Evaluation of a new commercial Clostridium difficile toxin A enzyme immunoassay using diarrhoeal stools.

A new, commercially available enzyme immunoassay for the detection of toxin A in stool specimens, the Premier Clostridium difficile Toxin A test (Meridian Diagnostics), was evaluated using 228 diarrhoeal stool specimens. Using a cytotoxin assay on HeLa cells as the reference method, this new test resulted in a sensitivity of 88% and a specificity of 95%. Using the presence or absence of a toxigenic strain in the stools as the reference method, the sensitivity was similar to that of the cytotoxin assay (71.7+ versus 70.5%) and the overall correlation was even better (89.4% versus 82%). The Premier Clostridium difficile Toxin A assay is rapid and easy to perform and is an excellent alternative to the usual toxin B assay.