Clostridioides difficile Infection

Clostridioides difficile infection (CDI) is a bacterial infection of the colon caused by C. difficile, typically following antibiotic use, leading to diarrhea, colitis, and potentially life-threatening complications.

Definition

Clostridioides difficile infection (CDI) is a bacterial infection of the colon caused by C. difficile, typically following antibiotic use, leading to diarrhea, colitis, and potentially life-threatening complications.

Epidemiology

Most common cause of healthcare-associated diarrhea
Incidence increasing worldwide due to widespread antibiotic use and aging populations
Risk higher in hospitalized patients and residents of long-term care facilities
Recurrence occurs in 15–30% of cases after initial treatment
Mortality ranges from 2–8% in non-severe cases, higher in severe or complicated disease

Etiology

Disruption of normal gut microbiota due to broad-spectrum antibiotics (clindamycin, cephalosporins, fluoroquinolones, penicillins)
Hospitalization or prolonged healthcare exposure
Advanced age (>65 years)
Immunosuppression (chemotherapy, corticosteroids)
Proton pump inhibitor use as a potential risk factor
Previous CDI increases risk of recurrence

Pathophysiology

C. difficile spores survive in the colon despite antibiotic therapy
Toxins A and B produced by the bacteria damage colonic epithelial cells
Toxin-mediated inflammation → watery diarrhea, pseudomembranous colitis
Severe cases: colonic mucosal necrosis, toxic megacolon, systemic inflammatory response
Host immune response and gut microbiota composition influence disease severity and recurrence