Examining the epidemiology and microbiology of Clostridium difficile carriage in elderly patients and residents of a healthcare facility in southern Ontario, Canada.

BACKGROUND: Whereas Clostridium difficile has been extensively studied in acute care facilities (ACFs), there is limited information about long-term care facilities (LTCFs), despite the high occurrence of putative risk factors (e.g. age, antimicrobial use, healthcare system contact).

AIM: To evaluate C. difficile colonization in elderly patients and residents from one ACF and its associated LTCF.

METHODS: Stool swabs were collected from 884 LTCF and elderly (>65 years) hospital patients. Selective culture, polymerase chain reaction ribotyping and toxin gene characterization were performed.

FINDINGS: C. difficile was isolated from 92/410 (22.4%) ACF and 89/474 (18.8%) LTCF samples. Ribotypes 027 (35%) and 020 (10.4%) predominated in the LTCF whereas ribotypes AI-82/1 (20.7%) and ribotype O (14.1%) predominated at the ACF (P = 0.031). In the LTCF, C. difficile colonization was associated with a history of proton pump inhibitor (PPI) use, and the interaction terms of male residents with prior medical leave of absence, and a prior history of C. difficile infection (CDI) combined with fluoroquinolone use. In the ACF, C. difficile colonization was associated with length of stay, feeding through a tube, antibiotic use, immunosuppressive therapy and VRE colonization, as well as the interaction terms for cephalosporin and fluoroquinolone use, prior CDI and cephalosporin use, and prior CDI and fluoroquinolone use.

CONCLUSION: C. difficile colonization by ACF and LTCF residents was common, despite a low apparent incidence of CDI. The association with PPI provides further evidence of the potential importance of this widely used drug class in C. difficile colonization. Wide genetic diversity was present, highlighting the likelihood of multiple unidentified routes of C. difficile acquisition.