How should I interpret a positive Treponema serology by enzyme immunoassay (EIA) in my elderly patient with dementia?

A positive EIA treponema-specific test (e.g. Trep-Sure) suggests either current or prior syphilis.  It should be followed by an RPR to better assess disease activity (1).  If the RPR is positive, syphilis can be assumed and further evaluation for neurosyphilis with lumbar puncture may be necessary in this elderly patient with neurological symptoms.

If the RPR is negative, a more specific treponema test (e.g. fluorescent tryponemal antibody [FTA], or  Treponema pallidum particle agglutination [TP-PA]) should be performed for confirmation of the treponema-specific test (1). 

Recall that the treponema-specific antibody tests by EIA  are much more sensitive and specific than RPR, especially during the primary and late stages of syphilis.   Also remember that serum RPR may be negative in about 30% of patients with neurosyphilis (2); so a negative serum RPR should not rule out neurosyphilis.

Liked this post? Download the app on your smart phone and sign up below to catch future pearls right into your inbox, all for free!

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.


1. Binnicker MJ, Jespersen DJ, Rollins LO. Treponema-specific tests for serodiagnosis of syphilis: comparative evaluation of seven assays 2011;49:1313-1317.

2. Whitefield SG, Everett As, Rein MF. Case 32-1991;tests for neurosyphilis. N Engl J Med 1992;326:1434.


Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Massachusetts General Hospital, Harvard Catalyst, Harvard University, its affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

How should I interpret a positive Treponema serology by enzyme immunoassay (EIA) in my elderly patient with dementia?