# Evaluating the Utility of UV Lamps to Mitigate the Spread of Pathogens in the ICU
## 1 Introduction  
The Center for Disease Control (CDC) estimates that 1 in 31 hospitalized patients suffers a healthcare-associated infection (HAI) annually [1]. The economic implications of HAIs are far-reaching and cost the medical system between $35.7 and $45 billion each year [2; 3; 4]. In one meta-analysis looking at additional hospital costs per case, central-line-associated bloodstream infections incurred an additional $45,$14 (95% CI, $30,919-$65,245) to the total hospital stay, followed by ventilator-associated pneumorias at $40,144 (95% CI, $36,286-$44,220), surgical site infections at $20,785 (95% CI, $18,902-$22,667), _Clostridium difficile_ infections at $11,285 (95% CI, $9118-$13,574), and catheter-associated urinary tract infections at $896 (95% CI, $603-$1189) [5]. A commonality among many HAIs is their association with these devices: e.g., lines, catheters, and ventilators [6].  
Portable equipment and other shared devices, e.g., keyboards, touchscreens, and pens, may be an underappreciated source of transfer of healthcare-associated pathogens; these items are oftencontaminated by microbes and cleaning may be suboptimal [7]. In several outbreak investigations, shared equipment has been implicated as a reservoir for the transfer of pathogens [8]. One study from a laboratory at the University of Siena analyzed keyboards in a shared working space and found microbes in counts ranging from 6 colony-forming units/computer keyboard key (CFU/key) to 430 CFU/key, including _Staphylococcus_, _Streptococcus_, and _Enterococcus_ species [9]. Thus, it is plausible that decreasing the rate of cross-contamination of hospital equipment might be an effective strategy to mitigate the spread of HAIs [10; 11; 12]. This paper explores the application of passive, real-time disinfection technology to high-risk surfaces within the hospital to reduce the prevalence of contaminated surfaces and protect against pathogen transfer between patient rooms.  
Since first described in 1903 by Nobel Laureate [PERSON], ultraviolet (UV) light has been recognized as an effective decontamination technique [13; 14]. UV light works by disrupting the structure of the microorganism's DNA [15; 16] and is a well-validated sterilization tool. In one study looking at the role of UV light in stethoscope sterilization, short-wavelength ultraviolet light (UV-C) demonstrated the capacity to maintain high levels of disinfection against common HAI microorganisms [17]. Historically, the deployment of UV light in the presence of humans required significant measures to protect staff and patients from exposure. Recent developments in UV technology have yielded a new class of devices capable of monitoring for user input and delivering a low dose of UV-C light when human exposure is not detected. Each dose is set to a safe and optimal disinfection cycle to eliminate pathogens with minimal human exposure [17]. Should a human need to interact with the device being sterilized, the UV light automatically pauses its operation, waits for use to cease, then resumes the cleaning cycle.  
A 2016 study in the _American Journal of Infection Control_ demonstrated the utility of low-intensity UV-C devices in reducing the bioburden on hospital computer keyboards [18]. In the current study, we investigated the capacity of these UV-C devices in reducing the spread of a mosaic virus DNA tracer, i.e., a proxy for pathogens, across hospital rooms in the intensive care unit (ICU).