Risk factors for Clostridium difficile stool cytotoxin b among critically ill patients: role of sucralfate.

To identify risk factors other than antimicrobial exposure for Clostridium difficile stool cytotoxin b, subjects admitted to critical care units over 18 months and who had stool cytotoxin assays were evaluated. Twenty-two cases (cytotoxin b-positive) were compared with 125 controls (cytotoxin b-negative). Cases and controls were similar with respect to age, sex, therapeutic index severity score, duration of hospitalization before cytotoxin b testing, and antimicrobial exposure. Adjusted odds ratios (OR) revealed white blood cell count of > 12,000 on the day of stool sampling (OR, 4.0; 95% confidence interval [CI], 1.3-12.4) and sucralfate exposure (OR, 0.15; 95% CI, 0.05-0.42) as significant independent positive and negative risk factors, respectively. Sucralfate exposure may decrease risk for C. difficile stool cytotoxin b by interfering with its detection, altering toxin production, or inhibiting colonization by the organism. Additional evaluation is needed to elucidate the mechanisms involved.