CJIDMM Canadian Journal of Infectious Diseases and Medical Microbiology 1712-9532 Pulsus Group Inc 685603 10.1155/2015/685603 CPHLN Laboratory Guidelines Canadian Public Health Laboratory Network Laboratory Guidelines for the Use of Direct Tests to Detect Syphilis in Canada Tsang Raymond SW raymond.tsang@phac-aspc.gc.ca 1 Morshed Muhammad 2 3 Chernesky Max A 4 Jayaraman Gayatri C 5 Kadkhoda Kamran 6 7 1 National Microbiology Laboratory Public Health Agency of Canada Winnipeg Manitoba Canada phac-aspc.gc.ca 2 BC Public Health Microbiology and Reference Laboratory University of British Columbia Vancouver British Columbia Canada ubc.ca 3 Department of Pathology and Laboratory Medicine University of British Columbia Vancouver British Columbia Canada ubc.ca 4 McMaster University Hamilton Canada mcmaster.ca 5 Centre for Communicable Diseases and Infection Control Public Health Agency of Canada Ottawa Ontario Canada phac-aspc.gc.ca 6 Cadham Provincial Laboratory University of Manitoba Winnipeg Manitoba Canada umanitoba.ca 7 Department of Medical Microbiology & Infectious Diseases and Department of Immunology University of Manitoba Winnipeg Manitoba Canada umanitoba.ca 2015 26 Supplement A 13A 17A 2015 Copyright © 2015 Hindawi Publishing Corporation. This open-access article is distributed under the terms of the Creative Commons Attribution Non-Commercial License (CC BY-NC) (http://creativecommons.org/licenses/by-nc/4.0/), which permits reuse, distribution and reproduction of the article, provided that the original work is properly cited and the reuse is restricted to noncommercial purposes.

Treponema pallidum subsp. pallidum and/or its nucleic acid can be detected by various methods such as microscopy, rabbit infectivity test or polymerase chain reaction (PCR) tests. The rabbit infectivity test for T. pallidum, although very sensitive, has been discontinued from most laboratories due to ethical issues related to the need for animal inoculation with live T. pallidum, the technically demanding procedure and long turnaround time for results, thus making it impractical for routine diagnostic use. Dark-field and phase-contrast microscopy are still useful at clinic- or hospital-based laboratories for near-bedside detection of T. pallidum in genital, skin or mucous lesions although their availability is decreasing. The lack of reliable and specific anti-T. pallidum antibodies and its inferior sensitivity to PCR may explain why the direct fluorescent antibody test for T. pallidum is not widely available for clinical use. Immunohistochemical staining for T. pallidum also depends on the availability of specific antibodies, and the method is only applicable for histopathological examination of biopsy and autopsy specimens necessitating an invasive specimen collection approach. With recent advances in molecular diagnostics, PCR is considered to be the most reliable, versatile and practical for laboratories to implement. In addition to being an objective and sensitive test for direct detection of Treponema pallidum subsp. pallidum DNA in skin and mucous membrane lesions, the resulting PCR amplicons from selected gene targets can be further characterized for antimicrobial (macrolide) susceptibility testing, strain typing and identification of T. pallidum subspecies.

 Treponema pallidum Direct detection PCR Syphilis