title: [Reproducibility of serological tests for the diagnosis of Trypanosoma cruzi infection in pregnant women in an endemic area of Santander, Colombia].
abstract: BACKGROUND
  The diagnosis of chronic Trypanosoma cruzi infection is supported by serological tests whose reproducibility has not been well documented.
  
  
  OBJECTIVE
  To evaluate the reproducibility of the serological tests ELISA, IFAT and IHAT for the diagnosis of T. cruzi infection in pregnant women in an endemic zone in Santander.
  
  
  METHODS
  Through an evaluation study of diagnostic technologies, the reproducibility of the serological tests ELISA, IFAT and IHAT was determined in serum and eluted blood from pregnant women living in an endemic area for Chagas' disease in Santander. The samples were selected by cross sectional sampling. The software Stata  version 10.0 was used for statistical analysis. By means of the comparison of the highest kappa coefficient of each technique, the test with the best reproducibility was determined.
  
  
  RESULTS
  A total of 777 samples were tested. In serum, ELISA (cutoff point: 0.3), IFAT (cutoff point: 1/32) and IHAT (cutoff point: 1/16) had kappa coefficients greater than 0.8 (0.98, 95% CI: 0.93-1.00; 0.98, 95% CI: 0.92-1.00 and 0.88, 95% CI: 0.74-0.97, respectively); no statistically significant differences among the three tests were found (p> 0.05). For the blood eluates, kappa coefficients were below 0.8 (highest kappa: 0.55, 95% CI: 0.41-0.68).
  
  
  CONCLUSIONS
  For the three serological tests using serum, the reproducibility determined by the kappa coefficient was perfect. Selecting any of them is useful for the diagnosis of T. cruzi infection. Given its simplicity and cost, the ELISA test is recommended for screening for this infection.
authors: Facultad de Salud, Universidad Industrial de Santander, Bucaramanga, Colombia.
authors: Yeny Zulay
authors: YZ
authors: Castellanos
authors: Grupo de Parasitología, Instituto Nacional de Salud, Bogotá, D.C, Colombia.
authors: Zulma Milena
authors: ZM
authors: Cucunubá
authors: Grupo de Parasitología, Instituto Nacional de Salud, Bogotá, D.C, Colombia.
authors: Astrid Carolina
authors: AC
authors: Flórez
authors: Escuela de Enfermería, Universidad Industrial de Santander, Bucaramanga, Colombia.
authors: Luis Carlos
authors: LC
authors: Orozco-Vargas
mesh_terms: D000293:Adolescent; D000328:Adult; D000913:Antibodies, Protozoan / Q000097:blood*; D014355:Chagas Disease / Q000175:diagnosis* / Q000453:epidemiology; D003105:Colombia / Q000453:epidemiology; D003430:Cross-Sectional Studies; D019353:Endemic Diseases; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D008875:Middle Aged; D010865:Pilot Projects; D011159:Population Surveillance; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis* / Q000453:epidemiology; D015203:Reproducibility of Results; D014349:Trypanosoma cruzi / Q000276:immunology*; D055815:Young Adult
chemical_list: D000913:Antibodies, Protozoan