Limited reduction in Clostridioides difficile and Methicillin-Resistant Staphylococcus aureus with the use of an aerosolized hydrogen peroxide disinfection system in tertiary health care facilities in Alberta, Canada

BACKGROUND

Nonmanual room disinfection systems may reduce the transmission of infections. A variety of systems have emerged; however, a paucity of evidence exists to make an evidence-informed decision for the implementation of a specific system. Alberta Health Services assessed one of these systems.

METHODS

A quasi-experimental prepost design assessed an aerosolized hydrogen peroxide disinfection system on 6 units at 3 acute care facilities in Alberta. To assess clinical effectiveness an interrupted time-series analysis with Poisson distribution compared changes in hospital-acquired Clostridioides difficile infection (HA-CDI) and hospital-acquired Methicillin-resistant Staphylococcus aureus (HA-MRSA) between preintervention, intervention, and postintervention periods. To assess operational feasibility cleaning turnaround time, time to operate, and utilization were considered. A participatory research framework was used to understand the benefits and challenges of operationalization.

RESULTS

Incidence rate ratio (IRR) of HA-CDI decreased by 25.7% on FMC-A and 6.9% on RAH-B. Following withdrawal, the IRR of HA-CDI continued to decrease. IRR of HA-MRSA decreased by 25.0% on RAH-B. Following withdrawal, the IRR of HA-MRSA continued to decrease. None of the results were statistically significant. The average time to operate was 3.2 hours. Utilization was between 1.7% and 25.6%. Most staff reported benefits and challenges.

DISCUSSION

None of the changes observed in HA-CDI and HA-MRSA after the introduction of the aerosolized hydrogen peroxide system were statistically significant. While most respondents reported multiple benefits and challenges in using the system, the core challenge was delays in inpatient admissions due to the time operate the system.

CONCLUSION

Successful implementation of a nonmanual room disinfection system as an addition to standard cleaning and disinfection requires significant investment and must consider a variety of factors.

The in situ efficacy of whole room disinfection devices: a literature review with practical recommendations for implementation

BACKGROUND

Terminal cleaning and disinfection of hospital patient rooms must be performed after discharge of a patient with a multidrug resistant micro-organism to eliminate pathogens from the environment. Terminal disinfection is often performed manually, which is prone to human errors and therefore poses an increased infection risk for the next patients. Automated whole room disinfection (WRD) replaces or adds on to the manual process of disinfection and can contribute to the quality of terminal disinfection. While the in vitro efficacy of WRD devices has been extensively investigated and reviewed, little is known about the in situ efficacy in a real-life hospital setting. In this review, we summarize available literature on the in situ efficacy of WRD devices in a hospital setting and compare findings to the in vitro efficacy of WRD devices. Moreover, we offer practical recommendations for the implementation of WRD devices.

METHODS

The in situ efficacy was summarized for four commonly used types of WRD devices: aerosolized hydrogen peroxide, H₂O₂ vapour, ultraviolet C and pulsed xenon ultraviolet. The in situ efficacy was based on environmental and clinical outcome measures. A systematic literature search was performed in PubMed in September 2021 to identify available literature. For each disinfection system, we summarized the available devices, practical information, in vitro efficacy and in situ efficacy.

RESULTS

In total, 54 articles were included. Articles reporting environmental outcomes of WRD devices had large variation in methodology, reported outcome measures, preparation of the patient room prior to environmental sampling, the location of sampling within the room and the moment of sampling. For the clinical outcome measures, all included articles reported the infection rate. Overall, these studies consistently showed that automated disinfection using any of the four types of WRD is effective in reducing environmental and clinical outcomes.

CONCLUSION

Despite the large variation in the included studies, the four automated WRD systems are effective in reducing the amount of pathogens present in a hospital environment, which was also in line with conclusions from in vitro studies. Therefore, the assessment of what WRD device would be most suitable in a specific healthcare setting mostly depends on practical considerations.

Aerosolized Hydrogen Peroxide Decontamination of N95 Respirators, with Fit-Testing and Viral Inactivation, Demonstrates Feasibility for Reuse during the COVID-19 Pandemic

In response to the demand for N95 respirators by health care workers during the COVID-19 pandemic, we evaluated decontamination of N95 respirators using an aerosolized hydrogen peroxide (aHP) system. This system is designed to dispense a consistent atomized spray of aerosolized, 7% hydrogen peroxide (H₂O₂) solution over a treatment cycle. Multiple N95 respirator models were subjected to 10 or more cycles of respirator decontamination, with a select number periodically assessed for qualitative and quantitative fit testing. In parallel, we assessed the ability of aHP treatment to inactivate multiple viruses absorbed onto respirators, including phi6 bacteriophage, herpes simplex virus 1 (HSV-1), coxsackievirus B3 (CVB3), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). For pathogens transmitted via respiratory droplets and aerosols, it is critical to address respirator safety for reuse. This study provided experimental validation of an aHP treatment process that decontaminates the respirators while maintaining N95 function. External National Institute for Occupational Safety & Health (NIOSH) certification verified respirator structural integrity and filtration efficiency after 10 rounds of aHP treatment. Virus inactivation by aHP was comparable to the decontamination of commercial spore-based biological indicators. These data demonstrate that the aHP process is effective, with successful fit-testing of respirators after multiple aHP cycles, effective decontamination of multiple virus species, including SARS-CoV-2, successful decontamination of bacterial spores, and filtration efficiency maintained at or greater than 95%. While this study did not include extended or clinical use of N95 respirators between aHP cycles, these data provide proof of concept for aHP decontamination of N95 respirators before reuse in a crisis-capacity scenario.

IMPORTANCE The COVID-19 pandemic led to unprecedented pressure on health care and research facilities to provide personal protective equipment. The respiratory nature of the SARS-CoV2 pathogen makes respirator facepieces a critical protective measure to limit inhalation of this virus. While respirator facepieces were designed for single use and disposal, the pandemic increased overall demand for N95 respirators, and corresponding manufacturing and supply chain limitations necessitated the safe reuse of respirators when necessary. In this study, we repurposed an aerosolized hydrogen peroxide (aHP) system that is regularly utilized to decontaminate materials in a biosafety level 3 (BSL3) facility, to develop a method for decontamination of N95 respirators. Results from viral inactivation, biological indicators, respirator fit testing, and filtration efficiency testing all indicated that the process was effective at rendering N95 respirators safe for reuse. This proof-of-concept study establishes baseline data for future testing of aHP in crisis-capacity respirator-reuse scenarios.

Use of a Hydrogen Peroxide Nebulizer for Viral Disinfection of Emergency Ambulance and Hospital Waiting Room

Disinfection of hospital facilities and ambulances is an important issue for breaking the chain of transmission of viral pathogens. Hydrogen peroxide has provided promising results in laboratory assays. Here, we evaluate the efficacy of a hydrogen peroxide nebulizer for the inactivation of surrogate MS2 bacteriophage and murine norovirus (MNV) in a patient waiting room and the fully equipped cabin of a medical ambulance. We observed an average 3 log₁₀ titer reduction in both settings, which represents the destruction of over 10⁶ and 10⁹ infectious particles of MNV and MS2 per cm², respectively. The potential for viral exposure is high for health workers when disinfecting confined and cluttered spaces, so the use of a hydrogen peroxide mist might offer an affordable and efficient solution to minimize the risk of viral contaminations.

An Artificial Intelligence Approach for Expurgating Edible and Non-Edible Items

In the pandemic of COVID-19, it is crucial to consider the hygiene of the edible and nonedible things as it could be dangerous for our health to consume infected things. Furthermore, everything cannot be boiled before eating as it can destroy fruits and essential minerals and proteins. So, there is a dire need for a smart device that could sanitize edible items. The Germicidal Ultraviolet C (UVC) has proved the capabilities of destroying viruses and pathogens found on the surface of any objects. Although, a few minutes exposure to the UVC can destroy or inactivate the viruses and the pathogens, few doses of UVC light may damage the proteins of edible items and can affect the fruits and vegetables. To this end, we have proposed a novel design of a device that is employed with Artificial Intelligence along with UVC to auto detect the edible items and act accordingly. This causes limited UVC doses to be applied on different items as detected by proposed model according to their permissible limit. Additionally, the device is employed with a smart architecture which leads to consistent distribution of UVC light on the complete surface of the edible items. This results in saving the health as well as nutrition of edible items.

The Effectiveness of Ultraviolet-C (UV-C) versus Aerosolized Hydrogen Peroxide (aHP) in ICU Terminal Disinfection

BACKGROUND

According to the Centers for Disease Control and Prevention, 10% of patients with healthcare-acquired infections (HAIs) died during their hospitalisation in 2015. Thus, the reduction in HAI prevalence is critical. One strategy to achieve this is the adequate disinfection of patient rooms within the hospital.

AIM

To compare the effectiveness of an Ultraviolet-C room sanitizer against that of an aerosolized hydrogen peroxide device in eliminating selected healthcare-associated (HA) pathogens and other HA-organisms in an ICU setting.

METHODS

The disinfection systems were tested on the following organisms: meticillin-resistant Staphylococcus aureus, extended-spectrum beta-lactamase-producing Klebsiella pneumoniae, carbapenem-resistant K. pneumoniae, vancomycin-resistant enterococci, multidrug-resistant Acinetobacter baumannii, and Candida auris. Media plates with known densities of each organism and placed at preselected regions within an ICU room. The mean kill rate was determined for each organism. Additionally, swabs were taken from five high-touch areas from different ICU rooms prior to manual cleaning, following manual cleaning, and following each disinfection method in order to compare their effectiveness.

FINDINGS

The UV-C device achieved a 96.75% mean microbial reduction in non-shaded areas. It was significantly less effective in the shaded regions. The aHP system achieved a mean kill rate of 50.71% for all areas. The swab results revealed that 15% of manually cleaned surfaces still harboured a microbial load, which was eradicated after use of either no-touch disinfection system.

CONCLUSION

This study presents the notable differences between two no-touch disinfection methods, highlights their effectiveness and advocates for their incorporation alongside a manual cleaning regimen.

Public Buses Decontamination by Automated Hydrogen Peroxide Aerosolization System

BACKGROUND: Public transportation has been linked to an increase in the risk of coronavirus disease 2019 transmission. The effective decontamination system using aerosolized hydrogen peroxide can mitigate the transmission risk from using public transportation. AIM: The aim of this study was to develop and validate an effective decontamination system for public transport. METHODS: The experimental research was performed in 13 inter-city public buses. The aerosol generator with ultrasonic atomizer was used in the experiment. The validation process for disinfection was conducted using both a chemical indicator (CI) and spore discs biological indicator (inoculated with 106 Geobacillus stearothermophilus enclosed in glassine envelopes). The CIs and biological indicators were marked by number and placed in nine locations on each bus. The decontamination cycle was developed by analyzed of various aerosolized and decomposition period. Both concentrations of hydrogen peroxide, 5% and 7%, were used for comparison. RESULTS: In an aerosolized period, both concentrations of hydrogen peroxide at 30 min were effective for sporicidal 6-log reductions. The decontamination cycle totaled 100 min, based on a 70 min average decomposition time. CONCLUSIONS: The automated hydrogen peroxide aerosolized system is a highly effective and safe method of decontaminating public buses.

Evaluation of dry hydrogen peroxide in reducing microbial bioburden in a healthcare facility

BACKGROUND

Standard manual cleaning and disinfection practices are often inadequate. Persistent contamination in the environment poses an infection risk that may be mitigated by no-touch disinfection systems. This study evaluates the efficacy of dry hydrogen peroxide (DHP) on microbial air and surface contamination as an adjunct to routine cleaning and disinfection in a large urban hospital.

METHODS

Surface samples were collected in five different hospital units, two pediatric and three adult, after manual cleaning on multiple days before and after DHP implementation. Air samples were also collected in each unit pre- and post-DHP use. Data outcomes were reported as colony forming units (CFU) with species identification.

RESULTS

The overall mean surface microbial burden was reduced by 96.5 percent for all units post-DHP compared to baseline (P < 0.001), with the greatest reductions achieved on privacy curtains (99.5 %). Mean microbial air sample counts were also reduced post-DHP compared to pre-DHP.

CONCLUSIONS

This study demonstrates that DHP was effective in reducing both air and surface microbial contamination in a variety of settings within a large, tertiary care hospital.

Effectiveness of dry hydrogen peroxide on reducing environmental microbial bioburden risk in a pediatric oncology intensive care unit

BACKGROUND

Routine manual cleaning and disinfection of the health care environment is often suboptimal. Residual contamination poses an infection risk, particularly for immunocompromised patients. This study evaluates the efficacy of dry hydrogen peroxide (DHP) on microbial surface contamination in a pediatric oncology intensive care unit.

METHODS

Surface samples from 5 high-touch and 2 low-touch surfaces were obtained for culture and adenosine triphosphate readings after manual cleaning on multiple days in 4 intensive care unit rooms, before and after DHP was deployed. Air samples were collected as well at the study site. Data outcomes were measured in terms of total colony-forming units for the cultures and relative light units for adenosine triphosphate.

RESULTS

The overall mean surface microbial burden was significantly reduced in the intervention group compared to the control group (mean 5.50 vs 11.77, P<.001). These reductions in colony-forming units were seen across all sampling sites in the intervention group. A reduction in the mean relative light units levels was also noted in the intervention group when compared to the control group (172.08 vs 225.83, P <.006). Reductions with the air samples were also noted (P = .139).

CONCLUSIONS

Study demonstrates that DHP was effective in reducing microbial surface contamination and improves quality of environmental cleaning.

A Systematic Review on the Efficacy of Vaporized Hydrogen Peroxide as a Non-Contact Decontamination System for Pathogens Associated with the Dental Environment

Aerosol generation and a wide range of pathogens originating from the oral cavity of the patient contaminate various surfaces of the dental clinic. The aim was to determine the efficacy of vaporized hydrogen peroxide fogging on pathogens related to the dental environment and its possible application in dentistry. PICOS statement (Population, Intervention, Comparison/Control, Outcome and Study design statement) was used in the review. Six electronic databases were searched for articles published from 2010 to 2020. Articles written in English reporting vaporized hydrogen peroxide on pathogens deemed to be relevant to the dental environment were assessed. The quality of the studies was assessed using the risk-of-bias assessment tool designed for the investigation of vaporized hydrogen peroxide application in dentistry. A total of 17 studies were included in the qualitative synthesis. The most commonly reported single bacterial pathogen was Methicillin-resistant Staphylococcus aureus in five studies, and the viruses Feline calicivirus, Human norovirus, and Murine norovirus were featured in three studies. The results of the studies reporting the log kill were sufficient for all authors to conclude that vaporized hydrogen peroxide generation was effective for the assessed pathogens. The studies that assessed aerosolized hydrogen peroxide found a greater log kill with the use of vaporized hydrogen peroxide generators. The overarching conclusion was that hydrogen peroxide delivered as vaporized hydrogen peroxide was an effective method to achieve large levels of log kill on the assessed pathogens. The hydrogen peroxide vapor generators can play a role in dental bio-decontamination. The parameters must be standardized and the efficacy assessed to perform bio-decontamination for the whole clinic. For vaporized hydrogen peroxide generators to be included in the dental bio-decontamination regimen, certain criteria should be met. These include the standardization and efficacy assessment of the vaporized hydrogen peroxide generators in dental clinics.

Efficacy of aerosolized hydrogen peroxide (Deprox) cleaning compared to physical cleaning in a Burns Unit

BACKGROUND

The performance of Deprox aerosolized hydrogen peroxide (aHP) has not been extensively studied in real-world clinical settings. A comparative study of aHP terminal disinfection was conducted in a Burns Unit and its performance compared to physical cleaning alone.

METHODS

Environmental surfaces were sampled pre-cleaning, post-cleaning and post-aHP disinfection. Samples were cultured for MRSA, VRE, Gram-negative multi-resistant organisms and other Gram-negative bacilli.

RESULTS

310 sites were sampled. There was a reduction in the rates of contaminated surfaces post-aHP, though pathogens were still recoverable in most cases, except for VRE. There was a marked reduction in MRSA contamination of soft surfaces (12% post-clean vs 6% post-aHP), and patient room surfaces (8.3% post-clean vs 2.8% post-aHP). It does not work as well for MRSA in bathrooms: 7% of surfaces were positive post-clean, and 9% post-aHP. There was a reduction in multiresistant Gram-negative bacteria (7%-3%), mostly due to drains (33%-13%).

CONCLUSION

aHP is a useful method of environmental disinfection, especially for Gram-negative pathogens in drains and MRSA on hard and soft surfaces. Where ongoing acquisition of MRSA is a problem, an adjunctive method of terminal disinfection in bathrooms could be considered.

Examination of Material Compatibilities with Ionized and Vaporized Hydrogen Peroxide Decontamination

Hydrogen peroxide (HP) decontamination is effective for a wide spectrum of pathogenic microorganisms. However, exposure to HP causes deleterious effects on some materials. The purpose of this study was to examine material compatibilities with ionized and vaporized hydrogen peroxide (iHP and VHP). With regard to iHP, 24 kinds of materials were exposed up to 100 cycles to iHP. The tested materials included plastics, metals, woods and plated or coated goods. The procedure of iHP decontamination was as following: gas time (11 min), dwell time (15 min) and aeration time (120 min). iHP decontamination caused some damage to copper, brass, chromium plate and galvanized iron immediately after exposure. Repeated iHP decontamination caused marked damage in stainless steel and urethane-, silicone- or epoxy-coating materials. Condensation of iHP decontamination posed severe damage for the material surfaces. With regard to VHP, 36 kinds of materials were exposed for up to 200 cycles to VHP decontamination. Under dry (dehumidified) conditions, VHP decontamination caused few changes on the surfaces of resin materials in dry conditions, although some resins began to develop hardening or softening. Discoloration was found in the stainless steel and changes in its coating materials. Bleaching was also observed in wooden materials. Under condensation conditions of VHP, nylon softened and butyl rubber hardened. Condensation of VHP caused material damage such as discoloration in the stainless steel, corrosion of zinc-plated steel, and air-bubbling under the color-steel sheet. The high concentrations of HP with condensation caused severe changes in metals and resins after repeated exposure. The VHP decontamination tests provided evidence that the material damage was more severe under condensation conditions than under dry conditions. Our results demonstrate the importance of condensation of HP when using it to decontaminate equipment.

Environmental Disinfection of a Dental Clinic during the Covid-19 Pandemic: A Narrative Insight

BACKGROUND

The control of biological hazard risk in health care and dental clinic environments represents a critical point in relation to the Covid-19 infection outbreak and international public health emergency. The purpose of the present review was to evaluate the scientific literature on the no-touch disinfection procedures in dental clinics aiming to limit transmission via airborne particles or fomites using no-touch procedures for environmental decontamination of dental clinics.

METHODS

An electronic database literature search was performed to retrieve research papers about Covid-19 and no-touch disinfection topics including full-length articles, editorials, commentaries, and outbreak studies. A total of 86 papers were retrieved by the electronic research.

RESULTS

No clinical article about the decontamination of a dental clinic during the Covid-19 pandemic was detected. About the topic of hospital decontamination, we found different no-touch disinfection procedures used in hospital against highly resistant organisms, but no data were found in the search for such procedures with respect to SARS-CoV-2: (1) aerosolized hydrogen peroxide, (2) H2O2 vapor, (3) ultraviolet C light, (4) pulsed xenon, and (5) gaseous ozone. One paper was retrieved concerning SARS-CoV-2; 32 documents focused on SARS and MERS. The cleaning and disinfection protocol of health care and dental clinic environment surfaces are essential elements of infection prevention programs, especially during the SARS-CoV-2 pandemic.

CONCLUSION

The decontamination technique that best suits the needs of the dental clinic is peroxide and hypochlorous which can be sprayed via a device at high turbine speed with the ability of producing small aerosol particles, recommendable also for their low cost.

Disinfecting noncritical medical equipment-Effectiveness of hydrogen peroxide dry mist as an adjunctive method

BACKGROUND

Manual disinfection of medical devices is prone to failure. Disinfection by aerosolized hydrogen peroxide might be a promising adjunctive method. We aimed to assess effectiveness of dry mist of hydrogen peroxide (HPDM) on noncritical medical equipment.

METHODS

One cycle of HPDM was applied on a convenience sample of 16 different types of "ready to use" noncritical medical devices in a closed, but nonsealed room. Of every object, 2 adjacent areas with assumed similar bacterial burden were swabbed before and after HPDM deployment, respectively. After culturing, colony forming units (CFU) were counted, and bacterial burden per cm² calculated.

RESULTS

Of 160 objects included in the study, 36 (23%) showed a CFU-count of zero both before and after HPDM use. A decrease from a median of 0.14 CFU/cm² (range: 0.00-125.00/cm²) to a median of 0.00 CFU/cm² (range: 0.00-4.00/cm²) (P < .001) was observed. The bacterial burden was reduced by more than 90% in 45% (95% CI: 37-53) of objects. No pathogenic bacteria were identified.

DISCUSSION

HPDM reduced bacterial burden on noncritical medical items. Since cleanliness of the included "ready to use" objects was high and no pathogens were found before nebulization, the HPDM device did not increase patient safety in this setting.

CONCLUSION

HPDM nebulization can be a useful nonmanual adjunctive disinfection method in high-risk settings.

Innovations in Infection Prevention and Treatment

Background: Patients with large, acute burn injuries are a major challenge for clinicians. The loss of skin barrier protection against micro-organisms combined with the induced immunosuppression after burn injury makes this population especially vulnerable to infection. For burn-injured patients who survive immediate management considerations and burn resuscitation after acute injury, sepsis remains the primary cause of death. The purpose of this article is to describe current strategies and innovations in burn sepsis prevention and management. Methods: This work reviews the current understanding of the systemic inflammatory response to burn injury and burn sepsis as well as current strategies in insolation and infection prevention, newer burn unit design strategies in the context of infection prevention, and novel therapies being considered in topical antimicrobial wound care management. Results: A review of burn sepsis is key to understanding current paradigms and innovation in burn management and prevention. Key management principles begin from the time of injury and persist throughout the patient's hospital course. This includes use of personal protective equipment, burn unit design considerations, and knowledge of critical care principles such as central venous catheter management strategies. Innovations on wound dressing types, forms, and use have been key to better controlling burn wound sepsis and improving wound healing. Products incorporating nanotechnology, novel anions, oxygen, and even light have been key to introducing previously unconsidered methods to fight or prevent infection. Conclusion: Understanding the pathophysiology and source identification of sepsis from burn wounds has been a key contributor in developing innovative prevention and therapeutic strategies in burn management. The emergence of drug-resistant pathogens and the difficulty of systemic antibiotic agents to reach poorly vascularized wounds have further reinforced the need to anticipate management strategies moving forward. A proactive, multidisciplinary approach is necessary to minimize the morbidity and mortality associated with infection control.

An overview of automated room disinfection systems: When to use them and how to choose them

Conventional disinfection methods are limited by reliance on the operator to ensure appropriate selection, formulation, distribution, and contact time of the agent. Automated room disinfection (ARD) systems remove or reduce reliance on operators and so they have the potential to improve the efficacy of terminal disinfection. The most commonly used systems are hydrogen peroxide vapor (H₂O₂ vapor), aerosolized hydrogen peroxide (aHP), and ultraviolet (UV) light. These systems have important differences in their active agent, delivery mechanism, efficacy, process time, and ease of use. The choice of ARD system should be influenced by the intended application, the evidence base for effectiveness, practicalities of implementation, and cost considerations.

Opinion: Airtightness for Decontamination by Fumigation of High-Containment Laboratories

INTRODUCTION

While the European legislation states that laboratories of high-containment must be sealable for fumigation, they do not prescribe a minimal value for airtightness. Starting from a previous study in which we measured the airtightness in 4 BSL-3 laboratories with blower-door tests, we discuss the connection between airtightness and a successful decontamination by fumigation.

METHODS

Biological indicators (BIs) consisting of spores of Geobacillus stearothermophilus on metal disks were laid out in laboratories of different levels of airtightness before performing a fumigation with aerosolized hydrogen peroxide using an automated device, according to the manufacturer's instructions.

RESULTS

Incubation of all BI disks placed in the facility with the highest level of airtightness showed complete inactivation of spores. However, in the facility with a lower level of airtightness, not all spores were inactivated.

DISCUSSION

Air leaks might be a factor in the outcome of the decontamination of a room by fumigation, as seen in the laboratory with a lower level of airtightness, but other factors associated with the fumigation process might also be critical for a successful decontamination.

CONCLUSION

We argue that a validation of the decontamination procedure, before first use or after important renovations of a laboratory of high-containment, is a more effective endpoint than reaching a predefined level of airtightness.

Plasma-Activated Aerosolized Hydrogen Peroxide (aHP) in Surface Inactivation Procedures

INTRODUCTION

Hydrogen peroxide is a strong oxidant that possesses an antimicrobial activity. It has been successfully used in surface/room decontamination processes either under the form of hydrogen peroxide vapor (HPV) or of vaporized hydrogen peroxide (VHP). Aerosolized hydrogen peroxide (aHP) offers a third alternative. The technology relies on the dispersion of aerosols of a hydrogen peroxide solution often complemented with silver cations. aHP provides an inexpensive and safe approach to treat contaminated rooms but sometimes fails to achieve the 6-log10 reduction limit in the number of viable microorganisms.

METHODS

Here, we used a venturi-based aHP generator that generates 4 mm in size aerosols from a 12% plasma-activated hydrogen peroxide solution free of silver cations.

RESULTS & DISCUSSION

We could successfully and constantly inactivate bacterial growth from biological indicators containing at least 106 spores of Geobacillus stearothermophilus placed on stainless steel discs wrapped in Tyvek pouches. We could also show that the biological indicators placed at various locations in a class II biosafety cabinet were equally inactivated, showing that hydrogen peroxide aerosols migrate through HEPA filters.

CONCLUSIONS

Considering that our method for aerosol generation is simple, reproducible, and highly effective at inactivating spores, our approach is expected to serve as a relatively cost effective alternative method for disinfecting potentially contaminated rooms or surfaces.

Novel Methods for Efficacy Testing of Disinfectants – Part I

The pathogens which are the effective transmitters of various infections pose a serious problem in restraining their interference in maintaining a sterile environment. The practical applicability of traditional methods of disinfection is restricted due to their cumbersomeness, toxic product generation, and cost-effectiveness. Therefore, the objective of the current review is to elaborate the efficacies and limitations of various novel disinfectants that can show their activity in a few minutes of treatment. The expected outcome would be feasibility for selection of a favorable disinfectant through various technologies that can generate uniform results and form a basis for the true estimation required parameters. Hence, the current paper ends with the consideration of unique new techniques that distinguishes their simplicity, safety, and efficacy in generating a sterile environment.

Whole room disinfection with hydrogen peroxide mist to control Listeria monocytogenes in food industry related environments

Listeria monocytogenes surviving daily cleaning and disinfection is a challenge for many types of food industries. In this study, it was tested whether whole room disinfection (WRD) with H₂O₂ mist could kill L. monocytogenes under conditions relevant for the food industry. Survival of a mixture of four L. monocytogenes strains exposed to H₂O₂ mist was investigated in a 36 m³ room. A commercial machine produced H₂O₂ mist by pumping a 5% H₂O₂ solution containing 0.005% silver through a nozzle, and breaking the liquid up in droplets using pressurized air. When a suspension of bacteria in 0.9% NaCl applied on stainless steel coupons was exposed to WRD with H₂O₂ mist, a >5 log reduction (LR) of L. monocytogenes was observed. Similar reductions were observed in all tests with conditions between 12 and 20 °C, H₂O₂ concentrations of 35-80 ppm and 1-2 h exposure. It was shown that the H₂O₂ in the mist dissolved and accumulated in the liquid on the steel, and acted against L. monocytogenes in the liquid phase. At high cell concentrations, the effect was reduced if cells were pregrown at highly aerated conditions. The anti-listerial effect was robust against protein and fat, but the effect was quenched by raw meat and raw salmon, probably due to high catalase activity. The effect of whole room disinfection with H₂O₂ against dried L. monocytogenes cells was 1-2 LR, however the effect of air-drying by itself lead to 3-4 LR. When biofilms were exposed to WRD, no surviving L. monocytogenes were observed on stainless steel, however for L. monocytogenes on a PVC conveyor belt material, there were surviving bacteria, with about 2 LR. Screening of 54 L. monocytogenes strains for growth susceptibility to H₂O₂ showed that their sensitivity to H₂O₂ was very similar, thus WRD with H₂O₂ are likely to be robust against strain variation in susceptibility to H₂O₂. Production of H₂O₂ mist resulted in increased room humidity, and this may limit the maximum H₂O₂ concentration achievable, especially at low temperatures. The results in this study show that whole room disinfection with H₂O₂ may have potential to control L. monocytogenes in the food industry, however intervention studies in the food industry are needed to verify the effect in practical use.

Evaluating different concentrations of hydrogen peroxide in an automated room disinfection system

A comparative study was made on the efficacy of 5, 10 and 35% weight by weight (w/w) hydrogen peroxide solutions when applied using an automated room disinfection system. Six-log biological indicators of methicillin-resistant Staphylococcus aureus (MRSA) and Geobacillus stearothermophilus were produced on stainless steel coupons and placed within a large, sealed, environmentally controlled enclosure. Five percent hydrogen peroxide was distributed throughout the enclosure using a Bioquell hydrogen peroxide vapour generator (BQ-50) for 40 min and left to reside for a further 200 min. Biological indicators were removed at 10-min intervals throughout the first 120 min of the process. The experiment was repeated for 10 and 35% hydrogen peroxide solutions. Five percent and 10% hydrogen peroxide solutions failed to achieve any reduction of MRSA, but achieved full kill of G. stearothermophilus spores at 70 and 40 min respectively. Thirty-five percent hydrogen peroxide achieved a 6-log reduction of MRSA after 30 min and full kill of G. stearothermophilus at 20 min. The concentration of 5% hydrogen peroxide within the enclosure after the 200-min dwell was measured at 9·0 ppm. This level exceeds the 15-min Short Term Exposure Limit (STEL) for hydrogen peroxide of 2·0 ppm. Users of automated hydrogen peroxide disinfection systems should review system efficacy and room re-entry protocols in light of these results.

SIGNIFICANCE AND IMPACT OF THE STUDY

This research allows hospital infection control teams to consider the impact and risks of using low concentrations of hydrogen peroxide for disinfection within their facilities, and to question automated room disinfection system providers on the efficacy claims they make. The evidence that low concentration hydrogen peroxide solutions do not rapidly, autonomously break down, is in contradiction to the claims made by some hydrogen peroxide equipment providers and raises serious health and safety concerns. Facilities using hydrogen peroxide systems that claim autonomous break down of hydrogen peroxide should introduce monitoring procedures to ensure rooms are safe for re-entry and patient occupation.

Effectiveness of ultraviolet devices and hydrogen peroxide systems for terminal room decontamination: Focus on clinical trials

Over the last decade, substantial scientific evidence has accumulated that indicates contamination of environmental surfaces in hospital rooms plays an important role in the transmission of key health care-associated pathogens (eg, methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, Clostridium difficile, Acinetobacter spp). For example, a patient admitted to a room previously occupied by a patient colonized or infected with one of these pathogens has a higher risk for acquiring one of these pathogens than a patient admitted to a room whose previous occupant was not colonized or infected. This risk is not surprising because multiple studies have demonstrated that surfaces in hospital rooms are poorly cleaned during terminal cleaning. To reduce surface contamination after terminal cleaning, no touch methods of room disinfection have been developed. This article will review the no touch methods, ultraviolet light devices, and hydrogen peroxide systems, with a focus on clinical trials which have used patient colonization or infection as an outcome. Multiple studies have demonstrated that ultraviolet light devices and hydrogen peroxide systems have been shown to inactivate microbes experimentally plated on carrier materials and placed in hospital rooms and to decontaminate surfaces in hospital rooms naturally contaminated with multidrug-resistant pathogens. A growing number of clinical studies have demonstrated that ultraviolet devices and hydrogen peroxide systems when used for terminal disinfection can reduce colonization or health care-associated infections in patients admitted to these hospital rooms.

Hydrogen Peroxide Vapor Decontamination in a Patient Room Using Feline Calicivirus and Murine Norovirus as Surrogate Markers for Human Norovirus

OBJECTIVE

To determine whether hydrogen peroxide vapor (HPV) could be used to decontaminate caliciviruses from surfaces in a patient room.

DESIGN

Feline calicivirus (FCV) and murine norovirus (MNV) were used as surrogate viability markers to mimic the noncultivable human norovirus. Cell culture supernatants of FCV and MNV were dried in triplicate 35-mm wells of 6-well plastic plates. These plates were placed in various positions in a nonoccupied patient room that was subsequently exposed to HPV. Control plates were positioned in a similar room but were never exposed to HPV.

METHODS

Virucidal activity was measured in cell culture by reduction in 50% tissue culture infective dose titer for FCV and by both 50% tissue culture infective dose titer and plaque reduction for MNV.

RESULTS

Neither viable FCV nor viable MNV could be detected in the test room after HPV treatment. At least 3.65 log reduction for FCV and at least 3.67 log reduction for MNV were found by 50% tissue culture infective dose. With plaque assay, measurable reduction for MNV was at least 2.85 log units.

CONCLUSIONS

The successful inactivation of both surrogate viruses indicates that HPV could be a useful tool for surface decontamination of a patient room contaminated by norovirus. Hence nosocomial spread to subsequent patients can be avoided.

APSIC Guidelines for environmental cleaning and decontamination

This document is an executive summary of APSIC Guidelines for Environmental Cleaning and Decontamination. It describes best practices in routine cleaning and decontamination in healthcare facilities as well as in specific settings e.g. management of patients with isolation precautions, food preparation areas, construction and renovation, and following a flood. It recommends the implementation of environmental hygiene program to keep the environment safe for patients, staff and visitors visiting a healthcare facility. Objective assessment of cleanliness and quality is an essential component of this program as a method for identifying quality improvement opportunities. Recommendations for safe handling of linen and bedding; as well as occupational health and safety issues are included in the guidelines. A training program is vital to ensure consistent adherence to best practices.

Efficiency of hydrogen peroxide in improving disinfection of ICU rooms

INTRODUCTION

The primary objective of this study was to determine the efficiency of hydrogen peroxide (H₂O₂) techniques in disinfection of ICU rooms contaminated with multidrug-resistant organisms (MDRO) after patient discharge. Secondary objectives included comparison of the efficiency of a vaporizator (HPV, Bioquell) and an aerosolizer using H₂O₂, and peracetic acid (aHPP, Anios) in MDRO environmental disinfection, and assessment of toxicity of these techniques.

METHODS

This prospective cross-over study was conducted in five medical and surgical ICUs located in one University hospital, during a 12-week period. Routine terminal cleaning was followed by H₂O₂ disinfection. A total of 24 environmental bacteriological samplings were collected per room, from eight frequently touched surfaces, at three time-points: after patient discharge (T0), after terminal cleaning (T1) and after H₂O₂ disinfection (T2).

RESULTS

In total 182 rooms were studied, including 89 (49%) disinfected with aHPP and 93 (51%) with HPV. At T0, 15/182 (8%) rooms were contaminated with at least 1 MDRO (extended spectrum β-lactamase-producing Gram-negative bacilli 50%, imipenem resistant Acinetobacter baumannii 29%, methicillin-resistant Staphylococcus aureus 17%, and Pseudomonas aeruginosa resistant to ceftazidime or imipenem 4%). Routine terminal cleaning reduced environmental bacterial load (P <0.001) without efficiency on MDRO (15/182 (8%) rooms at T0 versus 11/182 (6%) at T1; P = 0.371). H₂O₂ technologies were efficient for environmental MDRO decontamination (6% of rooms contaminated with MDRO at T1 versus 0.5% at T2, P = 0.004). Patient characteristics were similar in aHPP and HPV groups. No significant difference was found between aHPP and HPV regarding the rate of rooms contaminated with MDRO at T2 (P = 0.313). 42% of room occupants were MDRO carriers. The highest rate of rooms contaminated with MDRO was found in rooms where patients stayed for a longer period of time, and where a patient with MDRO was hospitalized. The residual concentration of H₂O₂ appears to be higher using aHPP, compared with HPV.

CONCLUSIONS

H₂O₂ treatment is efficient in reducing MDRO contaminated rooms in the ICU. No significant difference was found between aHPP and HPV regarding their disinfection efficiency.

How to eradicate Clostridium difficile from the environment

During the last decade, Clostridium difficile has emerged as a major cause of healthcare-associated diarrhoea and death. Transmission of this spore-forming bacterium is thought to occur via the hands of healthcare providers or via the contaminated environment. Therefore, enhanced environmental cleaning/disinfection of the rooms housing C. difficile-infected patients is warranted. Guidelines from various scientific bodies have been published. They recommend performing environmental decontamination of rooms of patients with C. difficile infection (CDI) using hypochlorite (diluted 1/10) or a sporicidal product. Compliance with cleaning and disinfection is a critical point and is often suboptimal. Novel 'no-touch' methods for room disinfection have recently been introduced. Ultraviolet (UV) light or hydrogen peroxide systems are most widely used. In-vitro studies suggest that hydrogen peroxide vapour (from 30% hydrogen peroxide) methods achieve a >6 log10 reduction in C. difficile spores placed on carriers, and that aerosolized hydrogen peroxide systems (from 5% to 6% hydrogen peroxide) achieve ∼4 log10 reduction, whereas UV-based methods achieve ∼2 log10 reduction. Very few studies have assessed the impact of these devices on the transmission of C. difficile. Major limitations of these devices include the fact that they can only be used after the patient's discharge, because patients and staff must be removed from the room. The new no-touch methods for room disinfection supplement, but do not replace, daily cleaning.

The role of the healthcare environment in the spread of multidrug-resistant organisms: update on current best practices for containment

The role of the environment in harboring and transmitting multidrug-resistant organisms has become clearer due to a series of publications linking environmental contamination with increased risk of hospital-associated infections. The incidence of antimicrobial resistance is also increasing, leading to higher morbidity and mortality associated with hospital-associated infections. The purpose of this review is to evaluate the evidence supporting the existing methods of environmental control of organisms: environmental disinfection, contact precautions, and hand hygiene. These methods have been routinely employed, but transmission of multidrug-resistant organisms continues to occur in healthcare facilities throughout the country and worldwide. Several new technologies have entered the healthcare market that have the potential to close this gap and enhance the containment of multidrug-resistant organisms: improved chemical disinfection, environmental monitoring, molecular epidemiology, self-cleaning surfaces, and automated disinfection systems. A review of the existing literature regarding these interventions is provided. Overall, the role of the environment is still underestimated and new techniques may be required to mitigate the role that environmental transmission plays in acquisition of multidrug-resistant organisms.

A guide to no-touch automated room disinfection (NTD) systems

Conventional disinfection methods are limited by reliance on the operator to ensure appropriate selection, formulation, distribution and contact time of the agent. ‘No-touch’ automated room disinfection (NTD) systems remove or reduce reliance on operators and so they have the potential to improve the efficacy of terminal disinfection. The most commonly used systems are hydrogen peroxide vapour (H₂O₂ vapour), aerosolised hydrogen peroxide (aHP) and ultraviolet (UV) radiation. These systems have important differences in their active agent, delivery mechanism, efficacy, process time and ease of use. The choice of NTD system should be influenced by the intended application, the evidence base for effectiveness, practicalities of implementation and cost constraints.

Saving costs through the decontamination of the packaging of unused medical supplies using hydrogen peroxide vapor

OBJECTIVE. Individually packaged sterile supply items may become contaminated and act as vectors for nosocomial transmission of multidrug-resistant organisms (MDROs). Thus, many hospitals have a policy to dispose of these unused, packaged supply items at patient discharge from the hospital, which has considerable cost implications. We evaluated the frequency of contamination of these items, the efficacy of hydrogen peroxide vapor (HPV) in disinfecting them, and costs associated with discarded supplies. DESIGN. Before-after study. METHODS. A pilot study was performed in the rooms of 20 patients known to be colonized or infected with vancomycin-resistant enterococci (VRE), and a follow-up study was performed in an additional 20 rooms of patients under precautions for various MDROs in 6 high-risk units. Five pairs of supply items were selected. One item of each pair was sampled without exposure to HPV, and the other was sampled after HPV exposure. The cost of discarded supplies was calculated by examining stock lists of supplies stored on the study units. RESULTS. Seven (7%) of 100 items were contaminated with VRE in the pilot study, and 9 (9%) of 100 items were contaminated with MDROs in the follow-up study. None of the items were contaminated after exposure to HPV (P < .02 in both the pilot and the follow-up study). The annual cost of supplies discarded at patient hospital discharge was $387,055. This figure does not include the cost of waste disposal and is therefore likely to be an underestimation of the financial burden. CONCLUSIONS. HPV effectively disinfected the packaging of supply items, which could generate considerable financial and environmental benefits.

The Role of the Hospital Environment in the Prevention of Healthcare-Associated Infections by Contact Transmission

OBJECTIVE:

This article describes the role of the hospital environment in the spread of pathogens by direct and indirect contact. In addition, the prevention of transmission through interventions involving the built environment is discussed.

BACKGROUND:

The hospital environment can become contaminated with pathogenic microorganisms, some of which can persist for long periods of time. Although contamination is common, the contribution of the hospital environment to the development of healthcare-associated infections remains unclear. In part spurred by the development of newer technologies to enhance environmental cleaning or to prevent contamination, research into the role of the environment in causing healthcare-associated infections has accelerated.

TOPICAL HEADINGS:

A review of the recent literature finds an increasing body of evidence implicating contaminated surfaces in patient care areas in the transmission of pathogens and the development of infections. Single-patient rooms and optimally placed alcohol hand rub dispensers and other design features can mitigate infection risk. Enhanced environmental cleaning including touchless technologies and self-cleaning surfaces can reduce environmental contamination and may prevent infections.

CONCLUSIONS:

The hospital environment contributes to transmission of pathogens in hospitals and to the development of healthcare-associated infections. Newer technologies to prevent environmental contamination or to enhance cleaning are promising although additional studies with the endpoints of reduction of infections are needed before the role of these technologies is known.

The role of 'no-touch' automated room disinfection systems in infection prevention and control

BACKGROUND

Surface contamination in hospitals is involved in the transmission of pathogens in a proportion of healthcare-associated infections. Admission to a room previously occupied by a patient colonized or infected with certain nosocomial pathogens increases the risk of acquisition by subsequent occupants; thus, there is a need to improve terminal disinfection of these patient rooms. Conventional disinfection methods may be limited by reliance on the operator to ensure appropriate selection, formulation, distribution and contact time of the agent. These problems can be reduced by the use of 'no-touch' automated room disinfection (NTD) systems.

AIM

To summarize published data related to NTD systems.

METHODS

Pubmed searches for relevant articles.

FINDINGS

A number of NTD systems have emerged, which remove or reduce reliance on the operator to ensure distribution, contact time and process repeatability, and aim to improve the level of disinfection and thus mitigate the increased risk from the prior room occupant. Available NTD systems include hydrogen peroxide (H(2)O(2)) vapour systems, aerosolized hydrogen peroxide (aHP) and ultraviolet radiation. These systems have important differences in their active agent, delivery mechanism, efficacy, process time and ease of use. Typically, there is a trade-off between time and effectiveness among NTD systems. The choice of NTD system should be influenced by the intended application, the evidence base for effectiveness, practicalities of implementation and cost constraints.

CONCLUSION

NTD systems are gaining acceptance as a useful tool for infection prevention and control.

Comparison of the microbiological efficacy of hydrogen peroxide vapor and ultraviolet light processes for room decontamination

OBJECTIVE

To compare the microbiological efficacy of hydrogen peroxide vapor (HPV) and ultraviolet radiation (UVC) for room decontamination.

DESIGN

Prospective observational study.

SETTING

500-bed teaching hospital.

METHODS

HPV and UVC processes were performed in 15 patient rooms. Five high-touch sites were sampled before and after the processes and aerobic colony counts (ACCs) were determined. Carrier disks with ∼10(6) Clostridium difficile (CD) spores and biological indicators (BIs) with 10(4) and 10(6) Geobacillus stearothermophilus spores were placed in 5 sites before decontamination. After decontamination, CD log reductions were determined and BIs were recorded as growth or no growth.

RESULTS

93% of ACC samples that had growth before HPV did not have growth after HPV, whereas 52% of sites that had growth before UVC did not have growth after UVC (P < .0001). The mean CD log reduction was >6 for HPV and ∼2 for UVC. After HPV 100% of the 10(4) BIs did not grow, and 22% did not grow after UVC, with a range of 7%-53% for the 5 sites. For the 10(6) BIs, 99% did not grow after HPV and 0% did not grow after UVC. Sites out of direct line of sight were significantly more likely to show growth after UVC than after HPV. Mean cycle time was 153 (range, 140-177) min for HPV and 73 (range, 39-100) min for UVC (P < .0001).

CONCLUSION

Both HPV and UVC reduce bacterial contamination, including spores, in patient rooms, but HPV is significantly more effective. UVC is significantly less effective for sites that are out of direct line of sight.

Inactivation of stable viruses in cell culture facilities by peracetic acid fogging

Looking for a robust and simple method to replace formaldehyde fumigation for the disinfection of virus-handling laboratories and facilities, we tested peracetic acid fogging as a method to inactivate stable viruses under practical conditions. Peracetic acid/hydrogen peroxide (5.8%/27.5%, 2.0 mL/m³) was diluted in sufficient water to achieve ≥ 70% relative humidity and was vaporized as <10 μm droplets in a fully equipped 95 m³ laboratory unit. High titers of reovirus 3, MVM parvovirus and an avian polyomavirus were coated on frosted glass carriers and were exposed to the peracetic acid fog in various positions in the laboratory. After vaporization, a 60 min exposure time, and venting of the laboratory, no residual virus was detected on any of the carriers (detection limit <1 infectious unit/sample volume tested). The log reduction values were 9.0 for reovirus, 6.4 for MVM parvovirus, and 7.65 for the polyomavirus. After more than 10 disinfection runs within 12 months, no damage or functional impairment of electrical and electronic equipment was noted.