Abstract Ultraviolet C (UV‐C) not only has a bactericidal effect, but is also cytotoxic; however, UV‐C at a wavelength of 222 nm with a high absorption coefficient for proteins is considered safe. We have previously reported the safety of 222‐nm UV‐C irradiation in humans and rabbits. This study evaluated the bactericidal effect of 222‐nm UV‐C irradiation on exposed surgical fields. Sixteen‐week‐old female rabbits were used, and the exposed area on their backs was sprayed with a bacterial solution from swabs collected from their soles. Three groups were formed based on UV‐C irradiation: 500 mJ/cm 2 of 222‐nm UV‐C, 200 mJ/cm 2 of 254‐nm UV‐C, which is commonly used in germicidal lamps, and non‐UV‐C irradiation. The bacterial colonies were counted after irradiation. Both UV‐C groups showed a significant reduction in bacterial colonies compared to the nonirradiated group, with no significant difference between the two UV‐C groups. Microbiota analysis identified species that could cause surgical site infections. The results of the study suggest that 500 mJ/cm 2 of 222‐nm UV‐C irradiation effectively reduces bacterial load, with a bactericidal effect comparable to 254‐nm UV‐C; hence, 222‐nm UV‐C irradiation is a promising and safe tool for minimizing the risk of surgical site infections.
Fukui et al. (Tue,) studied this question.