Environmental Cleaning: A Round-Up of Reports from the Medical Literature

By Kelly M. Pyrek

Work habits of environmental services professionals as well as their perceptions of the profession are among the topics addressed by recent studies in the literature. Let's examine the findings of some research from the U.S. and around the world. 

Global Environmental Hygiene

Environmental hygiene in healthcare institutions vary, as one might expect, and development of guideline recommendations for cleaning and disinfection could improve practices and set minimum standards worldwide, according to Kenters, et al. (2018), who designed a 30-question survey to evaluate differences in healthcare facility cleaning practices around the world. The survey was completed by infection preventionists (68 percent), ID physicians (13 percent), clinical microbiologists (6 percent), facility managers (2 percent), and other healthcare professionals (11 percent). A total of 110 healthcare professionals, representing 23 countries, participated in the online survey. 
Ninety-six percent of the facilities participating in the survey had a written cleaning policy for clinical areas and 82 percent had a policy for shared clinical equipment. Ninety percent of the facilities had a cleaning policy in place for the operating theatre; 6 percent of respondents were not sure. When surveyed as to which healthcare personnel were responsible for cleaning of clinical areas, it was found that this was mostly carried out by employees of the healthcare setting (57 percent), followed by employees of an external contractor (34 percent); in 9% of institutions responsibilities were shared between internal staff and contractors. 

The researchers report that among the facilities reporting that healthcare personnel were responsible for cleaning the areas outside of patients' rooms on the ward, 82 percent said that the institution's dedicated cleaners were responsible, 14 percent that nursing staff were responsible, and in 4 percent the role was shared by nursing staff and dedicated cleaners. The healthcare personnel responsible for the cleaning and disinfection of shared equipment were nurses (89 percent), cleaning staff (41 percent), physicians (20 percent), and other personnel (23 percent) -- meaning staff members who used the equipment, according to survey participants. Regarding training, the researchers report that 70 percent of facilities train at employment; 46 percent received yearly training, 15 percent twice yearly, and 20 percent sporadic training.

Routine room cleaning was performed daily in 92 percent of surveyed facilities; in 2 percent it was performed twice weekly, in 2 percent weekly, and 4 percent used a different cleaning frequency (i.e. twice daily or no routine cleaning). Of the respondents, 92 percent cleaned ‘high-touch’ surfaces (e.g. bedside table, remote control) daily, 1 percent cleaned these twice weekly, 2 percent weekly, and 5 percent had another frequency than the aforementioned (i.e. twice daily or no routine cleaning). Enhanced cleaning and/or disinfection practices while patients are under contact precautions (e.g. MDRO) varied. This included no extra cleaning (15 percent), extra cleaning in outbreaks only (31 percent), cleaning more frequently (19 percent), disinfection added to regular cleaning (9 percent), extra cleaning and disinfection (26 percent). Most respondents relied only on daily visual monitoring for the assessment of cleaning (47 percent).

The researchers call for a "reference standard that is accessible and appropriate to both high- and low-income countries. This standard could include a minimum and full package to make it feasible for both high- and low-resource countries.

Barriers and Perceptions of Environmental Cleaning

Pedersen, et al. (2018) studied environmental services (EVS) professionals' perceptions and knowledge of environmental cleaning using an anonymous Likert scale survey. A total of 118 surveys were collected (response rate, 47 percent). In terms of demographics, the researchers found that 41 percent of respondents were aged 40 years or younger, 48 percent had been employed for fewer than two years, and 8 percent were supervisors.

As the researchers note, "Regardless of age, position, or experience, most respondents believe that environmental cleaning is important for infection prevention. They are also open to having regular classes on cleaning."
Survey questions included the following, with the percentage of respondents agreeing with the statement:
- Terminal cleaning is important to prevent the spread of infection: 97 percent
- Daily cleaning is important to prevent the spread of infection: 97 percent
- The people I work with think cleaning is important for patient safety: 97 percent
- Doctors respect my work: 81 percent
- Nurses respect my work: 84 percent
- I am a valuable member of the healthcare team: 95 percent
- My job is important for patient safety: 99 percent
- If my loved one or I were a patient here, I would be satisfied with the terminal cleaning performed: 89 percent
- I feel rushed to clean rooms quickly so another patient can use the room: 61 percent

As Pedersen, et al. (2018) observe, "Overall, EVS staff believe themselves to be valuable members of the team. This contrasts previous studies that have shown EVS workers feel unappreciated with a 'me versus them' mentality. 
Nevertheless, EVS workers do not feel appreciated by physicians and nurses. This underappreciation is to a lesser degree than previously reported. The institutional difference may be due to the culture of appreciating and empowering EVS employees that is instilled by EVS leadership, thereby fostering job satisfaction within the department. Despite feeling valued, respondents report feeling rushed to clean patient rooms. At our institution, 15 minutes is allotted for daily room cleaning and approximately 30 minutes is given for terminal disinfection at the time of patient discharge. This time frame is tailored based on factors such as contact precautions and length of stay."

The researchers add, "Hospitals strengthening their EVS program for infection prevention purposes should be knowledgeable of perceptions and barriers of environmental cleaning at their institutions. Subsequent knowledge gaps should be addressed for all levels of experience. Workflow efficiency should be routinely monitored and improved. Finally, the importance of our environmental service colleagues in preventing infection transmission should be recognized at an institution level."

Cleaning Interventions

Doll, et al. (2018) conducted a review of the literature regarding environmental cleaning in the healthcare setting. As the researchers noted, "Despite evidence of the transmission of infectious organisms from environment to patient, the role of a clean environment in hospital prevention remains controversial. The extent to which environmental contamination contributes to healthcare-associated infections is unclear. Surface cleaning is certainly not a substitute for other infection control practices such as handwashing, limiting medical device usage, and gowning or gloving when indicated. However, routine efforts to decrease the overall bioburden of the hospital environment via cleaning is likely foundational to other efforts; lower levels of infectious organisms on surfaces translates to less contamination of healthcare worker hands and patient care objects as they make contact with the hospital environment. Essentially all literature related to the optimization of environmental cleaning in healthcare systems comes from countries with relatively abundant resources. In resource-limited healthcare settings, additional challenges may exist that contribute to inadequate cleaning. The minimum standards for environmental health reported in the World Health Organization’s Essential Environmental Health Standards in Health Care with regard to healthcare centers with limited resources, outline clean water, waste management, and a focus on visible dust and soil as essential temporary measures to protect patients. A comparison of these minimum standards against other published environmental cleaning recommendations highlights a striking disparity in the conditions of the hospital environment between different regions of the world."

The researchers add, "The hospital environment can be a source of HAIs, and current cleaning methods are only partially successful in mediating this risk. However, the extent to which the environment contributes to the transmission of infection and the level of cleanliness required to prevent the acquisition of organisms from the environment is unknown. There has been substantial interest in improving the cleaning process in recent years, and publications highlight a variety of strategies to accomplish this. Yet, fundamental issues remain unaddressed. There is an urgent need to overcome the challenges faced by manual cleaners (Bernstein et al., 2016) and to maximize the benefit of manual cleaning efforts. A tiered approach to cleaning that is tailored to the specific needs and resources of healthcare centers would be better defined with a wider representation of the global healthcare community in published studies. Human factors will ultimately determine the quality of environmental cleaning in the hospital and will remain the patient’s best defense against invisible threats from the hospital environment."

Combining Infection Prevention and Implementation Science to Improve Cleaning
Allen, et al. (2018) sought to assess the effectiveness of an environmental hygiene bundle in terms of changes to HAI rates, cleaning performance and environmental services (EVS) workers' knowledge and attitudes. A multi-modal bundle was designed and implemented with EVS personnel in eight wards in a 400-bed metropolitan teaching hospital, using a prospective, before-and-after study design. This consisted of a three-month pre-intervention phase and six-month intervention phase. This research used an implementation science framework to guide the transition from evidence into practice, with data collected in the pre-intervention phase synthesized to design the implementation strategy.

The researchers report that significant improvements in cleaning performance were observed, with the average proportion of ultraviolet markers removed during cleaning across the wards increasing from 61.1 percent to 95.4 percent. Results also demonstrate improvements to both the knowledge and attitudes of EVS professionals.

By combining infection prevention and implementation science, this bundle was an effective way to engage environmental services staff and improve hospital cleaning. The hospital environmental hygiene bundle included the following components:
- Targeted training for environmental hygiene (including addressing cleaning roles and responsibilities, bundle requirements, and local context)
- Defined and consistent product use
- Availability of point of care wipes for medical equipment (nurse-cleaned items)
- Defined and consistent cleaning technique: (including addressing sequence, pressure and movement, as well as adherence to manufacturers' instructions for product use, including contact time and dilution)
- Regular audits, with results fed back directly to EVS personnel
- Enhanced communication between EVS workers and other healthcare personnel
- Hospital-wide promotion of environmental hygiene

The researchers surveyed EVS personnel before and after the bundle was implemented and found that most participants had been professional cleaners for more than a decade, with approximately half the survey participants holding at least one related workplace certification. Infection prevention-related knowledge questions scored high in the pre-intervention survey and remained consistent throughout the intervention period. According to the researchers, the major positive shifts in knowledge were related to cleaning-specific knowledge as well as correct product use; however, there were no knowledge improvements for disinfectant contact time. There was no change across many of the attitude questions, particularly relating to environmental services team culture, as these scored consistently high throughout the intervention. 

As Allen, et al. (2018) observe, "By combining an infection prevention bundle with multi-modal elements and an implementation science framework we have demonstrated a novel integrated approach to bridge the evidence-practice gap for hospital hygiene. It builds on previous research on individual cleaning and disinfection interventions and products. The results from this study lend weight to previous researcher's arguments that improvements in patient outcomes, cooperation and practice change from a bundle of interventions are greater than that seen from single interventions." They add, "The improvements in both attitudes and subsequent performance demonstrated in this research may represent a change in individual EVS personnel motivation or interdisciplinary cooperation at the site. The positive results shown in this research support the arguments by Matlow and colleagues who demonstrated that personal EVS personnel motivation is directly related to improved cleaning performance, and Zoutman and colleagues who observed that better cooperation between infection control and environmental services is correlated with lower MRSA rates. While these studies measured slightly different outcomes to this study, they do infer that interpersonal factors affect performance. Future research involving EVS is needed to more conclusively demonstrate this association between improving the knowledge and attitudes of EVS personnel and improved performance."

Environmental Contamination in the ICU

Several studies have investigated environmental hygiene in the intensive care unit. Wille, et al. (2018) sought to assess the degree of environmental contamination close to and distant from patients, and contamination of healthcare workers' (HCWs) hands with nosocomial pathogens under real-life conditions and to investigate potential transmission events. Over the course of three weeks, agar contact samples were taken close to and distant from patient areas and from HCWs' hands in eight ICUs of a tertiary-care hospital. Each ICU was visited once without announcement. Among 523 samples, the researchers found that HCWs' hands were most frequently contaminated with potentially pathogenic bacteria (15.2 percent), followed by areas close to patients (10.9 percent) and areas distant from patients (9.1 percent). Gram-positive bacteria were identified most often (67.8 percent), with Enterococcus spp. being the most prevalent species (70 percent vancomycin sensitive and 30 percent vancomycin resistant) followed by Staphylococcus aureus, of which 64 percent were classified as methicillin-resistant Staphylococcus aureus. Molecular typing documented identical strains among patient, environment and hand isolates.

As Wille, et al. (2018) observe, "This point prevalence survey identified a high level of environmental contamination, with relevant pathogens including MDRM being present in areas distant from patients and areas close to patients. In general, areas distant from patients are considered to be of little importance in terms of transmission of organisms. Areas close to patients were frequently contaminated despite the recommended infection control measures, including twice-daily environmental disinfection. In addition, HCWs' hands (15.2 percent) revealed a considerable number of facultative pathogenic microorganisms. These data raise concern about the potential role of contamination as a reservoir for resistant species, and subsequent development of ICU-acquired colonization and infection."

The reasoning is that hospital workers may not adhere closely to local infection control guidelines, and it is possible that the formation of biofilms may complicate proper surface decontamination. In addition, resistance to disinfectants may be an issue, say the researchers. "Despite carrying out patient-related precautions and twice-daily decontamination of surfaces close to patients with certified disinfectants based on QACs, high levels of microbial contamination were found. Hence, one can argue that the execution of environmental disinfection is poorly implemented, and probably reflects non-adherence to infection control guidelines. Multiple studies have shown that cleaning and disinfection of surfaces in hospitals is suboptimal. Only 40 percent to 50 percent of surfaces that should be cleaned are wiped by housekeepers, and frequent turnover of personnel may contribute to the problem." 

The researchers emphasize, "The identification of MDRM in areas distant from patients highlights the need to evaluate the in-house hygiene standards at the study hospital, and discussion is required regarding whether extended cleaning and disinfection procedures are indicated in areas distant from patients. This measure is supported by the presence of identical strains from patients, the environment and staff. Based on the results of seven potential transmission events, it is concluded that pathogens might be transmitted from patients to HCWs and the environment, or vice versa. Furthermore, identical strains from patients discharged two weeks prior to sampling suggest that the patients' microbial footprint is not eliminated in the hospital surrounding." 

Smith, et al. (2018) endeavored to correlate environmental contamination of air and surfaces in the ICU; as well as to examine any association between environmental contamination and ICU-acquired staphylococcal infection. Patients, air, and surfaces were screened on 10 sampling days in a mechanically ventilated 10-bed ICU for a 10-month period. Near-patient hand-touch sites (N = 500) and air (N = 80) were screened for total colony count and Staphylococcus aureus. Air counts were compared with surface counts according to proposed standards for air and surface bioburden. Patients were monitored for ICU-acquired staphylococcal infection throughout. Overall, 235 of 500 (47 percent) surfaces failed the standard for aerobic counts. Half of passive air samples failed the ‘index of microbial air’ contamination, and 15/40 active air samples failed the clean air standard. 

As Smith, et al. (2018) observe, "On 10 out of 40 occasions, either MSSA or MRSA or both were recovered from surfaces or air; for these 10 occasions, nine showed surface hygiene failures from bed sites adjacent to a specific sampling point. This reflects previous work that noted the association of MSSA/MRSA with higher surface counts. The more microbial soil in the vicinity, the more likely it is that a pathogen can be isolated. Surfaces in the side-room were cleaner than the rest of ICU although the data varied. This was attributed to the fact that the door was kept shut when the room was occupied and the room itself was often left unused. More people-traffic and positive correlation with active air sampling (P = 0.04) at higher bed occupancy is also unsurprising. However, there was no association between surface counts and people-traffic, nor between passive air data and people-traffic. This may have been due to the method used for auditing footfall in ICU. People-traffic was measured beside the nurses' station, which is situated away from beds and sampling points. Furthermore, air samples were collected in the morning, which illustrates a major limitation of the study. A previous study in a naturally ventilated ward showed that airborne bioburden fluctuated significantly with activity during the day and yielded values that were considerably higher than this study." The researchers suggest that passive air sampling provides quantitative data analogous to that obtained from surfaces. Settle plates could serve as a proxy for routine environmental screening to determine the infection risk in the ICU.

Antimicrobial-Driven Surface Modifications in the Healthcare Environment

Adlhart, et al. (2018) conducted a literature review of the impact of antimicrobial-driven surface modifications in the healthcare environment. As the researchers explain, "A state-of-the-art innovation to combat pathogenic bacteria is the creation of self-disinfecting surfaces through the application of coatings with antibiofouling and/or bactericidal properties. Bactericidal coatings are interesting in healthcare because of the capability of these coatings to kill pathogens upon contact. Many different chemical strategies and technologies for antibacterial coatings are described in the literature. For instance, antibacterial coatings may contain active eluting agents (e.g. ions or nanoparticles of silver, copper, zinc, or antibiotics, chloride, iodine), immobilized molecules that become active upon contact (e.g. quaternary ammonium polymers or peptides), or light-activated molecules (e.g. TiO2 or photosensitizers). In addition to chemical modifications, the topography of a surface can by itself significantly affect its hygienic status, either in a beneficial manner (reducing microbial retention) or otherwise (increasing retention). As such, modifications of surfaces to enhance antimicrobial properties should always take into account the effect of surface wear on subsequent fouling and cleanability. Therefore, efforts should be undertaken to characterize typical wear, assess interactions with the most likely micro-organisms in that environment, and define the most appropriate and least damaging cleaning and sanitizer regimes. The best way to achieve such outcomes is to ensure that multidisciplinary expertise is integrated into developmental processes, and that testing methods are appropriately robust.

The researchers found that chemical modifications to achieve functional antimicrobial coatings were classified according to their functional principle as: anti-adhesive, contact active, and biocide release. The majority of chemical modifications includes hydrogels or poly(ethylene glycol) (PEG) to repel approaching microbes, metals (in particular, silver and copper), antimicrobial peptides (AMPs), quaternary ammonium compounds (QACs), and nanoparticles. 

Adlhart, et al. (2018) emphasize that, "…an effective antimicrobial coating must achieve a multitude of characteristics: be able to control the pathogenic population of a surface; be stable (mechanically, tribologically and chemically) in the wide range of hospital settings; minimize (eco)toxicological hazards and risks of antimicrobial resistance emergence; be affordable and easily implemented. Future technological developments should hence aim at tackling most, if not all, of these points. The ultimate goal of the antimicrobial coating, namely the prevention of thousands of deaths occurring as a direct consequence of HAI in healthcare facilities, cannot be tackled by the coating alone. But a tremendous common effort involving coating technology providers, clinical and cleaning staff as well as the responsible handling of antibiotics – to name merely the clinical and agricultural sectors among many others – is required. Regarding the ability to control the pathogenic population of a surface, very promising strategies have emerged. One of these is widely known as selective killing, or the ability of antimicrobial surfaces to target only those species that are deemed to cause a risk to patients or hospital staff. Strategies such as the use of quorum sensing at a threshold concentration to release an antimicrobial compound have recently appeared. Others, such as the modulation of the colonization consortia as a whole to inhibit the dominance of pathogens, in a strategy similar to the one used to control the human microbiome, should start appearing as microbial ecological concepts are better deciphered."

The researchers issue a caveat: "Depending on their intended use, antimicrobial surfaces will be challenged by a number of factors. For instance, door handles are in intermittent contact with hands, but nonetheless are not expected to be exposed to as much wear as bed linens, that should be washed on a daily basis. Studies on the weariness or robustness of the different materials under different conditions are available, but they require further methodological standardization to allow for a more meaningful interpretation of the results. Overall, the novel strategies that are continuously being developed in the area of nanosurfaces bring some hope to the field of antimicrobial control, while decreasing microbial resistance to antibiotics and associated infections in clinical settings. It is then crucial to provide suitable standardized assessment tests and a fast transition of these strategies from the lab bench to the market, by conjugating efforts between academia and industry."

References:
Adlhart C, Verran J, et al. Surface modifications for antimicrobial effects in the healthcare setting: a critical overview. Journal of Hospital Infection. Vol. 99, No. 3, Pages 239-249. July 2018.

Allen M, Hall L, Halton K and Graves N. Improving hospital environmental hygiene with the use of a targeted multi-modal bundle strategy. Infection, Disease & Health. Volume 23, Issue 2, June 2018, Pages 107-113.

Doll M, Stevens M and Bearman G. Review: Environmental cleaning and disinfection of patient areas. International Journal of Infectious Diseases. Vol. 67, Pages 52-57. February 2018.

Kenters N, T.Gottlieb T, Hopman J, Mehtar S, Schweizer ML, et al. An international survey of cleaning and disinfection practices in the healthcare environment. Journal of Hospital Infection. Article in press, 2018.

Pedersen L, Masroor N, Cooper K, Patrick A, Razjouyan F, Doll M, Stevens MP, and Bearman G. Brief Report: Barriers and perceptions of environmental cleaning: An environmental services perspective. American Journal of Infection Control. Online July 3, 2018. 

Smith J, Adams CF, King MF, Noakes CJ, Robertson C and Dancer SJ. Is there an association between airborne and surface microbes in the critical care environment? Journal of Hospital Infection. Online April 9, 2018.

Wille I, Mayr A, Kreidl P, et al. Cross-sectional point prevalence survey to study the environmental contamination of nosocomial pathogens in intensive care units under real-life conditions. Journal of Hospital Infection. Vol. 98, No. 1. Pages 90-95. January 2018.