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Access to safe water and sanitation is a critical global challenge, posing significant health risks worldwide due to waterborne diseases. This study investigates the efficacy of ultraviolet type C radiation as a disinfection method for improving water quality. The research elucidates UV-C's mechanism of action, highlighting its ability to disrupt DNA and RNA replication, thereby inactivating pathogens. Furthermore, the study analyses the influence of key factors on UV-C disinfection effectiveness, including water turbidity and the presence of dissolved organic matter, which can attenuate UV-C penetration and reduce treatment efficiency. The experimental results demonstrate a substantial reduction in microbial content following UV-C treatment. River water samples exhibited a 57.143% reduction in microbial load, while well water samples showed a 50% reduction. Notably, Escherichia coli (E. coli) concentrations decreased significantly, with an 83.33% reduction in well water and a 62.5% reduction in borehole water. This study makes a novel contribution to the understanding of UV-C disinfection by identifying the presence of resistant organisms, including Adenoviruses, Bacterial spores, and the Protozoan Acanthamoeba, in water samples. This finding expands the scope of UV-C research beyond easily culturable bacteria. To address this challenge, future investigations should explore synergistic disinfection strategies, such as combining UV-C treatment with advanced oxidation processes. Optimising UV-C system designs and developing robust, real-time monitoring systems capable of detecting and quantifying known and emerging UV-resistant pathogens are crucial for ensuring comprehensive water decontamination. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Aircraft cabins, susceptible to disease transmission, require effective strategies to minimize the spread of airborne diseases. This paper reviews the James Reason Swiss Cheese Theory in mitigating these risks, as implemented by the International Civil Aviation Organization during the COVID-19 pandemic. It also evaluates the use of airborne ultraviolet-C (UV-C) light as an additional protective measure. METHODS: Our approach involved a thorough literature review by experts and a detailed risk-vs.-benefit analysis. The review covered existing research to understand the scientific foundation, while the analysis used established techniques to assess the impact of influenza and COVID-19 in terms of infections, deaths, and economic costs. RESULTS: Integrating UV-C light in aircraft cabins, when applied with appropriate scientific understanding and engineering safeguards, has the potential to reduce in-flight disease transmission. This additional mitigation strategy can work synergistically with existing measures. DISCUSSION: The research and risk-vs.-benefit analysis present strong evidence for the safety and effectiveness of continuous UV-C disinfection in aircraft cabins. It suggests that UV-C light, maintained below exposure limits, can be a valuable addition to existing measures against disease transmission during flights. [ABSTRACT FROM AUTHOR]

This document is a list of acknowledgements, author contributions, declarations of conflicting interests, funding sources, and references for a research article on the effects of COVID-19 isolation measures on physical activity and air quality. The article discusses the impact of the pandemic on physical activity levels and sedentary behaviors, as well as the potential transmission of the virus through airborne particles. It also explores the use of UV-C LED and ionizer-based air sanitation systems for indoor environments. The document provides a comprehensive list of sources and resources related to the topic. [Extracted from the article]

Introduction: Healthcare-associated infections in the post-pandemic era are as important as they were before COVID-19. The dominant route of transmission of microorganisms in health care units is the contact route, for which hand hygiene is of cardinal importance, but also effective disinfection of touch surfaces. Traditional disinfection based on chemical compounds is sensitive to human errors. Therefore, a valuable supplement to it can be contactless disinfection methods, including the use of UV-C. The aim of the study was to assess the effectiveness of UV-C radiation in eliminating selected, most important pathogens of particular epidemic importance from surfaces made of various materials: stainless steel, plastic and glass, most often found in hospital conditions. Material and Method: In laboratory conditions, the study was conducted using bacterial strains of great epidemiological importance and Candida auris. In hospital wards, samples were taken before and after disinfection for comparisons of the composition and quantity of bacteria. In laboratory conditions, carriers made of steel, plastic and glass were contaminated with a bacterial suspension with a density of approx. 0.5 McFarland, and then the density of persistent microorganisms was assessed after 10 min of UV-C irradiation. Results: The high effectiveness of UV-C radiation in eliminating bacteria contaminating touch surfaces in hospital wards and in laboratory conditions has been confirmed. The elimination efficiency in laboratory conditions was slightly lower (statistically insignificant) on the plastic surface, which is probably related to subtle differences in the thickness of the contaminating layer. Hydrophobic properties and the smallest suspension diameter were confirmed for the tested plastic carriers. Conclusions: UV-C disinfection is a desirable element to support traditional, chemical methods of disinfection in hospital conditions, effective against multidrug-resistant bacteria and C. auris. [ABSTRACT FROM AUTHOR]

We propose a special design enclosure device that promotes isotropic distribution of germicidal UV-C light for the effective disinfection of difficult to reach surfaces. We used experimental and computational approaches to investigate the disinfection efficacy of this device against Escherichia coli and Listeria innocua. Stainless steel, Copper metal, and a Copper polymer were used as solid substrates of varying roughness and hydrophobicity. Bacteria reductions of up to 6.9 log CFU were achieved at various locations relative to the UV-C source after 3 min of treatment (20–990 mJ/cm2 cumulative fluence depending on the location). Inactivation kinetics was nonlinear and followed the Weibull model (0.77 ≤ R2 ≤ 0.97). Optical ray tracing simulation was used to generate maps of spatial light distribution, which were then coupled with microbial inactivation kinetics to create spatial maps of inactivation. The modeling approach used accurately predicted microbial inactivation at various locations, with only small discrepancies (±8%) between predicted and experimental data. These findings demonstrate that the proposed device is suitable for disinfecting various hard to reach surfaces, with numerous possible applications in the food and healthcare industries. Additionally, the modeling approach used here can be used to aid in the design of a highly effective Ultraviolet treatment system.

Ultraviolet (UV)-C light for disinfection has experienced a surge in popularity since the outbreak of COVID-19. Currently, many different UV-C systems, with varied properties that impact disinfection performance, are available on the market. Therefore this review aims to bundle the available information on UV-C disinfection to obtain an overview of its advantages, disadvantages, and performance-influencing parameters. A literature search was performed using the snowball search method in Google Scholar and PubMed with the following keywords: UV-C disinfection, UV-C dose, UV-C light source, UV-C repair mechanism, UV-C photoreactivation, and UV-C disinfection standards. The main parameters of UV-C disinfection are wavelength, dose, relative humidity, and temperature. There is no consensus about their optimal values, but, in general, light at a high dose and a spectrum of wavelengths containing 260 nm is preferred in an environment at room temperature with low relative humidity. This light can be generated by mercury-vapour, light-emitting diode (LED), pulsed-xenon, or excimer lamps. Multiple factors are detrimental to disinfection performance such as shadowing, a rough surface topography, a high level of contamination, repair mechanisms, and the lack of standardization. Also, there are health and safety risks associated with the UV-C technology when used in the proximity of people. UV-C disinfection systems have promising features and the potential to improve in the future. However, clarifications surrounding the different parameters influencing the technologies' effectiveness in hospital environment are needed. Therefore UV-C disinfection should currently be considered for low-level rather than high-level disinfection. [ABSTRACT FROM AUTHOR]

Background: Among no-touch automatized disinfection devices, UV-C radiation proved to be one of the most effective against a broad-spectrum of microorganisms causing healthcare-associated infections., Aim: To evaluate the antimicrobial efficacy of an experimental UV-C robotic platform, under controlled conditions and in a real hospital scenario, when used to implement the Standard cleaning Operating Protocol (SOP)., Methods: In vitro, after dose calibration tests, bactericidal and virucidal efficacy was tested according to the ASTM E3135-18. In hospital settings, twelve high-touch surfaces were sampled after healthcare activity and after SOP or SOP and UV-C treatments, for a total of 180 samples., Findings: In vitro, the dose necessary to completely remove Staphylococcus aureus and Pseudomonas aeruginosa was less than 4 mJ/cm 2 , 194 mJ/cm 2 was required to completely inactivate Adenovirus HadV5, while 38.8 mJ/cm 2 was sufficient for Coronavirus 229E. In the real scenario, the UV-C dose emitted on the sampled surfaces was in mean 29.31 mJ/cm 2 . We found a significant difference in data obtained both after SOP (p-value = 0.022) and after UV-C treatment (p-value = 0.007) compared to dirty condition. The average percentage of the Total Viable Count (TVC) reduction was 67% after SOP and 96% after the combination of SOP and UV-C., Conclusions: By comparing the tests conducted in vitro and in the real scenario we demonstrated that in the hospital setting the efficacy of the UV-C robot was reduced, since a higher dose than that observed in vitro was necessary to obtain a reduction in the TVC that was not even total, unlike that found in vitro., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2024. Published by Elsevier Ltd.)

Background: The current COVID-19 pandemic has demonstrated the enormous importance of maintaining good hygienic conditions in everyday indoor environments for the prevention of infectious diseases. This includes sanitization methods capable of significantly reducing the microbial load in the air and on surfaces. However, in line with the ecological transition, alternative systems for environmental sanitization with reduced environmental impact are urgently needed. The photocatalytic reaction using UV-C light-emitting diode (UV-C LED) lamps with short wavelengths, especially in the range of 200–280 nanometers (nm), can significantly reduce the microbial load, safeguarding the environment thanks to reduced energy consumption. The objective of this review is to describe the latest innovations in the use of UV-C LED technology in the sanitization of indoor environments, reporting the fundamental principles on which its activity relies. Methods: Two databases (PubMed, Web of Science), were searched, following PRISMA guidelines. Results: A total of 1348 publications were identified, of which 379 were assessed in detail and, of these, 16 were included in the review. Conclusions: This literature review highlighted that UV-C LEDs irradiation represents a valid, eco-sustainable sanitization method that could be exploited as an alternative to chemical compounds to contain indoor microbiological pollution in living and working environments. [ABSTRACT FROM AUTHOR]

Abstract Background UltraViolet-C (UV-C) lamps may be used to supplement current hospital cleaning and disinfection of surfaces contaminated by SARS-CoV-2. Our aim is to provide some practical indications for the correct use of UV-C lamps. Methods We studied three UV-C lamps, measuring their spatial irradiance and emission over time. We quantify the error that is committed by calculating the irradiation time based exclusively on the technical data of the lamps or by making direct irradiance measurements. Finally, we tested specific dosimeters for UV-C. Results Our results show that the spatial emission of UV-C lamps is strongly dependent on the power of the lamps and on the design of their reflectors. Only by optimizing the positioning and calculating the exposure time correctly, is it possible to dispense the dose necessary to obtain SARS-CoV-2 inactivation. In the absence of suitable equipment for measuring irradiance, the calculated irradiation time can be underestimated. We therefore consider it precautionary to increase the calculated times by at least 20%. Conclusion To use UV-C lamps effectively, it is necessary to follow a few simple precepts when choosing, positioning and verifying the lamps. In the absence of instruments dedicated to direct verification of irradiance, photochromic UV-C dosimeters may represent a useful tool for easily verifying that a proper UV-C dose has been delivered.

The use of ultraviolet germicidal irradiation (UVGI) to combat disease transmission has come into the international spotlight again because of the recent SARS-CoV-2 pandemic and ongoing outbreaks of multidrug resistant organisms in hospitals. Although the implementation of ultraviolet disinfection technology is widely employed in healthcare facilities and its effectiveness has been repeatedly demonstrated, the use of such technology in the commercial sector has been limited. Considering that most disease transmission occurs in commercial, public, and residential indoor environments as opposed to healthcare facilities, there is a need to understand whether ultraviolet (UV) disinfection technology can be effective for mitigating disease transmission in these environments. The results presented here demonstrate that the installation of fixed in-room UVGI air cleaners in commercial buildings, including restaurants and offices, can produce significant reductions in both airborne and surface-borne bacterial contamination. Total airborne reductions after UV implementation at six separate commercial sites averaged 73% (p < 0.0001) with a range of 71–88%. Total non-high touch surface reductions after implementation averaged 55% (p < 0.0001) with a range of 28–88%. All reductions at the mitigated sites were statistically significant. The mean value of indoor airborne bacteria was 320 CFU/m3 before intervention and 76 CFU/m3 after. The mean value of indoor non-high touch surface borne bacteria was 131 CFU/plate before intervention and 47 CFU/plate after. All test locations and controls had their required pandemic cleaning procedures in place for pre- and post-sampling events. Outdoor levels of airborne bacteria were monitored and there was no significant correlation between the levels of airborne bacteria in the outside air as opposed to the indoor air. Rooms with fixed in-room UVGI air cleaners installed had significant CFU reductions on local surface contamination, which is a novel and important finding. Installation of fixed in-room UVGI air cleaners in commercial buildings will decontaminate the indoor environment and reduce hazardous exposure to human pathogens. [ABSTRACT FROM AUTHOR]

Background: The current COVID-19 pandemic has demonstrated the enormous importance of maintaining good hygienic conditions in everyday indoor environments for the prevention of infectious diseases. This includes sanitization methods capable of significantly reducing the microbial load in the air and on surfaces. However, in line with the ecological transition, alternative systems for environmental sanitization with reduced environmental impact are urgently needed. The photocatalytic reaction using UV-C light-emitting diode (UV-C LED) lamps with short wavelengths, especially in the range of 200–280 nanometers (nm), can significantly reduce the microbial load, safeguarding the environment thanks to reduced energy consumption. The objective of this review is to describe the latest innovations in the use of UV-C LED technology in the sanitization of indoor environments, reporting the fundamental principles on which its activity relies. Methods: Two databases (PubMed, Web of Science), were searched, following PRISMA guidelines. Results: A total of 1348 publications were identified, of which 379 were assessed in detail and, of these, 16 were included in the review. Conclusions: This literature review highlighted that UV-C LEDs irradiation represents a valid, eco-sustainable sanitization method that could be exploited as an alternative to chemical compounds to contain indoor microbiological pollution in living and working environments.

Summary: Handheld Electronic Devices (HEDs) play a central role in the hospital environment. However, they can be a vehicle for transmitting (pathogenic) microorganisms. We studied whether disinfection with UV-C light is successful in disinfecting three different HEDs in a clinical setting. Disinfection with UV-C light was performed with the UV-Smart® D25. We took a total of 800 samples on two departments and counted colony forming units. More than half of the baseline measurements were moderately (>10CFU) or highly (>50 CFU) contaminated. Post-disinfection the CFU was 0 in 87% of measurements. We conclude that the UV-Smart® D25 can be used to disinfect non-critical HEDs in clinical healthcare.

Background: UltraViolet-C (UV-C) lamps may be used to supplement current hospital cleaning and disinfection of surfaces contaminated by SARS-CoV-2. Our aim is to provide some practical indications for the correct use of UV-C lamps.Methods: We studied three UV-C lamps, measuring their spatial irradiance and emission over time. We quantify the error that is committed by calculating the irradiation time based exclusively on the technical data of the lamps or by making direct irradiance measurements. Finally, we tested specific dosimeters for UV-C.Results: Our results show that the spatial emission of UV-C lamps is strongly dependent on the power of the lamps and on the design of their reflectors. Only by optimizing the positioning and calculating the exposure time correctly, is it possible to dispense the dose necessary to obtain SARS-CoV-2 inactivation. In the absence of suitable equipment for measuring irradiance, the calculated irradiation time can be underestimated. We therefore consider it precautionary to increase the calculated times by at least 20%.Conclusion: To use UV-C lamps effectively, it is necessary to follow a few simple precepts when choosing, positioning and verifying the lamps. In the absence of instruments dedicated to direct verification of irradiance, photochromic UV-C dosimeters may represent a useful tool for easily verifying that a proper UV-C dose has been delivered. [ABSTRACT FROM AUTHOR]

In this study, removal of organic matter and nitrogen from a cattle slaughterhouse wastewater was investigated in a two‐stage anoxic–aerobic biological system, followed by UV‐C disinfection. Ecotoxicity of the raw, biotreated, and disinfected wastewater against the microalgae Scenedesmus sp. was evaluated in short‐term tests, while the potential of the microalgae as a nutrient removal step was addressed in long‐term experiments. Throughout 5 operational phases, the biological system was subjected to gradual reduction of the hydraulic retention time (8–1.5 day), increasing the organic (0.21–1.11 kgCOD·m−3·day−1) and nitrogen (0.05–0.28 kgN·m−3· day−1) loading rates. COD and total ammoniacal nitrogen (TAN) removal ranged within 83%–97% and 83%–99%, respectively. While providing alkalinity source, effluent TAN concentrations were below 5 mg·L‐1. Nitrate was the main nitrification product, while nitrite levels remained low (<1 mgN·L‐1). Upon supplementation of external COD as ethanol, total nitrogen removal reached up to 90% at the highest load (0.28 kgN·m−3·day−1). After UV‐C treatment, 3‐log reduction of total coliforms was attained. The 96‐hr ecotoxicity tests showed that all non‐diluted samples tested (raw, biologically treated and UV‐C irradiated wastewater) were toxic to microalgae. Nevertheless, these organisms were able to acclimate and grow under the imposed conditions, allowing to achieve nitrogen and phosphorous removal up to 99.1% and 43.0%, respectively. Practitioner points: The treatment of a slaughterhouse wastewater in an anoxic–aerobic biological system followed by a UV‐C disinfection step was assessed.The pre‐denitrification system showed efficient simultaneous removal of organic matter and nitrogen from the wastewater under increasing applied loads.UV‐C disinfection worked effectively in reducing coliforms from the biotreated effluent, boosting the performance of microalgae on nutrients removal.Despite the toxicity to microalgae, they were capable to acclimate to the aqueous matrices tested, reducing efficiently the nutrients content.The combined stages of treatment presented great capacity for depleting up to 97% COD, 99% nitrogen, and 43% phosphorous. [ABSTRACT FROM AUTHOR]

Ultraviolet-C (UV-C) radiation, spanning wavelengths between 200 nm and 280 nm, has proven germicidal qualities and medical, industrial, and environmental applications. The need for new disinfection technologies and the prospect of eliminating mercury-based radiation sources compels research on ultraviolet (UV) light-emitting diodes (LEDs). UV-LED technology could be used for customized and point-of-use products for disinfection and sterilization. We focused on the design and development of a surface disinfection device using UV-C LEDs, including potential user targets, important design parameters, and final validation methods. Optical and thermal simulations were used to illustrate the design process and associated challenges. A sample device prototype was developed, and microbial validation results are presented. [ABSTRACT FROM AUTHOR]

Healthcare-associated infections are a significant concern in acute care facilities across the US. Studies have shown the importance of a hygienic patient environment in reducing the risk of such infections. This has caused an increased interest in ultraviolet (UV-C) light disinfectant technology as an adjunct technology to provide additional pathogen reduction to environmental surfaces and patient care equipment (i.e., surfaces). It is also well known that UV-C light can cause premature degradation of materials, particularly certain plastic materials. However, there is little information in the literature regarding characterizing this degradation of plastics and other materials used for surfaces in healthcare. This study aims to evaluate multiple characterization techniques and propose a systematic approach to further understand early onset degradation of plastics due to UV-C exposure. Susceptibility and modes of degradation of multiple plastic materials were compared using the techniques evaluated. Ten grades of plastic materials were exposed to UV-C light in a manner consistent with standards given in the healthcare and furniture industry to achieve disinfection. These materials were characterized for visual appearance, chemical composition, surface roughness and hardness using light microscopy, spectrophotometry, contact angle analysis, infrared spectroscopy, profilometry and nanoindentation. All characterization methods were able to identify one or more specific degradation features from UV-C exposure covering different aspects of physicochemical properties of the surfaces. However, these methods showed different sensitivity and applicability to identify the onset of surface damage. Different types of surface materials showed different susceptibility and modes to degradation upon UV-C light exposure. UV-C disinfection can cause detectable damage to various surfaces in healthcare. A characterization approach consisting of physical and chemical characterizations is proposed in quantifying surface degradation of a material from UV-C exposure to address the complexity in modes of degradation and the varied sensitivity to UV-C from different materials. Methods with high sensitivity can be used to evaluate onset of damage or early stage damage. [ABSTRACT FROM AUTHOR]

The use of incorrectly cleaned or disinfected hospital's equipment can also pose an infection risk and may contribute to the dissemination of microorganisms. Generally, stethoscopes are not considered a main infection risk, but the stethoscope is the most-used medical tool in the world. A new light-emitting diode (LED) disinfection option has recently been introduced by the LED industry. We wanted to determine where and when thi s new disinfection system would be useful in reducing contamination and whether any specific type of patient would benefit more from the use of this device. The evaluation was conducted using a multidisciplinary approach and has provided an analysis of the 7 domains recommended by EUnetHTA (Health problem and current use of the technology, technical characteristic, clinical effectiveness, safety, economic evaluation, organizational aspects, ethical aspects). We observe the use of sthethoscope while deliver ing routine care in three different intensity of care departments on at least one hour every week for three months. Between one patient and another, a disinfection or cleaning procedure is never performed by most operators. We collected 248 samples from different departments to evaluate the efficacy of a new device. We observed a reduction in the bacterial load in 70% of the cases after using the UV-C LED device. Discussion and Conclusion: This device could be useful in encouraging the adoption of good hy giene practices and could reduce the risks associated with the treatment of infections. The tool has proved to be particularly useful in the intensive care unit. [ABSTRACT FROM AUTHOR]

Mobile ultraviolet C (UV-C) room decontamination devices are widely used in health care facilities; however, there is limited information on the perceptions of patients, health care workers (HCWs), and environmental services staff (EVS-staff) regarding their use for environmental decontamination. An anonymous questionnaire was administered to participants in 4 medical/surgical units of a tertiary care hospital where UV-C devices were deployed for a 6-month period. Survey questions assessed perceptions regarding the importance of environmental disinfection, effectiveness of UV-C decontamination, willingness to delay hospital admission in order to use UV-C, and safety of UV-C devices. Questionnaires were completed by 102 patients, 130 HCWs, and 47 EVS-staff. All of the HCWs and EVS-staff and 99% of the patients agreed that environmental disinfection is important to reduce the risk of exposure from contaminated surfaces. Ninety-eight percent of the EVS-staff, 89% of the HCWs, and 96% of the patients felt that the use of UV-C as an adjunct to routine cleaning increased confidence that rooms are clean. Ninety-four percent of the EVS-staff, 85% of the HCWs, and 90% of the patients expressed a willingness to delay being admitted to a room in order to have UV-C decontamination completed. Seventy-nine percent of the EVS-staff, 76% of the HCWs, and 86% of the patients had no concerns about the safety of UV-C devices. Patients, HCWs, and EVS-staff agreed that environmental disinfection is important and that UV-C devices are efficacious and safe. Educational tools are needed to allay safety concerns expressed by a minority of HCWs and EVS-staff. [ABSTRACT FROM AUTHOR]

Nontuberculous mycobacteria are resistant to conventional water treatments, and are opportunistic human pathogen, particularly in hospitalized patients. The aim of this investigation was to assess the effectiveness of an ultraviolet UV-C lamp treatment against Mycobacterium avium subspecies hominissuis in drinking tap water. Ultraviolet treatments (0-192 mJ/cm2) were performed using UV lamp immerged onto cylindrical glass tubes containing artificially contaminated water. The results showed that susceptibility to UV varied considerably according to the strains and the diameter of the tube. With a dose of 32 mJ/cm2, a significant inactivation (p < .05) of 3 log (99.9%) or more was obtained in only 5 of the 14 strains. To obtain a complete inactivation of all strains an irradiation of 192 mJ/cm2 was needed, a dose that is much higher than the limits recommended by the international standards for UV disinfection of drinking water. In conclusion, it may be difficult to standardize a UV dose for the elimination of waterborne mycobacteria. [ABSTRACT FROM AUTHOR]

Background Hospital-acquired infections (HAIs) are a significant contributor to adverse patient outcomes and excess cost of inpatient care. Adjunct ultraviolet-C (UV-C) disinfection may be a viable strategy for reducing HAIs. This study aimed to measure the clinical, operational, and financial impact of a UV-C terminal disinfection intervention in a community hospital setting. Methods Using a pre-post study design, we compared the HAI rates of 5 multidrug-resistant bacteria (Acinetobacter baumannii , Klebsiella pneumoniae , methicillin-resistant Staphylococcus aureus , vancomycin-resistant Enterococcus , and Pseudomonas aeruginosa) from 6 culture sites before and after a 12-month facility-wide UV-C intervention. To measure impact of UV-C disinfection on hospital operations, mean inpatient emergency room wait time was calculated. Finally, we conducted a cost saving analysis to evaluate the financial benefits of the intervention. Results Overall, 245 HAIs among 13,177 inpatients were observed during a 12-month intervention period, with an incidence rate of 3.94 per 1,000 patient days. This observed HAIs incidence was 19.2% lower than the preintervention period (4.87 vs 3.94 per 1,000 patient days; P =.006). The intervention did not adversely impact emergency department admissions (297.9 vs 296.2 minutes; P =.18) and generated a direct cost savings of $1,219,878 over a 12-month period. Conclusions The UV-C disinfection intervention was associated with a statistically significant facility-wide reduction of multidrug-resistant HAIs and generated substantial direct cost savings without adversely impacting hospital operations. [ABSTRACT FROM AUTHOR]

Mobile phones and tablet computers may be contaminated with micro-organisms and become a potential reservoir for cross-transmission of pathogens between healthcare workers and patients. There is no generally accepted guidance on how to reduce contamination on mobile devices in healthcare settings. Our aim was to determine the efficacy of the Codonics D6000™ UV-C disinfection device. Daily disinfection reduced contamination on screens and on protective cases (test) significantly, but not all cases (control) could be decontaminated. The median aerobic colony count on the control and the test cases was 52 cfu/25 cm2 (interquartile range: 33-89) and 22 cfu/25 cm2 (10.5-41), respectively, before disinfection. [ABSTRACT FROM AUTHOR]

Disinfection by UV radiation is one of the most promising solutions to reduce the bacterial load and antibiotic resistance in the final effluents of urban wastewater treatment plants (UWTP). Our aim was to evaluate the fate of cefotaxime-resistant Enterobacteriaceae and Extended Spectrum Beta-Lactamase (ESBL) producers in a full-scale system that includes UV-C disinfection. Over treatment, the abundance of cefotaxime-resistant Enterobacteriaceae was reduced, with reductions of 1.9 log units after secondary treatment (STW samples) and 1.8 log following UV disinfection (UTW samples). These reductions, did not reflect the variations in the prevalence of cefotaxime-resistant Enterobacteriaceae , estimated to be of 3% in raw wastewater (RW), 18% in STW and 3% in UTW. A significant increase of cefotaxime-resistant bacterial counts (0.5 log; p  < 0.05) was observed after 3 days of storage. In a total of 1799 cefotaxime-resistant Enterobacteriaceae isolates, 15% harboured bla CTX-M ( n  = 274), 11% bla TEM ( n  = 194) and 4% bla SHV ( n  = 72). While the ESBL gene prevalence decreased over treatment, the prevalence of the intI 1 gene decreased after ST but slightly increased in UTW samples. The bla CTX-M -carriers were identified as Escherichia coli and Klebsiella pneumoniae , mostly multi-drug resistant (90.5%) and carrying integrase genes (82.8%). The bla CTX-M gene variants (48 bla CTX-M-15 , 9 bla CTX-M-32, 8 bla CTX-M-1, 5 bla CTX-M-27, and 2 bla CTX-M-14 ) were flanked by IS Ecp1 , IS Ecp 1/IS 26 , IS 903 and ORF477 in 8 different arrangements. The IncF plasmid replicon type was highly prevalent among bla CTX-M -carrying Escherichia coli (74.5%) while IncR predominated among K. pneumoniae (54.5%). Our results confirmed the potential of UV-C disinfection to remove antibiotic resistant bacteria. Still, resistant Enterobacteriaceae (about 30 × 10 6  cells per m 3 of water), presenting traits that might potentiate antibiotic resistance spread, are released in the final effluent. In addition, a significant regrowth was observed after storage. These results suggest that improvements of wastewater disinfection are still required to minimize the risks associated with UWTP discharges. [ABSTRACT FROM AUTHOR]

Abstract: This study addresses how cultures of three phytoplankton species –Chaetoceros calcitrans, Chlorella autotrophica and Phaeocystis globosa – can recover from the effects of UV-C exposure if the cells are placed in a rich medium. Flow cytometry and pulse amplitude modulation (PAM) were used to determine cell recovery after UV treatment. The recovery of C. calcitrans was complete 9days after treatment. For C. autotrophica, the recovery was noticeable 5days after treatment. P. globosa only recovered if the UV dose did not exceed 7.3×105 μWs/cm2. The recovery of the UV-treated cultures introduced to a regrowth medium, compared with the recovery of the irradiated cultures kept in their original environment, had two main characteristics: cell recovery was slower but was more efficient. This pattern of recovery has very important implications for real ballast water management systems because such systems discharge treated water into the environment. [Copyright &y& Elsevier]

Abstract: Introducing invasive species in new environments through ballast water is a specific problem of contamination and has recently become one of the main concerns of Maritime Organizations. Ultraviolet-C radiation (UV-C) is a technological alternative to prevent this maritime pollution. This study addresses the effect of UV-C on different phytoplankton cultures and also the ability to recover following exposure to damage. A UV-C low-pressure lamp irradiates the cultures. The distance from the source and the thickness of the layer prevent part of the energy from reaching the culture and the disinfective process is diminished. Some cultures such as Chlorella autotrophica and Chaetoceros calcitrans can easily recover from UV-C damage. However, Phaeocystis globosa does not have this ability. C. calcitrans forms cysts and exhibits two different behaviours depending on the dose applied. [Copyright &y& Elsevier]

Ultraviolet (UV-C) light irradiation is gaining rapid acceptance within the food and beverage industry as a non-thermal disinfection technique. A series of trials, using a pilot scale UV-C treatment system, were conducted to investigate the effect of UV-C on beer with specific attention to lightstruck flavour formation. Both commercial and micro-brewed beers were treated with UVC light at 254 nm. Samples were analysed by consumer and trained panels. Sensory analyses revealed that at a low UV-C level, lightstruck flavour was apparent and this increasingly gave way to a more intense burnt rubber off-flavour as the UV-C exposure was increased. A sample enrichment probe technique coupled with a gas chromatography-mass spectrometry (SEP/GCMS) revealed the presence of lightstruck flavour in all the treated beers. [ABSTRACT FROM AUTHOR]

Ultraviolet-C (UV-C) radiation, spanning wavelengths between 200 nm and 280 nm, has proven germicidal qualities and medical, industrial, and environmental applications. The need for new disinfection technologies and the prospect of eliminating mercury-based radiation sources compels research on ultraviolet (UV) light-emitting diodes (LEDs). UV-LED technology could be used for customized and point-of-use products for disinfection and sterilization. We focused on the design and development of a surface disinfection device using UV-C LEDs, including potential user targets, important design parameters, and final validation methods. Optical and thermal simulations were used to illustrate the design process and associated challenges. A sample device prototype was developed, and microbial validation results are presented.

Handheld Electronic Devices (HEDs) play a central role in the hospital environment. However, they can be a vehicle for transmitting (pathogenic) microorganisms. We studied whether disinfection with UV-C light is successful in disinfecting three different HEDs in a clinical setting. Disinfection with UV-C light was performed with the UV-Smart® D25. We took a total of 800 samples on two departments and counted colony forming units. More than half of the baseline measurements were moderately (>10CFU) or highly (>50 CFU) contaminated. Post-disinfection the CFU was 0 in 87% of measurements. We conclude that the UV-Smart® D25 can be used to disinfect non-critical HEDs in clinical healthcare., (© 2021 The Authors.)