Main Menu Browse by Day or Program Author Keywords

185 Effectiveness of Empiric Contact Isolation and Treatment for Clostridium difficile: A Simulation-Based Approach

Saturday, April 2, 2011
Trinity Ballroom (Hilton Anatole)
Michael Rubin, MD, PhD , VA Salt Lake City IDEAS Center, Salt Lake City, UT
Makoto Jones, MD , University of Utah, Salt Lake City, UT
Angela Huttner, MD , University of Utah, Salt Lake City, UT
Jose Benuzillo, MS , IDEAS Center, Salt Lake City, UT
Damon Toth, PhD , University of Utah, Salt Lake City, UT
Karim Khader , University of Utah, Salt Lake City, UT
William R. Ray , VA Salt Lake City IDEAS Center, SLC, UT
Larry C. Ford, MD , University of Utah School of Medicine, Salt Lake City, UT
Theodore Sablay , IDEAS Center, Salt Lake City, UT
Dale Gerding, MD , Hines VA Hospital, Hines, IL
Matthew Samore, MD , VA Salt Lake City IDEAS Center, Salt Lake City, UT
Background: Clostridium difficile causes endemic and epidemic gastrointestinal disease in hospitalized patients. Optimal control strategies remain largely unknown.

Objective: Assess the impact of a policy of empiric isolation, testing, and treatment for nosocomial C. difficile infection (CDI) compared with a policy of isolation and treatment only upon positive C. difficile testing.

Methods: We designed a high-fidelity agent-based computer simulation of nosocomial C. difficile transmission that includes static and dynamic components including: patients, health care workers (HCW), and rooms, including ICU and non-ICU wards; patient flow such as admission, discharge, and transfer; a network of dynamic interactions between HCW and patients; a model of CDI that progresses from acquisition through symptomatic illness and recovery; importation of toxigenic and non-toxigenic strains of C. difficile; contamination of environmental surfaces by patients who shed C. difficile; acquisition of C. difficile by patients following contact with contaminated surfaces or HCW hands; patient antimicrobial use, which impacts C. difficile susceptibility and transmissibility; HCW hand carriage upon contact with colonized patients or contaminated surfaces; and removal of C. difficile from HCW hands via hand hygiene. Model parameters were derived from local data and the literature where available, with expert opinion. The model was calibrated against data obtained locally or through the literature, and validated internally and externally.

Two hospitals were simulated 100 times each over a one-year period. In one hospital, patients who developed symptoms suggestive of CDI were empirically placed in contact isolation and started on antimicrobial therapy for CDI while awaiting the results of testing; in the other hospital, patients were placed in isolation and on therapy only after a positive test for CDI. The effect of empiric contact isolation and treatment was measured by comparing the rates of C. difficile acquisition and symptomatic CDI between hospitals, and was tested against a range of values for adherence of HCW to contact isolation practice in a sensitivity analysis.

Results: In the base-case scenario, empiric isolation and treatment reduced the rate of nosocomial C. difficile acquisition from 35.1 to 28.0 events/1,000 patient-days (P<0.001), and reduced the rate of symptomatic nosocomial CDI from 3.1 to 2.3 infections/1,000 patient-days (P<0.001). Varying the adherence to contact isolation practice across a wide range of values did not affect the differences observed between the two policies.

Conclusions: A policy of empirically isolating and treating patients with symptomatic disease suggestive of CDI while awaiting testing is likely to significantly reduce nosocomial C. difficile acquisitions and CDI, at the expense of increased isolation and antimicrobial use.