title: [Comparison of conventional and non-conventional serological tests for the diagnosis of imported Chagas disease in Spain].
abstract: BACKGROUND
  Trypanosoma cruzi infection is a major imported parasitic disease in Spain, because of the increase of immigrants from endemic areas. Since the laboratory diagnosis during the chronic phase is based on detection of anti-T. cruzi IgG antibodies, our aims were to compare 10 tests for determining anti-T. cruzi antibodies, to assess their cross-reactivity with related diseases, and to evaluate the rk39-ELISA and IFAT-Leishmania tests as tools for the differential diagnosis of leishmaniasis due to Leishmania infantum.
  
  
  METHODS
  A total of 223 sera were tested: 40 had been previously characterized by Qpanel, and 183 were obtained from the serum library of the Parasitology Department, Centro Nacional de Microbiología (66 chagasic, 97 healthy, 30 visceral leishmaniasis, and 30 malaria). Samples were examined using in-house IFAT and ELISA, 5 commercial ELISAs (Certest/Abbot Laboratories/BiosChile; Ortho Clinical Diagnostics; BLK Diagnostic; bioMérieux; and Biokit), particle gel agglutination (ID-PaGIA), and two immunochromatographic assays (Operon and CTK Biotech). The last 4 tests are based in recombinant antigens (non-conventional tests).
  
  
  RESULTS
  The IFAT and ELISAs showed a sensitivity of 97% to 100%. The immunochromatographic tests had somewhat lower sensitivity (92%-96%). All non-conventional tests presented a smaller number of cross-reactions. Leishmania-Rk39-ELISA did not show cross-reactivity with chagasic sera.
  
  
  CONCLUSIONS
  In general, our results confirm the data obtained by other authors. The sensitivity of ELISA is higher than other tests; therefore, these techniques would be the most appropriate for screening of T. cruzi infection. A suitable approach is the combination of a test using total antigen with another based on either recombinant antigens or synthetic peptides.
authors: Servicio de Parasitología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, España.
authors: María
authors: M
authors: Flores-Chávez
authors: Israel
authors: I
authors: Cruz
authors: Mercedes
authors: M
authors: Rodríguez
authors: Javier
authors: J
authors: Nieto
authors: Elena
authors: E
authors: Franco
authors: Teresa
authors: T
authors: Gárate
authors: Carmen
authors: C
authors: Cañavate
mesh_terms: D000913:Antibodies, Protozoan / Q000097:blood*; D014355:Chagas Disease / Q000097:blood*; D054242:Emigrants and Immigrants; D006801:Humans; D012680:Sensitivity and Specificity; D012698:Serologic Tests; D013030:Spain; D014349:Trypanosoma cruzi / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan