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

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.

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.

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.

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.