Evaluation of an automated ultraviolet-C light disinfection device and patient hand hygiene for reduction of pathogen transfer from interactive touchscreen computer kiosks

Robots in travel clinics: building on tourism's use of technology and robots for infection control during a pandemic

The arrival of COVID-19 impacted every aspect of life around the world. The virus, whose spread was facilitated overwhelmingly by people's close contact at home and by travelling, devastated the tourism, hospitality, and transportation industry. Economic survival depended largely on demonstrating to authorities and potential travellers the strict adherence to infection control measures. Fortunately, long before the pandemic, the industry had already employed digital technology, artificial intelligence, and service robots, not to keep the world safe, but to either bridge staff shortages or save costs, reduce waiting times, streamline administration, complete unattractive, tedious, or physical tasks, or use technology as marketing gimmicks. With COVID-19, offering social distancing and touchless service was an easy step by extending quickly what was already there. The question arose: could travellers' acceptance of technology and robots for infection control be useful in travel medicine? COVID-19 fostered the rapid and increased acceptance of touchless technology relating to all things travel. The public's expectations regarding hygiene, health and safety, and risk of infection have changed and may stay with us long after the pandemic is 'the new normal', or a new one approaches. This insight, combined with the current experience with robots in health and medicine, is useful in exploring how robots could assist travel medicine practice. However, several aspects need to be considered in terms of type of robot, tasks required, and the public's positive or negative attitudes towards robots to avoid known pitfalls. To meet the crucial infection control measures of social distancing and touch avoidance, the use of robots in travel medicine may not only be readily accepted but expected, and implications for management, practice, and research need to be considered.

Review of microbial touchscreen contamination for the determination of reasonable ultraviolet disinfection doses

Background: Touchscreens are usually microbially contaminated and can therefore act as fomites inside and outside healthcare environments. Due to the increasing use of such touchscreens and the growing awareness of infection risks, approaches that allow safe and automatic disinfection are desired. Ultraviolet (UV) irradiation, with its known antimicrobial efficacy, could achieve this goal, but should be executed with limited touchscreen degradation, disinfection duration, and energy consumption. It should also pose as little harm as possible to humans even in case of failure. Materials and methods: A literature search was performed first to identify the microorganisms most commonly found on touchscreens. Then, the 90% reduction doses (D90 doses) for the different relevant microorganisms and UV spectral ranges were determined from the literature, and irradiation doses are suggested that should reduce most of these important microorganisms by 5 log-levels. Results: The most frequent microorganisms are staphylococci, bacilli, micrococci, enterococci, pseudomonads and E. coli with small differences between hospital and community environments, if antibiotic resistance properties are ignored. The determined irradiation doses for a 5 log-reduction of the most frequent microorganisms are about 40 mJ/cm2, 80 J/cm2, 500 J/cm2 and 50 mJ/cm2 for the UV spectral ranges UVC, UVB, UVA and far-UVC, respectively. These doses are also sufficient to inactivate all nosocomial ESKAPE pathogens on touchscreens by at least 99.999%. Conclusion: Disinfection is achievable in all UV spectral ranges, with UVC being the most effective, enabling automatic disinfection within a minute or less. The much higher doses required in the UVB and UVA spectral range result in much longer disinfection durations, with the advantage of a reduced risk to humans. For all kinds of UV irradiation, the doses should be limited to reasonable values to avoid irradiating an already more or less sterile surface and to prevent degradation of touchscreen devices.

Efficacy of UV-C disinfection in hyperbaric chambers

Ultraviolet C (UV-C) light reduces contamination on high-touch clinical surfaces. We assessed the efficacy of 2 UV-C devices at eradicating important clinical pathogens in hyperbaric chambers. Both devices were similarly efficacious against MRSA but differed significantly against C. difficile. Additionally, direct UV-C exposure was more efficacious against both species than indirect exposure.

Evaluation of Ultraviolet-C Light for Rapid Decontamination of Airport Security Bins in the Era of SARS-CoV-2

Background:

Contaminated surfaces are a potential source for spread of respiratory viruses including SARS-CoV-2. Ultraviolet-C (UV-C) light is effective against RNA and DNA viruses and could be useful for decontamination of high-touch fomites that are shared by multiple users.

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 UV-C light for rapid decontamination of plastic airport security bins inoculated at 3 sites with methicillin-resistant Staphylococcus aureus (MRSA) and bacteriophages MS2, PhiX174, and Phi6, an enveloped RNA virus used as a surrogate for coronaviruses. Reductions of 3 log₁₀ on inoculated plastic bins were considered effective for decontamination.

Results:

UV-C light administered as 10-, 20-, or 30-second cycles in proximity to a plastic bin reduced contamination on each of the test sites, including vertical and horizontal surfaces. The 30-second cycle met criteria for decontamination of all 3 test sites for all the test organisms except bacteriophage MS2 which was reduced by greater than 2 log₁₀ PFU at each site.

Conclusions:

UV-C light is an attractive technology for rapid decontamination of airport security bins. Further work is needed to evaluate the utility of UV-C light in real-world settings and to develop methods to provide automated movement of bins through a UV-C decontamination process.

Understanding ultraviolet light surface decontamination in hospital rooms: A primer

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.

Beyond high-touch surfaces: Portable equipment and floors as potential sources of transmission of health care-associated pathogens

Efforts to improve environmental cleaning and disinfection typically focus primarily on high-touch surfaces in patient rooms. This review highlights evidence that portable equipment and other shared devices and floors may be underappreciated as sources of dissemination of health care-associated pathogens. Practical approaches to address these sites of contamination are emphasized.

Decontamination devices in health care facilities: Practical issues and emerging applications

"No-touch" decontamination devices are increasingly used as an adjunct to standard cleaning and disinfection in health care facilities. Although there is evidence that these devices are effective in reducing contamination, there are several areas of controversy regarding their use. This review addresses some of the questions frequently posed by infection prevention and environmental services personnel about decontamination devices.

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

Objective

To evaluate the efficacy of multiple ultraviolet (UV) light decontamination devices in a radiology procedure room.

Design

Laboratory evaluation.

Methods

We 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.

Results

Four 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.

Conclusions

Many currently available UV devices could provide an effective and efficient adjunct to manual cleaning and disinfection in radiology procedure rooms.