C. difficile Flashcards
What is the main symptom associated with a C. Difficile infection?
Clostridioides difficile associated diarrhea (CDAD)
What are some signs of a C. difficile infection?
- More than 3 unformed stools per 24h and more than 2 days with no other recognized cause
- Detection of toxin A or B or C. difficile in stool
- Pseudomembranes in the colon
- Patients with recent antibiotic use (within the previous 3 months)
What are the clinical manifestations of C. difficile infections?
- Diarrhea (almost never grossly bloody or purulent)
- Fever (28% of cases)
- Abdominal pain (22%)
- Leukocytosis (50%)
- Mild diarrhea to life-threatening toxic megacolon
What are the steps of pathogenesis for C. difficile?
Step 1: Exposure to antimicrobial agents establishes susceptibility to C. diff thrigh disruption of normal colonic microbiota
Step 2: Exposure to toxigenic C. diff (can be carried asymptomatically)
Step 3: Virulent strain or high risk antibiotic or inadequate host immune response
What is the most common environment where a patient can become colonized with C. difficile?
Acquired exogenously (most often in hospital or nursing homes
What are some characteristics of the C. difficile bacteria?
- Gram positive
- Spore forming
- Anaerobic bacillus
- Causes toxin mediated disease (toxins A and B)
How is diagnosis of C. difficile infection confirmed?
Presence of Toxins A and B
Which antibiotics cause C. difficile infections?
All antibiotics have been associated with C. difficile infections
Which antibiotics are associated with higher risk of C. difficile infections?
- Clindamycin
- Fluoroquinolones
- Cephalosporins (3rd and 4th gen in particular)
- Ampicillin
- Carbapenems
Which antibiotics are associated with lower risk of C. difficile infections?
- Penicillin
- Macrolides
- Tetracyclines
- TMP/SMX
- Aminoglycosides
How long does the risk of C. difficile infection last after stopping antibiotic therapy?
3 months past therapy
What are some risk factors associated with C. difficile infections?
- Older age
- Greater severity of underlying illness
- GI surgery
- Use of rectal electronic thermometers
- Enteral tube feeding
- Antacid therapy (PPIs higher risk than H2RAs)
- Hospitalization
Are recurrent C. difficile infections common?
- 15-30% of patients experience recurrence after their first infection
- Recurrences are either relapses (same strain) or new infection (new strain)
How are C. difficile infections managed?
- Stop the offending antibiotic if possible (need to make clinical judgement)
- Fluid and electrolyte replacement therapy (concerned about dehydration)
- Avoid antimotility drugs (ex. loperamide)
- Categorize as mild-moderate to severe and uncomplicated to complicated
What patient factors qualify a C. difficile infection to be severe?
Elevated WBC (leukocytes are over 15 thousand/microlitre) and/or SCr over 1.5x baseline