Repeat stool testing for Clostridium difficile using enzyme immunoassay in patients with inflammatory bowel disease...

Area of Science:

• Gastroenterology
• Infectious Diseases
• Clinical Diagnostics

Background:

• Clostridium difficile infection (CDI) is increasingly prevalent and severe in inflammatory bowel disease (IBD) patients.
• Current CDI diagnostics include toxin enzyme immunoassay (EIA) and real-time polymerase chain reaction (PCR) on stool samples.
• Previous research suggested repeat stool testing may enhance CDI diagnosis in IBD patients.

Purpose of the Study:

• To evaluate if repeat stool testing improves CDI diagnostic accuracy in hospitalized IBD patients.
• To compare the diagnostic yield of repeat testing in IBD patients versus non-IBD patients with CDI.

Main Methods:

• Retrospective analysis of 63,086 hospitalized patients tested for CDI (EIA or PCR) from January 2005 to May 2011.
• Included 2579 IBD patients; transition probabilities calculated from repeated test results.

Main Results:

• For non-IBD patients, the first stool sample was positive in 90% (EIA) and 94% (PCR).
• In IBD patients diagnosed with CDI via EIA, only 81% tested positive on the first stool sample.
• Second and third stool samples identified an additional 14% and 5% of CDI-positive IBD patients, respectively.

Conclusions:

• Approximately 20% of IBD patients with CDI require repeat stool testing for a positive EIA result.
• Repeat testing offers minimal diagnostic benefit for CDI in non-IBD patients.
• Repeat stool testing using EIA is recommended for improving CDI diagnostic yield in IBD patients.