Table 4: Summary of Clinical Aspects of Clostridium difficile Infection (CDI).

Risk Factors for CDI*

• Antibiotic or antimicrobial agent exposure (duration, and the number of antibiotics the patient has been exposed to increases the risk for CDI, but cases have been shown to results from a single course of an antibiotic)

• Acid reducing medications (including histamine‐2 blockers and proton pump inhibitors)

• Gastrointestinal surgery/manipulation

• Longer duration of hospitalization

• Underlying co-morbidities

• Immunocompromising conditions (ex. cancer chemotherapy, HIV, autoimmune disease)

• Advanced age (specifically > 64 years of age)

Antibiotic Classes Associated with increased risk for CDI †
Frequently Associated Occasionally Associated Rarely Associated

Fluoroquinolones

Clindamycin‡

Penicillins (broad spectrum example: ampicillin and amoxicillin) ‡

Cephalosporins (broad spectrum) ‡

 

Other Penicillins

Macrolides‡

Trimethoprim

Trimethoprim-sulfamethoxazole

Sulfonamides

 

Aminoglycosides

Bacitracin

Tetracyclines‡

Chloramphenicol

Metronidazole‡

Vancomycin

Laboratory tests used to diagnose CDI¶
Polymerase Chain Reaction (PCR): Detects one or more genes responsible for CDI as quickly as within an hour and is almost as sensitive as the CCCA. EIA for toxin A&B: This assay tests for toxin A and B. One, or both toxins can be present with CDI, however toxin B is the most clinically relevant toxin. EIA for glutamate dehydrogenase (GDH): Great for initial screening however this is less sensitive than PCR and cannot differentiate between toxigenic and non-toxigenic strains. Selective Anaerobic Culture: Cultures grow Clostridium difficile, the most sensitive test however it does not differentiate between toxigenic and non-toxigenic strains. Cell Culture Cytotoxic Assay (CCCA): This is the gold standard for testing for CDI, it takes about 2 days for the lab tests to be complete.

Resources Used: *CDC-Clostridium difficile Infection Information for Patients (https://www.cdc.gov/hai/organisms/cdiff/cdiff-patient.html). (Archived by WebCite® at http://www.webcitation.org/archive.php); †[39], ‡[29], ¶[40].