title: The Type of Trypanosoma Cruzi Strain (Native or Non-Native) Used as Substrate for Immunoassays Influences the Ability of Screening Asymptomatic Blood Donors.
abstract: BACKGROUND
  The origin (native or non-native) of Trypanosoma cruzi strains used as substrate for immunoassays may influence their performance.
  
  
  OBJECTIVE
  To assess the performance of an immunoassay based on a native T. cruzi strain compared to another based on non-native T. cruzi strains, in asymptomatic blood donors from Mexico.
  
  
  METHODS
  Serum samples from a tertiary referral center were tested by both ELISA-INC9 (native) and Chagatest (non-native) assays. All reactive serum samples were further analyzed by indirect immunofluorescence.
  
  
  RESULTS
  Sera from 1,098 asymptomatic blood donors were tested. A 4.3 and 0.7% serum reactivity prevalence was observed using ELISA-INC9 and Chagatest, respectively (kappa = 0.13; -0.11 to 0.38). Subsequently, indirect immunofluorescence analyses showed higher positivity in serum samples reactive by ELISA-INC9 compared to those reactive by Chagatest (79 vs. 62.5%; p < 0.001). Furthermore, out of the 47 positive samples by both ELISA-INC9 and indirect immunofluorescence, only four (8.5%) were reactive in Chagatest assay. Meanwhile, four (80%) out of the five positive samples by both Chagatest and indirect immunofluorescence were reactive using ELISA-INC9.
  
  
  CONCLUSIONS
  Immunoassays based on a native T. cruzi strain perform better than those based on non-native strains, highlighting the need to develop and validate screening assays in accordance to endemic T. cruzi strains.
authors.affiliation: Department of Molecular Biology, Instituto Nacional de Cardiología Ignacio Chávez, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico.|Department of Immunology, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico.
authors.forename: Martha A
authors.initials: MA
authors.lastname: Ballinas-Verdugo
authors.affiliation: Blood Bank, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Mejía-Domínguez
authors.affiliation: Blood Bank, Instituto Nacional de Cancerología, Mexico City, Mexico.
authors.forename: Sergio A
authors.initials: SA
authors.lastname: Sánchez-Guerrero
authors.affiliation: Department of Electromechanic Instrumentation, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico.
authors.forename: Claudia
authors.initials: C
authors.lastname: Lerma
authors.affiliation: Perronee-Gatonee Veterinary Clinics, Mexico City, Mexico.
authors.forename: Mariana
authors.initials: M
authors.lastname: Martínez-Cruz
authors.affiliation: Blood Bank, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico.
authors.forename: Elsa
authors.initials: E
authors.lastname: Álvarez-Manilla-Toquero
authors.affiliation: Blood Bank, Instituto Nacional de Cancerología, Mexico City, Mexico.
authors.forename: Xochiquetzali
authors.initials: X
authors.lastname: Jiménez-Díaz
authors.affiliation: Blood Bank, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico.
authors.forename: Francelia
authors.initials: F
authors.lastname: Barrera-Trujillo
authors.affiliation: Blood Bank, Instituto Nacional de Cancerología, Mexico City, Mexico.
authors.forename: Marisela Del R
authors.initials: MD
authors.lastname: Ticante-Cruz
authors.affiliation: Department of Immunology, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico.
authors.forename: Irving O
authors.initials: IO
authors.lastname: Estevez-Garcia
authors.affiliation: Department of Immunology, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico.|Health Care Department, Universidad Autónoma Metropolitana, Mexico City, Mexico.
authors.forename: Luis M
authors.initials: LM
authors.lastname: Amezcua-Guerra
authors.affiliation: Division of Research, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico.
authors.forename: Pedro A
authors.initials: PA
authors.lastname: Reyes-Lopez
mesh_terms: D001782:Blood Donors; D014355:Chagas Disease / Q000175:diagnosis* / Q000469:parasitology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D019084:Fluorescent Antibody Technique, Indirect / Q000379:methods; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008800:Mexico; D012698:Serologic Tests / Q000379:methods; D013045:Species Specificity; D014349:Trypanosoma cruzi / Q000302:isolation & purification*