Room Decontamination Research Articles

Development and Validation of a Customized Amplex UltraRed Assay for Sensitive Hydrogen Peroxide Detection in Pharmaceutical Water.

For clean-room technologies such as isolators and restricted access barrier systems (RABS), decontamination using hydrogen peroxide (H2O2) is increasingly attractive to fulfill regulatory requirements. Several approaches are currently used, ranging from manual wipe disinfection to vapor phase hydrogen peroxide (VPHP) or automated nebulization sanitization. Although the residual airborne H2O2 concentration can be easily monitored, detection of trace H2O2 residues in filled products is rather challenging. To simulate the filling process in a specific clean room, technical runs with water for injection (WfI) are popular. Thus, the ability to detect traces of H2O2 in water is an important prerequisite to ensure a safe and reliable use of H2O2 for isolator or clean room decontamination. The objective of this study was to provide a validated quantitative, fluorometric Amplex UltraRed assay, which satisfies the analytical target profile of quantifying H2O2 in WfI at low nanomolar to low micromolar concentrations (ppb range) with high accuracy and high precision. The Amplex UltraRed technology provides a solid basis for this purpose; however, no commercial assay kit that fulfills these requirements is available. Therefore, a customized Amplex UltraRed assay was developed, optimized, and validated. This approach resulted in an assay that is capable of quantifying H2O2 in WfI selectively, sensitively, accurately, precisely, and robustly. This assay is used in process development and qualification approaches using WfI in H2O2-decontaminated clean rooms and isolators.

Importance of carbapenem-resistant Enterobacteriaceae screening to prevent transmission within an acute-care hospital

Background: Carbapenem-resistant Enterobacteriaceae (CRE) present a serious public health risk because they are transmissible within the acute-care hospital setting, and they are associated with significant morbidity and mortality. Timely identification of CRE among hospitalized patients is essential to ensure that appropriate infection prevention measures are enforced to prevent transmission events. In 2022, 9 index CRE cases (5 Klebsiella pneumoniae carbapenemase (KPC)–producing and 4 New Delhi Metallo-β-lactamase (NDM)–producing cases) were identified within the University of Colorado Hospital (UCH) inpatient population. In response to index case identification, tracing was performed to identify patients with an epidemiologic link for targeted CRE screening to detect asymptomatic CRE carriage. Methods: In total, 645 patients were screened allowing for timely identification of CRE colonization within 6 patients (3-KPC; 1-OXA-48; 1-NDM; 1-KPC/OXA-48). Secondary case identification elicited additional evaluation of service team and mobile-device crossover between positive patients, as well as primary and ancillary treatment locations. Results: Investigations revealed 3 possible transmission events in 0.47% of the total screened population. Identification of secondary CRE cases prompted additional testing of exposed patients performed at 7-day intervals to capture a 21-day colonization period. In total, 95 additional patients were screened for CRE during secondary and tertiary CRE screening events. Discussion: Nursing staff collaboration and engagement were critical to achieving a high rate of compliance with CRE screening activities, not only collecting screening specimens but also providing explanation and reassurance to patients. Due to this partnership and diligence, UCH was able to achieve 77% compliance with initial CRE screening events. Secondary and tertiary CRE screening revealed testing compliance of 83% and 69%, respectively. To further reduce the risk of CRE transmission within hospitalized patients, UCH has implemented an enhanced cleaning process for high-risk patient rooms, which includes patients infected or asymptomatically colonized with CRE. This enhanced process is prompted based on CRE or infection status as documented in the electronic medical record (EMR), and it initiates a mandatory 2-phase cleaning process. Future plans include environmental testing audits to validate room decontamination and leveraging the EMR to capture pertinent healthcare and travel histories. Active engagement with public health partners will be pursued to enable molecular testing of high-risk touch points. Conclusions: Patient screening, enhanced decontamination, and monitoring activities are key elements to effectively prevent the spread of CRE within vulnerable patient populations and must be continuously evaluated for improvement opportunities.Disclosures: None

The impact of single-use digital flexible cystoscope for double J removal on hospital costs and work organization: A multicentric evaluation.

Isiris-α® is a single-use digital flexible cystoscope with an integrated grasper designed for double J (DJ) stent removal. Aim of this study was to conduct a multicentric evaluation of the costs and criticalities of stent removals performed with Isiris®-α in different hospitals and health systems, as compared to other DJ removal procedures. After gathering 10 institutions worldwide with experience on Isiris-α®, we performed an analysis of the reported costs of DJ removal with Isiris-α®, as compared to the traditional reusable equipment used in each institution. The cost evaluation included instrument purchase, Endoscopic Room (EnR)/ Operatory Room (OR) occupancy, medical staff, instrument disposal, maintenance, repairs, decontamination or sterilization of reusable devices. The main factor affecting the costs of the procedure was OR/EnR occupancy. Decontamination and sterilization accounted for a less important part of total costs. Isiris-α® was more profitable in institutions where DJ removal is usually performed in the EnR/OR, allowing to transfer the procedure to outpatient clinic, with a significant cost saving and EnR/OR time saving to be allocated to other activities. In the only institution where DJ removal was already performed in outpatient clinics, there is a slight cost difference in favor of reusable instruments in high-volume institutions, given a sufficient number to guarantee the turnover. Isiris-α® leads to significant cost benefit in the institutions where DJ removal is routinely performed in EnR/OR, and brings significant improvement in organization, cost impact and turnover.

Finding the best hardware configuration for 2D SLAM in indoor environments via simulation based on Google Cartographer

One of the most challenging topics in robotics is simultaneous localization and mapping (SLAM) in the indoor environments. Due to the fact that Global Navigation Satellite Systems cannot be successfully used in such environments, different data sources are used for this purpose, among others light detection and ranging (LiDARs ), which have advanced from numerous other technologies. Other embedded sensors can be used along with LiDARs to improve SLAM accuracy, e.g. the ones available in the Inertial Measurement Units and wheel odometry sensors. Evaluation of different SLAM algorithms and possible hardware configurations in real environments is time consuming and expensive. In our study, we evaluate the accuracy of mapping and localization (based on Absolute Trajectory Error and Relative Pose Error). Our use case is a robot used for room decontamination. The results for a small room show that for our robot the best hardware configuration consists of three LiDARs 2D, IMU and wheel odometry sensors. On the other hand, for long hallways, a configuration with one LiDAR 3D sensor and IMU works better and more stable. We also described a general approach together with tools and procedures that can be used to find the best sensor setup in simulation.

Computational and experimental studies into the hydrodynamic operation conditions of container filters for ion-selective treatment

Formation of radioactive waste (RW) is specific to the NPP operation. Liquid radioactive waste (LRW) forms in the process of the reactor plant operation, and in decontamination of equipment, rooms and overalls. The radionuclides found mostly in vat residues are 134, 137 Cs in the form of ions and 60Co and 54Mn isotopes in the form of chelates including substances used for equipment decontamination. Among the well-known conditioning techniques, selective sorption provides for the greatest reduction of LRW amounts. The efficiency of using the amount of the filter material can be increased by supplying the treated medium simultaneously to several sorbent layers. The paper presents computer simulation results for three proposed options of improved container filter designs for ion-selective treatment differing in the ways used both to separate the treated water flows and to deliver these to the sorbent layers. The improved efficiency of the sorption processes in the proposed designs was estimated using computer simulation in SolidWorks Flow Simulation. Three sorbent grades from NPP Eksorb were used for the study. A series of experimental studies of the flow through the sorbent layer was undertaken to determine the hydraulic resistance of the studied samples. The obtained experimental data was added to the Solidworks Flow Simulation engineering database for simulation of the earlier presented designs. Representative parameters of the flow inside of container filters were obtained as a result of the simulation.

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.

Automated room decontamination: report of a Healthcare Infection Society Working Party

This report provides advice to hospital managers, hospital-based service providers, infection prevention and control (IPC) teams and end users who intend to employ automated room decontamination devices as part of their IPC regimens. Conventional cleaning and disinfection approaches are long established and can be very effective if thorough, but recently automated systems have become available that offer the effectiveness and safety to supplement manual methods. Some chemicals such as formaldehyde have had a place within the contained laboratory setting for many years but are too toxic for use in patient areas.

Dry-fog disinfection as an alternative method for room decontamination

Abstract Due to the fact that a relatively large area can be disinfected in a short time, dry-fog disinfection could have a great potential to improve hygienic measures. However, there are few studies to date on the effectiveness and combinability of this technology with other devices. In this work, the disinfecting potential of the TBT dry fogging technology (TBT Desinfektion GmbH & Co. KG, Germany) and the corresponding disinfectant Defeat AR (Biofluid GmbH, Germany) was examined with regard to microbiological decontamination and potential damaging effects on different devices. The airburden measurement did show a reduction of approx. 66% of the microbiological room contamination. Similarly, decontamination of test surfaces was shown to be effective at all measuring points we selected in the experimental setup. Depending on the accessibility of the surfaces this effect was in the range of several log levels. Nevertheless, a first test run showed that some technical equipment was negatively affected by the process.

Wireless, Accumulation Mode Dosimeters for Monitoring Pulsed and Non-Pulsed Germicidal Lamps

Mitigating the spread of infectious diseases such as the one associated with the COVID-19 pandemic demands simple and effective disinfection techniques. Ultraviolet germicidal irradiation (UVGI) is one such method, in common use for decontamination of hospital rooms. Practical technologies designed to monitor UVGI ensure the delivery of sufficient doses for germicidal efficacy. Existing UVGI dosimeters rely on intermittent measurements of intensity as the basis for a numerical integration scheme that approximates dose. Traditional devices are ineffective, particularly with pulsed UVGI lamps that emit pulses of light with durations shorter than the interval of measurement. Here, we present a compact, accumulation mode dosimeter (AMD) that detects continuously, as opposed to intermittently, at single or multiple UVGI wavelengths. The AMD utilizes an array of photodiodes and supercapacitors to passively transduce and capture photocurrent generated by UVGI without the use of external power. The accumulated voltage across the supercapacitors then serves as a measure of UVGI dose. A key result is that sampling intervals of AMD do not constrain measurement accuracy. When implemented with a wireless transponder, AMD supports a light-adaptive sampling scheme designed to adjust the sampling interval to the intensity and period of UVGI exposure. Compared to time-based sampling schemes adopted by conventional sensors, light-adaptive approaches autonomously optimize battery life by minimizing current consumption during periods of low or no UVGI. Benchtop studies of the use of this technology with pulsed Xenon lamps (pulse ~5 ms) sampled at long intervals (>1s) highlight the key features of operation. Demonstration of AMD during UVGI of E. Coli cultures represents an example in dose dependent effects on disinfection.

Inactivation of Candida auris and Candida albicans by ultraviolet-C

We evaluated the ability of an ultraviolet-C (UV-C) room decontamination device to kill Candida auris and C. albicans. With an organic challenge (fetal calf serum), the UV-C device demonstrated the following log10 reductions for C. auris of 4.57 and for C. albicans of 5.26 with direct line of sight, and log10 reductions for C. auris of 2.41 and for C. ablicans of 3.96 with indirect line of sight.

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

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. 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. 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. 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. 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.

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

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

An automated room disinfection system using ozone is highly active against surrogates for SARS-CoV-2

BackgroundThe presence of coronaviruses on surfaces in the patient environment is a potential source of indirect transmission. Manual cleaning and disinfection measures do not always achieve sufficient removal of surface contamination. This increases the importance of automated solutions in the context of final disinfection of rooms in the hospital setting. Ozone is a highly effective disinfectant which, combined with high humidity, is an effective agent against respiratory viruses. Current devices allow continuous nebulization for high room humidity as well as ozone production without any consumables.AimIn the following study, the effectiveness of a fully automatic room decontamination system based on ozone was tested against bacteriophage Φ6 (phi 6) and bovine coronavirus L9, as surrogate viruses for the pandemic coronavirus SARS-CoV-2.MethodsFor this purpose, various surfaces (ceramic tile, stainless steel surface and furniture board) were soiled with the surrogate viruses and placed at two different levels in a gas-tight test room. After using the automatic decontamination device according to the manufacturer's instructions, the surrogate viruses were recovered from the surfaces and examined by quantitative cultures. Then, reduction factors were calculated.FindingsThe ozone-based room decontamination device achieved virucidal efficacy (reduction factor >4 log10) against both surrogate organisms regardless of the different surfaces and positions confirming a high activity under the used conditions.ConclusionOzone is highly active against SARS-CoV-2 surrogate organisms. Further investigations are necessary for a safe application and efficacy in practice as well as integration into routine processes.

Evaluation of the Effectiveness of Two Automated Room Decontamination Devices Under Real-Life Conditions.

To evaluate the effectiveness of automated room decontamination devices, a common aerosolized hydrogen peroxide (aHP) as well as a recent gaseous ozone-based device, which produces the disinfectant reagent without the need of consumables, were tested under real-life conditions. Twenty-two contaminated surfaces were positioned in different areas in a patient room with adjacent bathroom and anteroom. Following the decontamination process bacteria were recovered and reduction factors were calculated after performing quantitative culture. Following the manufactures instructions, the ozone-based device displayed a bactericidal effect (log10 > 5), whereas the aHP system failed for a high bacterial burden and achieves only a complete elimination of a realistic bioburden (log10 2). After increasing the exposure time to 30 min, the aHP device also reached a bactericidal effect. Nevertheless, our results indicate, that further research and development is necessary, to get knowledge about toxicity, efficacy and safety by using in complex hospital conditions and achieve meaningful integration in cleaning procedures, to reach positive effects on disinfection performance.

Adherence to recommendations for endoscopy practice during COVID-19 pandemic in Latin America: how are we doing it?

Background and aimsDigestive endoscopy is considered a high-risk procedure for COVID-19. Recommendations have been made for its practice during the pandemic. This study was conducted to determine adherence to recommendations...

Evaluation of Hydrogen Peroxide Fumigation and Heat Treatment for Standard Emergency Arthropod Inactivation in BSL-3 Insectaries.

Climate change and global movements of people and goods have accelerated the spread of invasive species, including insects that vector infectious diseases, which threaten the health of more than half of the world’s population. Increasing research efforts to control these diseases include the study of vector – pathogen interactions, involving the handling of pathogen-infected vector insects under biosafety level (BSL) 2 and 3 conditions. Like microbiology BSL-3 laboratories, BSL-3 insectaries are usually subjected to fixed-term or emergency room decontamination using recognized methods such as hydrogen peroxide (H2O2) or formaldehyde fumigation. While these procedures have been standardized and approved for the inactivation of diverse pathogens on surfaces, to date, there are no current standards for effective room-wide inactivation of insects in BSL-3 facilities in case of an emergency such as the accidental release of a large number of infected vectors. As H2O2 is often used for standard room decontamination in BSL-3 facilities, we evaluated H2O2 fumigation as a potential standard method for the safe, room-wide deactivation of insects in BSL-3 insectaries in comparison to heat treatment. To account for physiological diversity in vector insect species, six species from three different orders were tested. For the H2O2 fumigation we observed a strong but also varying resilience across all species. Lethal exposure time for the tested dipterans ranged from nine to more than 24 h. Furthermore, the coleopteran, Tribolium castaneum, did not respond to continuous H2O2 exposure for 48 h under standard room decontamination conditions. In contrast, temperatures of 50°C effectively killed all the tested species within 2 to 10 min. The response to lower temperatures (40–48°C) again showed a strong variation between species. In summary, results suggest that H2O2 fumigation, especially in cases where a gas generator is part of the laboratory equipment, may be used for the inactivation of selected species but is not suitable as a general emergency insect inactivation method under normal room decontamination conditions. In contrast, heat treatment at 48 to 50°C has the potential to be developed as an approved standard procedure for the effective inactivation of insects in BSL-3 facilities.

Inactivation of Candida auris and Candida albicans by Ultraviolet-C

Background:Candida auris is an emerging fungal pathogen that is often resistant to major classes of antifungal drugs. It is considered a serious global health threat because it has caused severe infections with frequent mortality in over a dozen countries. C. auris can survive on healthcare environmental surfaces for at least 7 days, and it causes outbreaks in healthcare facilities. C. auris has an environmental route of transmission. Thus, infection prevention strategies, such as surface disinfection and room decontamination technologies (eg, ultraviolet [UV-C] light), will be essential to controlling transmission. Unfortunately, data are limited regarding the activity of UV-C to inactivate this pathogen. In this study, a UV-C device was evaluated for its antimicrobial activity against C. auris and C. albicans. Methods: We tested the antifungal activity of a single UV-C device using the vegetative bacteria cycle, which delivers a reflected dose of 12,000 µW/cm2. This testing was performed using Formica sheets (7.6 × 7.6 cm; 3 × 3 inches). The carriers were inoculated with C. auris or C. albicans and placed horizontal on the surface or vertical (ie, perpendicular) to the vertical UV-C lamp and at a distance from 1. 2 m (~4 ft) to 2.4 m (~8 ft). Results: Direct UV-C, with or without FCS (log10 reduction 4.57 and 4.45, respectively), exhibited a higher log10 reduction than indirect UV-C for C. auris (log10 reduction 2.41 and 1.96, respectively), which was statistically significant (Fig. 1 and Table 1). For C. albicans, although direct UV-C had a higher log10 reduction (log10 reduction with and without FCS, 5.26 and 5.07, respectively) compared to indirect exposure (log10 reduction with and without FCS, 3.96 and 3.56, respectively), this difference was not statistically significant. The vertical UV had statistically higher log10 reductions than horizontal UV against C. auris and C. albicans with FCS and without FCS. For example, for C. auris with FCS the log10 reduction for vertical surfaces was 4.92 (95% CI 3.79, 6.04) and for horizontal surfaces the log10 reduction was 2.87 (95% CI, 2.36–3.38). Conclusions:C. auris can be inactivated on environmental surfaces by UV-C as long as factors that affect inactivation are optimized (eg, exposure time). These data and other published UV-C data should be used in developing cycle parameters that prevent contaminated surfaces from being a source of acquisition by staff or patients of this globally emerging pathogen.Funding: NoneDisclosures: None

Gastrointestinal endoscopy infection control strategy during COVID-19 pandemic: Experience from a tertiary medical center in China.

ObjectivesCoronavirus disease 2019 (COVID‐19) has spread globally and become a pandemic. The severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) not only infects the gastrointestinal (GI) tract and causes GI symptoms, but also increases nosocomial transmission risk during endoscopic procedures for aerosol generation. We hereby share our infection control strategies aiming to minimize COVID‐19 transmission in the endoscopy center.MethodsWe established our infection control strategies based on the guidance of Chinese Society of Digestive Endoscopy and inputs from hospital infection control experts: admission control through the procedure and patient triage, environmental control to reduce possible virus exposure, proper usage of personal protective equipment (PPE), and scope disinfection and room decontamination. All endoscopic procedures accomplished during COVID‐19 outbreak and progress of stepwise resumption of elective endoscopy procedures were retrospectively reviewed.ResultsOnly urgent or semi‐urgent procedures were performed during COVID‐19 outbreak. After no local new‐onset COVID‐19 case in Beijing for four weeks, we reopened the endoscopy center for elective procedures and monitored the outbreak continuously while maintaining a sustainable endoscopy service.ConclusionsIt is imperative that all endoscopy centers should establish standard infection control strategies in order to fight COVID‐19 pandemic based on national guidance and academic society guidelines and tailor them to individual resources. These measures and setup can also be reserved for future pandemics.

Considerations for Pediatric Heart Programs During COVID-19: Recommendations From the Congenital Cardiac Anesthesia Society.

Considerations for Pediatric Heart Programs During COVID-19: Recommendations From the Congenital Cardiac Anesthesia Society.

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.