The Laboratory Diagnosis of Syphilis

TLDR

Syphilis presents with diverse clinical manifestations, and because Treponema pallidum cannot be cultured, serological testing is essential for diagnosis, often uncovering unsuspected cases in North America. This paper aims to review the available serological and alternative tests for syphilis, examining their limitations and how results correspond to disease stages. The authors discuss the necessity of employing multiple tests and emphasize quality control, highlighting the role of reference laboratories and clinical experts in interpreting complex serology.

Abstract

Syphilis has several clinical manifestations, making laboratory testing a very important aspect of diagnosis. In North America, many unsuspected cases are discovered by laboratory testing. The etiological agent, Treponema pallidum, cannot be cultured, and there is no single optimal alternative test. Serological testing is the most frequently used approach in the laboratory diagnosis of syphilis. The present paper discusses the various serological and alternative tests currently available along with their limitations, and relates their results to the likely corresponding clinical stage of the disease. The need to use multiple tests is discussed, and the importance of quality control is noted. The complexity of syphilis serology means that the services of reference laboratories and clinical experts are often needed.