In this hospital, cleaning services were outsourced. According to the contract and the cleaning and disinfection standard operating protocol (SOP), during terminal disinfection, the housekeeping staff applied a chlorine-based detergent, Antisapril Detergent %, Angelini, followed by a chlorine-based disinfectant (Deornet Clor (COSÌ, Forlì-Cesena, Italy), active chlorine mgr/L) on furniture surfaces and electromedical devices.

The UV-C disinfection robot (Mediland Enterprise Corporation, Taoyuan City, Taiwan) uses amalgam lamps (UV lamp NNI / XL Niederdruck VUV Strahler) and protective reflector technology to generate high-energy, broad-spectrum ultraviolet light (UV-C &#x; nm). The manufacturer of the lamps declares in the technical data sheet that the lamps have a filter that blocks radiation between &#x; nm, eliminating the possibility of producing ozone as a by-product of UV-C radiation. The UV-C device uses min disinfection cycles and multiple positions with minimal distances from high-touch surfaces. Due to the use of high-intensity UV-C radiation, the device must operate in unoccupied rooms. There are multi-motion sensors that shut off the device if any movement is detected inside the room being disinfected or if the door is accidentally opened. When the robot operates in accordance with these procedures, the manufacturer declares that the amalgam lamps produce no ozone gas and leave no toxic residues.

Moreover, it would be important to evaluate the advantages of implemented cleaning and disinfection protocols with the use of UV-C devices in areas hosting fragile and vulnerable patients, e.g., in intensive care units. The principal limitation is the continuous presence of people in this type of setting. For this reason, it would be worth evaluating strategies aimed at protecting the patient&#x;s safety using protective devices, which may be evaluated for human security during UV-C emission at specific dosages and times.

Our study has some limitations. Firstly, the non-homogeneous sampling for all of the settings, where a greater number of analyses were dedicated to the OTs rather than the ICUs or patient rooms: it was not always possible to proceed with the UV-C treatment at the patient discharge because trained personnel were limited and not always available. This problem underlines the importance of having dedicated personnel identifiable as that of the outsourced cleaning company. The use of new technologies could in fact be included in outsourcing contracts as an improvement action in the event of non-compliance in the cleaning service. These personnel could be adequately trained not only on the cleaning protocols to be adopted but also on infection control issues.

The role of the environment, particularly of high-touch surfaces in the patient&#x;s room (e.g., bedrails, over-bed tables, and call-buttons) and reusable care equipment that is moved between rooms, has been demonstrated to be fundamental in the transmission of healthcare-related infections. Together with standard precautions and the application of good practices in invasive procedures, environmental cleaning and disinfection represents one of the three pillars of infection risk prevention in healthcare settings.