# Evaluating the Utility of UV Lamps to Mitigate the Spread of Pathogens in the ICU
## 4 Discussion  
HAIs are commonly spread through contaminated hospital surfaces, air, water, or providers that serve to transport pathogens [21; 22]. Countless surfaces in hospitals are reservoirs for viable pathogens including Methicillin-Resistant Staphylococcus Aureus (MRSA) and Vancomycin Resistant Enterococcus (VRE). In rooms of patients with diarrhea, viable MRSA has been collected from 59% of the room surfaces and viable VRE has been collected from 46% of room surfaces [23]. Despite the known prevalence of contaminated surfaces, current cleaning practices are inadequate [24]. Terminal room cleaning after patient discharge only reduced bacterial contamination to undetectable levels on 49% of surfaces, including less than 30% for toilet hand holds, bedpan cleaners, room doorknobs, and bathroom light switches [25]. Furthermore, these cleaning practices occur, at best, once per day [12]. These high-touch surfaces serve as potent sources for bacterial and viral transfer and are concerning given the ratio of touches to cleanings that they receive [26]. In one analysis, it was noted that while nearly two thirds of clinical staff touched surfaces within a patient's room, these same surfaces were only cleaned by environmental services a maximum of once per day [27]. Alarmingly, it is these same surfaces nearest to the patient that confer the highest infection risk [28; 29; 30]. Despite numerous studies demonstrating its utility, UV light use remains underutilized in the hospital, in part due to issues regarding costs, safety, or staffing needs [13]. The small UV devices used in the current study have some advantages and disadvantages over larger UV room decontamination devices. The devices are intended to be used when people are present and are fully automated. In a previous study, we found that the UV devices effectively decontaminated keyboards with no interruption of workflow, no additional staffing, and no adverse effects due to UV exposure. This follow-up study again demonstrated the capacity of UV light to reduce bacterial burden on some of the most commonly touched surfaces in the hospital. It seems reasonable to conclude that UV treatment could help mitigate the spread of infectious agents by reducing cross-contamination from commonly used objects in the ICU, given the frequency with which these devices are used. Here, we sought to decontaminate as many device surfaces as possible post contact with staff via the application of passive UVC light. By providing real-time pathogen reduction technology to various surfaces, we reduced the probability that a mosaic virus was able to spread within the ICU. In combination with high handwashing rates, which were assumed to be constant throughout the study, as the probability of decontaminated surfaces in the hospital increases, the number of viable transfer routes between patients decreases [31]. Greater utilization of validated aseptic techniques like UV decontamination could enhance patient safety and improve outcomes, especially in critically ill and otherwise susceptible patients [32]. This study has limitations given the resources and time available to run the trial. While we significantly reduced the transfer of pathogens on the UV-protected devices, we do not know what percent of interactions those high-touch devices represent as it is impractical to count every touch that occurs in an ICU of this size. Given this limitation, we only tested known high-touch surfaces. These surfaces were identified by a review of time in motion studies [33]. Lastly, we were unable to consent patients for physical culturing, so it was not within the means of this analysis to provide direct evidence that the mosaic virus was transmitted to patients from the numerous in-room surfaces. Further study is needed to examine if this causal reduction in pathogen transfer leads to a reduction in specific healthcare-associated infections.