Risk Factors for Acquisition and Loss of Clostridium difficile Colonization in Hospitalized Patients

Asymptomatic colonization may contribute toClostridium difficile transmission. Few data identify which patients are at risk for colonization. We performed a prospective cohort study ofC. difficile colonization and risk factors forC. difficile acquisition and loss in hospitalized patients. Patients admitted to medical or surgical wards at a tertiary care hospital were enrolled; interviews and chart review were performed to determine patient demographics,C. difficile infection (CDI) history, medications, and health care exposures. Stool samples/rectal swabs were collected at enrollment and discharge; stool samples from clinical laboratory tests were also included. Samples were cultured forC. difficile , and the isolates were tested for toxins A and B and ribotyped. Chi-square tests and univariate logistic regression were used for the analyses. Two hundred thirty-five patients were enrolled. Of the patients, 21% were colonized withC. difficile (toxigenic and nontoxigenic) at admission and 24% at discharge. Ribotype 027 accounted for 6% of the strains at admission and 12% at discharge. Of the patients colonized at admission, 78% were also colonized at discharge. Cephalosporin use was associated withC. difficile acquisition (47% of patients who acquiredC. difficile versus 25% of patients who did not;P = 0.03). β-lactam–β-lactamase inhibitor combinations were associated with a loss ofC. difficile colonization (36% of patients who lostC. difficile colonization versus 8% of patients colonized at both admission and discharge;P = 0.04), as was metronidazole (27% versus 3%;P = 0.03). Antibiotic use affects the epidemiology of asymptomaticC. difficile colonization, including acquisition and loss, and it requires additional study.