Control of an Outbreak of Infection with the Hypervirulent Clostridium difficile BI Strain in a University Hospital Using a Comprehensive “Bundle” Approach.

Background: In June 2000, the hospital–acquired Clostridium difficile (CD) infection rate in our hospital (University of Pittsburgh Medical Center Presbyterian, Pittsburgh, PA) increased to 10.4 infections per 1000 hospital discharges (HDs); the annual rate increased from 2.7 infections per 1000 HDs to 7.2 infections per 1000 HDs and was accompanied by an increase in the frequency of severe outcomes. Forty–seven (51%) of 92 HA CD isolates in 2001 were identified as the “epidemic BI strain.” A comprehensive CD infection control “bundle” was implemented to control the outbreak of CD infection. Methods: The CD infection control bundle consisted of education, increased and early case finding, expanded infection–control measures, development of a CD infection management team, and antimicrobial management. Process measures, antimicrobial usage, and hospital–acquired CD infection rates were analyzed, and CD isolates were typed. Results: The rates of compliance with hand hygiene and isolation were 75% and 68%, respectively. The CD management team evaluated a mean of 31 patients per month (11% were evaluated for moderate or severe disease). Use of antimicrobial therapy associated with increased CD infection risk decreased by 41% during the period 2003–2005 (). The aggregate rate of CD infection during the period 2001–2006 decreased to 4.8 infections per 1000 HDs (odds ratio, 2.2; 95% confidence interval, 1.4–3.1; ) and by 2006, was 3.0 infections per 1000 HDs, a rate reduction of 71% (odds ratio, 3.5; 95% confidence interval, 2.3–5.4; ). During the period 2000–2001, the proportion of severe CD cases peaked at 9.4% (37 of 393 CD infections were severe); the rate decreased to 3.1% in 2002 and further decreased to 1.0% in 2006—a 78% overall reduction (odds ratio, 20.3; 95% confidence interval, 2.8–148.2; ). In 2005, 13% of CD isolates were type BI (20% were hospital acquired), which represented a significant reduction from 2001. Conclusions: The outbreak of CD infection with the BI strain in our hospital was controlled after implementing a CD infection control “bundle.” Early identification, coupled with appropriate control measures, reduces the rate of CD infection and the frequency of adverse events.