Multicentre evaluation of a commercial test for the rapid diagnosis of Clostridium difficile-mediated antibiotic-associated diarrhoea

An immunoassay for the detection of Clostridium difficile toxin A in stool samples (Clearview C. DIFF A: Unipath, UK) was evaluated against the cell c ytotoxicity assay using 407 stool samples from patients suspected to have, or considered at risk of, antibiotic-associated diarrhoea. Of the samples t ested, 98 were positive and 280 were negative by both tests (sensitivity 83 .1%, specificity 96.9%). Following resolution of the 29 discrepant results, the sensitivity and specificity of the immunoassay were 91% and 98%, respe ctively, and the sensitivity for the cell cytotoxicity assay was calculated as 91.5%, with a specificity of 99%. The Clearview C. DIFF A test proved t o be a rapid simple assay for the detection of Clostridium difficile toxin A in stool samples. The test was equally suited to single or batch testing, required minimal sample handling, and provided results within 30 min of ap plying the sample to the test unit.