Elecsys® Chagas

Immunoassay for the qualitative determination of antibodies to Trypanosoma cruzi

Elecsys Chagas

Immunoassay for the qualitative determination of antibodies to Trypanosoma cruzi

Chagas disease is caused by the flagellated protozoan parasite Trypanosoma cruzi (T. cruzi).1 It can be transmitted by hematophagous triatomine insects in endemic areas, by infected blood components, organ transplantations, congenitally from mother to infant and by ingestion of contaminated food.1

T. cruzi is found in the Americas, and has also become an issue in Canada, USA, several countries in Europe, and elsewhere, including Japan and Australia.2,3,4 It is estimated that 6 - 7 million people are infected with T. cruzi worldwide and 20 to 30 % of these develop symptomatic, potentially life-threatening Chagas cardiomyopathy and gastrointestinal disease.5

A positive serology is considered as a sign of active T. cruzi infection or past exposure.6 The Elecsys® Chagas assay uses recombinant antigens for the determination of antibodies to T. cruzi.

Elecsys Chagas

Elecsys® Chagas

  • 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 immunoassay. Assay detects IgG antibodies against T. cruzi.

  • Calibration

    2-point

  • Interpretation

    COI < 1.0 = non-reactive
    COI ≥ 1.0 = reactive

  • 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. Plasma tubes containing separating gel can be used.

  • Sample volume

    30 μL cobas e 411 analyzer, cobas e 601 / cobas e 602 modules
    18 μL cobas e 801 module

  • Onboard stability

    28 days cobas e 411 analyzer, cobas e 601 / cobas e 602 modules
    16 weeks cobas e 801 module

  • Intermediate precision in positive samples

    cobas e 411 analyzer: CV 3.9 – 4.3 %
    cobas e 601 / cobas e 602 modules CV 3.3 – 4.3 %
    cobas e 801 module CV 1.6 – 2.4 %

  • Relative sensitivity

    100 % (n = 674)

  • Analytical specificity

    593 out of 594 samples with other infectious diseases showed no cross reactivity*

  • Relative specificity

    99.90 % (n = 14,681 blood donors)
    100 % (n = 313 pregnant women)
    100 % (n = 517 hospitalized patients)

*1 (out of 204) Malaria positive samples was found positive with Elecsys Chagas. 6 additional samples (Dengue: 5/Leishmaniosis: 1) were excluded from the table. These samples were from Chagas endemic regions and were found reactive in the Elecsys Chagas assay as well as in at least one additional Chagas antibody assay.

References

 

  1. Rassi, A.Jr., Rassi, A., Marin-Neto, J.A. (2010). Chagas disease. Lancet 375, 1388-1402.
  2. Gascon, J., Bern, C., Pinazzo, M.J. (2010). Chagas disease I Spain, the United States and other non-endemic countries. Acta Trop 115 (1-2), 22-27.
  3. Bern, C. (2015). Chagas disease. N Engl J Med. 373, 456-466.
  4. World Health Organization (WHO). Chagas Disease in Latin America: an epidemiological update based on 2010 estimates. (2015). Wkly Epidemiol Rec 90, 33-43.
  5. World Health Organization (WHO). Chagas disease (American trypanosomiasis). Fact sheet. Available at: http://www.who.int/news-room/fact-sheets/detail/chagas-disease-(american-trypanosomiasis). Last visited: July, 2018.
  6. Elecsys® Chagas Package Insert 2016-09, V 1.0.