Clostridium Difficile

(Gastroenterology 2006;130:1311-16. Am J Gastroenterol 1997;92:739-50)

DEFINITION:

EPIDEMIOLOGY:

20-30% of persons who take antibiotics develop diarrhea
C. difficile frequency is unknown, estimated at 12/100,000 outpatients and 21/100 inpatients
- The most severe complication, Pseudomembranous Colitis occurs in about 5-8% of all cases of C. difficile infections

ETIOLOGIES:

Suspect in anyone with diarrhea:
- Who has received antibiotics within the previous 2 months
  - Clindamycin, cephalosporins (esp. 3rd generation), Ampicillin
  - Can occur with any antibiotic, even a single-dose (including topical antibiotics)
- Whose diarrhea began 72 hours or more after hospitalization
Not always associated with antibiotics: Key factors appear to be alteration in colon flora that allows the organism to grow and produce toxins
- Other factors: sporadic development or in association with chemotherapy, sepsis, etc.
- Other factors: GI procedures/surgeries, renal failure, nursing home residents
Control epidemics by quality hand washing with soap (not gels/foams) and infectious control programs; No need to treat asymptomatic carriers

PATHOPHYSIOLOGY:

Overgrowth of the anaerobic gram-positive bacteria C. difficile, which causes disease by production of two cytotoxins: A & B
- 3-5% have an abnormal version of toxin A not detected, so if strongly suspect, treat until endoscopy can be done to confirm
Most commonly as a result of antibiotic therapy, which disrupts the normal colonic flora and allows C. difficile to grow
Some develop C. difficile diarrhea and some are simply colonized (asymptomatic carriers are mostly infants):
- Some develop higher levels of IgG antibody to toxin A (but not toxin B), thus immune response may explain the differences