Evaluation of a new immunochromatography test for rapid and simultaneous detection of Clostridium difficile antigen and toxins.

BACKGROUND Clostridium difficile infection is considered the most common cause of nosocomial infectious diarrhea among adults in the developed world. It is responsible for virtually all cases of pseudomembranous colitis. The Tox A/B enzyme immunoassay (EIA) is the most widely used test for the detection of C. difficile toxins A and B. However, it is associated with poor sensitivity and an unacceptable high rate of false-negative results. OBJECTIVES To evaluate the performance of the C. DIFF QUIK CHEK COMPLETE assay, designed to simultaneously detect C. difficile-produced glutamate dehydrogenase (GDH) and toxins A and B. METHODS Using the C. DIFF QUIK CHEK COMPLETE assay, the Tox A/B EIA, and polymerase chain reaction (PCR), we tested 223 stool specimens from hospitalized patients with antibiotics-associated diarrhea. Sensitivity and specificity, and positive and negative predictive values (PPV, NPV) were calculated for the C. DIFF QUIK CHEK COMPLETE test and the Tox A/B EIA against PCR RESULTS: The C. DIFF QUIK CHEK COMPLETE test had a sensitivity of 83.5% and specificity of 94.3% compared to PCR for Tox A/B, with 93.7% correlation (PPV 98.5%, NPV 91.7%). The Tox A/B EIA yielded corresponding values of 72.1% and 93.1%, with 85.6% correlation (PPV 85.1%, NPV 85.8%). CONCLUSIONS Given the importance of an early and appropriate diagnosis of Clostridium difficile-associated infection, the C. DIFF QUIK CHEK COMPLETE test may be of huge benefit to practitioners.