Peer-review started: July 9, 2015
First decision: September 22, 2015
Revised: October 2, 2015
Accepted: November 23, 2015
Article in press: November 23, 2015
Published online: March 27, 2016
The methods and strategies used to screen for syphilis and to confirm initially reactive results can vary significantly across clinical laboratories. While the performance characteristics of these different approaches have been evaluated by multiple studies, there is not, as of yet, a single, universally recommended algorithm for syphilis testing. To clarify the currently available options for syphilis testing, this update will summarize the clinical challenges to diagnosis, review the specific performance characteristics of treponemal and non-treponemal tests, and finally, summarize select studies published over the past decade which have evaluated these approaches. Specifically, this review will discuss the traditional and reverse sequence syphilis screening algorithms commonly used in the United States, alongside a discussion of the European Centre for Disease Prevention and Control syphilis algorithm. Ultimately, in the United States, the decision of which algorithm to use is largely dependent on laboratory resources, the local incidence of syphilis and patient demographics.
Core tip: Many laboratories have adapted automated immunoassay methods for syphilis screening in the past decade. Since measurement of antibodies to Treponema pallidum (treponemal) antigens cannot readily distinguish current from past infection, additional tests, including traditional non-treponemal tests, are required to further clarify the disease state. As the incidence of syphilis and population demographics influence test performance, and due to local differences in the way clinical follow-up is offered, there is no single approach to syphilis testing that is universally applicable.