Asymptomatic Clostridium difficile colonization in a tertiary care hospital: Admission prevalence and risk factors

Background The role of Clostridium difficile (CD) carriers in health care-associated CD transmission has been identified as an area needing research. We investigated the prevalence of, and risk factors for, asymptomatic CD colonization at hospital admission. Methods Adults admitted to a tertiary care hospital in Minnesota on predetermined study days between March 1 and April 30, 2009, and without symptoms of C difficile infection, were eligible. The first stool sample after admission was requested from each consenting patient and tested for toxigenic CD using polymerase chain reaction (PCR) that detects tcdC . Clinical data were obtained through interviews and chart reviews. Results Of 320 participants, 31 (9.7%) were positive for toxigenic CD. Using multivariate logistic regression, independent predictors of CD colonization were recent hospitalization (odds ratio [OR], 2.45; 95% confidence interval [CI]: 1.02-5.84), chronic dialysis (OR, 8.12; 95% CI: 1.80-36.65), and corticosteroid use (OR, 3.09; 95% CI: 1.24-7.73). Screening patients with risk factors (48% participants) would identify 74% (95% CI: 55%-88%) of CD carriers. Conclusion Asymptomatic CD colonization at hospital admission was detected in nearly 1 of 10 patients. The majority of colonized patients had one or more identifiable risk factors. These data could provide the basis for designing studies of targeted surveillance for C difficile .