Elecsys® Syphilis

Immunoassay for the qualitative determination of total antibodies against Treponema pallidum

Elecsys Syphilis

Immunoassay for the qualitative determination of total antibodies against Treponema pallidum

Syphilis is caused by the intracellular Gram-negative spirochete bacterium Treponema pallidum subspecies pallidum. There are an estimated 6 million new syphilis cases each year, worldwide in person aged 15-49 years. In addition, over 300,000 fetal and neonatal deaths are attributed to syphilis, and 215,000 infants are at increased risk of early death.1

Most people with syphilis are asymptomatic, but if untreated the infection can cause significant complications.2 Although syphilis is usually transmitted sexually, it can also be transmitted from mother to fetus with an estimated 1.5 million pregnancies affected globally each year.3,4 However, if diagnosed in the early stages, syphilis can be successfully treated and congenital syphilis prevented.2,3

Finally, syphilis can be transmitted through blood transfusions.4 Serologic tests like the Elecsys® Syphilis assay are the method of choice for the reliable detection of total antibodies against Treponema pallidum in blood donations and clinical routine samples.5


General representation of the reverse and traditional syphilis testing algorithms
Elecsys Syphilis

ECLIA, electrochemiluminescence immunoassay; EIA, enyzme immunoassay; RPR, rapid plasma reagin; TPLA, Treponema pallidum latex agglutination; VDRL, Veneral Disease Reasearch Laboratory test, Adapted from Binnicker (2012)5 and Katz (2010)6


The Mediace® Syphilis Rapid Plasma Reagin (RPR2; 07 404 174 190) assay for the quantitative in vitro determination of syphilitic anti-lipid antibodies7 and the T. pallidum Latex Agglutination® (TPLA2; 07 404 182 190) assay for the in vitro determination of anti-T. pallidum antibodies8 are both available from Roche Diagnostics.

Elecsys Syphilis

Elecsys® Syphilis

  • Systems

    cobas e 411 analyzer
    cobas e 601 / cobas e 602 modules
    cobas e 801 module

  • Testing time

    18 minutes

  • Test principle

    One-step double-antigen sandwich assay
    Assay detects total IgG and IgM against bacterial TpN15, TpN17 and TpN47

  • Sample material

    Serum collected using standard sampling tubes or tubes containing separating gel. Li‑heparin, Na‑heparin, K2‑EDTA, K3‑EDTA, ACD, CPD, CP2D, CPDA and Na‑citrate plasma. K2‑EDTA plasma tubes containing separating gel can be used.

  • Sample volume

    cobas e 411 analyzer, cobas e 601 / 602 modules: 10 μL
    cobas e 801: 6 μL

  • Intermediate precision in positive samples

    cobas e 411 analyzer: CV 3.3 – 7.2 %
    cobas e 601 / 602 modules: CV 1.6 – 2.3 %
    cobas e 801 module: CV 1.7 - 2.7 %

  • Clinical sensitivity

    100 % (n = 924), including all stages

  • Clinical specificity

    99.93 %, n = 4,579 (blood donors)
    99.80 %, n = 3,500 (unselected routine samples)
    99.88 %, n = 8,079 (overall, the 95 % lower confidence limit was 99.60 %)

  • Analytical specificity

    >200 samples containing antibodies against different pathogens showed no cross re-activity



  1. Kojima, N. and Klausner, J.D. (2018) An Update on the Global Epidemiology of Syphilis. Curr Epidemiol Rep. 5(1):24-38. 
  2. Workowski, K.A., Berman, S.; CDC. (2010). Sexually transmitted diseases treatment guidelines, 2010. MMWR Recomm Rep 59, 1-110.
  3. World Health Organisation (2012). Investment case for eliminating mother-to-child transmission of syphilis. Available from: http://apps.who.int/iris/bitstream/10665/75480/1/9789241504348_eng.pdf (accessed November 2020).
  4. World Health Organisation (2010). Screening donated blood for transfusion-transmissible infections: recommendations. Available from: http://www.who.int/bloodsafety/ScreeningDonatedBloodforTransfusion.pdf (accessed November 2020).
  5. Binnicker, M.J. (2012). Which algorithm should 1 World Health Organisation (2012). Baseline report on global sexually transmitted infection surveillance 2012. Available from: https://apps.who.int/iris/bitstream/handle/10665/85376/9789241505895_eng.pdf?sequence=1 (accessed November 2020).
  6. Katz, K. (2010). Newer laboratory testing algorithms for syphilis begin with EIA. MLO Med Lab Obs. 42, 18-20.
  7. RPR2 Package Insert 2017-10, V2.0.
  8. TPLA2 Package Insert 2017-10, V3.0.be used to screen for syphilis? Curr Opin Infect Dis 25, 79-85.