Clostridium difficile

Background

• Most common cause of infectious diarrhea in hospitalized pts
• Use contact isolation if suspect
• Risk factors for pseudomembranous colitis:
  • Recent abx use (any)
  • GI surgery
  • Severe underlying medical illness
  • Chemo
  • Elderly

Diagnosis

History

• Diarrhea that develops during abx use or w/in 2wk of discontinuation
• Recent discharge from hospital
• Profuse watery diarrhea

Exam

• Abdominal pain
• Fever
• Leukocytosis
• +Fecal leukocytes (distinguishes from benign forms of abx-induced diarrhea)

Labs

• C. diff toxin assay
  • Sn 63-94%, Sp 75-100%
• Culture
  • Positve culture only means C. diff present, not necessarily that it is causing disease

Harbor Testing Algorithm

• Repeat testing
  • Never a need for repeat testing within 7 days of a previous test
  • NO NEED to repeat positive tests as symptoms resolve as a “test of cure”
  • NO NEED to repeat test soon after initial negative test (more likely to be a false positive test than a true positive test)

1. Patient with suspected Clostridium difficile associated diarrhea (CDAD)
   1. Low suspicion for CDAD
      1. Send stool for C. diff toxin assay
         1. Positive --> treat (no further testing indicated)
         2. Negative --> do not treat (no further testing indicated)
   2. High suspicion for CDAD
      1. Send stool for C. diff toxin assay AND treat empirically
         1. Positive --> treat (no further testing indicated)
         2. Negative --> Consider discussion with ID (false negative tests may occur); eval for other causes of diarrhea

Treatment

• Mild
  • Either d/c offending abx (if possible) or give metronidazole 500mg PO q6hr x10-14d
• Moderate
  • Metronidazole 500mg PO or IV q6hr x10-14d
• Severe
  • Criteria
    • Age >60yr
    • Temp >38.4 (101)
    • Serum albumin <2.5
    • WBC >15K
    • Pt requires ICU admission
    • Pseudomembranous colitis on endoscopy
  • Tx
    • Vancomycin 125-250mg PO q6hr x10d (IV form is not effective)
    • Add metronidazole 500mg IV q6hr if ileus or pt cannot tolerate PO
• Emergency colectomy should be considered if:
  • WBC >20K
  • Lactate >5
  • Age >75
  • Immunosuppression
  • Toxic megacolon
  • Colonic perforation
  • Multi-organ system failure

Recurrent Infection

1. Occurs <=4 weeks after the completion of therapy
   1. Otherwise consider other (more common) causes
2. Antimicrobial resistance is not clinically problematic, first recurrence treated with the same agent used to treat the initial episode

Disposition

• Admit:
  • Severe diarrhea
  • Oupt abx failure
  • Systemic response (fever, leukocytosis, severe abdominal pain)

Source

Tintinalli