Environmental Cleaning is Imperative to Infection Prevention


The good news is that an increasing number of hospitals are becoming aware of the role that contaminated environmental surfaces play in the transmission of pathogenic organisms. The bad news is that many hospitals still are not doing everything they can to ensure rigorous environmental cleaning protocols and practices, hence the continued proliferation of multidrug-resistant organisms (MDROs) and infections that can trigger increased healthcare costs, lengths of stay and mortality. It’s certainly not for a lack of data on the subject; Goodman (2008) observes, “Environmental contamination with pathogens commonly occurs during routine medical care. Many studies have described transmission of pathogenic organisms through contact with contaminated room surfaces.” And Eckstein (2007) notes, “Patients colonized or infected with healthcare-associated pathogens often shed these organisms onto their skin and into the environment. Although direct contact with patients is generally considered the major source for acquisition of pathogens on healthcare workers’ hands and subsequent transmission to other patients, several recent studies suggest that contaminated environmental surfaces may also play an important role in pathogen transmission.”

Goodman (2008) found that vancomycin-resistant Enterococci (VRE) and Staphylococcus aureus were frequently acquired on hands after contact with contaminated objects such as bed rails and bedside tables in colonized patients’ rooms. However, they also found that daily disinfection of environmental surfaces in VRE-colonized patients’ rooms was associated with reduced acquisition of this pathogen on hands. Studies have demonstrated that routine environmental cleaning can decrease VRE contamination on surfaces and healthcare workers’ hands, and also control VRE cross-transmission. Other studies indicate that a reduction in Clostridium difficile infection can be achieved through environmental decontamination.

It’s a message that hasn’t been lost on Phillip C. Carling, MD, director of infectious diseases and epidemiology at Caritas Carney Hospital in Boston and a professor at Boston University School of Medicine. Carling has long been an advocate of pairing the basics of infection prevention such as handwashing, with environmental cleaning and better education of environmental services (ES) personnel to cultivate greater awareness of sanitation technique.

“The critical importance of environmental cleaning has been coming to the forefront, particularly with the emergence of C. diff, VRE, MRSA and other MDROs that are showing their strength, virulence and persistence despite improvements in hand hygiene clarification of isolation and the revised isolation guidelines developed by the Centers for Disease Control and Prevention (CDC) several years ago,” Carling says. And while infection preventionists (IPs) and epidemiologists have been among the earliest adopters of evidence-based practices to prevent infections – and specifically acknowledging the effectiveness of surface and terminal cleaning – ES personnel have embraced these concepts to a lesser degree.

“Environmental services personnel have not yet had the opportunity to embrace these concepts and that’s what’s needed to change,” Carling confirms. “Despite recommendations by the CDC since 2003 that hospitals ensure that appropriate environmental hygiene practices are utilized and as well as specific mandated standards related to ensuring appropriate environmental hygiene practice requirements implemented by Medicare in 2007, adoption of these practices has been slow and inconsistent among institutions.”

The Guidelines for Environmental Infection Control in Health-Care Facilities (2003) from the CDC emphasize that environmental infection-control strategies can effectively prevent healthcare-acquired infections (HAIs), and these strategies include appropriate use of hospital-grade, EPA-registered cleaners and disinfectants in accordance with the manufacturers’ instructions; keeping surfaces such as floors, walls, tabletops visibly clean on a regular basis; and cleaning and disinfecting high-touch surfaces such as doorknobs, bed rails, light switches and surfaces in and around toilets in patients’ rooms, on a more frequent schedule than minimal-touch surfaces. Also, a recent study showed that a rigorous environmental cleaning intervention can reduce the transmission of methicillin-resistant Staphylococcus aureus (MRSA) and other MDROs in hospital intensive care units (ICUs). Researchers found that following an enhanced cleaning protocol reduced the spread of MRSA to patients exposed to rooms in which the prior occupant had been colonized or infected. The multi-modal cleaning intervention consists of three parts: a change from use of a pour bottle to bucket immersion for applying disinfectant to cleaning cloths; an educational campaign involving the environmental services staff at the hospital; and feedback method using removal of intentionally applied marks visible only under UV light.

“We know that environmental contamination with highly antibiotic-resistant bacteria can still occur in hospitals where cleaning policies exceed national standards established by the CDC,” says Rupak Datta, MPH, an MD/PhD candidate at the University of California at Irvine. “Although the risk of acquiring MRSA and VRE is already low, this study suggests that there are additional preventive measures that hospitals can take to reduce the risk of transmission from one patient to another.”

The retrospective study of more than 13,000 hospital stays in10 ICUs at a large, tertiary care academic medical center in Boston, measured the risk of MRSA and VRE acquisition before and during the cleaning intervention. Routine admission and weekly screenings for MRSA and VRE were conducted during both periods providing a systematic method to identify new cases of MRSA and VRE. During the pre-intervention period, 3.9 percent of the 1,454 patients exposed to a prior occupant with MRSA acquired the pathogen compared to just 1.5 percent of the 1,443 patients exposed during the intervention. Of the 1,291 patients exposed to VRE prior to the intervention, 4.5 percent acquired VRE compared to 3.5 percent of 1,446 patients during intervention.

The study builds upon a body of research conducted by Datta and his co-authors. In a 2006 study, they found that patients admitted to an ICU room whose prior occupant had been infected with MRSA or VRE had as much as a 40 percent increased risk of acquiring either pathogen, suggesting environmental contamination could play a significant role in their transmission. In a subsequent study, the authors showed that a multi-modal cleaning intervention could reduce environmental cultures for MRSA and VRE. The current study now suggests that this same intervention reduces acquisition of these pathogens, particularly MRSA, in subsequent room occupants.

Despite the overall reduction in MRSA and VRE acquisition, the cleaning intervention appears to be more effective against MRSA compared to VRE. The difference could be due to a generally higher rate of VRE room contamination and Datta suggests it is a question for future research. “The results suggest that a multi-modal cleaning intervention can reduce MRSA and, to a lesser extent, VRE transmission in high-risk patient areas including the ICU,” Datta says.

With so much at stake, Carling suggests that hospitals not only bolster their environmental cleaning regimens, but also monitor the cleaning processes to determine efficacy. He advocates the adoption of a fluorescent targeting method by which to check the thoroughness of cleaning measures. Carling and colleagues (2006) developed a new method using an invisible fluorescent marker to target standardized high-touch surfaces in hospital rooms. The nontoxic target solution, which intensely fluoresces with a black light, was formulated to be inconspicuous yet readily removed by housekeeping products. Small volumes of material were confidentially applied to 12 target sites in patient rooms in three hospitals following terminal cleaning. The targets were re-evaluated following terminal cleaning after several patients had occupied the room.

In the study, the evaluation of 1,404 surface objects in 157 rooms in three hospitals revealed that an average of 47 percent of targets had been were removed by routine terminal cleaning/disinfecting activities. The frequency with which various individual sites were cleaned varied widely but was similar in all hospitals. Educational interventions were implemented, leading to sustained improvement in cleaning of all objects and a greater than two-fold improvement in cleaning of surfaces previously cleaned less than 85 percent of the time. Carling (2006) concluded, “The use of a novel target compound to evaluate housekeeping practices confirmed high rates of cleaning of traditional sites but poor cleaning of many sites that have significant potential for harboring and transmitting microbial pathogens. This methodology has the potential for being used to evaluate objectively the cleaning/disinfecting activities in various healthcare settings.”

Boyce et al. (2009) sought to evaluate the usefulness of an adenosine triphosphate (ATP) bioluminescence assay for assessing the efficacy of daily hospital cleaning practices through a two-phase prospective intervention study at a university-affiliated community teaching hospital. During phase I of their study, the researchers sampled five hightouch surfaces in 20 patient rooms before and after daily cleaning. Moistened swabs were used to sample these surfaces and were then plated onto routine and selective media, and aerobic colony counts were determined after 48 hours of incubation. Specialized ATP swabs were used to sample the same hightouch surfaces in the 20 patient rooms and were then placed in luminometers, and the amount of ATP present was expressed as relative light units. During phase II of our study, after inservice housekeeper educational sessions were given, the housekeepers were told in advance when ATP readings would be taken before and after cleaning.

The researchers report that during phase I, the colony counts revealed that the five hightouch surfaces were often not cleaned adequately. After cleaning, 24 (24 percent) of the 100 surface samples were still contaminated with methicillinresistant Staphylococcus aureus, and 16 (16 percent) of the 100 surface samples still yielded vancomycinresistant enterococci. ATP readings (expressed as relative light units) revealed that only bathroom grab bars and toilet seats were significantly cleaner after daily cleaning than before. During phase II, a total of 1,013 ATP readings were obtained before and after daily cleaning in 105 rooms. The median relative light unit was significantly lower (i.e., surfaces were cleaner) after cleaning than before cleaning for all 5 hightouch surfaces.

The researchers conclude that suboptimal cleaning practices were documented by determining aerobic colony counts and by use of an ATP bioluminescence assay, and that ATP readings provided quantitative evidence of improved cleanliness of high-touch surfaces after the implementation of an intervention program.

Regardless of whether a high-tech or low-tech method to environmental hygiene is used, the bottom line is that some kind of cleaning protocol is sorely needed in today’s hospitals. And no longer can this issue be ignored in an era of newfound transparency.

Carling et al. (2008) observe, “The quality of environmental hygiene in hospitals is under increasing scrutiny from both healthcare providers and consumers because the prevalence of serious infections due to multidrug-resistant pathogens has reached alarming levels.”

Carling et al. (2008) sought to evaluate the thoroughness of terminal cleaning and disinfection in the patient's immediate environment and to identify opportunities for improvement in a diverse group of acute care hospitals. This prospective multi-center study was conducted in 23 acute-care hospitals to evaluate the thoroughness of terminal room cleaning in hospitals using a novel targeting method to mimic the surface contamination of objects in the patient's immediate environment.

The researchers applied a transparent, easily cleaned, environmentally stable solution that fluoresces when exposed to a hand-held ultraviolet light to 14 high-touch surfaces, a group of objects which the Centers for Disease Control and Prevention (CDC) has previously recommended should be cleaned on a more frequent schedule than “minimal touch housekeeping services” and which are considered to be  highrisk objects (HROs). Approximately 0.1 mL to 0.2 mL of the targeting solution was applied to an easily accessible portion of the HRO using a small squeeze bottle to create a 1.5 cm target. Once moistened, the dried targeting solution can be removed completely by wiping with a damp cloth for less than 5 seconds using light pressure.

Infection preventionists and hospital epidemiologists were charged with performing the actual target placement and cleaning evaluations. Randomly selected patient rooms and bathroom areas in at least four different areas of each hospital, including intensive care units (ICUs), were evaluated over periods ranging from three to 12 weeks. Researchers report that the results were collated according to type of HRO for individual hospitals, for geographic areas within hospitals, and between institutions to allow for a standardized analysis of the epidemiology of terminal room cleaning.

The overall thoroughness of terminal cleaning, expressed as a percentage of surfaces evaluated, was 49 percent (the range for all 23 hospitals was from 35 percent to 81 percent). Despite the tight clustering of overall cleaning rates in 21 of the hospitals, the researchers say that there was significant variation within object categories that was notable with respect to the cleaning of toilet handholds, bedpan cleaners, light switches, and door knobs (mean cleaning rates, less than 30 percent; institutional ranges, 0 percent to 90 percent). Sinks, toilet seats, and tray tables, in contrast, were consistently relatively well cleaned (mean cleaning rates were more than 75 percent). Patient telephones, nurse call devices, and bedside rails were inconsistently cleaned.

Significant unit-specific differences came to light in this study. The researchers report that there was a statistically significant difference between regular care units and ICUs in three hospitals; each of these institutions showed significantly lessthorough cleaning in the ICU. Staffing issues in environmental services, high rates of hospital occupancy and high staff turnover rates were identified as risk factors for lessthorough cleaning in two of the hospitals; a lack of oversight for the ICU environmental services staff as the result of an unfilled environmental services supervisory position was identified as a contributing factor in another hospital. An evaluation of the thoroughness of cleaning for the two bestcleaned types of HRO in each hospital revealed several distinct patterns of cleaning. In 10 hospitals, at least two types of HROs had a cleaning rate of more than 90 percent. In the remaining 13 hospitals, the mean cleaning rate for the two bestcleaned types of objects was 77 percent to 79 percent.

Carling et al. (2008) note, “Given the consistently high cleaning rates for sinks (93 percent), toilet seats (92 percent), and tray tables (90 percent) , it is likely that the lessthorough cleaning of many types of HROs, such as bedpan cleaners, toilet area handholds, and doorknobs, was the result of a lack of appreciation for the important role such objects play in transmitting healthcareassociated pathogens, rather than suboptimal terminal disinfection cleaning caused by motivational limitations of the environmental services staff. The identification of hospitals with very high rates of cleaning for certain types of HRO also suggests that high levels of motivation, along with traditional approaches to terminal room cleaning, led to thorough cleaning of certain objects, but the failure to appreciate the need to clean all HROs led to suboptimal cleaning of other objects. In these hospitals, it is possible that focused educational interventions with the environmental services staff could result in rapid and substantial improvement in the overall thoroughness of cleaning.”

The researchers conclude, “We identified significant opportunities in all participating hospitals to improve the cleaning of frequently touched objects in the patient's immediate environment. The information obtained from such assessments can be used to develop focused administrative and educational interventions that incorporate ongoing feedback to the environmental services staff, to improve cleaning and disinfection practices in healthcare institutions.”

Goodman et al. (2008) sought to evaluate the adequacy of discharge room cleaning and the impact of a cleaning intervention on the presence of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) on environmental surfaces in intensive care unit (ICU) rooms in an academic hospital.

The intervention consisted of a change from the use of pour bottles to bucket immersion for applying disinfectant to cleaning cloths, an educational campaign, and feedback regarding adequacy of discharge cleaning. Cleaning of 15 surfaces was evaluated by inspecting for removal of a pre-applied mark, visible only with an ultraviolet lamp or black light. Six surfaces were cultured for MRSA or VRE contamination. Outcomes of mark removal and culture positivity were evaluated; the black-light mark was removed from 44 percent of surfaces at baseline, compared with 71 percent during the intervention. The intervention increased the likelihood of removal of black-light marks after discharge cleaning, controlling for ICU type (medical vs surgical) and type of surface. The intervention reduced the likelihood of an environmental culture positive for MRSA or VRE (proportion of cultures positive, 45 percent at baseline vs 27 percent during the intervention. The researchers discovered that broad, flat surfaces were more likely to be cleaned than were doorknobs and sink or toilet handles.

The researchers conclude, “Increasing the volume of disinfectant applied to environmental surfaces, providing education for environmental services staff, and instituting feedback with a black-light marker improved cleaning and reduced the frequency of MRSA and VRE contamination.”


Boyce JM, Havill NL, Dumigan DG, Golebiewski M, Balogun O and Rizvani R. Monitoring the effectiveness of hospital cleaning practices by use of an adenosine triphosphate bioluminescence assay. Infect Control Hosp Epidemiol. 2009 Jul;30(7):678-84.

Carling PC, Parry MF and Von Beheren SM. Identifying opportunities to enhance environmental cleaning in 23 acute care hospitals. Infect Control Hosp Epidemiol. 2008 Jan;29(1):1-7.

Carling PC, Briggs JL, Perkins J and Highlander D.Improved cleaning of patient rooms using a new targeting method. Clin Infect Dis. 2006;42:385–388

Dancer SJ. How do we assess hospital cleaning? A proposal for microbiological standards for surface hygiene in hospitals. J Hosp Infect 2004;56:1015.

Goodman ER, Platt R, Bass R, Onderdonk AB, Yokoe DS and Huang SS. Impact of an environmental cleaning intervention on the presence of methicillin-resistant Staphylococcus aureus and Vancomycin-Resistant Enterococci on surfaces in intensive care unit rooms. Infect Control Hosp Epidemiol. 2008 July; 29(7): 593–599.

Hayden MK, Bonten JM, Blom DW, Lyle EA. Reduction in acquisition of vancomycinresistant Enterococcus after enforcement of routine environmental cleaning measures. Clin Infect Dis 2006;42:15521560.



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