Quaternary Ammonium

QACs are widely used EPA-registered health care disinfectants and are generally regarded as effective, surface-compatible agents with some persistent antimicrobial activity when left undisturbed on surfaces. These compounds frequently are used for routine cleaning and disinfection of noncritical environmental surfaces (e.g., floors, HTOs such as bed rails and tray tables, medical equipment that contacts intact skin [such as blood pressure cuffs]). These agents are bactericidal, virucidal against enveloped viruses (e.g., HIV), and fungicidal.

However, they are not sporicidal and generally not mycobactericidal or virucidal against nonenveloped viruses. High water hardness and materials such as cotton towels and cloths can diminish microbicidal activity.^24-26 Finally, case reports of occupational asthma have been documented due to use of benzalkonium chloride.^27,28

Hypochlorite

Hypochlorites are EPA-registered surface disinfectants and the most commonly used of the chlorine disinfectants. For example, commercially available concentrations of 4% to 6% sodium hypochlorite solutions are formulated as concentrated household bleach, which are typically diluted by a factor of 10 for a final-use concentration of 0.4% to 0.6%. Hypochlorites are bactericidal, fungicidal, virucidal, mycobactericidal, and sporicidal. They are commonly used for disinfecting surfaces in bathrooms and surfaces used in food preparation and are generally included in recommendations for disinfecting surfaces or objects contaminated with hepatitis viruses, HIV, and C. difficile. Hypochlorites are also used to disinfect blood spills in the hospital setting. Depending on the surface being cleaned and the pathogens targeted, instructions for specific formulations, concentrations, and contact times must be followed. Hypochlorites must be freshly prepared when diluting from higher concentrations and proper dilution protocols must be followed to reduce chemical irritation or decreased efficacy. Hypochlorites are unaffected by water hardness, relatively stable and fast-acting, and generally safe with a low incidence of serious toxicity.^29,30

However, sodium hypochlorite (i.e., household bleach) may cause skin and eye irritation, as well as oropharyngeal, esophageal, and gastric burns.^31-33 Hypochlorites also are corrosive to metals in high concentrations (>500 ppm) and can discolor fabrics. Finally, given that their activity is significantly reduced by organic matter (e.g., blood, fecal matter), surfaces must be precleaned before disinfection.^29,30

Accelerated Hydrogen Peroxide

Accelerated hydrogen peroxide products are recently introduced EPA-registered surface disinfectants; they are bactericidal, virucidal, fungicidal, sporicidal, and mycobactericidal. These products have a generally short contact time, with some products having a 30-second to 1-minute bactericidal and virucidal claim, and a 5-minute mycobactericidal claim.³⁴ Lower-level concentrations are used for disinfecting hard surfaces, while higher-level concentrations (2%) are used for high-level disinfection. These compounds are commonly used, considered safe for EVS staff (i.e., lowest EPA toxicity category IV), surface compatible, noncorrosive, and unaffected by organic material.³⁴ In addition, accelerated hydrogen peroxide products are generally considered benign for the environment. However, they are more expensive than other disinfectants such as quaternary ammonium.

Phenolics

Phenolics are EPA-registered and bactericidal, mycobactericidal, fungicidal, and virucidal and are used for surface disinfection (e.g., bedrails, tables) and for disinfecting noncritical medical devices.³⁵ While inexpensive, they are less commonly used because of several disadvantages, including absorption by porous materials, ability for residual product to irritate tissue, and depigmentation of skin. In addition, phenolics are not sporicidal and can cause hyperbilirubinemia in infants when they are not prepared per manufacturers' recommendations.^36,37

Peracetic Acid

Peracetic acid preparations are EPA-registered disinfectants with rapid activity against microorganisms and are bactericidal, fungicidal, virucidal, mycobactericidal, and sporicidal. Peracetic acid generally remains active in the presence of organic material and lacks harmful decomposition materials (e.g., oxygen, hydrogen peroxide). Disadvantages include lack of stability, particularly following dilution, and potential to corrode metals such as copper and brass. Peracetic acid is most commonly used in automated machines designed to sterilize medical instruments (e.g., endoscopes, dental instruments), and in a formulation with hydrogen peroxide, to disinfect hemodialyzers.

Copper

High levels of copper ions are toxic to most microorganisms due to generation of reactive oxygen species, resulting in damage of nucleic acids, proteins, and lipids and, ultimately, cell death. In the health care setting, copper has been used to control Legionella spp. in water supplies and, more recently, incorporated into self-disinfecting surfaces used in hospital rooms. Given its bactericidal properties, contact with copper has been examined as a mechanism to kill many clinically important pathogens, including MRSA, Escherichia coli, Enterococcus spp., and Mycobacterium tuberculosis.

However, no standardization exists as to type of alloy and selection of specific surfaces. The effectiveness of copper-containing surfaces in reducing the risk of HAIs is under active investigation, and real-world experience remains limited to date. A study performed in three hospitals demonstrated a significant reduction in the microbial burden of certain intensive care unit (ICU) surfaces following installation of copper-impregnated surfaces.³⁸ Furthermore, a recent randomized controlled trial (RCT) evaluating the use of copper alloy-coated surfaces for several HTOs (e.g., bed rails, tray tables) in the ICU demonstrated decreased rates of HAIs and MRSA and VRE colonization.³⁹

Silver

Silver ions have the greatest level of antimicrobial activity of all the heavy metals. While its mechanism of action has not been completely elucidated, its bactericidal properties likely involve binding of disulfide and sulfhydryl groups present in the proteins of microbial cell walls. The use of silver-impregnated environmental surfaces has recently been studied and shown to reduce experimental surface contamination, but the clinical impact of this modality has not been evaluated.^39,40

Altered Topography

Materials with altered surface topography to inhibit bacterial biofilm formation are currently under investigation. An example of this design is Sharklet AF (Sharklet Technologies, Alachua, FL), which uses topography similar to shark skin and has been shown to reduce biofilm formation and growth of S. aureus on molds utilizing Sharklet technology.⁴¹ However, no data exist on use in the real-world hospital environment, and disadvantages include potential difficulty in retrofitting surfaces with these materials, as well as lack of microbicidal properties.

Light-Activated Antimicrobial Coatings

Light-activated antimicrobial coatings have been recently studied for self-disinfection of surfaces. Irradiation of certain compounds (e.g., titanium dioxide, photosensitizers) with visible or UV light results in the production of reactive radicals that nonselectively target microorganisms. These surfaces may provide a less toxic approach than the use of chemical disinfectants and are broadly microbicidal.^42-44 However, a constant source of photoactivation is required, and it is unclear whether these surfaces are sporicidal. Studies are still required on long-term disinfecting properties of these surfaces in the real-world hospital environment.

Ultraviolet Light

The use of a UV wavelength light as a no-touch, automated modality for hospital room disinfection has received significant recent attention. The UV-C wavelength of 200 to 270 nanometers is germicidal and involves breaking of molecular bonds in DNA, resulting in microorganism death. Advantages of UV-C technology include its microbicidal activity against a wide range of health-care-associated pathogens, including C. difficile, and the ability for more rapid room decontamination compared to hydrogen peroxide systems. Automated UV-C systems have most commonly been tested for postdischarge terminal disinfection in hospital rooms of patients with C. difficile infection.

This technology's disadvantages include the requirement for the room to be vacated and disinfected before decontamination, its use only for terminal disinfection (vs. daily disinfection), and its significant cost. Also, equipment and furniture must be moved away from walls to prevent shadowing because UV-C systems cannot disinfect areas without a direct or indirect line of sight. Finally, these units require significant time for effective disinfection and can therefore adversely affect bed turnover time. While dependent on many factors (e.g., system being used, dose, organism being targeted), the turnaround time for these devices can range from approximately 15 to 20 minutes for vegetative bacteria to approximately 50 to 100 minutes for C. difficile spores. A recent study utilizing a UV-reflective wall coating resulted in significantly decreased decontamination times, from ∼25 minutes to ∼3 minutes for MRSA, and from ∼43 minutes to ∼9 minutes for C. difficile spores.⁴⁵

Hydrogen Peroxide-Producing Systems

The use of hydrogen peroxide-producing systems for disinfecting hospital room surfaces and objects has been recently studied. Several systems that produce hydrogen peroxide using differing methods are available (e.g., dry mist, hydrogen peroxide vapor). Advantages of these include reliable microbicidal activity against a variety of pathogens associated with HAIs, including C. difficile, as well as uniform distribution in the room via an automated dispersal system, such that furniture and equipment do not need to be moved away from walls.

However, as with UV-C devices, all patients and health care staff must leave the room before decontamination, and these devices are used for terminal room disinfection (i.e., not for daily disinfection). Costs of these devices can also be substantial, and a lot of time is required for effective disinfection. High-level training is required to operate these devices. Air vents, doors, and windows must be isolated and sealed, and active monitoring with sensors is necessary to monitor for leaks and ensure that the room is safe for personnel to enter. A safety concern with improper use is airway and mucous membrane irritation. As with UV-C devices, hydrogen peroxide–producing systems are a relatively recent disinfection technology and, pending further studies, are not yet routinely used for disinfecting hospital rooms.

Structural Organizational Characteristics

An important approach some hospitals have adopted is outsourcing EVS. Environmental support services provided by outside contractors can include training and development programs, designing of comprehensive protocols, competency testing, and participation on infection prevention teams.^70,71 While supporting a large EVS department (over 650 employees) at Mount Sinai Hospital (New York, NY), one supplier implemented multiple interventions, including retraining staff (e.g., chemical dilution and use), updating departmental processes (e.g., hospitality training), and introducing new technologies (e.g., a UV irradiation device).⁷¹ One study, Brakovich et al. 2013,⁵⁷ indicated that followup disinfection of rooms formerly occupied by patients with C. difficile infection was outsourced to a company that provided hydrogen peroxide vapor devices and services.

Outsourcing has grown in recent years, according to several KIs, although national economic patterns may partly drive cycles of expansion and decline in use of outsourced service companies. One KI felt that while outsourcing may be cost-effective, better guidance is needed on process monitoring and standardization. Some KIs discouraged outsourcing because outside contractors may not understand local hospital culture, which is a major component of any patient safety program. Lastly, one KI commented that how EVS is organized in a hospital (e.g., location of EVS in the administrative hierarchy) is an important structural factor that can affect the success of EC processes.

External Factors

Compliance with “evidence-based policies and procedures” from organizations such as CDC, EPA, CMS, Joint Commission, FDA, and OSHA are important external factors. In its 2008 “Guideline for Disinfection and Sterilization in Healthcare Facilities,” CDC notes that health care workers need to understand requirements pertaining to them when applying disinfectants and sterilants as well as the relative roles of CDC, EPA, FDA and others in regulating these agents. EPA plays a particularly important role as the agency charged with setting national regulations for the safety and appropriate use of many of the disinfection agents reviewed in this Technical Brief (http://www2.epa.gov/pesticide-registration/antimicrobial-pesticide-registration). For a list of EPA and OSHA regulations related to sterilants and disinfectants, see Table 2.⁷²

Table 2

EPA and OSHA regulations for disinfectants.

CMS reimbursement policies will begin to shape EC efforts in the near future. Beginning in 2017, payment penalties under the Hospital Value-based Purchasing Program will be linked to National Quality Forum-endorsed measures of MRSA and C. difficile infection.⁷³

Patient Safety Culture

Institutional culture has been described as “the accumulation of invisible, often unspoken ideas, values, and approaches that permeate organizational life.”⁷⁴ Clarke et al. 2006⁷⁵ adds that culture may be partially formed by leadership decisions that ultimately result in cultural norms. Five (7%) studies reported on this domain; three recently published studies (2013–2014) described participation in planning and managing of EC processes by leaders from Infection Control,⁵⁴ Quality and Safety,⁵⁷ and EVS.⁵⁸ Two earlier studies reported the influence of project directors⁶⁴ and the Department of Infection Control.⁶⁶

Collaboration between infection prevention and control and EVS management during implementation phases (both planning and ongoing) is one of several key components presented by CDC in a two-level program to evaluate EC. The 2010 toolkit, “Options for Evaluating Environmental Cleaning,”⁷⁶ presents context (specific to terminal room cleaning) to assist hospitals in developing programs to improve HTO cleaning. The toolkit recommends that institutions start with a basic program that is consistent with previously issued guidelines.^23,77 It stresses the importance of the two disciplines working together to set expectations for staff, to develop metrics for competency evaluation and educational programs for hospital and EVS staff.

Administrative leadership is also “critical in managing outbreak situations,” according to APIC's “Guide to Preventing Clostridium difficile Infections.”⁷⁸ The administrator's responsibilities include ensuring staff have sufficient time to thoroughly clean (including adequate contact time for cleaning agents) and working with EVS and infection prevention staff to develop a monitoring program that provides desired information and timely feedback.

Implementation and Management Tools

Another component of CDC's program is the development of a hospital-specific program (consistent with CDC standards^23,77) and use of a checklist for cleaning “objects in the patient zone.” Cleaning checklists for HTOs were used in five studies;^{52,54,56,57,60} one study used a 43-point room cleaning checklist.⁵⁴ CDC also specifies that the responsibilities for cleaning HTOs should be clearly defined to avoid miscommunication among staff. One KI noted that roles are not usually clearly defined—for example, nursing staff believe that EVS personnel are responsible for cleaning an undesignated area of a patient's room and vice versa, which may result in inadequate room cleaning.

Next, CDC encourages “structured education for EVS staff” and outlines educational elements for EVSs frontline personnel such as:

• Provide an overview of the importance of HAIs in a manner commensurate with their educational level.
• Review specific terminal room cleaning practice expectations.
• Discuss the manner in which their practice will be monitored.
• Repeatedly reinforce the importance of their work.

Of the 24 (32%) studies that integrated implementation tools, 23 (96%) studies reported education as a key component while five studies specifically reported on training staff.^54,57,79-81 Smith et al. 2014⁵⁶ reported integrating educational interventions such as hands-on education with ATP devices and use of the “Clean Sweep” electronic game in which users rank three high-touch surfaces (from cleanest to least clean) from a drop-down menu, then submit the data for feedback. In 2007, Whitaker et al. provided education for staff, patients, and visitors,⁸² while other studies used a training DVD, competency-based training,⁷⁹ training on preparation, use and storage of products,⁸⁰ and training on the use of chemicals.⁵⁷

Next, CDC recommends developing measures for monitoring staff competency and performance that may include evaluations and utilize patient satisfaction surveys. One approach to evaluate skill acquisition is the Dreyfus model.⁸³ This model describes five levels of expertise from novice to expert level and can be used “(a) to provide a means of assessing and supporting progress in the development of skills or competencies, and (b) to provide a definition of an acceptable level for the assessment of competence or capability.” Five studies (all published since 2012) described audits.^58-60,80,84 One study included a UV monitoring audit tool,⁵⁹ while another integrated monthly EC audits.⁸⁰ Ramphal et al. 2014⁵³ implemented “blinded monitoring with transparent reporting of the results in a positive, engaging manner,” while Hota et al. 2009⁶² utilized “intensified” monitoring “providing immediate, specific feedback.” One KI recommended leveraging organizations such as APIC (http://www.apic.org/) and Infection Control and Prevention-Canada (http://www.ipac-canada.org/) to inform and encourage “translation of knowledge” to frontline staff. Another KI emphasized the importance of identifying those who can best communicate to EVS staff, particularly when staff knowledge deficits or other concerns are identified.

According to CDC, each “cycle of evaluation” should be followed by feedback to EVS staff, with results “shared widely within and beyond the institution.” Distinct methods of feedback described in primary studies were weekly electronic feedback (e.g., unit rates, rankings) to EVS, hospital leadership, and unit administrators;⁸⁵ feedback of UV-powder and gel surveillance results to EVS staff, hospital leadership, and unit administrators,⁸⁵ feedback from staff focus groups;⁸⁶ and feedback to EVS staff (monthly meetings, small group meetings, and individual meetings).⁸⁷ To optimize the thoroughness of terminal room cleaning and disinfection, CDC recommends discussing the results of monitoring programs and interventions as “a standing agenda item for the Infection Control Committee.”

One acute care hospital used patient satisfaction surveys to measure patient satisfaction after the introduction of a pulsed xenon ultraviolet (PX-UV) device.⁸⁸ Satisfaction scores were measured on the Hospital Consumer Assessment of Healthcare Providers and Systems survey on a quarterly basis over 13 quarters. Forwalt and Riddell noted that “after the introduction of the PX-UV system, the score for cleanliness and the overall rating of the hospital rose from below the [50th] to the [99th] percentile,” which ultimately resulted in financial benefits to the hospital.

Study Characteristics

Thirteen studies used historical controls, including before-and-after study designs (9), and interrupted time series (4).^52,53,57,63 Three studies used nonrandomized concurrent controls,^56,59,61 and one was an uncontrolled, descriptive study.⁵⁵ Study length ranged from 8 weeks to 4 years. Three studies implemented multicomponent strategies.^52,53,57 One study implemented an infection prevention bundle that included contact precautions for patients with diarrhea and sign placement for patients with confirmed/suspected C. difficile infection.⁵² Other studies incorporated hand hygiene⁵³ and antibiotic stewardship⁵⁷ with their EC strategies.

The unit of analysis in order of most to least common were patient rooms, HTOs, hospital units, hospitals, beds, and patients. The primary setting for six studies was the ICU.^55,60-63,89 Other settings included burn units,⁵² telemetry units,⁵² long-term acute care hospitals,⁵⁷ general medical wards,⁵⁹ respiratory step-down units,⁶⁵ and a surgical ward.⁶⁶ Wards were not specified in three studies.^51,53,58

C. difficile was the primary focus of three studies.^52,57,59 VRE was the primary focus of two studies.^62,67 The remaining studies focused on at least two of the three pathogens of interest. Five studies reported cleaning and disinfection of more than 15 HTOs.^{52,53,55,56,65} One study's sole focus was the bathroom.⁵⁹ Most commonly reported HTOs included bed rails, call buttons, light switches, tray tables, and toilets, but there was substantial variety in selection of HTOs across studies.

Use of ATP bioluminescence and fluorescent/UV markers was widely integrated into implementation strategies as monitoring and educational tools. Cleaning and disinfection methods reported by some studies included hypochlorite-based disinfectant,⁵² QAC,^56,61,62 hydrogen peroxide vapor, and microfiber mops.⁵⁷

Study Outcomes

Primary outcomes for most studies were variants of surface contamination (e.g., surfaces cleaned, positive cultures, compliance with room cleaning and disinfection protocols). Acquisition of pathogens was reported as a primary outcome in two studies.^61,67 Infection rate was reported as a primary outcome in three studies^57,61,67 and as a secondary outcome in two studies.^52,53

All three studies implementing multicomponent preventive strategies reported positive results. Koll et al. 2014⁵² reported significant reductions in hospital-onset C. difficile infection rates at 35 participating New York metropolitan regional hospitals. Ramphal et al. 2014⁵³ reported statistically significant improvements in cleaning rates due to repeated training, while Brakovich et al. 2013⁵⁷ reported success in decreasing C. difficile incidence.

Of the remaining 14 implementation studies, the study length of 6 studies was 6 months or fewer. Two studies (2 months in duration)^51,60 reported that use of ATP and fluorescent markers as monitoring tools resulted in “rapid improvements in cleaning thoroughness”⁶⁰ and “enhanced collaboration, communication and education.”⁵¹ One 4-month trial (Rupp et al. 2014)⁵⁵ identified a subgroup of housekeepers or “optimum outliers” who were significantly more efficient and effective than their coworkers. The authors hoped to use their exemplary performance to increase overall performance improvement. Three studies described various monitoring methods (e.g., swab cultures,⁶⁶ fluorescent markers,⁵⁸ UV markers⁵⁹) as useful tools to audit and educate staff.

One recently conducted 4-year study (Rupp et al. 2014)⁵⁴ concluded that monthly feedback and face-to-face meetings with frontline staff were crucial to EC success. Hayden et al.⁶⁷ demonstrated that a multimodal intervention to improve EC and hand hygiene reduced VRE acquisition in an endemic setting. Datta et al. 2011⁶¹ concluded that enhanced cleaning (bucket immersion of cloths into QAC) may reduce MRSA and VRE transmission and eliminate risk of MRSA acquisition from a room previously occupied by a patient colonized with MRSA. Results from three studies demonstrated improvements in cleaning rates,^63,65 with an expectation that the decrease in environmental contamination would help control spread of multi-drug-resistant organisms (MDROs).⁶⁷

Lastly, Hota et al. 2009⁶² purported that VRE contamination is caused by poor adherence to procedures and use of products “rather than to a faulty cleaning procedure or product.” Carling et al. 2008⁶⁴ conducted the largest study (a collaborative of 36 hospitals) and concluded that an EC program's success relies on support by administrative leadership and institutional flexibility.

Several studies reported on the sustainability of their preventive strategies. Ramphal et al. 2014⁵³ reported sustaining gains for 6 months. Trajtman et al. 2013⁵⁹ described use of graphs posted on the wards and in the EVS office to assist in “sustained improvement in cleaning compliance.” In 2011, Murphy et al.⁵⁸ reported unsustainable gains without ongoing education. In 2008, Carling et al.⁶⁴ reported results of collaborative efforts by 36 hospitals to improve cleaning practices. Eight hospitals that had participated for over 2 years in the program reported data on sustainability. They found that the thoroughness of cleaning decreased by 10% to 20% within 6 to 18 months of the last feedback session. Of the remaining 59 studies, only 1 study reported sustainability of its EVS strategy and reported “prolonged benefits” from 12-week use of fluorescent markers combined with regular feedback of results.⁸⁵

Study Characteristics

Five studies were RCTs, and one was a randomized crossover study. Fourteen studies used nonrandomized concurrent controls, while 27 used historical controls, including 22 before/after study designs and 5 interrupted time series. Study length ranged from 4 weeks to 43 months. Three studies implemented multicomponent strategies (i.e., integrated an additional non-EC-related strategy).^79,119,123 The multicomponent strategies in one study included monitoring of hand-hygiene compliance and antimicrobial usage, additional active MRSA surveillance with more rapid turnaround of laboratory results, and implementation of isolation precautions.⁷⁹ Preventive strategies in another study included hand-hygiene education and enforcement of an antibiotic policy.¹¹⁹ The third study integrated modified protocols to rely on alcohol-based hand hygiene and sleeveless aprons in place of long-sleeved gowns and gloves.¹²³ One study (Byers et al. 1998)¹¹⁰ was a description of disinfection practices in the context of an outbreak.

The units of analysis were most commonly patient rooms or microbiologic samples. Numbers of rooms ranged from 4¹²¹ to 11,389.¹⁰⁰ Numbers of samples ranged from 142¹¹² to 20,736.¹¹⁹ The primary setting for most studies was the ICU or general medical or surgical wards. Other settings included cancer wards,^84,123 “intensive therapy unit,”¹²² transplant ward,¹²³ and a long-term care ward.¹¹⁶

Monitoring methods used in these studies were categorized as swab cultures (13 studies), contact plates (9 studies), agar slide cultures (8 studies), fluorescent/UV markers (5 studies), and visual observation (3 studies). Other monitoring methods were described as sponge/wipe cultures, agar contact plates for aerobic bacteria, surface contact plates and seeded petri dishes, wipes, glove and hand plate cultures, and wipe/swatch cultures.

C. difficile was the primary focus of 13 studies.^{80,81,87,90,91,94,97,99,101,111,118,120,126} VRE was the primary focus of four studies,^{84,110,117,123} and MRSA was the focus of two studies.^9,79 The remaining studies focused on at least two pathogens, including one of the three pathogens of interest (C. difficile, MRSA, VRE). Most commonly reported HTOs were bed rails, side/tray tables, toilets, and floors. Table 3 includes the modalities by type of pathogen.

Study Outcomes

The primary outcome for 31 (66%) studies was surface contamination (e.g., bacterial burden, number of surfaces cleaned, positive cultures).^{9,38,80,84,86,87,92-94,96,98,103-107,111-113,115-118,120-122,124,125,127-129} Sixteen (34%) studies reported infection rate (e.g., incidence rate expressed per 1,000 patient-days)^{9,79,81,82,90,91,97,99-101,111,114,126} or colonization^80,102,123 as a primary outcome. Eight studies reported on C. difficile, two studies reported on MRSA, one study reported VRE infection rates, and three studies reported overall HAI rates. Other reported primary outcomes included compliance with room cleaning protocol,⁹⁸ contamination rates for health care worker gowns/gloves,⁹⁵ and number of bed areas where target pathogens were isolated during a sampling day.¹¹⁹

Secondary outcomes of interest included C. difficile ribotypes,¹¹¹ cleaning time,^9,98 adverse effects,⁹⁶ hospital-acquired C. difficile infection–attributable deaths/colectomies,⁹⁹ ease of use of ATP and Tru-D device,^121,128 and recontamination.¹²⁹

Studies examining chemical disinfectants reported mixed findings. Grabsch et al. 2012¹²³ found marked reductions in new VRE colonization after implementing the Bleach-Clean program (a multicomponent strategy). Four studies examining bleach^82,90-92 reported reduced C. difficile rates. One study examining the effectiveness of accelerated hydrogen peroxide versus stabilized hydrogen peroxide suggested that the accelerated hydrogen peroxide formulation was significantly better.¹²⁰

Other studies, however, reported no difference or identified strategies that were ineffective. One study reported that use of Difficil-S, a chlorine-based product, was ineffective in reducing C. difficile contamination and C. difficile infection rates.⁸⁰ Sjoberg et al. 2014⁹⁴ reported a “moderate spread of C. difficile spores despite use of a potassium monopersulfate-based disinfectant (Virkon™).”⁹⁴ One randomized trial by Schmidt et al. 2012⁹³ reported no difference in “mean relative reduction of microbial burden” after use of Virex soaked on a washcloth or quaternary ammonium as a microdroplet from the PureMist system. Lastly, Stewart et al.¹²⁹ reported that while electrolyzed water significantly reduced microbial counts (including MRSA) 1-hour postcleaning, microbial counts exceeded original levels at 24 hours.

Studies integrating wipes into their cleaning and disinfection regimens reported positive findings. Friedman et al. 2013⁸⁴ studied the application of a QAC (Viraclean) or V-wipe against VRE contamination. The authors reported significantly lower residual levels of VRE compared with earlier levels using a benzalkonium chloride-based product for disinfection. Other studies integrating wipes into a surface-cleaning routine reported a nonsignificant reduction in contamination of health care worker gowns and gloves after routine patient care activities,⁹⁵ a significant reduction in C. difficile rates,⁸¹ effectiveness as a surface disinfectant,⁹⁶ and sustained reductions in hospital-acquired C. difficile infection.⁹⁷ They supported the use of ready-to-use wipes over a traditional bucket method.⁹⁸

Authors of the 10 studies examining UV light devices^{87,112,118,122,124,125,128} or PPX-UV devices^9,99,100 as adjunctive infection control measures, concluded that the devices effectively reduced bacterial bioburden,^{87,112,118,122,125,128} significantly reduced hospital-acquired C. difficile infection rates,⁹⁹ significantly decreased overall hospital-acquired MDRO rates,¹⁰⁰ or was superior to manual disinfection.⁹ One study stated that integration of education, monitoring, feedback, a dedicated daily disinfection team, and implementation of a standardized process played a role in improved thoroughness.⁸⁷ One study comparing UV-C to hydrogen peroxide vapor¹²⁴ indicated effectiveness of both devices in reducing bacterial bioburden, but indicated that hydrogen peroxide vapor was significantly more effective due to UV-C's ineffectiveness “for sites out of direct line of sight.”

Of the six remaining studies evaluating hydrogen peroxide vapor^{79,101,111,114,117} or steam vapor,¹¹⁶ investigators reported reductions in MRSA contamination from a multicomponent strategy,⁷⁹ significant reductions in C. difficile-associated diarrhea rates,¹⁰¹ reduced environmental contamination and risk of acquiring MDROs compared with standard cleaning/disinfection,¹¹⁴ and >90% or highly effective reduction in bacterial levels.^111,116,117

Of the eight studies examining enhanced coatings or surfaces, authors indicated significantly lower rates of incident HAI and/or colonization compared with patients in standard rooms;¹⁰² that the integration of copper reduced^103,104 or significantly reduced^38,105-107 surface bacterial bioburden, and no sustained impact on antimicrobial activity for organosilane products tested.¹²⁷

Anderson et al. 2009¹²¹ compared various modes of mopping and indicated that wet, moist, and dry mopping more effectively reduced bacterial burden on the floor than spray mopping. Lastly, Byers et al. 1998¹¹⁰ indicated that the “new bucket method” of delivering quaternary ammonium resulted in “uniformly negative cultures.”

Study Characteristics

Five studies used nonrandomized concurrent controls, four used historical controls, and three studies did not have comparison arms. One study (Al-Hamad and Maxwell 2008)¹³⁹ was also designed to study the “correlation of two monitoring methods.” Study length ranged from 4 weeks to 8 months (4 studies did not report study length). All the studies implemented a single-component EC strategy. The reported units of analysis were rooms (7 studies) or microbiologic samples (6 studies). Numbers of rooms ranged from 10 to 1,119. Numbers of microbiologic samples ranged from 90 to 3,532. Other units of analysis included surfaces (3 studies), hospitals (1 study reported, including 27 hospitals),¹³² patients (1 study), and hospital wards (1 study). The unit of analysis in one study (Carling et al. 2008)¹³⁶ was 13,369 high-risk objects. Of the studies reporting setting (4 did not), four studies were set in the ICU and one was set in a general medical and surgical ward. Four studies focused on a single pathogen.^{18,133,135,139} The most commonly reported HTOs were bed rails, tray/side table, toilet, call buttons, light switches, and door knobs.

Study Outcomes

Primary outcomes for eight studies were reported as percent of targets cleaned^17,132-134 or cleaning rate.^{18,85,135,136} Two studies^138,140 reported air or surface microbial burden counts (RLUs or colony-forming units [CFUs]), while other studies reported sensitivity to detect pathogens¹³⁷ or number of positive cultures¹³⁹ as the primary outcome of interest.

Six studies mainly focusing on fluorescent/UV markers^85,132-136 reported positive results. The technologies were reported as useful, inexpensive, simple, highly objective surface targeting methods^85,132,134 that helped achieve significant improvements ^132,136 in cleaning and disinfection practices at their respective institutions. Blue et al. 2008¹³³ reported that the fluorescent chemical GlitterBug was “superior to previous visual inspection methods.”

Results from the six studies^{17,18,137-140} evaluating various monitoring methods mostly described the inferiority of visual observation compared to other monitoring methods. Of the six studies, five had nonrandomized controls.^{17,18,137,138,140} Luick et al. 2013¹³⁷ reported that fluorescent marker and ATP assay “demonstrated better diagnosticity” than visual inspection. Smith et al. 2013¹³⁸ reported that despite measuring different aspects of environmental contamination, quantitative microbiology and ATP both “generally agree in distinguishing clean from dirty surfaces.” Snyder et al. 2013¹⁷ reported poor correlation between ATP/fluorescent markers and a microbiologic comparator. One study¹⁸ proposed an ATP benchmark value of 100 RLUs since it would offer the closest correlation with microbial growth levels <2.5 CFU/cm². A 2003 study¹⁴⁰ recommended assessing effectiveness of hospital disinfection with internal audit and rapid hygiene testing. Lastly, results from a before/after study (Al-Hamad and Maxwell 2008)¹³⁹ indicated a “poor correlation between the findings of total aerobic count and MRSA isolation.” See Appendix C for further details on the outcomes and conclusions reported in these studies.