Diagnosis of Clostridium difficile associated diarrhea: comparison of three rapid methods employing different markers for detection.

Latex agglutination and the enzyme immunoassays Cytoclone (EIA-C) and VIDAS (EIA-V) were compared with a cytotoxicity assay for the diagnosis of Clostridium difficile associated diarrhea. Among patients with discrepant results, the cytotoxicity assay and clinical assessment were used to evaluate the performance of the latex agglutination and EIA tests. Clostridium difficile associated diarrhea was documented in 30/149 samples (20.1%) from 130 patients. All test results matched in 113 instances. Latex agglutination, EIA-C, and EIA-V yielded false positive results in 10, 4, and 7 samples and false negative results in 8, 9, and 14 samples, respectively. Latex agglutination demonstrated 87.8% efficiency compared with 91.3% for EIA-C and 85.7% for EIA-V and 3 min hands-on time compared with 4.5 min for EIA-V and 10 min for EIA-C. On the basis of these findings and given the fact that all rapid tests have their shortcomings, we believe that latex agglutination is the most practical method.