title: A simulation-based assessment of strategies to control Clostridium difficile transmission and infection.
abstract: BACKGROUND
  Clostridium difficile is one of the most common and important nosocomial pathogens, causing severe gastrointestinal disease in hospitalized patients. Although "bundled" interventions have been proposed and promoted, optimal control strategies remain unknown.
  
  
  METHODS
  We designed an agent-based computer simulation of nosocomial C. difficile transmission and infection, which included components such as: patients and health care workers, and their interactions; room contamination via C. difficile shedding; C. difficile hand carriage and removal via hand hygiene; patient acquisition of C. difficile via contact with contaminated rooms or health care workers; and patient antimicrobial use. We then introduced six interventions, alone and "bundled" together: aggressive C. difficile testing; empiric isolation and treatment of symptomatic patients; improved adherence to hand hygiene and contact precautions; improved use of soap and water for hand hygiene; and improved environmental cleaning. All interventions were tested using values representing base-case, typical intervention, and optimal intervention scenarios.
  
  
  RESULTS
  In the base-case scenario, C. difficile infection rates ranged from 8-21 cases/10,000 patient-days, with a case detection fraction between 32%-50%. Implementing the "bundle" at typical intervention levels had a large impact on C. difficile acquisition and infection rates, although intensifying the intervention to optimal levels had much less additional impact. Most of the impact came from improved hand hygiene and empiric isolation and treatment of suspected C. difficile cases.
  
  
  CONCLUSIONS
  A "bundled" intervention is likely to reduce nosocomial C. difficile infection rates, even under typical implementation conditions. Real-world implementation of the "bundle" should focus on those components of the intervention that are likely to produce the greatest impact on C. difficile infection rates, such as hand hygiene and empiric isolation and treatment of suspected cases.
authors.affiliation: Department of Internal Medicine, George E. Wahlen Department of Veterans Affairs Medical Center, Salt Lake City, Utah, United States of America ; Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, Utah, United States of America.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Rubin
authors.forename: Makoto
authors.initials: M
authors.lastname: Jones
authors.forename: Molly
authors.initials: M
authors.lastname: Leecaster
authors.forename: Karim
authors.initials: K
authors.lastname: Khader
authors.forename: Willy
authors.initials: W
authors.lastname: Ray
authors.forename: Angela
authors.initials: A
authors.lastname: Huttner
authors.forename: Benedikt
authors.initials: B
authors.lastname: Huttner
authors.forename: Damon
authors.initials: D
authors.lastname: Toth
authors.forename: Theodore
authors.initials: T
authors.lastname: Sablay
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Borotkanics
authors.forename: Dale N
authors.initials: DN
authors.lastname: Gerding
authors.forename: Matthew H
authors.initials: MH
authors.lastname: Samore
mesh_terms: D016360:Clostridioides difficile / Q000502:physiology*; D003198:Computer Simulation; D004761:Enterocolitis, Pseudomembranous / Q000382:microbiology / Q000517:prevention & control* / Q000635:transmission*; D006801:Humans; D017053:Infection Control / Q000379:methods*; D008954:Models, Biological