Disinfection capabilities of a 222 nm wavelength ultraviolet lighting device: a pilot study

Abstract

Objective: To demonstrate the efficacy of the SafeZone UVC (Ushio Inc., Japan) 222 nm ultraviolet C (UVC) light to reduce bacterial burden in pressure ulcers (PUs) in human patients. This research is the first human clinical trial using 222 nm UVC in eradicating bacteria in human wounds. Method: Patients with Stage 2 or 3 (as defined by the revised National Pressure Ulcer Advisory Panel Pressure Injury Staging System) sacral or gluteal pressure ulcers (PUs) were subjected to four sessions of 222 nm UVC light therapy over two weeks. Pre- and post-UVC therapy, wound cultures were taken and quantitative analysis of bacterial colony forming units (CFU) were performed. Results: A total of 68 UV light sessions across 16 different patients were conducted. Of these sessions, 59 (87.0%) sessions showed a reduction in CFU counts, with 20 (29.4%) showing complete eradication of bacteria. Bacteria identified included meticillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa and Klebsiella Pneumoniae. The overall median reduction in CFU of the 68 sessions was 78.9%. No adverse events were reported in any of the UV sessions. Conclusion: In this study, 222 nm UVC light was safe and effective in reducing bacterial CFU counts in sacral and gluteal PUs across numerous different species of bacteria.

222-Nanometer Far-UVC Exposure Results in DNA Damage and Transcriptional Changes to Mammalian Cells

“…It is alarming that clinical scientists and researchers have taken the initial optimism regarding the safety profile of 222-nanometer far UVC and begun to pursue clinical trials for performing such illumination on open wounds [ 23 ] and in healthy humans [ 24 ]. The excitement generated in the field has also seen significant interest in this technology from hospitals and facilities management, which have adopted the tool for open human exposure.…”

Safety of 222 nm UVC Irradiation to the Surgical Site in a Rabbit Model

“…Furthermore, no erythema or ear swelling was observed in mice with either genotype following 222 nm UVC exposure. In a recent clinical study, 540 mJ cm −2 of 222 nm UVC was irradiated onto sacral or gluteal pressure ulcers in human patients, and there was no evidence of complications or side effects during the 2 weeks of intermittent irradiation sessions ( 28 ). Based on this evidence, it is proposed that UVC with a shorter wavelength (e.g.…”

222-nm far UVC exposure results in DNA damage and transcriptional changes to mammalian cells

“…It is alarming that clinical scientists and researchers have taken the initial optimism regarding the safety profile of 222-nm far UVC and started to pursue clinical trials for performing such illumination on open wounds 25 and in healthy humans 26 . The excitement generated in the field has also seen huge interest for this technology in hospitals and facilities management adopting the tool for open human exposure.…”