title: Evaluation of three enzyme immunoassays and a nucleic acid amplification test for the diagnosis of Clostridium difficile-associated diarrhea at a university hospital in Brazil.
abstract: BACKGROUND
  Despite the known importance of Clostridium difficile as a nosocomial pathogen, few studies regarding Clostridium difficile infection (CDI) in Brazil have been conducted. To date, the diagnostic tests that are available on the Brazilian market for the diagnosis of CDI have not been evaluated. The aim of this study was to compare the performances of four commercial methods for the diagnosis of CDI in patients from a university hospital in Brazil.
  
  
  METHODS
  Three enzyme immunoassays (EIAs) and one nucleic acid amplification test (NAAT) were evaluated against a cytotoxicity assay (CTA) and toxigenic culture (TC). Stool samples from 92 patients with suspected CDI were used in this study.
  
  
  RESULTS
  Twenty-five (27.2%) of 92 samples were positive according to the CTA, and 23 (25%) were positive according to the TC. All EIAs and the NAAT test demonstrated sensitivities between 59 and 68% and specificities greater than 91%.
  
  
  CONCLUSIONS
  All four methods exhibited low sensitivities for the diagnosis of CDI, which could lead to a large number of false-negative results, an increased risk of cross-infection to other patients, and overtreatment with empirical antibiotics.
authors.affiliation: Faculdade de Medicina Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, BRAZIL.
authors.forename: Rodrigo Otávio Silveira
authors.initials: RO
authors.lastname: Silva
authors.affiliation: Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, MG, BRAZIL.
authors.forename: Eduardo Garcia
authors.initials: EG
authors.lastname: Vilela
authors.affiliation: Faculdade de Medicina Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, BRAZIL.
authors.forename: Monique Silva
authors.initials: MS
authors.lastname: Neves
authors.affiliation: Faculdade de Medicina Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, BRAZIL.
authors.forename: Francisco Carlos Faria
authors.initials: FC
authors.lastname: Lobato
mesh_terms: D001427:Bacterial Toxins / Q000235:genetics / Q000302:isolation & purification; D001938:Brazil; D016360:Clostridioides difficile / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D003015:Clostridium Infections / Q000175:diagnosis*; D003967:Diarrhea / Q000382:microbiology*; D005243:Feces / Q000382:microbiology; D006785:Hospitals, University; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods*; D021141:Nucleic Acid Amplification Techniques; D012680:Sensitivity and Specificity
chemical_list: D001427:Bacterial Toxins