A Protocol for a Controlled, Phase II, Multi-arm, Parallel-group, Superiority, Six-month Trial Comparing the Effectiveness of Far-UVC (222 nm) in Two Experimental Arms Against Standard Care in Preventing Viral and Bacterial Infections in Long-term Care Facilities

Background Elderly residents in long-term care (LTC) facilities are highly susceptible to infections, often leading to hospitalizations and placing significant strain on the healthcare sector. The COVID-19 pandemic underscored the importance of airborne pathogen transmission and highlighted the necessity for targeted interventions that require minimal healthcare personnel resources to protect elderly populations. Far-UVC light has emerged as a promising technology offering both germicidal efficacy and safety for human exposure, although its clinical impact remains sparsely studied. This study aims to evaluate the effectiveness of far-UVC (222 nm) in mitigating hospitalizations due to viral and bacterial infections among LTC residents.

Methods The study is designed as a controlled, phase II, multi-arm, parallel-group, superiority, 6-month trial conducted in LTC facilities in Denmark. The LTC facilities will receive either far-UVC lamps or standard care with an allocation ratio of 1:1:10. One of the LTC facilities will be equipped with far-UVC lamps (experimental arm one) in common areas, while another will be equipped with far-UVC lamps (experimental arm two) in common areas and residents' apartments. We plan to include 12 public LTC facilities in Vejle with 542 residents. Outcome data will be obtained from nationally validated health registers. The primary outcome is LTC facility-acquired infections (lower respiratory tract infections, urinary tract infections, and bloodstream infections), which cause hospitalization. The key secondary outcome is prescribed antibiotics at LTC facilities, alongside monitoring all-cause mortality, cause-specific mortality (infection), and adverse events.

Discussion This trial aims to determine the clinical impact of far-UVC technology in LTC facilities. In the case of sufficiently promising effectiveness, a large-scale cluster randomized phase III will be carried out.