Efficacy of pulsed-xenon ultraviolet light for disinfection of high-touch surfaces in an Ecuadorian hospital

Performance of an Autonomous Sanitary Sterilisation Ultraviolet Machine (ASSUM) on terminal disinfection of surgical theaters and rooms of an intensive-intermediate care unit

Background

Ultraviolet- C (UV-C) light is effective for reducing environmental bioburden in hospitals, and the use of robots to deliver it may be advantageous.

Aim

To evaluate the feasibility and clinical efficacy of an autonomous programmable UV-C robot in surgical and intensive care unit (ICU) rooms of a tertiary hospital.

Method

During ten consecutive months, the device was used in six theatres where cardiac, colorectal and orthopaedic surgeries were performed, and in the rooms previously occupied by patients subjected to contact precautions of a 14-bed ICU. Surgical site infection (SSI) rates of procedures performed in the UV-cleaned theatres were compared with those of the previous year. Incidence in clinical samples of ICU-acquired multiple-drug resistant (MDR) microorganisms was compared with that of the same period of the previous year. An UV-C exposure study done by semi-quantitative dosimeters and a survey of the bioburden on surfaces were carried out.

Findings

SSI rates in the pre- and post-intervention periods were 8.67% (80/922) and 7.5% (61/813), respectively (p=0.37). Incidence of target microorganisms in clinical samples remained unchanged (38.4 vs. 39.4 per 10,000 patient-days, p=0.94). All the dosimeters exposed to ≤1 meter received ≥500 mJ/cm2. The bacterial load on surfaces decreased after the intervention, particularly in ICU rooms (from 4.57±7.4 CFU to 0.27±0.8 CFU, p<0.0001).

Conclusion

Deployment of an UV-C robot in surgical and ICU rooms is feasible, ensures adequate delivery of germicidal UV-C light and reduces the environmental bacterial burden. Rates of surgical site infections or acquisition of MDR in clinical samples of critically-ill patients remained unchanged.

Assessment of Soiling on Highly Touched Clinical Surfaces in Intensive Care Units

AIM

The aim of this study is to evaluate highly touched clinical surfaces using visual inspection methods and adenosine triphosphate by bioluminescence to identify soiling in intensive care units.

METHOD

Descriptive, cross-sectional study carried out in three intensive care units located in Belo Horizonte, MG, Brazil. Data collection included 142 assessments of environmental surfaces. For data analysis, the Pareto diagram and descriptive statistics were used through measures of central tendency.

RESULTS

The visual inspection identified dirtiness in the infusion pump, alcohol dispenser, and telephone. The surface that showed a high level of contamination by organic matter identified by the adenosine triphosphate bioluminescence test was the telephone, with a median of 1012 RLU/cm2 (±348.8).

CONCLUSION

The surface evaluation methods used in the intensive care units made it possible to identify dirt on surfaces highly touched by hands, reinforcing the need for investments in training and audits in the process of cleaning and disinfecting surfaces.

Using photon disinfection technologies for reducing bioburden in hospitals

BACKGROUND

Environmental cleaning and disinfection is the basis of the prevention of healthcare-acquired infections (HAIs).

AIM

This study aimed to describe photon disinfection technologies (PDTs), report their impact on inactivating micro-organisms and preventing HAIs and to create recommendations for their implementation in hospital settings.

METHODS

An integrated literature review was completed to evaluate and report the impact of PDTs in hospital settings. The quality of 23 articles were assessed, their contents analysed and results reported according to the PICOT model.

FINDINGS

The microbiological impact of the PDT varied by micro-organism, settings and according to the used devices. It was crucial that environmental cleaning was completed before the disinfection.

CONCLUSION

The implementation of PDT in the hospital setting requires inquiry from the viewpoints of microbiological, environmental, occupational, technical and human safety. To enhance the safe implementation of PDTs, the construction and use of evidence-based global standards for PDT are crucial.

A systematic review of the germicidal effectiveness of ultraviolet disinfection across high-touch surfaces in the immediate patient environment

Background

There is not yet a consensus regarding the in-use effectiveness of ultraviolet irradiation (UV-C) as a supplementary tool for terminal room disinfection.

Aims and Objectives

To summarize and evaluate literature detailing the germicidal effectiveness of UV-C disinfection on high-touch surfaces in the patient environment.

Methods

A literature search was carried out utilizing PRISMA guidelines. Studies were included if intervention included UV-C after standard room disinfection in hospital rooms evaluated microbiologically by surface type.

Findings/Results

Twelve records met our criteria for inclusion. Studies predominantly focused on terminal disinfection of patient rooms, including five reports carried out in isolation rooms and three studies including operating room (OR) surfaces. Bedrails, remote controls, phones, tray tables, assist rails, floors, and toilets were the most commonly reported surfaces. Across study designs, surfaces, and room types, flat surfaces tended to showcase UV-C effectiveness best, particularly isolation room floors. In contrast, handheld surfaces (i.e., bed controls and assist bars) tended to show reduced efficacies (81-93%). In the OR, complex surfaces similarly demonstrated reduced UV-C effectiveness. Bathroom surfaces demonstrated 83% UV-C effectiveness overall, with surface characteristics uniquely impacted depending on the room type. Isolation room studies tended to include effectiveness comparison with standard treatment, reporting UV-C superiority most of the time.

Discussion

This review highlights the enhanced effectiveness of UV-C surface disinfection over standard protocols across various study designs and surfaces. However, surface and room characteristics do appear to play a role in the level of bacterial reduction.

Bioengineered corneal tissue for minimally invasive vision restoration in advanced keratoconus in two clinical cohorts

Visual impairment from corneal stromal disease affects millions worldwide. We describe a cell-free engineered corneal tissue, bioengineered porcine construct, double crosslinked (BPCDX) and a minimally invasive surgical method for its implantation. In a pilot feasibility study in India and Iran (clinicaltrials.gov no. NCT04653922 ), we implanted BPCDX in 20 advanced keratoconus subjects to reshape the native corneal stroma without removing existing tissue or using sutures. During 24 months of follow-up, no adverse event was observed. We document improvements in corneal thickness (mean increase of 209 ± 18 µm in India, 285 ± 99 µm in Iran), maximum keratometry (mean decrease of 13.9 ± 7.9 D in India and 11.2 ± 8.9 D in Iran) and visual acuity (to a mean contact-lens-corrected acuity of 20/26 in India and spectacle-corrected acuity of 20/58 in Iran). Fourteen of 14 initially blind subjects had a final mean best-corrected vision (spectacle or contact lens) of 20/36 and restored tolerance to contact lens wear. This work demonstrates restoration of vision using an approach that is potentially equally effective, safer, simpler and more broadly available than donor cornea transplantation.

Effectiveness of Manual Terminal Cleaning Varies on High-Touch Surfaces Near the Operative Field

Background

Periprosthetic joint infection may result from pathogen to patient transmission within the environment. The purpose of this study is to evaluate the contamination level of selected high-touch surfaces in the operating room (OR) using a blacklight fluorescent marking system after a manual terminal clean.

Methods

Prior to the manual terminal clean, 16 high-touch surfaces were marked using a blacklight fluorescent gel. The marked areas were assessed the next morning for thoroughness of cleaning. Surfaces were categorized based on the average percent of the marks removed as “clean” (>75%), “partially clean” (26%-74%), or poorly cleaned (<25%). This process was repeated randomly 12 times. Terminal cleaning was done in the standard fashion, and the perioperative team was unaware of the initiation of this study.

Results

A total of 936 marks were analyzed. There was a significant difference in the number of marks completely clean (29.1%, 272/936) vs marks that were not touched (40.8%, 382/936), P < .001. Only the OR back table (75%) had a rating of clean. Partially clean areas included Mayfield table (72%), overhead lights (70.1%), infusion pump (61.1%), clock reset button (58.3%), table remote control (50%), tourniquet machine (50%), and the OR table (33.3%). Poorly cleaned surfaces included anesthesia medication cart (21.8%), door handles (20.8%), phone (16.7%), electrocautery unit (16.7%), foot pedal (16.7%), anesthesia cart (16.2%), nurses’ station (14.1%), and supply cabinet doors (6%).

Conclusions

Effectiveness of manual terminal cleaning varied greatly across surfaces. In general, surfaces further from the operative field were less likely to have markings removed.

Hospital surface disinfection using ultraviolet germicidal irradiation technology: A review

Ultraviolet germicidal irradiation (UVGI) technologies have emerged as a promising alternative to biocides as a means of surface disinfection in hospitals and other healthcare settings. This paper reviews the methods used by researchers and clinicians in deploying and evaluating the efficacy of UVGI technology. The type of UVGI technology used, the clinical setting where the device was deployed, and the methods of environmental testing that the researchers followed are investigated. The findings suggest that clinical UVGI deployments have been growing steadily since 2010 and have increased dramatically since the start of the COVID-19 pandemic. Hardware platforms and operating procedures vary considerably between studies. Most studies measure efficacy of the technology based on the objective measurement of bacterial bioburden reduction; however, studies conducted over longer durations have examined the impact of UVGI on the reduction of healthcare associated infections (HCAIs). Future trends include increased automation and the use of UVGI technologies that are safer for use around people. Although existing evidence seems to support the efficacy of UVGI as a tool capable of reducing HCAIs, more research is needed to measure the magnitude of these effects and to establish recommended best practices.

An Autonomous Robot-Aided Auditing Scheme for Floor Cleaning

Cleaning is an important factor in most aspects of our day-to-day life. This research work brings a solution to the fundamental question of “How clean is clean” by introducing a novel framework for auditing the cleanliness of built infrastructure using mobile robots. The proposed system presents a strategy for assessing the quality of cleaning in a given area and a novel exploration strategy that facilitates the auditing in a given location by a mobile robot. An audit sensor that works by the “touch and inspect” analogy that assigns an audit score corresponds to its area of inspection has been developed. A vision-based dirt-probability-driven exploration is proposed to empower a mobile robot with an audit sensor on-board to perform auditing tasks effectively. The quality of cleaning is quantified using a dirt density map representing location-wise audit scores, dirt distribution pattern obtained by kernel density estimation, and cleaning benchmark score representing the extent of cleanliness. The framework is realized in an in-house developed audit robot to perform the cleaning audit in indoor and semi-outdoor environments. The proposed method is validated by experiment trials to estimate the cleanliness in five different locations using the developed audit sensor and dirt-probability-driven exploration.

The efficacy of ultraviolet light-emitting technology against coronaviruses: a systematic review

The ongoing pandemic of COVID-19 has underlined the importance of adopting effective infection prevention and control (IPC) measures in hospital and community settings. Ultraviolet (UV)-based technologies represent promising IPC tools: their effective application for sanitation has been extensively evaluated in the past but scant, heterogeneous and inconclusive evidence is available on their effect on SARS-CoV-2 transmission. With the aim of pooling the available evidence on the efficacy of UV technologies against coronaviruses, we conducted a systematic review following PRISMA guidelines, searching Medline, Embase and the Cochrane Library, and the main clinical trials' registries (WHO ICTRP, ClinicalTrials.gov, Cochrane and EU Clinical Trial Register). Quantitative data on studies' interventions were summarized in tables, pooled by different coronavirus species and strain, UV source, characteristics of UV light exposure and outcomes. Eighteen papers met our inclusion criteria, published between 1972 and 2020. Six focused on SARS-CoV-2, four on SARS-CoV-1, one on MERS-CoV, three on seasonal coronaviruses, and four on animal coronaviruses. All were experimental studies. Overall, despite wide heterogenicity within included studies, complete inactivation of coronaviruses on surfaces or aerosolized, including SARS-CoV-2, was reported to take a maximum exposure time of 15 min and to need a maximum distance from the UV emitter of up to 1 m. Advances in UV-based technologies in the field of sanitation and their proved high virucidal potential against SARS-CoV-2 support their use for IPC in hospital and community settings and their contribution towards ending the COVID-19 pandemic. National and international guidelines are to be updated and parameters and conditions of use need to be identified to ensure both efficacy and safety of UV technology application for effective infection prevention and control in both healthcare and non-healthcare settings.

Potential of pulsed light technology for control of SARS-CoV-2 in hospital environments

The emergence of the SARS-CoV-2 infection and its potential transmission through touching surfaces in clinical environments have impelled the use of conventional and novel methods of disinfection to prevent its spreading. Among the latter, pulsed light may be an effective, non-chemical decontamination alternative. Pulsed light technology inactivates microorganisms and viruses by using high intensity polychromatic light pulses, which degrades nucleic acids and proteins. This review describes this technology, compiles and critically analyzes the evidence about the virucidal efficacy of pulsed light technology with view on its potential use against SARS-CoV-2 in touching surfaces in health-care facilities. The efficacy of pulsed light proved against many different kind of viruses allows to conclude that is a suitable candidate to inactivate SARS-CoV-2 as long as the required fluence is applied and the appropriated exposure to contaminated surfaces is guaranteed.

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Pulsed light can inactivate many different types of viruses.

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Its antimicrobial efficacy has been proved in different health care facilities.

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Pulsed light produces fast inactivation and it is ecologically friendly.

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Evidence shows that it should be effective for SARS-CoV-2 inactivation.

Control of Methicillin-Resistant Staphylococcus aureus Strains Associated With a Hospital Outbreak Involving Contamination From Anesthesia Equipment Using UV-C

Methicillin-resistant Staphylococcus aureus (MRSA) is considered an opportunistic pathogen in humans and is mainly associated with healthcare-associated infections (HCAIs). This bacterium colonizes the skin and mucous membranes of healthy people and causes frequent hospital outbreaks. The aim of this study was to perform molecular typing of the staphylococcal cassette chromosome mec (SCCmec) and agr loci as wells as to establish the pulsotypes and clonal complexes (CCs) for MRSA and methicillin-sensitive S. aureus (MSSA) outbreaks associated with the operating room (OR) at a pediatric hospital. Twenty-five clinical strains of S. aureus (19 MRSA and 6 MSSA strains) were recovered from the outbreak (patients, anesthesia equipment, and nasopharyngeal exudates from external service anesthesia technicians). These clinical S. aureus strains were mainly resistant to benzylpenicillin (100%) and erythromycin (84%) and were susceptible to vancomycin and nitrofurantoin. The SCCmec type II was amplified in 84% of the S. aureus strains, and the most frequent type of the agr locus was agrII, which was amplified in 72% of the strains; however, the agrI and agrIII genes were mainly detected in MSSA strains. A pulsed-field gel electrophoresis (PFGE) analysis grouped the 25 strains into 16 pulsotypes (P), the most frequent of which was P1, including 10 MRSA strains related to the anesthesia equipment, external service anesthesia technicians, and hospitalized patients. Multilocus sequence typing (MLST) identified 15 sequence types (STs) distributed in nine CCs. The most prevalent ST was ST1011, belonging to CC5, which was associated with the SCCmec type II and agrII type. We postulate that the external service anesthesia technicians were MRSA carriers and that these strains were indirectly transmitted from the contaminated anesthesia equipment that was inappropriately disinfected. Finally, the MRSA outbreak was controlled when the anesthesia equipment disinfection was improved and hand hygiene was reinforced.

Use of ultraviolet-C in environmental sterilization in hospitals: A systematic review on efficacy and safety

OBJECTIVES

The study aimed to review the literature on the use of ultraviolet-C (UV-C) sterilization to assess its clinical efficacy in reducing risk and transmission of nosocomial infections as well as its associated health safety or hazards.

METHODS

Four main search engines were used to identify potential studies which included: (1) Google Scholar, (2) ScienceDirect, (3) PubMed, and (4) Cochrane. Studies in English and published from 2010 to 2020 were considered. Studies on efficacy were limited to those in unseeded hospital environments, examining environmental disinfection, and with true experimental, randomized controlled trial, or quasi-experimental study designs. No additional criterion was used for safety studies due to the scarcity of literature. In the end, a total of 17 studies were selected. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Risk of bias assessment and manual data extraction and tabulation were done.

RESULTS

Twelve eligible efficacy studies were identified together with five safety studies. It was found that UV-C irradiation had positive results when used as an adjunct for existing cleaning protocols. The germicidal effect of UV-C is potent against microorganisms including viruses, methicillin-resistant Staphylococcus aureus, and vancomycin-resistant enterococci. Safety study results showed dermal effects of UV-C exposure including DNA lesions, formation of cyclobutane pyrimidine dimers in cells, and effects on the skin's stratum corneum.

CONCLUSION

It was found that UV-C can be utilized as an adjunct to terminal manual cleaning because of its efficacy as a germicidal agent. Further studies must still be done to exact a standard for safe exposure dose, especially for 222 nm germicidal lamps. Direct evidence is needed for any targeted implementation of UV-C during Coronavirus Disease 2019 (COVID-19) pandemic.

Efficacy of pulsed xenon ultraviolet disinfection of multidrug-resistant bacteria and Clostridioides difficile spores

BACKGROUND

Contamination of healthcare environments by multidrug-resistant organisms (MDRO) and Clostridioides difficile is a risk for healthcare-associated infections. The efficacy of pulsed xenon ultraviolet (PX-UV) disinfection in healthcare environments has been described previously. However, there are few reports about PX-UV disinfection in Japan. The aim of this study was to investigate in vitro the efficacy of PX-UV disinfection of MDRO and C. difficile spores commonly isolated in Japanese hospitals.

METHODS

We investigated reductions in microbial counts after exposure to PX-UV of the following clinically-isolated organisms on seeding agar plates: methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium, carbapenemase-producing Klebsiella pneumoniae, extended spectrum β-lactamase-producing Escherichia coli, multidrug resistant Acinetobacter baumannii, and C. difficile spores. We also visually assessed the attenuation of disinfection by shielding of MRSA and carbapenemase-producing K. pneumoniae from PX-UV exposure.

RESULTS

PX-UV disinfection for 5 min induced >5-log colony-forming units (CFU)/cm² growth inhibition of all the MDRO. PX-UV disinfection for 15 min induced >3-log CFU/cm² growth inhibition of C. difficile spores. Where a plate was shielded from PX-UV exposure the bacteria showed confluent growth, but no colonies were observed on unshielded (exposed) parts of the plates.

CONCLUSION

This study shows the efficacy of PX-UV disinfection against clinical MDROs. C. difficile spores were more resistant to PX-UV disinfection than vegetative bacteria. Further evaluation of the efficacy of PX-UV disinfection in reducing the contamination of real-world surfaces and the incidence of healthcare-associated infections is needed.

Bacterial, Gut Microbiome-Modifying Therapies to Defend against Multidrug Resistant Organisms

Antibiotics have revolutionized human and animal healthcare, but their utility is reduced as bacteria evolve resistance mechanisms over time. Thankfully, there are novel antibiotics in the pipeline to overcome resistance, which are mentioned elsewhere in this special issue, but eventually bacteria are expected to evolve resistance to most new compounds as well. Multidrug resistant organisms (MDROs) that cause infections increase morbidity, mortality, and readmissions as compared with susceptible organisms. Consequently, many research and development pipelines are focused on non-antibiotic strategies, including fecal microbiota transplantation (FMT), probiotics and prebiotics, and a range of therapies in between. Studies reviewed here focus on efforts to directly treat or prevent MDRO infections or colonization. The studies were collected through clinicaltrials.gov, PubMed, and the International Conference on the Harmonisation Good Clinical Practice website (ichgcp.net). While the gold standard of clinical research is randomized controlled trials (RCTs), several pilot studies are included because the field is so young. Although a vast preclinical body of research has led to studies in humans, animal and in vitro studies are not within the scope of this review. This narrative review discusses microbiome-modifying therapies targeting MDROs in the gut and includes current results, ongoing clinical trials, companies with therapies in the pipeline specifically for MDROs, and commentary on clinical implementation and challenges.