Original Investigation 

Germicidal UV Light and Incidence of Acute Respiratory Infection in Long-Term Care for Older Adults: A Randomized Clinical Trial

Andrew P. Shoubridge, Amanda Brass, Maria Crotty, et al

JAMA Intern Med Published Online: July 28, 2025

doi: 10.1001/jamainternmed.2025.3388

Key Points

Question  Can germicidal UV light (GUV) appliances in common spaces reduce the incidence of acute respiratory infections (ARIs) in long-term care facilities for older adults?

Findings  In this randomized clinical trial that recorded 596 infections over 211 952 bed-days, GUV appliances did not result in a significant difference in the incidence rate per zone per cycle. When modeling ARIs across all cycles of the study, GUV appliances significantly reduced infections by 0.319 infections per week, equating to a 12.2% difference.

Meaning  The trial findings suggest that GUV appliances did not reduce the incidence rate of ARIs within study cycles but did significantly reduce the total numbers of ARIs among older adult residents of long-term care facilities.

Abstract

Importance  Infectious outbreaks of respiratory viruses within long-term care facilities (LTCFs) for older adults are associated with high rates of hospitalization and death. Despite evidence that airborne transmission contributes substantially to the spread of respiratory viruses within residential care for older adults, this mode of transmission has been largely unaddressed by existing infection control practices.

Objective  To determine whether germicidal UV (GUV) appliances reduce acute respiratory infection (ARI) incidence in LTCFs.

Design, Setting, and Participants  This multicenter, 2-arm, double-crossover, cluster randomized clinical trial assessed the effectiveness of GUV appliances in common spaces on the incidence of ARIs in 4 LTCFs in metropolitan and regional South Australia. LTCFs were divided into 2 equally sized zones (mean [SD] size, 44 [9] beds per zone). Within each LTCF, zones were randomized to active GUV appliances (intervention) or inactive (control) for 6 weeks, which was followed by a 2-week washout, crossover, and a further 2-week washout. Seven consecutive cycles were performed during the 110-week study period from August 31, 2021, to November 13, 2023. Data were analyzed from January 18, 2024, to December 4, 2024.

Intervention  Continuous GUV appliance activity within common (non–resident room) areas for 6 weeks.

Main Outcome and Measures  The primary outcome was the incidence rate of ARIs (per zone per cycle). A secondary analysis of long-term trends was performed based on infections per week.

Results  Eight assessed zones across 4 LTCFs represented a total of 211 952 bed-days. Of 596 ARIs recorded across all zones, 475 (79.7%) occurred during intervention or control periods. The incidence rate in the control arm was 4.17 infections per zone per cycle (95% CI, 2.43-5.91), compared with 3.81 infections per zone per cycle (95% CI, 2.21-5.41) in the intervention arm (incidence rate ratio, 0.91; 95% CI, 0.77-1.09; P = .33). A posteriori secondary analysis with time-series autoregressive modeling showed that the control group recorded 2.61 ARIs per week (95% CI, 2.51-2.70) compared with 2.29 ARIs per week (95% CI, 2.06-2.51) in the intervention group (mean difference, 0.32; 95% CI, 0.10-0.54; P = .004).

Conclusions and Relevance  This randomized clinical trial found that GUV light appliances in common areas of LTCFs did not reduce the incidence rate of ARIs per zone per cycle but did modestly reduce the total numbers of ARIs by the study conclusion. GUV appliances might be considered to support existing infection prevention and control practices in these settings.

Trial Registration  Australian and New Zealand Clinical Trial Registration: ACTRN12621000567820