Understanding the effect of ultraviolet light intensity on disinfection performance through the use of ultraviolet measurements and simulation

Tande, Brian M.; Pringle, Todd A.; Rutala, William A.; Gergen, Maria F.; Weber, David J.

doi:10.1017/ice.2018.144

Cited by 11 publications

(15 citation statements)

References 4 publications

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“…Our findings are consistent with 3 recent reports in demonstrating that measurements of irradiance may be useful in understanding decontamination performance of different devices. [20][21][22] If a radiometer is available, measurement of irradiance can be completed quickly and easily. Alternatively, commercial test cards can provide a simple and easy-to-use colorimetric assessment of UV output.…”

Section: Discussionmentioning

confidence: 99%

A comparison of the efficacy of multiple ultraviolet light room decontamination devices in a radiology procedure room

Cadnum

Jencson

Gestrich

et al. 2019

Infect. Control Hosp. Epidemiol.

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ObjectiveTo evaluate the efficacy of multiple ultraviolet (UV) light decontamination devices in a radiology procedure room.DesignLaboratory evaluation.MethodsWe compared the efficacy of 8 UV decontamination devices with a 4-minute UV exposure time in reducing recovery of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), and Clostridium difficile spores on steel disk carriers placed at 5 sites on a computed tomography patient table. Analysis of variance was used to compare reductions for the different devices. A spectrometer was used to obtain irradiance measurements for the devices.ResultsFour standard vertical tower low-pressure mercury devices achieved 2 log10CFU or greater reductions in VRE and MRSA and ~1 log10CFU reductions in C. difficile spores, whereas a pulsed-xenon device resulted in less reduction in the pathogens (P<.001). In comparison to the vertical tower low-pressure mercury devices, equal or greater reductions in the pathogens were achieved by 3 nonstandard low-pressure mercury devices that included either adjustable bulbs that could be oriented directly over the exam table, a robotic base allowing movement along the side of the table during operation, or 3 vertical towers operated simultaneously. The low-pressure mercury devices produced primarily UV-C light, whereas the pulsed-xenon device produced primarily UV-A and UV-B light. The time required to move the devices from the corner of the room and set up for operation varied from 18 to 59 seconds.ConclusionsMany currently available UV devices could provide an effective and efficient adjunct to manual cleaning and disinfection in radiology procedure rooms.

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Section: Discussionmentioning

confidence: 99%

A comparison of the efficacy of multiple ultraviolet light room decontamination devices in a radiology procedure room

Cadnum

Jencson

Gestrich

et al. 2019

Infect. Control Hosp. Epidemiol.

View full text Add to dashboard Cite

show abstract

“…Variables that affect the amount of UV delivered to surfaces and the resulting log 10 reductions of pathogens achieved include the amount of irradiance generated by the UV lamp(s), the distance from the lamp to the exposed surface, the angle at which the UV strikes the surface, and whether the surface is in direct line of sight of the lamp or receives light that has been reflected off other objects (ie, surfaces in shaded areas). 7,12,17,23 The intensity of UV irradiance is inversely proportional to the square of the distance between the lamp and the exposed surface, based on the "inverse square law." 28 Therefore, the UV intensity received by a surface decreases exponentially the further the surface is from the lamp.…”

Section: Basics Of Uv Lightmentioning

confidence: 99%

“…Irradiance levels of ∼1,000 uW/cm 2 were achieved on vertical surfaces located in the direct line of sight of the device at distances in the range of 1.3 m (4 feet), whereas irradiance of only 3-10 uW/cm 2 were achieved on horizontal surfaces located in shaded areas at distances in the range of 3.3 m (10 feet) from the device. 12,22,23 Despite the marked dropoff in UV-C dose in shaded areas, 2 log 10 reductions were achieved for MRSA at both 1.3 and 3.3 m. In contrast, C. difficile spores are relatively resistant to UV-C. Minimal reductions in C. difficile spores were achieved in shaded areas, and both distance and orientation of the carriers had a more marked impact on the efficacy of UV-C. Tande et al 23 reported similar findings for the UV-C doses delivered to various locations in a room, and other studies have also demonstrated that UV-C doses are lowest when the surface is not in the direct line of sight of the lamp.…”

Section: Basics Of Uv Lightmentioning

confidence: 99%

“…12,22,23 Despite the marked dropoff in UV-C dose in shaded areas, 2 log 10 reductions were achieved for MRSA at both 1.3 and 3.3 m. In contrast, C. difficile spores are relatively resistant to UV-C. Minimal reductions in C. difficile spores were achieved in shaded areas, and both distance and orientation of the carriers had a more marked impact on the efficacy of UV-C. Tande et al 23 reported similar findings for the UV-C doses delivered to various locations in a room, and other studies have also demonstrated that UV-C doses are lowest when the surface is not in the direct line of sight of the lamp. 12,17 Facilities using UV-C room decontamination devices can consider several strategies to reduce the impact of distance and shadowing on UV-C delivery to surfaces in patient rooms.…”

Section: Basics Of Uv Lightmentioning

confidence: 99%

“…7,16 Determining the effectiveness of devices is complicated by lack of standard methods for testing UV-C devices, limited published data on the doses of UV delivered to various surfaces in patient rooms, and conflicting data on the UV dose (fluence) necessary to achieve desired reductions of various healthcare pathogens, including C. difficile. 12,[17][18][19][20][21][22][23][24] Healthcare personnel would benefit from a basic understanding of the characteristics of UV-C, the availability of more evidence on the UV-C doses delivered to surfaces in patient rooms, and knowledge of the UV-C doses required to reduce specific healthcare pathogens.…”

Section: Introductionmentioning

confidence: 99%

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Understanding ultraviolet light surface decontamination in hospital rooms: A primer

Boyce¹,

Donskey

2019

Infect. Control Hosp. Epidemiol.

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Ongoing challenges in maintaining optimum manual cleaning and disinfection of hospital rooms have created increased interest in “no-touch” decontamination technologies including the use of ultraviolet light (UV). Trials have shown that some UV devices can decrease surface contamination and reduce healthcare-associated infections. Despite substantial marketing of these devices for use in healthcare settings, few data are available regarding the doses of UV-C necessary to yield desired reductions in healthcare pathogens and the ability of mobile devices to deliver adequate doses to various surfaces in patient rooms. This review summarizes the physical aspects of UV that affect the doses delivered to surfaces, the UV-C doses needed to yield 3 log10 reductions of several important healthcare-associated pathogens, the doses of UV-C that can be achieved in various locations in patient rooms using mobile UV-C devices, and methods for measuring UV doses delivered to surfaces.

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Best practices for disinfection of noncritical environmental surfaces and equipment in health care facilities: A bundle approach

Rutala

Weber

2019

American Journal of Infection Control

Self Cite

109

115

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Over the past decade, there is excellent evidence in the scientific literature that contaminated environmental surfaces and noncritical patient care items play an important role in the transmission of several key health care−associated pathogens including methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, Acinetobacter, norovirus, and Clostridium difficile. Thus, surface disinfection of noncritical environmental surfaces and medical devices is one of the infection prevention strategies to prevent pathogen transmission. This article will discuss a bundle approach to facilitate effective surface cleaning and disinfection in health care facilities. A bundle is a set of evidence-based practices, generally 3-5, that when performed collectively and reliably have been proven to improve patient outcomes. This bundle has 5 components and the science associated with each component will be addressed. These components are: creating evidencebased policies and procedures; selection of appropriate cleaning and disinfecting products; educating staff to include environmental services, patient equipment, and nursing; monitoring compliance (eg, thoroughness of cleaning, product use) with feedback (ie, just in time coaching); and implementing a "no touch" room decontamination technology and to ensure compliance for patients on contact and enteric precautions. This article will also discuss new technologies (eg, continuous room decontamination technology) that may enhance our infection prevention strategies in the future.

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Understanding the effect of ultraviolet light intensity on disinfection performance through the use of ultraviolet measurements and simulation

Cited by 11 publications

References 4 publications

A comparison of the efficacy of multiple ultraviolet light room decontamination devices in a radiology procedure room

A comparison of the efficacy of multiple ultraviolet light room decontamination devices in a radiology procedure room

Understanding ultraviolet light surface decontamination in hospital rooms: A primer

Best practices for disinfection of noncritical environmental surfaces and equipment in health care facilities: A bundle approach

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