Health Care-Associated Clostridium difficile Infection in Adults Admitted to Acute Care Hospitals in Canada: A Canadian Nosocomial Infection Surveillance Program Study

BACKGROUND: Clostridium difficile infection (CDI) is the most frequent cause of health care-associated infectious diarrhea in industrialized countries. The only previous report describing the incidence of health care-associated CDI (HA CDI) in Canada was conducted in 1997 by the Canadian Nosocomial Infection Surveillance Program. We re-examined the incidence of HA CDI with an emphasis on patient outcomes. METHODS: A prospective surveillance was conducted from 1 November 2004 through 30 April 2005. Basic demographic data were collected, including age, sex, type of patient ward where the patient was hospitalized on the day HA CDI was identified, and patient comorbidities. Data regarding severe outcome were collected 30 days after the diagnosis of HA CDI; severe outcome was defined as an admission to the intensive care unit because of complications of CDI, colectomy due to CDI, and/or death attributable to CDI. RESULTS: A total of 1430 adults with HA CDI were identified in 29 hospitals during the 6-month surveillance period. The overall incidence rate of HA CDI for adult patients admitted to these hospitals was 4.6 cases per 1000 patient admissions and 65 per 100,000 patient-days. At 30 days after onset of HA CDI, 233 patients (16.3%) had died from all causes; 31 deaths (2.2%) were a direct result of CDI, and 51 deaths (3.6%) were indirectly related to CDI, for a total attributable mortality rate of 5.7%. CONCLUSIONS: The rates are remarkably similar to those found in our previous study; although we found wide variations in HA CDI among the participating hospitals. However, the attributable mortality increased almost 4-fold (5.7% vs. 1.5%; P<.001).