The Cleveland Veterans Affairs Medical Center is a 368-bed acute care medical facility. Patients with CDAD are placed in contact precautions until diarrhea has resolved. Two years prior to the start of the study, the infection control department instituted bleach disinfection as a control measure for C. difficile. The housekeeping staff was in-serviced on the C. difficile outbreak and the importance of their role in preventing transmission was emphasized. The housekeepers were instructed to use 10% bleach solution (Sunstorm, State Chemical, Cleveland, OH) for terminal disinfection of CDAD patients' rooms. Terminal disinfection was to be performed using a clean cloth or mop soaked in 10% bleach, and it was stressed that frequently touched objects such as bed rails, bedside tables, and call buttons were to be disinfected. Subsequently, the housekeeping staff was periodically contacted to reinforce the bleach disinfection policy.
Patients with VRE colonization or infection were included as a comparison group because they are currently managed with standard precautions and routine terminal cleaning is performed. According to the housekeeping staff, routine terminal disinfection was to include bed rails and bedside tables, but telephones, call buttons, and door handles were not cleaned unless they were obviously soiled. The disinfectant used for routine decontamination of patient rooms is Super HDQ Neutral (Spartan Chemical Company, Inc., Maumee, OH), which is a quaternary ammonium compound.
Pre-intervention assessment of cleaning practices
A prospective 6-week before-after study was performed to assess the adequacy of terminal cleaning and disinfection practices in rooms of patients with CDAD and VRE colonization or infection. All patients with known CDAD and VRE colonization or infection during the study period were considered for enrollment; however, only those patients who were discharged between 9 AM and 5 PM from Monday to Friday were included in the assessment of housekeeping cleaning practices. Standardized chart review was performed to collect information regarding demographics, medical conditions, and culture results. The hospital's Institutional Review Board approved the study protocol.
Baseline cultures of environmental surfaces were obtained within 3 days of patient discharge from the room. Six sites were cultured in each room, including the bedrail, telephone, call button, door knob, toilet seat, and bedside table. Two sterile, pre-moistened cotton-tipped swabs were applied directly onto the selected surfaces in a uniform fashion. For rooms of VRE-colonized patients, one swab was plated directly onto Enterococcosel agar (Becton Dickinson and Company, Sparks, MD) containing 20 μg/mL of vancomycin and the other swab was placed directly into Enterococcosel broth (Becton Dickinson) containing 20 μg/mL of vancomycin. The plates and broth enrichment cultures were incubated for 48 hours at 37°C; broth cultures were then plated onto Enterococcosel agar containing 20 μg/mL of vancomycin and incubated another 48 hours. Colonies with unique morphology were subjected to identification and susceptibility testing in accordance with Clinical Laboratory Standards Institute guidelines .
For rooms of CDAD patients, the swabs were placed into an eppendorf tube and transferred to an anaerobic chamber within 1 hour of collection (Coy Laboratories, Grass Lake, MN). One swab was directly plated onto cycloserine-cefoxitin-fructose agar containing 0.1% taurocholic acid (CCFA-TA) and the other was placed into 300 μl of CCF broth containing 0.1% taurocholic acid and incubated for 48 hours prior to plating onto CCFA-TA. Plates were incubated for 72 hours at 37°C. Isolates were confirmed to be C. difficile on the basis of typical odor and appearance of colonies and by a positive reaction using Pro Disk (Key Scientific Products, Round Rock, TX). C. difficile isolates were tested for in-vitro cytoxin production using C. difficile Tox A/B II (Wampole Laboratories, Princeton, NJ), and isolates that did not produce toxin were not included in the number of positive cultures.
In order to assess the adequacy of housekeeping cleaning and disinfection practices, cultures of the same surfaces in the rooms were obtained after terminal cleaning was performed by the housekeeping staff, but prior to admission of another patient. Finally, in order to confirm the efficacy of 10% bleach for decontamination of C. difficile and VRE, one of us (B.C.E.) disinfected the same surfaces using a 10% bleach solution (Dispatch, Caltech Industries, Inc. Midland, MI). The surfaces were wiped with a cloth soaked with 10% bleach to provide physical removal of dirt or other substances and sprayed with bleach to ensure that the surfaces were thoroughly wet. The surfaces were allowed to air dry. Cultures were then obtained from the same surfaces.
Intervention and post-intervention assessment
After completion of the initial assessment of adequacy of housekeeping cleaning, the research team presented their findings to the housekeeping staff. Education was provided regarding the importance of environmental cleaning as a means to reduce transmission of pathogens. The importance of cleaning and disinfecting frequently touched surfaces was emphasized. In addition, the housekeeping staff was encouraged to provide input regarding measures that might improve their ability to perform adequate terminal cleaning. To assess the effect of the intervention, additional cultures were obtained before and after the housekeeping staff performed terminal cleaning of rooms of several patients with CDAD or VRE colonization or infection during the 10-week period after the intervention.
Data were analyzed using STATA 9.0 (StataCorp, College Station, TX). In describing the study population, continuous data were analyzed using unpaired t tests and categorical data were assessed using Fisher's exact test. In evaluating the effectiveness of the intervention, an exact McNemar's chi-square test was used to compare VRE and C. difficile culture positivity in rooms and on specific surfaces prior to and after cleaning by housekeeping staff. This test of significance was used to then compare culture positivity after cleaning by housekeeping staff and after cleaning by research staff.