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


This study was performed from April through December 2011 at Jackson Memorial Hospital, a 1,500-bed teaching hospital affiliated with the University of Miami Miller School of Medicine. The facility has 43 operating rooms, including 33 adult and pediatric, 4 obstetric, and 6 trauma suites. Cleaning of operating rooms was coordinated by the perioperative nursing director (M.R.), who evaluated cleaning practices performed by operating room technicians between surgical procedures and by environmental services staff at the end of the day (terminal cleaning). The administrators who supervised cleaning practices remained consistent throughout the study. Before implementation, the project was presented to the institutional review board, which waived informed consent documentation.

UV Markers

A transparent fluorescent gel marking system (DAZO) was used to mark operating room surfaces before the first case of the day, and these surfaces were subsequently evaluated 24 hours later using a UV lamp. Because of the design of the dispenser, the size of the markers remained constant at 2 cm in diameter. Throughout this project, only one member of the Infection Control Department (Y.F.-A.) performed applications and observations of UV markers. Objects tested were selected in accordance with the recommendations of the Association of Perioperative Registered Nurses (AORN) as well as those of the study by Jefferson and collaborators.[10,15] These objects included bed control panels, anesthesia-related equipment (keyboards, knobs, switches, oxygen reservoir bags, and adjacent medication drawers), Mayo stands, over-table lamps, and floors (within 3 feet of the operating room table). As described elsewhere,[16,17] the presence of UV material at 24 hours was considered to represent a lack of cleaning of the object tested. Removal of the UV marker was considered to be evidence of one or more episodes of cleaning of the monitored surfaces.

Environmental Cultures

Environmental cultures were obtained before 7 AM from inactive operating rooms that had undergone terminal cleaning the previous night. Objects tested included all areas marked with UV markers. Throughout the project, samples were obtained concomitantly by a team of 2 infection preventionists (Y.F.-A. and G.C.) and a microbiology technologist (D.D.P.). Premoistened 6-inch cotton swabs (Sterile Cotton-Tipped Applicators; MediChoice) were used to culture an area approximately 10***10 cm in area. Swab samples were immediately placed in 2 mL of tryptic soy broth (BD Diagnostics) and incubated overnight at 37°C. Broths that showed growth were streaked on blood and MacConkey agar plates (BD Diagnostics). After 48 hours of incubation at 37°C, visible colonies were subcultured and identified by the clinical microbiology laboratory (Vitek II; bioMérieux). For the purpose of this project, pathogens were defined as any gram-negative bacilli, S. aureus, or Enterococcus species. Objects were deemed positive for skin flora if cultures grew only such organisms as coagulase-negative Staphylococcus species, Streptococcus viridians, Bacillus species, Micrococcus species, or diphteroids.

Educational Interventions

Graphic electronic communications of the results of the fluorescent dye marking and the environmental cultures were sent to the environmental services department, the operating room administration, and the hospital administration (including the chief executive officer, chief medical officer, and the chief nursing officers as well as the quality and patient safety division) to monitor and encourage cleaning process improvement. Based on this feedback, verbal and graphic educational programs were performed by the area environmental services director for their staff (all shifts) during July 2011.


UV marker data were analyzed using logistic regression by object type. The dependent variable was cleaning status (cleaned vs not cleaned). The independent variable was the month of observation. Contrasts were used to compare adjacent months to determine whether a significant change had occurred. Results are reported as proportions with 95% confidence intervals (CIs). Positive culture results were analyzed with a generalized linear model. The dependent variable was the frequency of isolation of the organism, whereas the independent variable was time period (May through July and August through December). To control for the varying number of objects examined in each room, an offset variable was included. The results are reported as the proportion of contaminated objects (± standard error).