Clostridioides Difficile Infections¶

Anton de Witte

Background¶

Clostridioides difficile is the causative bacteria for antibiotic-associated colitis
Always consider C. diff in a hospitalized patient with unexplained leukocytosis
Microbiology: Anaerobic gram-positive, spore-forming, toxin-producing bacillus
Outside colon, exists in spore form – resistant to heat, acid, and antibiotics (why we must wash our hands)
Spores are transferred from environment to person, once in intestine convert to functional vegetative, toxin-producing forms susceptible to antibiotics
To be pathogenic, must release toxin (A+B) to cause colitis and diarrhea
Risk Factors: Antibiotic use (during use or typically up to 1 month after use), age >65, hospitalization, enteral feeding, obesity, stem cell transplant, chemo, IBD, cirrhosis, ± PPI use (no clear causal relationship)

Spectrum from asymptomatic carrier to fulminant colitis with toxic megacolon
Asymptomatic carrier: 20% of hospitalized patients (50% of adults in long term care facilities)
Non-severe disease: watery diarrhea (>3 unformed stools in 24 hours), lower abdominal pain, nausea, ± fever, leukocytosis (WBC >15,000)
Severe disease: diarrhea, diffuse abdominal pain, abdominal distention, fever, lactic acidosis, AKI (Cr > 1.5), marked leukocytosis (sometimes >40,000)
Fulminant disease: Severe criteria + hypotension/shock, ileus (rare), or megacolon (>7cm colon diameter and/or >12cm cecum diameter)
Recurrent disease (relapse > reinfection): resolution of symptoms on therapy followed by reappearance of symptoms within 2-8 weeks after stopping therapy; (Up to 25% of patients have recurrence)
If symptoms never resolve, consider refractory C. diff or alternative diagnosis

Stool PCR for toxigenic strains (very sensitive, can detect asymptomatic carriers w/o toxin production); with reflex EIA (enzyme immunoassay) for toxins A and B (specificity of 99%)
- PCR (+)/Toxin (-) = carrier
- PCR (+)/Toxin (+) = treat
- PCR (-) = no treatment
Imaging
- Nonsevere disease: no imaging necessary
- Severe or fulminant disease: CT a/p with oral and IV contrast
Endoscopy: Typically used when alternative diagnosis is suspected; not warranted for classical symptoms, positive laboratory tests, or clinical response to treatment

Contact precautions until at least 48 hours after diarrhea resolves
Classify patient disease severity to guide treatment algorithm
Do not repeat stool testing – 50% remain positive after treatment up to 6 weeks later

Clinical Condition	Treatment
Non-fulminant disease
Initial episode (non-severe or severe)	-First line: PO Vancomycin 125mg QID x 10 days OR PO Fidaxomicin 200mg BID x 10 days -Second line: (only for non-severe disease in low-risk patients): PO Metronidazole 500mg TID x 10-14 days
Recurrent episode	Consult GI First Recurrence: -First line: PO Fidaxomicin 200mg BID x 10 days -Second line: Vancomycin Taper (PO 125mg QID x 14 days PO 125mg BID x 7 days PO 125mg QD x 7 days PO 125mg q72h x 2-8 weeks) -Adjunctive therapy: IV Bezlotoxumab 10mg/kg x1 Second or Further Recurrence: -Same as above -Consider Fecal Microbiota Transplantation (FMT)
Fulminant disease
Fulminant disease	Consult GI and EGS Ileus Absent: -PO Vancomycin 500mg QID + IV Metronidazole 500mg TID Ileus Present -Same as above + consider Vancomycin enemas 500mg q6h Consider colectomy or FMT

Last update: 2022-06-13 16:59:01