Three-centre evaluation of laboratory Clostridium difficile detection algorithms and the EntericBio^® realtime...

Area of Science:

• Clinical Microbiology
• Infectious Diseases
• Molecular Diagnostics

Background:

• High costs and low prevalence of Clostridium difficile infection (CDI) necessitate efficient diagnostic algorithms.
• Current CDI testing often involves sensitive screening followed by specific confirmation.
• Evaluating novel diagnostic assays is crucial for improving CDI detection.

Purpose of the Study:

• To prospectively evaluate the efficacy of the EntericBio realtime C. difficile Assay (EBCD) for detecting toxigenic C. difficile.
• To compare the performance of EBCD against existing laboratory testing methods in the UK and Ireland.
• To assess the sensitivity, specificity, and predictive values of the EBCD assay.

Main Methods:

• Prospective study conducted across three centers (two in the UK, one in Ireland).
• EBCD assay was compared with established C. difficile detection methods, including C.diff Quik Chek Complete, C. DIFF CHEK™-60, and Meridian Bioscience Premier™ Toxins A&B.
• Discrepant results were further analyzed using Cepheid Xpert C. difficile PCR and/or PCR ribotyping.

Main Results:

• A total of 947 stool samples were analyzed; 0.8% were inhibitory to the EBCD assay.
• For valid tests (n=939), EBCD demonstrated high sensitivity (94.7%-100%) and specificity (99.6%-100%).
• Positive predictive values ranged from 94.7% to 100%, and negative predictive values ranged from 99.6% to 99.8%.

Conclusions:

• The EntericBio realtime C. difficile Assay (EBCD) is a highly sensitive and specific method for detecting toxigenic C. difficile.
• EBCD offers a reliable option for diagnosing C. difficile infection (CDI), potentially improving upon existing algorithms.
• The assay's performance supports its utility in clinical microbiology laboratories for CDI diagnostics.