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Disease Name: Syphilis

Quick Links

Please review the Idaho Reportable Disease Rules (IDAPA 16.02.10) for the most up-to-date information.

Syphilis: http://www.cdc.gov/std/syphilis/STDFact-Syphilis-detailed.htm

Overview / Case Definition

Case classification


A person with no clinical signs or symptoms who has one of the following:


Syphilis, Late Latent

Clinical description

A subcategory of latent syphilis (a stage of infection caused by T. pallidum in which organisms persist in the body of the infected person without causing symptoms or signs) when initial infection has occurred > 12 months previously.

Case classification


A person with no clinical signs or symptoms of syphilis who has one of the following:





Within 3 working days

Reportable by Healthcare and Labs:

Reportable by Food Service Facility:

Suspect Reportable:

Reporting Timeframe: Within 3 working days

Diagnosis / Testing

The definitive method for diagnosing syphilis is visualizing the spirochete via darkfield microscopy. This technique is rarely performed today because it is a technologically difficult method. Diagnoses are thus more commonly made using blood tests. There are two types of blood tests available for syphilis: 1) nontreponemal tests and 2) treponemal tests.

Nontreponemal tests (e.g., VDRL and RPR) are simple, inexpensive, and are often used for screening. However, they are not specific for syphilis, can produce false-positive results, and, by themselves, are insufficient for diagnosis. VDRL and RPR should each have their antibody titer results reported quantitatively. Persons with a reactive nontreponemal test should receive a treponemal test to confirm a syphilis diagnosis. This sequence of testing (nontreponemal, then treponemal test) is considered the “classical” testing algorithm.

Treponemal tests (e.g., FTA-ABS, TP-PA, various EIAs, chemiluminescence immunoassays, immunoblots, and rapid treponemal assays) detect antibodies that are specific for syphilis. Treponemal antibodies appear earlier than nontreponemal antibodies and usually remain detectable for life, even after successful treatment. If a treponemal test is used for screening and the results are positive, a nontreponemal test with titer should be performed to confirm diagnosis and guide patient management decisions. Based on the results, further treponemal testing may be indicated. For further guidance, please refer to the 2015 STD Treatment Guidelines. This sequence of testing (treponemal, then nontreponemal, test) is considered the “reverse” sequence testing algorithm. Reverse sequence testing can be more convenient for laboratories, but its clinical interpretation is problematic, as this testing sequence can identify individuals not previously described (e.g., treponemal test positive, nontreponemal test negative), making optimal management choices difficult.


Sexually Transmitted Diseases Treatment Guidelines: http://www.cdc.gov/std/tg2015/default.htm

CDC Syphilis Treatment guidelines: http://www.cdc.gov/std/tg2015/syphilis.htm

Additional Information

Syphilis: http://www.cdc.gov/std/syphilis/STDFact-Syphilis-detailed.htm

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