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 (P<.001). 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; P<.001) 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; P<.001). 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; P<.001). In 2005, 13% of CD isolates were type BI (20% were hospital acquired), which represented a significant reduction from 2001 (P<.001).


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.
Muto
Carlene A
CA
Division of Hospital Epidemiology and Infection Control, Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA. mutoca@msx.upmc.edu
Blank
Mary Kathleen
MK
Marsh
Jane W
JW
Vergis
Emanuel N
EN
O'Leary
Mary M
MM
Shutt
Kathleen A
KA
Pasculle
Anthony W
AW
Pokrywka
Marian
M
Garcia
Juliet G
JG
Posey
Kathy
K
Roberts
Terri L
TL
Potoski
Brian A
BA
Blank
Gary E
GE
Simmons
Richard L
RL
Veldkamp
Peter
P
Harrison
Lee H
LH
Paterson
David L
DL
D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D015373:Bacterial Typing Techniques; D016360:Clostridioides difficile / Q000145:classification / Q000302:isolation & purification*; D003428:Cross Infection / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology*; D004196:Disease Outbreaks; D004493:Education; D004761:Enterocolitis, Pseudomembranous / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D006235:Hand Disinfection; D006785:Hospitals, University; D006801:Humans; D017053:Infection Control / Q000379:methods*; D017720:Molecular Epidemiology; D010356:Patient Isolation; D010414:Pennsylvania
D000900:Anti-Bacterial Agents