Decontamination devices in health care facilities: Practical issues and emerging applications

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.

Evaluation of a mobile disinfection cabinet using ultraviolet-C light and aerosolized hydrogen peroxide for disinfection of medical equipment

In laboratory testing, a mobile enclosed disinfection cabinet using ultraviolet-C light and aerosolized hydrogen peroxide was effective for disinfection of hard and soft surfaces. The addition of aerosolized hydrogen peroxide to ultraviolet-C light resulted in improved disinfection of soft surfaces and Clostridioides difficile spores.

Efficacy of a far-ultraviolet-C light technology for continuous decontamination of air and surfaces

A wall-mounted, far-ultraviolet-C light technology reduced aerosolized bacteriophage MS2 by >3 log10 plaque-forming units within 30 minutes. Vegetative bacterial pathogens on steel disk carriers in the center of the room were reduced by >3 log10 after 45 minutes of exposure, but Candida auris and Clostridioides difficile spores were not.

Update on potential interventions to reduce the risk for transmission of health care-associated pathogens from floors and sinks

Health care facility floors and sink drains and other wastewater drainage sites are universally contaminated with potential pathogens and there are plausible mechanisms by which organisms can be disseminated from these sites. However, floors and sink drains are not addressed as potential sources of pathogen transmission in most health care facilities. One factor that has hindered progress in addressing floors and sinks has been the lack of practical and effective measures to reduce the risk for dissemination of organisms from these sites. This article provides an update on some of the potential interventions being used to reduce the risk for transmission of health care-associated pathogens from floors and sinks. Practical approaches to address these sites of contamination are emphasized.

úNo touch..Ñ methods for health care room disinfection: Focus on clinical trials

BACKGROUND

Hospital patient room surfaces are frequently contaminated with multidrug-resistant organisms. Since studies have demonstrated that inadequate terminal room disinfection commonly occurs, ..úno touch..Ñ methods of terminal room disinfection have been developed such as ultraviolet light (UV) devices and hydrogen peroxide (HP) systems.

METHODS

This paper reviews published clinical trials of ..úno touch..Ñ methods and ..úself-disinfecting..Ñ surfaces.

RESULTS

Multiple papers were identified including clinical trials of UV room disinfection devices (N.ß=.ß20), HP room disinfection systems (N.ß=.ß8), handheld UV devices (N.ß=.ß1), and copper-impregnated or coated surfaces (N.ß=.ß5). Most but not all clinical trials of UV devices and HP systems for terminal disinfection demonstrated a reduction of colonization/infection in patients subsequently housed in the room. Copper-coated surfaces were the only ..úself-disinfecting..Ñ technology evaluated by clinical trials. Results of these clinical trials were mixed.

DISCUSSION

Almost all clinical trials reviewed used a ..úweak..Ñ design (eg, before-after) and failed to assess potential confounders (eg, compliance with hand hygiene and environmental cleaning).

CONCLUSIONS

The evidence is strong enough to recommend the use of a ..úno-touch..Ñ method as an adjunct for outbreak control, mitigation strategy for high-consequence pathogens (eg, Candida auris or Ebola), or when there are an excessive endemic rates of multidrug-resistant organisms.

A do-it-yourself test protocol using commercial Bacillus atrophaeus spores to evaluate the effectiveness of ultraviolet-C light room-decontamination devices

We developed a do-it-yourself test protocol using commercial Bacillus atrophaeus spores to assess the efficacy of ultraviolet-C (UV-C) light room-decontamination devices. Overall, 4 UV-C devices reduced B. atrophaeus by ≥3 log10 colony-forming units in 10 minutes, whereas a smaller device required 60 minutes. Of 10 in-use devices, only 1 was ineffective.

Rapid qualitative analysis in a mixed-methods evaluation of an infection prevention intervention in a UK hospital setting during the COVID-19 pandemic: A discussion of the CLEAN study methodology

The COVID-19 pandemic created an urgent need for high-quality rapid research. One clinical challenge was how to minimise the risk of transmission in the hospital setting. The CLEAN study conducted a rapid evaluation of the potential utility of a spray-based disinfectant in a hospital setting. The study was undertaken between December 2020 and March 2021 and involved the implementation of the spray in 10 different clinical areas in one UK teaching hospital. A mixed-methods approach was adopted (including observations, surveys, and qualitative interviews) informed by the theories for understanding the implementation of new healthcare technologies. The evaluation found that while the spray had a number of perceived benefits when added to existing disinfection processes, other factors limited its potential utility. These findings informed a number of recommendations for future adoption within hospital settings. This paper describes and reflects on the rapid methodology that allowed us to undertake the study and deliver results in a short space of time. We experienced a number of pressures during set-up and fieldwork due to the challenging conditions caused by the pandemic, and the methodological approach had to evolve throughout the study because of the changing clinical context. The involvement of clinicians from the research setting as full members of the research team was key to the rapid delivery of the research. They provided an essential link to the implementation environment, and their experiential knowledge of the setting added an important perspective to the analysis. Balancing their involvement with their clinical roles was challenging, however, as was coordinating a large and diverse team of interviewers in such a short space of time. Overall, the study highlighted the value of rapid research to inform urgent healthcare decisions in a pandemic. Although our experience suggests that conducting such research requires some practical and methodological trade-offs, we found that there were also numerous benefits of using rapid methods and identified various opportunities to ensure their robustness.

A randomized trial of ultraviolet-C (UV-C) light versus sodium hypochlorite delivered by an electrostatic sprayer for adjunctive decontamination of hospital rooms

In a randomized trial, adjunctive ultraviolet-C light treatment with a room decontamination device and sodium hypochlorite delivered via an electrostatic sprayer were similarly effective in significantly reducing residual healthcare-associated pathogen contamination on floors and high-touch surfaces after manual cleaning and disinfection. Less time until the room was ready to be occupied by another patient was required for electrostatic spraying.

Evaluation of UV-C Radiation Efficiency in the Decontamination of Inanimate Surfaces and Personal Protective Equipment Contaminated with Phage ϕ6

To help halt the global spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), appropriate disinfection techniques are required. Over the last years, the interest in Ultraviolet-C (UV-C) radiation as a method to disinfect inanimate surfaces and personal protective equipment (PPE) has increased, mainly to efficiently disinfect and prevent SARS-CoV-2 from spreading and allow for the safe reuse of said equipment. The bacteriophage ϕ6 (or simply phage ϕ6) is an RNA virus with a phospholipid envelope and is commonly used in environmental studies as a surrogate for human RNA-enveloped viruses, including SARS-CoV-2. The present study investigated the use of two new UV irradiation systems ((2)2.4W and (8)5.5W)) constituted by conventional mercury UV-C lamps with a strong emission peak at ~254 nm to potentially inactivate phage ϕ6 on different surfaces (glass, plastic, stainless steel, and wood) and personal protective equipment, PPE, (surgical and filtering facepiece 2, FFP2, masks, a clear acetate visor, and disposable protective clothing). The results showed that both UV-C systems were effective in inactivating phage ϕ6, but the UV-C sterilizing chamber (8)5.5W had the best disinfection performance on the tested surfaces. The inactivation effectiveness is material-dependent on all surfaces, reaching the detection limit of the method at different times (between 60 and 240 s of irradiation). The glass surface needed less time to reduce the virus (30 s) when compared with plastic, stainless, and wood surfaces (60 s). The virus inactivation was more effective in the disposable surgical and FFP2 masks (60 and 120 s, respectively) than in the disposable vest and clear acetate visor (240 s). Overall, this study suggests that UV-C lamps with peak emission at ~254 nm could provide rapid, efficient, and sustainable sanitization procedures to different materials and surfaces. However, dosage and irradiation time are important parameters to be considered during their implementation as a tool in the fight against human coronaviruses, namely against SARS-CoV-2.

A systematic review and meta-analysis of decontamination methods to prevent hospital environmental contamination and transmission of Clostridioidesdifficile

The current guidelines suggest that hospital rooms previously occupied with Clostridioides difficile infection (CDI) patients should be decontaminated with recommended decontamination methods because C. difficile can persist on surfaces despite adherence to the recommended procedures. Recently, ultraviolet (UV) light and hydrogen peroxide have increasingly been used as innovative decontamination methods. Hence, we conducted a systematic review and meta-analysis to investigate which decontamination methods are effective in reducing environmental C. difficile contamination. We systematically searched the EMBASE, PubMed, CINAHL, Scopus, and Ichushi until March 11, 2021. We evaluated the efficacy of decontamination methods in terms of the frequency of C. difficile contamination on high-touch surfaces in hospital rooms and the incidence of hospital-acquired C. difficile infection. Among the 15 studies retrieved in our meta-analysis, eight evaluated decontamination methods with the frequency of C. difficile detection among samples after disinfection procedures, and eight reported the number of hospital-acquired CDI cases. Pooled analysis indicated that hydrogen peroxide significantly reduced the frequency of environmental C. difficile contamination, compared with hypochlorite (odds ratios [OR]: 0.12; 95% confidence interval [CI]: 0.07-0.23). Additionally, hydrogen peroxide reduced the incidence of hospital-acquired CDI compared to other methods (OR: 0.52; 95% CI: 0.28-0.96). Decontamination with UV significantly reduced the incidence of hospital-acquired CDI compared to hypochlorite (OR 0.52, 95% CI 0.28-0.96). The use of hydrogen peroxide and UV can help prevent environmental C. difficile contamination and transmission in healthcare facilities.

Capturing portable medical equipment disinfection data via an automated novel disinfection tracking system

BACKGROUND

Portable Medical Equipment (PME) such as workstations-on-wheels (WOWs) and vital signs machines (VMs) have been linked to healthcare-associated infections. Routine visual monitoring of PME disinfection is difficult. An automated Disinfection Tracking System (DTS) was used to record and report the number of disinfection events of PME in a hospital setting.

METHODS

The study was conducted in 2 acute-care units for 25-days to determine the pattern of recorded events from DTS on PME. Devices record disinfection events as moisture events and automatically store on a central database. DTS devices with "screen-on" feedback and "screen-off" devices with no display were placed on 10 WOWs and 5 VMs on separate units.

RESULTS

A total of 421 moisture events were recorded for the "screen-on" and 345 for the "screen-off", during the 25-day implementation period on the 2 different hospital units. The highest number of events occurred between 6:00am-7:00am, with 69 & 75 moisture events recorded for Units 1 and 2, respectively.

CONCLUSIONS

The pattern of disinfection events for WOWs and VMs demonstrated that most events occurred regularly at the times corresponding with nursing shift change. The DTS has the potential to continuously record, and report data related to PME disinfection.

Efficacy of relatively low-cost ultraviolet-C light devices against Candida auris

BACKGROUND

Ultraviolet-C (UV-C) light devices could be useful to reduce environmental contamination with Candida auris. However, variable susceptibility of C. auris strains to UV-C has been reported, and the high cost of many devices limits their use in resource-limited settings.

OBJECTIVE

To evaluate the efficacy of relatively low-cost (<$15,000 purchase price) UV-C devices against C. auris strains from the 4 major phylogenetic clades.

METHODS

A modification of the American Society for Testing and Materials (ASTM) standard quantitative disk carrier test method (ASTM E 2197) was used to examine and compare the effectiveness of UV-C devices against C. auris, methicillin-resistant Staphylococcus aureus (MRSA), and bacteriophage Phi6. Reductions of 3 log10 were considered effective. UV-C irradiance measurements and colorimetric indicators were used to assess UV-C output.

RESULTS

Of 8 relatively low-cost UV-C devices, 6 met the criteria for effective decontamination of C. auris isolates from clades I and II, MRSA, and bacteriophage Phi6, including 3 room decontamination devices and 3 UV-C box devices. Candida auris isolates from clades III and IV were less susceptible to UV-C than clade I and II isolates; 1 relatively low-cost room decontamination device and 2 enclosed box devices met the criteria for effective decontamination of clade III and IV isolates. UV-C irradiance measurements and colorimetric indicator results were consistent with microorganism reductions.

CONCLUSIONS

Some relatively low-cost UV-C light technologies are effective against C. auris, including isolates from clades III and IV with reduced UV-C susceptibility. Studies are needed to evaluate the effectiveness of UV-C devices in clinical settings.

Numerical and experimental analyses for the improvement of surface instant decontamination technology through biocidal agent dispersion: Potential of application during pandemic

The transmission of SARS-CoV-2 through contact with contaminated surfaces or objects is an important form of transmissibility. Thus, in this study, we evaluated the performance of a disinfection chamber designed for instantaneous dispersion of the biocidal agent solution, in order to characterize a new device that can be used to protect individuals by reducing the transmissibility of the disease through contaminated surfaces. We proposed the necessary adjustments in the configuration to improve the dispersion on surfaces and the effectiveness of the developed equipment. Computational Fluid Dynamics (CFD) simulations of the present technology with a chamber having six nebulizer nozzles were performed and validated through qualitative and quantitative comparisons, and experimental tests were conducted using the method Water-Sensitive Paper (WSP), with an exposure to the biocidal agent for 10 and 30 s. After evaluation, a new passage procedure for the chamber with six nozzles and a new configuration of the disinfection chamber were proposed. In the chamber with six nozzles, a deficiency was identified in its central region, where the suspended droplet concentration was close to zero. However, with the new passage procedure, there was a significant increase in wettability of the surface. With the proposition of the chamber with 12 nozzles, the suspended droplet concentration in different regions increased, with an average increase of 266%. The experimental results of the new configuration proved that there was an increase in wettability at all times of exposure, and it was more significant for an exposure of 30 s. Additionally, even in different passage procedures, there were no significant differences in the results for an exposure of 10 s, thereby showing the effectiveness of the new configuration or improved spraying and wettability by the biocidal agent, as well as in minimizing the impact caused by human factor in the performance of the disinfection technology.

Toward a Test Protocol for Surface Decontamination Using a Mobile Whole-room UVGI Device†

Mobile whole‐room UVGI devices are used in healthcare settings to control surface‐borne pathogens. Unfortunately, no standard method comparing the efficacy of these devices is available. We accessed the effect of shadows on UVC 254 nm inactivation. The evaluation of a mobile whole‐room UVGI device used spores of Bacillus atrophaeus as a surrogate for Clostridium difficile and Staphylococcus aureus as a surrogate for MSRA. Inactivation after 10 min of exposure varied significantly depending on whether the spores received direct UV exposure (4.3 log reduction), both direct and reflected UV exposure (3.0–4.0 log reduction) or reflected UV exposure alone (<1.0 log reduction). The susceptibility (z‐value) for inactivation of B. atrophaeus spores on a glass surface was estimated to be 0.00312 m² J⁻¹. Staphylococcus aureus microbial log reductions were approximately 5.5 for direct UV exposure, 3.6–5.2 for both direct and reflected UV exposure and approximately 2.75 for only reflected UV exposure. Our measurement of reflected dose ranged from 0.46% to 1.47%. Based on our findings, B. atrophaeus spores should be considered as a model organism for testing the impact of shadows on mobile whole‐room UVGI device inactivation. Optimizing the reflected component of whole‐room UVGI is important, especially for UVC‐resistant organisms.

Ultraviolet-C (UV-C) monitoring made simple: Colorimetric indicators to assess delivery of UV-C light by room decontamination devices

OBJECTIVE

To evaluate the use of colorimetric indicators for monitoring ultraviolet-C (UV-C) light delivery to sites in patient rooms.

METHODS

In laboratory testing, we examined the correlation between changes in color of 2 commercial colorimetric indicators and log10 reductions in methicillin-resistant Staphylococcus aureus (MRSA) and Clostridioides difficile spores with exposure to increasing doses of UV-C from a low-pressure mercury room decontamination device. In patient rooms, 1 of the colorimetric indicators was used to assess UV-C dose delivery to 27 sites in the room.

RESULTS

In laboratory testing, the manufacturer's reference colors for MRSA and C. difficile reduction corresponded with doses of ∼10,000 and 46,000 µJ/cm2; these doses resulted in >3 log10 reductions in MRSA and C. difficile spores, respectively. In patient rooms, the colorimetric indicators demonstrated suboptimal delivery of UV-C dosing to shadowed areas, which was improved by providing cycles on each side of the patient bed rather than in a single position and altering device placement. Increasing duration of exposure increased the number of sites achieving adequate dosing to kill C. difficile spores.

CONCLUSIONS

Commercial colorimetric indicators provide rapid and easy-to-interpret information on the UV-C dose delivered to sites in patient rooms. The indicators may be useful for training environmental services personnel and optimizing the effectiveness of UV-C room decontamination devices.

Technological Advances in Ozone and Ozonized Water Spray Disinfection Devices

To control infectious diseases such as the severe acute respiratory syndrome coronavirus (Covid-19) that caused the current pandemic, disinfection measures are essential. Among building measures, disinfection chambers can help to decrease the transmission rate through the sanitizing capacity of the disinfectant used, which can thereby clean surfaces or humans. Out of existing biocides, ozone is considered one of the safest for humans, but one of the most powerful oxidizers, making the substance a better alternative as the biocidal solution in disinfection chambers. Analyses were carried out by using all patented documents related to disinfection chambers that used ozone as a disinfectant. A Derwent Innovation Index (DII) database search was undertaken to find these patents. Patent prospecting resulted in 620 patent documents that were divided into 134 patent families. There was no technology related to protective barriers for individuals, and the majority of patents in the retrieved data aimed at sterilizing medical devices and surfaces. Given that the specific Cooperative Patent Classification (CPC) code for ozone dissolved in liquid was used in the methodology search, but not included among the 10 most used codes in the patents, the use of ozonized water may be an innovative approach in the technology landscape of sterilization chambers.

Systematic review on use, cost and clinical efficacy of automated decontamination devices

BACKGROUND

More evidence is emerging on the role of surface decontamination for reducing hospital-acquired infection (HAI). Timely and adequate removal of environmental pathogens leads to measurable clinical benefit in both routine and outbreak situations.

OBJECTIVES

This systematic review aimed to evaluate published studies describing the effect of automated technologies delivering hydrogen peroxide (H202) or ultra-violet (UV) light on HAI rates.

METHODS

A systematic review was performed using relevant search terms. Databases were scanned from January 2005 to March 2020 for studies reporting clinical outcome after use of automated devices on healthcare surfaces. Information collected included device type, overall findings; hospital and ward data; study location, length and size; antimicrobial consumption; domestic monitoring; and infection control interventions. Study sponsorship and duplicate publications were also noted.

RESULTS

While there are clear benefits from non-touch devices in vitro, we found insufficient objective assessment of patient outcome due to the before-and-after nature of 36 of 43 (84%) studies. Of 43 studies, 20 (47%) used hydrogen peroxide (14 for outbreaks) and 23 (53%) used UV technology (none for outbreaks). The most popular pathogen targeted, either alone or in combination with others, was Clostridium difficile (27 of 43 studies: 63%), followed by methicillin-resistant Staphylococcus aureus (MRSA) (16 of 43: 37%). Many owed funding and/or personnel to industry sponsorship (28 of 43: 65%) and most were confounded by concurrent infection control, antimicrobial stewardship and/or cleaning audit initiatives. Few contained data on device costs and rarely on comparable costs (1 of 43: 2%). There were expected relationships between the country hosting the study and location of device companies. None mentioned the potential for environmental damage, including effects on microbial survivors.

CONCLUSION

There were mixed results for patient benefit from this review of automated devices using H202 or UV for surface decontamination. Most non-outbreak studies lacked an appropriate control group and were potentially compromised by industry sponsorship. Concern over HAI encourages delivery of powerful disinfectants for eliminating pathogens without appreciating toxicity or cost benefit. Routine use of these devices requires justification from standardized and controlled studies to understand how best to manage contaminated healthcare environments.

Classical and alternative disinfection strategies to control the COVID-19 virus in healthcare facilities: a review

The coronavirus disease COVID-19 has spread throughout the world and has been declared as a pandemic by the World Health Organization on March 11th, 2020. The COVID-19 is caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). One possible mode of virus transmission is through surfaces in the healthcare settings. This paper reviews currently used disinfection strategies to control SARS-CoV-2 at the healthcare facilities. Chemical disinfectants include hypochlorite, peroxymonosulfate, alcohols, quaternary ammonium compounds, and hydrogen peroxide. Advanced strategies include no-touch techniques such as engineered antimicrobial surfaces and automated room disinfection systems using hydrogen peroxide vapor or ultraviolet light.

Evaluation of No-Touch Technologies for Decontamination of Toys in Pediatric Healthcare Settings

No-touch technologies could be useful to decontaminate shared toys in healthcare settings. A high-level disinfection cabinet and electrostatic sprayer were effective against methicillin-resistant Staphylococcus aureus (MRSA), bacteriophage MS2, and Clostridioides difficile spores on toys. An ultraviolet-C light box was less effective but reduced MRSA and bacteriophage MS2 by >2 log₁₀.

Effectiveness of pulsed xenon ultraviolet disinfection for Clostridioides (Clostridium) difficile surface contamination in a Japanese hospital

BACKGROUND

Contaminated environmental surfaces are important sources of transmission for healthcare-associated pathogens, including Clostridioides (Clostridium) difficile. The effectiveness of manual bleach cleaning and pulsed xenon ultraviolet (PX-UV) disinfection on C. difficile contamination of hospital room high-touch surfaces in Japan was evaluated.

METHODS

The environmental surfaces of 20 C. difficile infection (CDI) isolation rooms were sampled immediately after CDI patients were discharged or transferred. High-touch surfaces were sampled before and after either bleach cleaning or PX-UV disinfection in addition to nonbleach cleaning. Changes in the number of C. difficile-positive samples and bacterial counts for each cleaning method were assessed.

RESULTS

Overall, 286 samples were collected (bleach cleaning, 144 samples; PX-UV disinfection, 142 samples). Before cleaning, the positive rates of C. difficile were 27.8% and 31.0% in bleach cleaning and PX-UV disinfection, respectively. Both bleach cleaning and PX-UV disinfection significantly reduced overall C. difficile-positive samples (P = .018 and P = .002, respectively) and C. difficile colony-forming unit counts (P = .002 and P = .001, respectively).

CONCLUSIONS

PX-UV disinfection in addition to manual nonbleach cleaning effectively reduces C. difficile contamination from high-touch surfaces. Further studies are warranted to evaluate the effect of PX-UV disinfection on CDI rates in Japanese hospitals.

Evaluation of a portable Ultraviolet C (UV-C) device for hospital surface decontamination

Background

Surface decontamination of hospital environments is essential to ensure the safety of health professionals and patients. This process is usually performed through active chemicals substances with high toxicity, and new decontamination technologies that do not leave residues have been currently used, such as UV-C light. Thus, the objective of the present study is to evaluate the effectiveness of a portable UV-C light device on the viability of standard pathogenic strains and other microorganisms isolated from different surfaces of a public health hospital.

Methods

In vitro decontamination was performed by applying Biosept Home© UV-C to Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica and Candida albicans. In real conditions, the application was made on different surfaces of a hospital. The device used in the experiment haa a 254 nm UV-C light and a radiation intensity of 45.6 mW/cm² over a distance of 1 cm from the surfaces. The light dose was 0.912 J/cm² for 20 s of application in both conditions (in vitro and hospital).

Results

After in vitro decontamination with UV-C light no bacterial growth was observed, demonstrating 100 % of bacterial inactivation under the conditions tested. Additionally, there was a reduction of approximately 4 logs for the yeast C. albicans. In all hospital surfaces, the number of colonies of microorganisms was significantly reduced after the procedure.

Conclusion

The results suggest that Biosept Home© UV-C is efficient and constitutes a promosing intervention for disinfection protocols in hospitals and clinics.

No-Touch Automated Room Disinfection after Autopsies of Exhumed Corpses

Autopsies of exhumed bodies pose a risk of infections with environmental bacteria or fungi, which may be life-threatening. Thus, it is important to use effective methods of disinfection in forensic pathology facilities. In this study, we investigated the effectiveness of no-touch automated disinfection (NTD) system after autopsies of exhumed bodies. Directly after 11 autopsies of exhumed bodies, we used an NTD system based on a peroxone vapor to disinfect the air and surfaces. We measured microbial burden in the air and on surfaces before and after NTD. The NTD system reduced the mean bacterial burden in the air from 171 colony forming units (CFU)/m³ to 3CFU/m³. The mean fungal burden in the air decreased from 221 CFU/m³ to 9CFU/m³. The mean all-surface microbial burden was 79 CFU/100 cm² after all autopsies, and it decreased to 2 CFU/100 cm² after NTD. In conclusion, the peroxone-based NTD system was effective for decontamination of the air and surfaces in a dissecting room after autopsies of exhumed bodies.

Evaluation of an electrostatic spray disinfectant technology for rapid decontamination of portable equipment and large open areas in the era of SARS-CoV-2

In the setting of the coronavirus disease 2019 pandemic, efficient methods are needed to decontaminate shared portable devices and large open areas such as waiting rooms. We found that wheelchairs, portable equipment, and waiting room chairs were frequently contaminated with potential pathogens. After minimal manual precleaning of areas with visible soiling, application of a dilute sodium hypochlorite disinfectant using an electrostatic sprayer provided rapid and effective decontamination and eliminated the benign virus bacteriophage MS2 from inoculated surfaces.

Evaluation of Ultraviolet-C Light for Rapid Decontamination of Airport Security Bins in the Era of SARS-CoV-2

Background:

Contaminated surfaces are a potential source for spread of respiratory viruses including SARS-CoV-2. Ultraviolet-C (UV-C) light is effective against RNA and DNA viruses and could be useful for decontamination of high-touch fomites that are shared by multiple users.

Methods:

A modification of the American Society for Testing and Materials standard quantitative carrier disk test method (ASTM E-2197-11) was used to examine the effectiveness of UV-C light for rapid decontamination of plastic airport security bins inoculated at 3 sites with methicillin-resistant Staphylococcus aureus (MRSA) and bacteriophages MS2, PhiX174, and Phi6, an enveloped RNA virus used as a surrogate for coronaviruses. Reductions of 3 log₁₀ on inoculated plastic bins were considered effective for decontamination.

Results:

UV-C light administered as 10-, 20-, or 30-second cycles in proximity to a plastic bin reduced contamination on each of the test sites, including vertical and horizontal surfaces. The 30-second cycle met criteria for decontamination of all 3 test sites for all the test organisms except bacteriophage MS2 which was reduced by greater than 2 log₁₀ PFU at each site.

Conclusions:

UV-C light is an attractive technology for rapid decontamination of airport security bins. Further work is needed to evaluate the utility of UV-C light in real-world settings and to develop methods to provide automated movement of bins through a UV-C decontamination process.

Effectiveness of Ultraviolet-C Light and a High-Level Disinfection Cabinet for Decontamination of N95 Respirators

BACKGROUND

Shortages of personal protective equipment (PPE) including N95 respirators are an urgent concern in the setting of the global COVID-19 pandemic. Decontamination of PPE could be useful to maintain adequate supplies, but there is uncertainty regarding the efficacy of decontamination technologies.

METHODS

A modification of the American Society for Testing and Materials standard quantitative carrier disk test method (ASTM E-2197-11) was used to examine the effectiveness of 3 methods, including ultraviolet-C (UV-C) light, a high-level disinfection cabinet that generates aerosolized peracetic acid and hydrogen peroxide, and dry heat at 70°C for 30 minutes. We assessed the decontamination of 3 commercial N95 respirators inoculated with methicillin-resistant Staphylococcus aureus (MRSA) and bacteriophages MS2 and Phi6; the latter is an enveloped RNA virus used as a surrogate for coronaviruses. Three and 6 log10 reductions on respirators were considered effective for decontamination and disinfection, respectively.

RESULTS

UV-C administered as a 1-minute cycle in a UV-C box or a 30-minute cycle by a room decontamination device reduced contamination but did not meet criteria for decontamination of the viruses from all sites on the N95s. The high-level disinfection cabinet was effective for decontamination of the N95s and achieved disinfection with an extended 31-minute cycle. Dry heat at 70°C for 30 minutes was not effective for decontamination of the bacteriophages.

CONCLUSIONS

UV-C could be useful to reduce contamination on N95 respirators. However, the UV-C technologies studied did not meet pre-established criteria for decontamination under the test conditions used. The high-level disinfection cabinet was more effective and met criteria for disinfection with an extended cycle.

Efficacy of an ultraviolet-A lighting system for continuous decontamination of health care-associated pathogens on surfaces

We found that ultraviolet-A (UV-A) light exposure resulted in a modest reduction in recovery of methicillin-resistant Staphylococcus aureus (MRSA), Candida auris, bacteriophage MS2, and bacteriophage Phi X174, but not Clostridioides difficile spores, on steel disk carriers. Four hours of UV-A exposure from a ceiling light fixture resulted in a significant reduction in pathogenic microorganisms recovered from in-use medical equipment. These findings suggest that UV-A could be useful as a means to provide continuous low-level decontamination of surfaces in health care facilities.

Comparative evaluation of operating room terminal cleaning by two methods: Focused multivector ultraviolet (FMUV) versus manual-chemical disinfection

BACKGROUND

This non-randomized comparative observational study evaluated the performance of a standard manual-chemical disinfection process with an automated process employing focused multivector ultraviolet (FMUV) light technology during operating room (OR) terminal cleaning.

METHODS

An Association of periOperative Registered Nurses terminal cleaning protocol was modified to incorporate the use of automated FMUV technology that allows workers to occupy the room during operation. This modified protocol was compared with a standard manual-chemical cleaning and disinfection protocol. Equipment surfaces were pre-sampled before and after terminal cleaning. A total of 165 objects were sampled in each process using a 5-point multisided sampling method.

RESULTS

The parallel process employing FMUV reduced the active microbial burden by 96.5% from baseline (P < .0001), which was over 2.5 times better than the standard process. The standard terminal manual-chemical disinfection process reduced the active microbial burden on sampled objects by 38.4% from baseline (P < .0001).

CONCLUSIONS

The data demonstrates that the performance of standard manual-chemical disinfection alone is variable in a live clinical setting even under the most ideal conditions. By comparison, automated FMUV treatment incorporated in a parallel process consistently produced thorough and significant reductions of microbial contamination levels on all visibly clean patient care equipment.