title: Evaluation of four commercially available enzyme immunoassays for laboratory diagnosis of Clostridium difficile-associated diseases.
abstract: Four commercial enzyme immunoassays (EIAs) for the detection of Clostridium difficile toxin A have recently been developed and marketed (Premier, Meridian Diagnostics, Cincinnati, Ohio; VIDAS, bioMerierux Vitek, Inc., Hazelwood, Mo.; Tox-A-Test, TechLab, Blacksburg, Va.; and Bartels, Baxter Diagnostics, McGaw Park, Ill.). The performances of these EIAs were compared with those of the tissue culture cytotoxicity assay and a definition of C. difficile-associated disease based on both laboratory and clinical criteria for 329 clinical specimens. Two EIAs (Premier and VIDAS) showed good overall agreement (96 and 95%, respectively) with the cytotoxicity assay. However, they were less sensitive (84 and 71%, respectively) than the Bartels (94%) or Tox-A-Test (93%) EIAs. The Bartels and Tox-A-Test assays were much less specific, resulting in poor positive predictive values (56%) of the two assays when compared with that of the cytotoxicity assay. Tox-A-Test had the added drawback of having a significant number of indeterminate results (6.4%). These data indicate that the four EIAs all have specific shortcomings. When using these EIAs, testing strategies that take these shortcomings into consideration should be developed.
authors.affiliation: Clinical Microbiology Laboratory, University of North Carolina Hospitals, Chapel Hill 27599.
authors.forename: S
authors.initials: S
authors.lastname: Whittier
authors.forename: D S
authors.initials: DS
authors.lastname: Shapiro
authors.forename: W F
authors.initials: WF
authors.lastname: Kelly
authors.forename: T P
authors.initials: TP
authors.lastname: Walden
authors.forename: K J
authors.initials: KJ
authors.lastname: Wait
authors.forename: L T
authors.initials: LT
authors.lastname: McMillon
authors.forename: P H
authors.initials: PH
authors.lastname: Gilligan
mesh_terms: D000328:Adult; D001427:Bacterial Toxins / Q000032:analysis*; D002648:Child; D016360:Clostridioides difficile / Q000472:pathogenicity*; D003365:Costs and Cost Analysis; D046508:Culture Techniques; D003967:Diarrhea / Q000382:microbiology*; D004768:Enterotoxins / Q000032:analysis*; D006801:Humans; D007124:Immunoenzyme Techniques / Q000191:economics
chemical_list: D001427:Bacterial Toxins; D004768:Enterotoxins; C041348:tcdA protein, Clostridium difficile