Purpose

Clostridioides difficile (formerly clostridium difficile) is an anaerobic, gram-positive bacillus that is the leading cause of antibiotic associated diarrhea and pseudomembranous colitis in health care facilities. Incidence of CDI has been increasing, and severe cases are becoming more common. CDI disease symptoms range from mild diarrhea to severe colitis, and even bowel perforation and death. The most common risk factor is exposure to antibiotics.

The diagnosis of C. difficile infection is based upon clinical signs and symptoms, such as diarrhea, as well as laboratory tests or pathologic finding consistent with toxigenic C. difficile. It appears that Toxin B is necessary for the development of CDI. While culture for toxigenic C. difficile followed by tissue culture cytotoxicity is highly sensitive and specific, it is also highly technical, time consuming and has very slow time to result (48 to 96 hours) making this method impractical in the management of patients. Enzyme immunoassay (EIA) used for the detection of toxin A and toxin B and glutamate dehydrogenase (GDH, an enzyme found in all C. difficile strains), are currently used in many clinical laboratories because results are available the same day, are easy to perform, and are relatively inexpensive. However, the sensitivity is low, especially for the toxin EIAs, which can lead to missed cases of CDI. PCR methods for the detection of toxin A and/or toxin B have been developed and have demonstrated high sensitivity and specificity as compared to toxigenic culture, cell cytotoxicity and immunoassays. Additionally, these tests can be performed in approximately 2 hours. The combination of a highly sensitive and specific assay with rapidly available results may allow for prompt targeted treatment of CDI patients and thus potential improvement in patient outcomes, reduced recovery times, and improved infection control practices.