Inactivating SARS-CoV-2 Using 275 nm UV-C LEDs through a Spherical Irradiation Box: Design, Characterization and Validation.

We report on the design, characterization and validation of a spherical irradiation system for inactivating SARS-CoV-2, based on UV-C 275 nm LEDs. The system is designed to maximize irradiation intensity and uniformity and can be used for irradiating a volume of 18 L. To this aim: (i) several commercially available LEDs have been acquired and analyzed; (ii) a complete optical study has been carried out in order to optimize the efficacy of the system; (iii) the resulting prototype has been characterized optically and tested for the inactivation of SARS-CoV-2 for different exposure times, doses and surface types; (iv) the result achieved and the efficacy of the prototype have been compared with similar devices based on different technologies. Results indicate that a 99.9% inactivation can be reached after 1 min of treatment with a dose of 83.1 J/m2.

UV-Based Technologies for SARS-CoV2 Inactivation: Status and Perspectives

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiologic agent of COVID-19, which has affected the international healthcare systems since the beginning of 2020. Among sanitizing approaches, UV irradiation is a well-known technology often used in different environments to reduce the microbial contamination and the viral transmission. In particular, several works have demonstrated that UVC radiation is able to inactivate SARS-CoV-2 compromising its viral genome and virion integrity. With this work we review and analyze the current status of the pandemic and the state of the art of the UV technology. With traditional UVC discharge lamps having a serious environmental issue, due to their working principle based on mercury, a primary focus is shifted on the aluminum gallium nitride based deep-ultraviolet light emitting diodes. These devices are exploited for compact and environmentally friendly disinfection systems, but efficiency and reliability still play a limiting role into their mass market adoption and system efficacy. In this work we then analyze the latest reports on the effects of dose and wavelength on viral inactivation, thus providing two key pillars for the development of UVC based disinfection systems: the status of the technology and a quantitative evaluation of the dose required to achieve an effective coronavirus inactivation.

Data-driven estimation of change points reveals correlation between face mask use and accelerated curtailing of the first wave of the COVID-19 epidemic in Italy.

BACKGROUND: Italy was the first Western country to be seriously affected by COVID-19, and the first to implement drastic measures, which successfully curtailed the first wave of the epidemic. METHODS: To understand which containment measures altered disease dynamics, we estimated change points in COVID-19 dynamics from official Italian data. RESULTS: We found an excellent correlation between nationwide lockdown and the epidemic peak in late March 2020. Surprisingly, we found a change point in mid-April, which did not correspond to national measures, but may be explained by regional interventions. Change points in regional COVID-19 dynamics correlated well with local distribution of free face masks and regional orders requiring their mandatory use. Regions with no specific interventions showed no change point during April. CONCLUSIONS: Our findings of the observed correlation between face mask use and disease dynamics lend further support to the importance of face masks in addition to lockdowns and other restrictions for the control of COVID-19.

Surging critical care capacity for COVID-19: Key now and in the future.

The COVID-19 pandemic has shocked health systems worldwide, with visible impacts on intensive care units and emergency departments. The concept of "surge capacity" should be analyzed within this context as this crisis could be seen as an opportunity to improve the knowledge base of intensive care units and emergency departments. We reflected, based on our experience from work at the frontlines, on health service planning and with epidemiological data, about the importance of surging critical care capacity for COVID, now and as lessons for the future. We summarize and relate virus clinical characteristics, epidemiological patterns and critical care surge capacity as important factors to consider for effective health systems response. Some practical aspects are described, but also the role that mathematical models can play to improve intensive care units surge capacity by considering its importance as a predictor of needs according to epidemiological patterns. Also, in the transitional phase, we consider the importance of coexisting COVID-19 and non-covid-19 health care services, and the importance of a new surge capacity for postponed activities. In this new transitional phase, also emergency departments will have to adapt their surge capacity for a rebound effect due to delayed visits from non-COVID-19 health conditions during the pandemic. Health systems and society must remain vigilant for potential resurgence of cases as measures are relaxed to restart the economy and a new normal. Emergency departments and intensive care units have to develop surge strategies to deal together with COVID-19 and non-COVID-19 flow of patients.