infection control and hospital epidemiology february 2009, vol. 30, no. 2 original article Multipronged Intervention Strategy to Control an Outbreak of Clostridium difﬁcile Infection (CDI) and Its Impact on the Rates of CDI from 2002 to 2007 Karl Weiss, MD, MSc, FRCPC; Annie Boisvert, BSc Nurs; Miguel Chagnon, PhD; Caroline Duchesne, BSc Nurs; Sylvie Habash, BSc Nurs; Yves Lepage, PhD; Julie Letourneau, BSc Nurs; Johanna Raty, BSc Nurs; Michel Savoie, MSc Pharm objective. At the end of 2002, a new, more virulent strain of Clostridium difﬁcile, designated BI/NAP1, was the cause of a massive outbreak of infection in the province of Quebec. This particular strain was associated with a dramatic increase in morbidity and mortality among affected patients in 2003–2004. We tested and implemented a multipronged infection control approach to curtail the rate of C. difﬁcile infection (CDI). design. Five-year observational study. setting. A 554-bed, acute care tertiary hospital, the largest single medical center in Quebec, Canada. methods. To curtail the magnitude of the outbreak, we implemented a global strategy consisting of rapid C. difﬁcile testing for all hospitalized patients who had at least 1 occurrence of liquid stool, the rapid isolation of patients infected with C. difﬁcile in a dedicated ward with a specially trained housekeeping team, a global hand hygiene program, and the hiring of infection control practitioners. Antibiotic consumption at the institutional level was also monitored during the 5-year surveillance period. Cases of hospital-acquired CDI per 1,000 admissions were continuously monitored on a monthly basis during the entire surveillance period. results. The highest recorded CDI rate was 42 cases per 1,000 admissions in January 2004. Once additional infection control resources were put in place, the rate descreased signiﬁcantly during the period from April 2005 to March 2007. During the 2003–2004 period, there were 762 cases of CDI (mean annual rate, 37.28 cases per 1,000 admissions) recorded in our study, compared with 292 cases of CDI (14.48 cases per 1,000 admissions) during the 2006–2007 period (OR, 0.379 [95% CI, 0.331–0.435]; ), a 61% reduction. In March 2007, P ! .001 the equivalent of 4 full-time equivalent infection control practitioners were in place, which gave a ratio of 0.96 infection control practitioners per 133 beds in use, compared with the ratio of 0.24 infection control practitioners per 133 beds in use in 2003, and the total number of hours dedicated to cleaning and housekeeping increased by 26.2%. The total amount of antibiotics used in the hospital did not vary signiﬁcantly from 2002 to 2007, although there were changes in the classes antibiotic used. conclusion. The implementation of a multipronged intervention strategy to control the outbreak of CDI signiﬁcantly improved the overall situation at the hospital and underlined the importance of investing in stringent infection control practices. Infect Control Hosp Epidemiol 2009; 30:156-162 From the Departments of Infectious Diseases and Microbiology (K.W., A.B., C.D., S.H., J.L., J.R.) and of Pharmacy (M.S.), Maisonneuve-Rosemont Hospital, Faculty of Medicine, and the Department of Mathematics and Statistics, University of Montreal (M.C., Y.L.), Montreal, Quebec, Canada. Received June 16, 2008; accepted September 18, 2008; electronically published January 6, 2009.  2009 by The Society for Healthcare Epidemiology of America. All rights reserved. 0899-823X/2009/3002-0007$15.00. DOI: 10.1086/593955 Since 2002, we have witnessed an increase in the incidence, severity, and mortality rate of Clostridium difﬁcile infection (CDI) among patients. It is estimated that, in the United States alone, more than 250,000 cases of CDI occurred in 2003. 1 The number of reported cases in the Centers for Dis- ease Control and Prevention National Hospital Discharge Survey database went from 31 cases per 100,000 hospitali- zations in 1996 to 61 cases per 100,000 hospitalizations in 2003. 1 The mortality rates associated with CDI and its com- plications were even higher among elderly patients, who are often afﬂicted with other underlying medical conditions. Mortality rates and the number of colectomies also increased over the past few years. Prolonged lengths of stay and medical care related to CDI led researchers to conclude that the direct cost of CDI in the United States was more than $1 billion per year. 2 Since December 2002, there has been an important surge in the number of cases of CDI in certain geographical areas of the province of Quebec, Canada, but not in other Canadian provinces, where the number of CDI episodes remains rel- atively stable. 3 Within Quebec, the Montreal area—the most populous region of the province—and its immediate sur-