THE DIAGNOSTIC USABILITY AND ACCURACY OF 3 MOLECULAR ASSAYS FOR THE DETECTION OF CLOSTRIDIUM DIFFICILEIN STOOL SAMPLES, AS COMPARED WITH THE XPERT^® C. DIFFICILE ASSAY

Background: Clostridium difficile infection (CDI) is the most common nosocomial infection acquired in hospitals. Therefore, fast and accurate diagnosis is very important for better monitoring and treatment adjustment. Currently several molecular- based assays for the detection of Clostridium difficile toxins are available.

Objective: To compare the performance and the diagnostic accuracy of three molecular tests for the detection of Clostridium difficile in stool samples, with the Xpert^® C. difficile assay.

Methods: Fifty nine positive and twenty five stool samples were analyzed by three molecular assays, the BDmax C. diff, the Simplexa C. difficile Direct, and the GenomEra C. difficile. The performance and the accuracy of these assays were compared with the Xpert^® C. difficile, which is routinely used in our laboratory.

Results: The highest sensitivity was 94.9% for the BDmax C. diff, followed by GenomEra C. difficile with 93.2% and Simplexa C. difficile Direct with 89.8%. The specificities of all assays were 100%. GenomEra C. difficile had the shortest hands on time but the highest retesting rate (12%). Simplexa C. difficile Direct is benefited with both short hands on time and total-turnaround time and 0% retesting.

Conclusions: The differences in performance and accuracy between these three molecular assays are insignificant and all assays may be used in the clinical diagnostic laboratory as part of the routine algorithm for detection of CDI.