Decreasing Operating Room Environmental Pathogen Contamination Through Improved Cleaning Practice

L. Silvia Munoz-Price, MD; David J. Birnbach, MD, MPH; David A. Lubarsky, MD, MBA; Kristopher L. Arheart, EdD; Yovanit Fajardo-Aquino, MD; Mara Rosalsky, RN; Timothy Cleary, PhD; Dennise DePascale, MT; Gabriel Coro, MD; Nicholas Namias, MD; Philip Carling, MD


Infect Control Hosp Epidemiol. 2012;33(9):897-904. 

In This Article


Cleaning Thoroughness

Four cycles of observations using UV markers were performed from June through October, 2011 (1 week per month). Overall, 194 operating rooms and 2,820 objects were evaluated during the study. At baseline (June–July, 2011), the proportion of UV marks removed by 24 hours after placement was 0.47 (284 of 600 marks; 95% CI, 0.42–0.53; Figure 1 and Table 1). This proportion increased during and after the educational intervention and reached 0.82 (634 of 777 marks; 95% CI, 0.77–0.85) during the last month of observations (P = < .0001). The most striking improvement during the study was related to the anesthesia equipment, particularly the cleaning of anesthesia machines, which increased more than 150%, from 0.25 to 0.77 (P = < .0001). Other objects that showed significant improvement in thoroughness of cleaning included bed control panels, Mayo stands, and overhead lamps. The objects that failed to show clear improvement included floors, intravenous poles, and operating room entry door handles.

Figure 1.

Changes in cleaning practices and environmental contamination of the operating rooms. The line indicates the percentage of UV markers removed (cleaned), and the columns indicate the percentage of environmental surface samples from which gram-negative bacilli were recovered.

Environmental Cultures

Over a 9-month period, 427 objects were cultured in 35 operating rooms. Overall, 65 objects (15.2%) had culture results that were positive for pathogens, 246 (57.6%) had cultures that grew skin flora, and 116 (27.2%) had negative culture results (Table 2).


Pathogens identified during the study included Pseudomonas species (24 isolates), Enterobacter aerogenes (14), S. aureus (11), Enterococcus species (11), Acinetobacter species (8), Klebsiella pneumoniae (4), Escherichia coli (3), and 10 other gram-negative bacilli, including Morganella species, Stenotrophomonas maltophilia, Alcaligenes species, Achromobacter species, Chryseomonas species, and Aeromonas species. Five (45%) of the 11 S. aureus isolates were resistant to methicillin. Acinetobacter species were isolated from 8 objects in 7 operating rooms; 6 (86%) of the rooms were trauma operating rooms. The objects contaminated with Acinetobacter species included intravenous poles (2 isolates), operating room beds (1), Mayo tables (1), and floors (4).

All Surfaces excluding Floors

Before educational interventions, 33 (12.6%) of 261 objects grew pathogens (Table 2). During the follow-up period, 10 (7.6%) of 132 objects were positive for pathogens (P = .998). As shown in Figure 1 and Table 3, identification of gram-negative bacilli significantly decreased from baseline during the study (10.7% vs 2.3%; P = .015). The number of samples with gram-positive pathogens and skin flora isolated failed to show statistically significant changes during the study (Table 2 and Table 3).


Thirty-four floor areas were cultured, including 22 at baseline and 12 at follow-up; pathogens were isolated from 63% and 66% of floor areas, respectively (Table 2; P = .917). Gram-negative bacilli were identified in 63% of floor samples at baseline and in 41.6% of floor samples at follow-up (P = .108).

Educational and Environmental Services Interventions

After 2 cycles of covert baseline data collection, operating room cleaning personnel from all shifts were reeducated regarding cleaning expectations for specific objects and were provided with the UV marker and environmental culture results. All new initiatives to enhance cleaning practice were performed by the directors of nursing and the environmental service managers. Personnel were also informed that regular cleaning surveillances would be ongoing. Other than the regular feedback of results, no major input regarding the cleaning of the operating rooms was provided by the infection control department.

Two main interventions were implemented as a result of the feedback from infection control. First, in July 2011, the anesthesia technologists were made responsible for the cleaning of the anesthesia machine and associated equipment between procedures; this equipment included the anesthesia machines, electrocardiography leads, blood pressure cuffs, intravenous pumps, intravenous poles, and oxygen reservoirs. Second, in September 2011, the cleaning product was changed from 17.2% isopropanolol (CaviWipes; Metrex) to 1:10 sodium hypochloride solution (Dispatch; Clorox). Ortho-phenylphenol (Wex-Cide 128; Wexford Labs), which was used for the floors, was the only disinfectant that remained constant throughout 2011. Our hospital's operating room cleaning policies for between procedures and for terminal cleaning, which were developed to be consistent with AORN-recommended protocols, remained unchanged during the study.