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Devin Mills, Delbert A Harnish, Caryn Lawrence, Megan Sandoval-Powers, Brian K Heimbuch
BACKGROUND: Safe and effective decontamination and reuse of N95 filtering facepiece respirators (FFRs) has the potential to significantly extend FFR holdings, mitigating a potential shortage due to an influenza pandemic or other pandemic events. Ultraviolet germicidal irradiation (UVGI) has been shown to be effective for decontaminating influenza-contaminated FFRs. This study aims to build on past research by evaluating the UVGI decontamination efficiency of influenza-contaminated FFRs in the presence of soiling agents using an optimized UVGI dose...
April 17, 2018: American Journal of Infection Control
Vincent Masse, Michael J Hartley, Michael B Edmond, Daniel J Diekema
Background: Ultraviolet germicidal irradiation (UVGI) systems are gaining popularity, however objective comparisons of their characteristics are lacking. While environmental cultures and reduction of hospital-associated infections rates are excellent study endpoints, they are impractical for centers with limited resources who want to compare or optimize UVGI systems use. Methods: We evaluated radiometry and commercial test cards, two simple and low cost tools, to compare 2 full size UVGI systems (Tru-D and Optimum-UV Enlight) and 2 small units (Lumalier EDU 435 and MRSA-UV Turbo-UV)...
2018: Antimicrobial Resistance and Infection Control
William G Lindsley, Tia L McClelland, Dylan T Neu, Stephen B Martin, Kenneth R Mead, Robert E Thewlis, John D Noti
Ambulances are frequently contaminated with infectious microorganisms shed by patients during transport that can be transferred to subsequent patients and emergency medical service workers. Manual decontamination is tedious and time-consuming, and persistent contamination is common even after cleaning. Ultraviolet germicidal irradiation (UVGI) has been proposed as a terminal disinfection method for ambulance patient compartments. However, no published studies have tested the use of UVGI in ambulances. The objectives of this study were to investigate the efficacy of a UVGI system in an ambulance patient compartment and to examine the impact of UVGI fixture position and the UV reflectivity of interior surfaces on the time required for disinfection...
January 2018: Journal of Occupational and Environmental Hygiene
Jaroslavas Belovickis, Aliaksei Kurylenka, Vadim Murashko
We report on the impact of direct ultraviolet germicidal irradiation (UVGI) on reflective optics, used in the excimer laser system Allegretto Eye-Q. The aim of our work was to confirm our hypothesis based on long-rate observations of obtained anomalies in post-operative results that are attributed to degradation of reflective optics upon ultraviolet radiation. The presence of direct UVGI coupled with humidity in the operating environment caused merging anomalies and unwanted post-operative correction values...
2017: International Journal of Ophthalmology
Katelyn C Jelden, Shawn G Gibbs, Philip W Smith, Angela L Hewlett, Peter C Iwen, Kendra K Schmid, John J Lowe
An ultraviolet germicidal irradiation (UVGI) generator (the TORCH, ClorDiSys Solutions, Inc.) was used to compare the disinfection of surface coupons (plastic from a bedrail, stainless steel, and chrome-plated light switch cover) in a hospital room with walls coated with ultraviolet (UV)-reflective paint (Lumacept) or standard paint. Each surface coupon was inoculated with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus faecalis (VRE), placed at 6 different sites within a hospital room coated with UV-reflective paint or standard paint, and treated by 10 min UVC exposure (UVC dose of 0-688 mJ/cm2 between sites with standard paint and 0-553 mJ/cm2 with UV-reflective paint) in 8 total trials...
June 2017: Journal of Occupational and Environmental Hygiene
Chunxiao Su, Josephine Lau, Fang Yu
Recently, the requirement to continuously collect bioaerosol samples using shorter response times has called for the use of real-time detection. The decreased cost of this technology makes it available for a wider application than military use, and makes it accessible to pharmaceutical and academic research. In this case study, real-time bioaerosol monitors (RBMs) were applied in elementary school classrooms-a densely occupied environment-along with upper-room ultraviolet germicidal irradiation (UVGI) devices...
January 8, 2017: International Journal of Environmental Research and Public Health
David A Pegues, Jennifer Han, Cheryl Gilmar, Brooke McDonnell, Steven Gaynes
OBJECTIVE To evaluate the impact of no-touch terminal room no-touch disinfection using ultraviolet wavelength C germicidal irradiation (UVGI) on C. difficile infection (CDI) rates on inpatient units with persistently high rates of CDI despite infection control measures. DESIGN Interrupted time-series analysis with a comparison arm. SETTING 3 adult hematology-oncology units in a large, tertiary-care hospital. METHODS We conducted a 12-month prospective valuation of UVGI. Rooms of patients with CDI or on contact precautions were targeted for UVGI upon discharge using an electronic patient flow system...
January 2017: Infection Control and Hospital Epidemiology
Sonya Milonova, Stephen Rudnick, James McDevitt, Edward Nardell
The threshold limit value (TLV) guideline for ultraviolet (UV) radiation specifies that irradiance measurements to ensure occupant safety be taken over an angle of 80° at the sensor. The purpose of this study was to evaluate the effect of an 80° field of view (FOV) tube on lower room UV-C irradiation measurements. Measurements were made in an experimental chamber at a height of 1.73m with and without an FOV tube. The FOV tube reduced the lower room irradiance readings by 18-34%, a statistically significant reduction compared to the bare sensor...
June 2016: Journal of Photochemistry and Photobiology. B, Biology
Katelyn C Jelden, Shawn G Gibbs, Philip W Smith, Angela L Hewlett, Peter C Iwen, Kendra K Schmid, John J Lowe
The estimated 721,800 hospital acquired infections per year in the United States have necessitated development of novel environmental decontamination technologies such as ultraviolet germicidal irradiation (UVGI). This study evaluated the efficacy of a novel, portable UVGI generator (the TORCH, ChlorDiSys Solutions, Inc., Lebanon, NJ) to disinfect surface coupons composed of plastic from a bedrail, stainless steel, chrome-plated light switch cover, and a porcelain tile that were inoculated with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus faecalis (VRE)...
September 2016: Journal of Occupational and Environmental Hygiene
Christopher F Green, Laura A Elbe, Tyler D Neal, John J Lowe, Shawn G Gibbs
Antibiotic misuse and overuse in both the healthcare and agricultural fields have dramatically increased the prevalence of antibiotic resistance in human pathogens. Two strains of methicillin-resistant Staphylococcus aureus (MRSA) (ATCC 43330 and a wild-type) and 1 strain of methicillin-susceptible S. aureus (ATCC 25923) were challenged (9 runs in triplicate) in a preliminary study with ultraviolet germicidal irradiation (UVGI) doses ranging from 0.25 to 3.00 mJ/cm(2). The mean percent kill was calculated for each strain when compared with the control plates (no exposure to UVGI)...
November 2015: Canadian Journal of Microbiology
Chunxiao Su, Josephine Lau, Shawn G Gibbs
This article describes a casestudythe authors conducted in an elementary school in the Midwest. The objective was to evaluate the performance of ultraviolet germicidal irradiation (UGVI) to reduce the bioaerosol concentration in a classroom. Two fourth grade classrooms with the same dimensions were studied. One classroom was designated as the UVGI group and the other as the control group. Two-stage Tisch culturable impactors were utilized for collecting airborne bacteria with monthly samples collected from October 2012 to January 2013...
May 2015: Journal of Environmental Health
William G Lindsley, Stephen B Martin, Robert E Thewlis, Khachatur Sarkisian, Julian O Nwoko, Kenneth R Mead, John D Noti
The ability to disinfect and reuse disposable N95 filtering facepiece respirators (FFRs) may be needed during a pandemic of an infectious respiratory disease such as influenza. Ultraviolet germicidal irradiation (UVGI) is one possible method for respirator disinfection. However, UV radiation degrades polymers, which presents the possibility that UVGI exposure could degrade the ability of a disposable respirator to protect the worker. To study this, we exposed both sides of material coupons and respirator straps from four models of N95 FFRs to UVGI doses from 120-950 J/cm(2)...
2015: Journal of Occupational and Environmental Hygiene
Jia-You Gong, Yen-Chi Chen, Yi-Ting Huang, Ming-Chien Tsai, Kuo-Pin Yu
Fungal spores are known as critical indoor allergens, and indoor air purification techniques including photocatalytic disinfection using titanium dioxide (TiO2), ultraviolet germicidal irradiation (UVGI) and ozonation, have been considerably investigated. However, most of the research is in regard to photocatalytic disinfection, focused on the anti-bacterial efficacy of TiO2 nanoparticles (NPs). Furthermore, some research even showed that the photocatalytic antifungal efficacy of TiO2 NPs may not be that significant...
September 2014: Photochemical & Photobiological Sciences
Shengwei Zhu, Jelena Srebric, Stephen N Rudnick, Richard L Vincent, Edward A Nardell
This study proposes a numerical modeling method for the indoor environment with ceiling fans and upper-room ultraviolet germicidal irradiation (UR-UVGI) fixtures. The numerical modeling deployed steady-state Computational Fluid Dynamics (CFD) with a rotating reference frame to simulate the rotation of fan blades. CFD was validated with experimental data of velocity field and fraction of microorganism remaining at the exhaust diffuser. The fraction of microorganism remaining represented the ratio of the concentration of airborne microorganisms measured with UVGI turned on to the one measured with UVGI turned off...
February 2014: Building and Environment
Hiroyuki Furuya
OBJECTIVES: Exogenous reinfections in tuberculosis (TB) have been reported among elderly patients in long-term care facilities. This study estimated the impact of upper room ultraviolet germicidal irradiation (UVGI) and negative air ionization on the reduction in TB infection assuming that current TB control failed. METHODS: Estimated probability distributions RA, RM, RUV+M, and RIO+M, denoting the reproduction numbers of cases with no intervention, wearing surgical mask of infector, upper room UVGI, and negative ionization with wearing mask, respectively were determined...
2013: Tokai Journal of Experimental and Clinical Medicine
J C Linnes, S N Rudnick, G M Hunt, J J McDevitt, E A Nardell
A novel whole ceiling upper-room ultraviolet germicidal irradiation (UVGI) system [eggcrate ultraviolet (UV)] has been developed that incorporates open-cell 'eggcrate'-suspended ceiling panels and bare UV lamps with a ceiling fan. Upper-room UVGI is more effective for air disinfection than mechanical ventilation at much lower installation and operating costs. Conventional upper-room UVGI fixtures employ multiple tightly spaced horizontal louvers to confine UV to the upper-room. These louvered fixtures protect occupants in the lower-room from UV-induced eye and skin irritation, but at a major cost to fixture efficiency...
April 2014: Indoor Air
Edward Nardell, Richard Vincent, David H Sliney
Upper-room ultraviolet germicidal irradiation (UVGI) has several applications, its most important use is to reduce tuberculosis transmission in high-burden, resource-limited settings, especially those dealing with epidemics of drug-resistant disease. The efficacy of upper-room (UVGI) to reduce the transmission of airborne infection in real-world settings is no longer in question. International application (dosing) guidelines are needed, as are safety standards and commissioning procedures. A recent symposium to build consensus on guidelines discussed specifications for affordable UVGI fixture designs, safety, performance, computer-aided design (CAD) for UVGI, maintenance, dosimetry, gonioradiometric measurement and innovation using germicidal LEDs...
July 2013: Photochemistry and Photobiology
Shelly L Miller, Jacqueline Linnes, Julia Luongo
Ultraviolet germicidal irradiation (UVGI) for air disinfection applications has relied on low-pressure mercury vapor lamps for decades. New design requirements have generated the need for alternatives in some uses. This study describes the current state of UVGI technology and describes future directions for technology development, including the use of lamps produced from nontoxic materials and light-emitting diode lamps. Important applications are discussed such as the use of ultraviolet germicidal lamps in developing countries, in heating, ventilating and air-conditioning systems to improve energy efficiency and indoor air quality, and for whole room disinfection...
July 2013: Photochemistry and Photobiology
Wilhelm Leuschner, Faatiema Salie
In upper-room ultraviolet germicidal irradiance (UVGI) design, irradiance is an important characteristic, with two opposing dominant dynamics: high-level irradiation on the microorganism and minimum levels of irradiance on human skin and eyes. The use of high-level ray-tracing procedures is followed in establishing radiance and irradiance levels. The main constants in a room influencing these calculations are the spectral and spatial characteristics of the radiation sources in the inter-reflecting surfaces inside the luminaire, as well as the surfaces in the room...
July 2013: Photochemistry and Photobiology
Peng Xu, Noah Fisher, Shelly L Miller
This research was conducted to evaluate the design of hospital ultraviolet germicidal irradiation (UVGI) systems and to assess their effectiveness for inactivating airborne mycobacteria. A computational fluid dynamics (CFD) model was developed and tested by simulating previous experiments measuring the effectiveness of a lab-based UVGI system. Model testing showed reasonable agreement with experimental measurements. The model captured trends similar to the experiments: Effectiveness of an upper-room UVGI system is higher when there is no ventilation compared with when there is ventilation, and wintertime ventilation conditions can markedly decrease the performance of an upper-room UVGI system...
July 2013: Photochemistry and Photobiology
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