Usefulness of simultaneous detection of toxin A and glutamate dehydrogenase for the diagnosis of Clostridium difficile-associated diseases

The aim of this study was to evaluate an immunoassay (Triage; Biosite Diagn ostics, BMD, France) for detecting both a specific antigen of Clostridium d ifficile (glutamate dehydrogenase [GDH]) and toxin A, Evaluation of the tes t was carried out in 304 fecal samples from patients suspected of having Cl ostridium difficile-associated diseases. The results with GDH and toxin A w ere compared with those of a culture and cytotoxicity assay (toxin B). The prevalence rates for toxin B-positive and culture-positive fecal samples we re 11.2% and 25%, respectively. The sensitivity of the Triage immunoassay w as 90.8% for GDH and 79.4% for toxin A. A negative result with both toxin A and GDH was very reliably able to eliminate a diagnosis of Clostridium dif ficile-associated disease (negative predictive value 99.6%). Triage is a ve ry rapid (20 min) and easy-to-perform test. It could be useful for diagnost ic purposes and also for detecting nontoxigenic strains in epidemiogical st udies.