CLOSTRIDIUM-DIFFICILE COLONIZATION AND DIARRHEA AT A TERTIARY CARE HOSPITAL

Clostridium difficile is the major identifiable infectious cause of no socomial diarrhea. A prospective study was conducted at New England De aconess Hospital (Boston) to examine risk factors for C. difficile car riage at both admission and follow-up. Specimens from patients admitte d to two wards (one medical, one surgical) and three intensive care un its (two surgical, one medical) were cultured weekly until discharge. For 89 (18%) of 496 patient admissions, at least one culture was posit ive. The prevalence of culture positivity within 72 hours of admission was 11%. Risk factors for culture positivity at admission were prior C. difficile diarrhea (adjusted odds ratio [OR] = 9.5), renal insuffic iency (OR = 6.7), and recent hospitalization elsewhere (OR = 3.1). Fif teen percent of patients for whom initial cultures were negative and f or whom followup cultures were performed acquired C. difficile. Admiss ion to the vascular surgery service (relative risk [RR] = 2.3) and liv er transplantation (RR = 4.2) were significant risk factors for C. dif ficile acquisition. Patients asymptomatically colonized on admission h ad very low risk (1 in 44) for subsequent development of C. difficile diarrhea. In contrast, nine (47%) of 19 patients who acquired toxigeni c strains developed C. difficile diarrhea, a finding suggesting that p rogression to diarrhea occurs early after acquisition or does not occu r at all. The relatively high prevalence of culture positivity at admi ssion may be characteristic of tertiary care hospitals and adds to the difficulty of controlling this nosocomial pathogen.