of elapsed time from initial infection. A subcategory of latent syphilis. When initial infection has occurred within the previous 12 months, latent syphilis is classified as early.