Diverse sources of C. difficile infection identified on whole-genome sequencing.

Background: It has been thought that Clostridium difficile infection is transmitted predominantly within health care settings. However, endemic spread has hampered identification of precise sources of infection and the assessment of the efficacy of interventions.

Methods: From September 2007 through March 2011, we performed whole-genome sequencing on isolates obtained from all symptomatic patients with C.