C. difficile Infection

Clostridioides difficile is an anaerobic, spore-forming bacterium and the leading cause of healthcare-associated infectious diarrhea. Spores persist on surfaces for months and resist alcohol-based sanitizers and routine cleaning agents. Risk factors include antibiotic use (fluoroquinolones, clindamycin, and broad-spectrum cephalosporins are highest risk), age over 65, proton pump inhibitor use, prolonged hospitalization, and immunosuppression. Clinical presentation includes watery diarrhea (≥3 unformed stools in 24 hours), fever, abdominal pain and distension, leukocytosis (WBC sometimes >20,000), and hypoalbuminemia. Fulminant disease can progress to toxic megacolon, bowel perforation, and septic shock. Diagnosis is by stool testing — PCR for toxin gene or enzyme immunoassay for toxins A and B. Critical rule: do NOT test formed stool and do NOT repeat testing during the same episode to confirm cure. First-line treatment per current IDSA/SHEA guidance: fidaxomicin 200 mg twice daily for 10 days is preferred when available; oral vancomycin 125 mg four times daily for 10 days is an acceptable alternative. Metronidazole is no longer preferred except when recommended agents are unavailable in nonsevere disease. For first recurrence, fidaxomicin is preferred. For multiple recurrences, fecal microbiota transplantation (FMT) is effective. Infection prevention: contact precautions with gown and gloves, hand hygiene with SOAP AND WATER (alcohol-based hand rub does NOT kill C. diff spores), private room preferred, bleach-based environmental disinfection (1:10 sodium hypochlorite solution), and discontinue the inciting antibiotic when possible.