Table 2.
Results of the environmental hygiene studies organized by type of intervention; systematic review; N = 26
| Type of intervention | Study title | Year | Authors | Study design | Interventions | Sample size proxy | Sample size (patients) | Control | Microorganisms studied for colonization or HAI (same type) | Outcome: rate/reduction/cases | Method recom-mended* | Quality | Grade | Reduction in Bioburden | Comments |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mechanical | Protective isolation in a burns unit: the use of plastic isolators and air curtains [25] | 1971 | Lowbury et al | Prospective quasi experimental study | Isolators for burn patients (plastic, ventilated, air curtains both open and closed topped, with pre-filter and main filter) | NA | 84 | Open wards | Coliform bacilli, P. aeruginosa, Proteus sp., S. aureus | Lower incidence of infection with P. aeruginosa with intervention. Proteus spp. and miscellaneous coliform bacilli appeared on burns at least as often in isolators as in the open ward | No | 12 | B | Yes | Limited results for P. aeruginosa, other IPCg measures are more important |
| Mechanical | Lack of nosocomial spread of Varicella in a pediatric hospital with negative pressure ventilated patient rooms [28] | 1985 | Anderson et al | Prospective before and after study | Negative pressure ventilation | NA | 125 | No | H. zoster, V. zoster | No cases of nosocomial spread in the new facility, with infected patients put in negative pressure rooms | Yes | 6 | C | NA | In a preceding study in an isolation facility without negative pressure ventilation, nosocomial infections occurred in 7 out of 41 susceptible patients who were on the same ward as two patients with chickenpox |
| Mechanical | Implementation and impact of ultraviolet environmental disinfection in an acute care setting [29] | 2014 | Haas et al | Retrospective before and after study | Pulsed Xenon UVC disinfection in the operating rooms (daily), dialysis unit (weekly), and terminal disinfection for all burn unit discharges | 11,389 room cleans | NA | No | C. difficile, MDR Gram negative, MRSA, VREf | Significant reduction in both incidence rates and HAI for VRE, MRSA, resistant gram-negative bacteria and C. difficile | Yes | 9 | C | NA | – |
| Mechanical | A Quasi-Experimental Study Analyzing the Effectiveness of Portable High-Efficiency Particulate Absorption Filters in Preventing Infections in Hematology Patients during Construction [26] | 2016 | Özen et al | Retrospective before and after study | HEPAh filters | NA | 413 | No | Invasive fungal infections | Reduction of the HAI rates and reduction of invasive fungal infections in all of the patients following the installation of the HEPA filters. Intervention was significantly protective against IFI infection for specific groups of patients | Yes | 10 | C | NA | Aspergillus was mentioned in abstract but not specifically analyzed. But initial assessment was on the infection rates of both bacteria and fungi. Economic results should be taken cautiously because patients bills are unclear and significance of results depends on exchange rates |
| Mechanical | Impact of pulsed xenon ultraviolet light on hospital-acquired infection rates in a community hospital [27] | 2016 | Vianna et al | Prospective before and after study | Pulsed Xenon UVC terminal disinfection | > 4400 rooms | NA | No | C. difficile, MRSA, VRE | In non-ICU areas, significant reduction of C. difficile, no significant reduction of VRE, and significant increase of MRSA. In the ICU, reduction of all infections, but only a significant reduction for VRE | Yes, (though MRSA increased significantly) | 5 | D | NA | In non-ICU only C. difficile rooms received the intervention, which explains the results for the other pathogens |
| Mechanical | Pulsed-xenon ultraviolet light disinfection in a burn unit: Impact on environmental bioburden, multidrug-resistant organism acquisition and healthcare associated infections [30] | 2017 | Green et al | Prospective before and after study | Pulsed Xenon UVCa terminal disinfection for C. difficile associated disease rooms, and some daily disinfection | 653 occupied bed days | NA | No | C. difficile, Extended spectrum beta-lactamase Enterobacteriaceae, MDRb P.aeruginosa, MRSAc, S. maltophilia | No statistically significant impact on HAId or MDR organisms acquisition. After intervention the ICUe experienced along interval without HAI-C. difficile infection | No | 8 | C | Yes | Intervention period too short to really measure effect on colonization and HAI, study was not designed for this |
| Mechanical | Evaluation of an ultraviolet room disinfection protocol to decrease nursing home microbial burden, infection and hospitalization rates [24] | 2017 | Kovach et al | Prospective before and after study | Pulsed Xenon UVC terminal disinfection and shared living spaces disinfection | 247 | NA | No | N/A | Significant reductions in nursing home acquired relative to hospital-acquired infection rates for the total infections. Significant reduction of Hospitalizations for infection, with a notable reduction in hospitalization for pneumonia | Yes | 6 | C | Yes | - |
| Mechanical | Effectiveness of ultraviolet disinfection in reducing hospital-acquired Clostridium difficile and vancomycin-resistant Enterococcus on a bone marrow transplant unit [23] | 2018 | Brite et al | Prospective before and after study | Pulsed Xenon UVC disinfection and active surveillance | NA | 579 | No | C. difficile, VRE | No significant reduction in the incidence of VRE or C. difficile after the intervention | No | 11 | B | NA | - |
| Chemical | Impact of hydrogen peroxide vapor room decontamination on Clostridium difficile environmental contamination and transmission in a Healthcare setting [31] | 2008 | Boyce et al | Prospective before and after study | Gaseous hydrogen peroxide terminal disinfection and intensive disinfection in high incidence wards | NA | NA | No | C. difficile | Significant reduction of the nosocomial C. difficile incidence | Yes | 8 | C | Yes | Study was after an epidemic, once the strain had become endemic |
| Chemical | Implementation of hospital-wide enhanced terminal cleaning of targeted patient rooms and its impact on endemic Clostridium difficile infection rates [35] | 2013 | Manian et al | Retrospective before and after study | Gaseous hydrogen peroxide | 196,313 patient-days | NA | No | C. difficile | Significant reduction of the nosocomial C. difficile associated disease rate between the preintervention period and intervention period | Yes | 12 | B | NA | - |
| Chemical | Copper surfaces reduce the rate of healthcare-acquired infections in the intensive care unit [37] | 2013 | Salgado et al | Randomized controlled trial | Copper alloy-coated objects | NA | 431 | Rooms without copper | MRSA, VRE | Significant lower rate of HAI and colonization in ICU rooms with intervention | Yes | 10 | C | Yes | Over half of intervention group not exposed to all copper surfaces, and over 13% of patients assigned to noncopper rooms were exposed to the intervention |
| Chemical | Use of a daily disinfectant cleaner instead of a daily cleaner reduced hospital-acquired infection rates [33] | 2015 | Alfa et al | Prospective quasi experimental study | Hydrogen peroxide disinfectant/detergent in disposable wipes | NA | NA | Similar hospital which only used detergent except for in C. difficile isolation rooms | C. difficile, MRSA, VRE | Significant reduction of all HAIs when cleaning compliance was high, and for VRE even when compliance was lower | Yes | 13 | B | NA | - |
| Chemical | Reduction in Clostridium difficile infection associated with the introduction of hydrogen peroxide vapour automated room disinfection [36] | 2016 | McCord et al | Retrospective before and after study | Gaseous hydrogen peroxide terminal disinfection | > 3000 patients room cleanings | NA | No | C. difficile | Significant reduction of the C. difficile infection rate | Yes | 6 | C | NA | Intervention is potentially cost saving |
| Chemical | Prospective cluster controlled crossover trial to compare the impact of an improved hydrogen peroxide disinfectant and a quaternary ammonium-based disinfectant on surface contamination and health care outcomes [32] | 2017 | Boyce et al | Randomized controlled trial | Daily cleaning with liquid hydrogen peroxide, feedback to staff | 22,231 patient days | NA | Quaternary ammonium compounds (bleach for C. difficile rooms) | C. difficile, MRSA, VRE | No significant reduction of the composite colonization and infection outcome. (HAI and acquisition for VRE and MRSA, HAI for C. difficile) | Yes | 17 | A | Yes | Method recommended because surface contamination was also significantly lower |
| Chemical | Environmental disinfection with photocatalyst as an adjunctive measure to control transmission of methicillin-resistant Staphylococcus aureus: a prospective cohort study in a high-incidence setting [34] | 2018 | Kim et al | Before and after prospective | Photocatalyst antimicrobial coating (TiO2) | NA | 621 | No | A. baumannii, C. difficile, MRSA, VRE | Significant reduction in MRSA acquisition rate, and no significant reduction in the MRSA and C. difficile incidence rate. Significant reduction in incidence rate of hospital-acquired pneumonia. VRE and A. baumannii increased (not significantly) | Yes, for MRSA | 11 | B | Yes | - |
| Human factors | Clostridium difficile infection incidence: impact of audit and feedback programme to improve room cleaning [40] | 2016 | Smith et al | Retrospective before and after study | Online training, monitoring, weekly feedback | 392,875 patient days | NA | No | C. difficile | Reduction of hospital-acquired C. difficile infection incidence following the intervention. After implementing the program, the rate of decline accelerated significantly | Yes | 10 | C | NA | Results may have been affected by confounding factors |
| Human factors | A Multicenter Randomized Trial to Determine the Effect of an Environmental Disinfection Intervention on the Incidence of Healthcare-Associated Clostridium difficile Infection [39] | 2017 | Ray et al | Randomized controlled trial | Training and monitoring of EVS personnel with feedback | 1,683,928 patient days | NA | Disposable bleach wipes for daily and terminal disinfection, bleach, regular monitoring | C. difficile | No reduction in the incidence of healthcare-associated C. difficile infection during the intervention and postintervention periods | No | 15 | B | Yes | Environment was cleaner but no effect on C. difficile infection. No correlation between bioburden and HAI |
| Human factors | Environmental services impact on healthcare-associated Clostridium difficile reduction [38] | 2019 | Daniels et al | Retrospective quasi experimental design | Culture of safety with constructive feedback, education, auditing certifications, and accountability | 52,290 patients days | NA | Hospitals where this system was already in use | C. difficile | Significant reduction in healthcare − associated C. difficile infections | Yes | 15 | B | NA | - |
| Bundle: chemical, human factors (minor) | Comparison of the effect of detergent versus hypochlorite cleaning on environmental contamination and incidence of Clostridium difficile infection [44] | 2003 | Wilcox et al | Prospective quasi experimental study | Hypochlorite with training | NA | NA | Detergent | C. difficile | Significant reduction in C. difficile infection associated with the use of hypochlorite in one of the study wards but not the other, where the C. difficile infection rate increased | Yes | 11 | B | Yes | - |
| Bundle: chemical, human factors | Controlling methicillin-resistant Staphylococcus aureus (MRSA) in a hospital and the role of hydrogen peroxide decontamination: an interrupted time series analysis [46] | 2014 | Mitchell et al | Retrospective before and after study | Gaseous hydrogen peroxide and liquid hydrogen peroxide disinfection; monitoring and feedback | 3600 discharges, 32,600 swabs | NA | No | MRSA | Significant reduction of the incidence of MRSA colonization and infection after the introduction of the disinfectant | Yes | 10 | C | Yes | Study showed HEH can reduce infections, it does not prove superiority of hydrogen peroxide disinfectant, as it was compared to detergent |
| Bundle: chemical, human factors | A Successful Vancomycin-Resistant Enterococci Reduction Bundle at a Singapore Hospital [45] | 2016 | Fisher et al | Prospective before and after study | Training, gaseous hydrogen peroxide, workplace reminders (first part of study, before/during breakpoint), changed bleach cleaning solution, expanded surveillance, and automated alert system (later date, after reduction) | NA | 270,000 (at least) | No | VRE | Significant reduction in the VRE rate | Yes | 10 | C | NA | Active surveillance, automated system and change in manual cleaning solution was only implemented well after the breakpoint in the reduction, so not causal for it.. Minimum sample size calculated form rate and total cases of VRE over 85 months is 270,000 patients) |
| Bundle: mechanical, chemical | Enhanced terminal room disinfection and acquisition and infection caused by multidrug-resistant organisms and Clostridium difficile (the Benefits of Enhanced Terminal Room Disinfection study): a cluster-randomised, multicentre, crossover study [48] | 2017 | Anderson et al | Randomized controlled trial | UVC terminal room disinfection ± Bleach | NA | 21 395 | Quaternary ammonium compounds(bleach for C. difficile rooms) | C. difficile, MDR A. baumannii, S. aureus, VRE | Significant reduction of composite risk of colonization for all organisms except C. difficile. For VRE, only bleach and bleach + UVC interventions caused significant reductions in HAI. No statistically significant decrease was seen when using UVC with bleach vs bleach alone (in C. difficile rooms) | Yes, when used with quaternary ammonium compounds (so recommended except for C. difficile) | 19 | A | Yes | Composite risk reduction is due to the major significant reduction for VRE |
| Bundle: chemical, mechanical, workflow | Control of endemic multidrug-resistant Gram-negative bacteria after removal of sinks and implementing a new water-safe policy in an intensive care unit [43] | 2018 | Shaw et al | Prospective before and after study | Deep cleaning and disinfection of drains and valves; antibacterial water filters in the taps; external cleaning with microfiber cloths and hypochlorite solution | 35,909 patients-days | NA | No | Klebsiella, Pseudomonas spp. | Significant reduction of the incidence rates of MDR-Gram-negative bacteria after the intervention | Yes | 10 | C | NA | Different IPC interventions implemented during the study period (UVC, sink removal, antibiotic stewardship, environmental cleaning changes). No major changes in hand hygiene compliance |
| Bundle: human factors, mechanical, workflow | Reducing health care-associated infections by implementing separated environmental cleaning management measures by using disposable wipes of four colors [42] | 2018 | Wong et al | Prospective before and after study | Training, education and awareness regarding cleaning and 4 color coded reusable wipes | NA | 635 | Reusable wipes soaked with hypochlorite solution, visual inspection | C. difficile, MRSA, VRE | No reduction in HAI density after intervention, but it was during the follow-up period | No | 7 | C | Yes | Calling the wipes "disposable" is misleading, wipes were disposed after a number of uses depending on the color/environment |
| Bundle: chemical (minor), human factors, mechanical (minor) | An environmental cleaning bundle and health-care-associated infections in hospitals (REACH): a multicentre, randomised trial [47] | 2019 | Mitchell et al | Randomized controlled trial | Training, auditing, feedback, implementation of enhanced cleaning practices, and the incorporation of disposable wipes | 3,534,439 patient bed-days | NA | Periods where hospitals were not implementing the bundle | C. difficile, S. aureus, VRE | Significant reduction of VRE infections. No significant changes in the incidence of S. aureus bacteremia and of C. difficile infections | Yes, for VRE | 19 | A | NA | Not all hospitals used the wipes, and not all disinfected appropriately for C. difficile, which explains the results |
| Bundle: human factors, workflow | Implementation of human factors engineering approach to improve environmental cleaning and disinfection in a medical center [41] | 2020 | Hung et al | Prospective before and after study | Education, feedback, redesigned workflow of terminal cleaning and disinfection, a regular method of bleach dilution, and a checklist-form reminder) | NA | NA | No | Carbapenem-resistant A. baumannii complex, MRSA, VRE | Significant reduction in total MDRO colonization, but no reduction in HAI | Yes | 5 | D | Yes | Very few results on HAI, results are technically correlation. No information on specific pathogens for HAI, no adjustment for confounding factors. Authors recommend measures although HAI rates did not improve |
*Recommended by the study authors, aUVC ultraviolet-C light, bMDR multidrug resistant, cMRSA multidrug-resistant S. aures; dHAI Healthcare-associated infections; eICU Intensive Care Unit; fVRE vancomycin-resistant enterococci, gIPC infection prevention and control, hHEPA high efficiency particulate air (filter)