An environmental odyssey

Research from the Cleveland VA published in the ICHE special edition tells a fascinating story of sequential interventions to reduce environmental contamination with C. difficile. The research includes pretty much the whole battery of environmental interventions at our disposal: education of housekeepers, the introduction of a specially trained “A” team, ATP bioluminescence, fluorescent markers and UVC for “no-touch” disinfection. About the only thing missing is copper surfaces!

Before we get to the interventions, let’s just reflect on the fact that somewhere between 60-70% of rooms were contaminated with C. difficile after terminal disinfection in the baseline period. It’s little wonder that admission to a room previously occupied by a patient with C. difficile increased the chances of developing C. difficile infection! Related to this, there’s some interesting thoughts at the beginning of the discussion about whether there could be a “safe” level of C. difficile contamination. I discussed this in a previous blog post here.

The introduction of fluorescent marking with feedback did not eliminate the C. difficile environmental contamination, with 50-60% of cultures remaining contaminated. Similarly, the introduction of a UVC “no-touch” room disinfection system for terminal disinfection did not solve the problem, with 30-40% of cultures remaining contaminated. Only when daily disinfection was performed by a dedicated team and terminal disinfection was performed by EVS supervisors and/or the infection control team was the problem finally solved and C. difficile could no longer be cultured from surfaces. It’s disappointing that the intervention that worked in eliminating C. difficile room contamination comprised improvements in both daily and terminal cleaning, so it’s not possible to determine which was most important. It seems likely that a combination of the two did the trick.

environmental-odyssey2

Figure: sequential interventions to tackle environmental contamination with C. difficile.

The study used robust microbiology methods to sample the environment, comprising swabs plated directly onto selective agar, and gauze pads from the same surfaces cultured through broth enrichment. The % positive sites from the enriched gauzes was approximately double the swabs inoculated directly onto agar, demonstrating the value of broth enrichment for environmental sampling.

Another important study finding was that the effectiveness of room cleaning prior to UVC room disinfection was sub-optimal, indicating that the housekeepers were placing too much faith in the automated system, which is designed only to disinfect and not to clean.

So what does this odyssey mean? Firstly that a combination of interventions can be useful, and secondly, the extraordinary lengths required to eliminate C. difficile spores from the environment.

Article citation:

Sitzlar B, Deshpande A, Fertelli D, Kundrapu S, Sethi AK, Donskey CJ. An Environmental Disinfection Odyssey: Evaluation of Sequential Interventions to Improve Disinfection of Clostridium difficile Isolation Rooms. Infect Control Hosp Epidemiol 2013;34:459-465.

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