ประสิทธิผลของระบบแสงฆ่าเชื้อ 405 นาโนเมตร ต่อการลดปริมาณเชื้อแบคทีเรียในสิ่งแวดล้อม: ประสิทธิผลของระบบแสงฆ่าเชื้อ 405 นาโนเมตร

Kajorn  Suntrapiwat; Sarat  Kiartivich; Ladda  Viriyawong

Authors

Kajorn Suntrapiwat Department of Internal Medicine, Buddhachinaraj Phitsanulok Hospital
Sarat Kiartivich Department of Internal Medicine, Buddhachinaraj Phitsanulok Hospital
Ladda Viriyawong Department of Internal Medicine, Buddhachinaraj Phitsanulok Hospital

Keywords:

405 nanometer antimicrobial light system, bacterial decontamination efficacy, hospital infection prevention and control

Abstract

The medical intensive care unit and the Chinaraja Endoscopy Center are high-risk areas for infection control, therefore light sterilization should be used. This pilot quasi-experimental, uncontrolled before-andafter study aimed to evaluate the effectiveness of a 405-nanometer high-intensity narrow-spectrum light environmental disinfection system in reducing bacterial contamination on high-touch surfaces at Buddhachinaraj Phitsanulok Hospital. The study was conducted in two primary areas: medical intensive care unit 2 and the Chinaraja Endoscopy Center. Confounding variables, cleaning routines and ventilation configurations were strictly controlled. Surface samples were collected using contact-plate sampling with irradiated agar before and after a 24-hour continuous exposure to the light system. Data were analyzed using median (IQR) paired comparisons were performed using the Wilcoxon signed-rank test. It was found that after 24 hours of lighting system activation, the average bacterial count decreased significantly in all zones (81-90% reduction) (p = 0.002). For the endoscopy center, in patient-free conditions and in patient-occupant, the average bacterial count decreased by 98.88-99.03% and 94.61-96.81% respectively, all examination rooms showing statistically significant decreases (p < 0.001). In conclusion, the 405 nm antimicrobial light system for 24 hours significantly reduced bacterial counts on frequently touched surfaces. Therefore, the 405 nm light system should be used as a supplementary measure in conjunction with routine environmental cleaning

References

Kulthamrong V, Wanchai A, Choosri P, Thophed W, Chanuwat S, Peerapu P. The development of nursing system for patients with multiple trauma in Buddhachinaraj Phitsanulok Hospital. Nurs Health Public Health J 2025;4(2):76-90.

MED I. Medical Intensive Care Unit, Buddhachinaraj Phitsanulok Hospital. Clin Crit Care [Internet]. 2013 Mar 29 [cited 2025 Nov 26];21(1):17-8. Available from: tci-thaijo.org

Thanyathada P. Antimicrobial Resistance (AMR) situation in Buddhachinaraj Phitsanulok Hospital during 2021-2023. Buddhachinaraj Med J 2025;42(1):42-52.

Clean Edge Thailand. About us: Clean Edge light decontamination system [Internet]. Pathum Thani: Clean Edge Thailand; [cited 2026 Jul 23]. Available from: https://cleanedgethailand.com/about/.

Health Protection Scotland, National Services Scotland (NHS Scotland). Literature Review and Practice Recommendations: Existing and emerging technologies used for decontamination of the healthcare environment–HINS Light. Version 1.0. May 2017 [cited 2025 Nov 26]. Available from: https://www.hps.scot.nhs.uk/web-resources-container/literature-review-and-practice-recommendations-existing-and-emerging-technologies-used-for-decontamination-of-the-healthcare-environment-hins-light/

Murdoch LE, Maclean M, Endarko E, MacGregor SJ, Anderson JG. Bactericidal effects of 405 nm light exposure demonstrated by inactivation of Escherichia, Salmonella, Shigella, Listeria, and Mycobacterium species in liquid suspensions and on exposed surfaces. Sci World J 2012;2012:137805. doi:10.1100/2012/137805

Maclean M, MacGregor SJ, Anderson JG, Woolsey G. Inactivation of bacterial pathogens following exposure to light from a 405-nanometer light-emitting diode array. Appl Environ Microbiol 2009;75(7):1932-7. doi:10.1128/aem.01892-08

Amodeo D, Manzi P, De Palma I, Puccio A, Nante N, Barcaccia M, et al. Efficacy of violet blue (405 nm) LED lamps for disinfection of high environmental contact surfaces in healthcare facilities: Leading to the inactivation of microorganisms and reduction of MRSA contamination. Pathogens 2023;12(11):1338. doi:10.3390/pathogens12111338.

McKenzie K, Maclean M, Grant MH, Ramakrishnan P, MacGregor SJ, Anderson JG. The effects of 405 nm light on bacterial membrane integrity determined by salt and bile tolerance assays, leakage of UV absorbing material and SYTOX green labelling. Microbiology 2016;162(9):1680-8. doi:10.1099/mic.0.000350

Dougall L, Anderson JG, MacGregor SJ, MacLean M. Efficacy of antimicrobial 405 nm blue-light for inactivation of airborne bacteria. In: Proceedings of SPIE Photonics West 2018 [Internet]; 2018 Jan 27-Feb 1; San Francisco, CA. [cited 2026 Jul 23]. Available from: https://doi.org/10.1117/12.2289987

Vashishtha K, Xi F, Dharmalingam P, Douplik A. Comparative study of blue light with ultraviolet (UVC) radiation on Betacoronavirus 1. Appl Sci 2023;13(3):1426. doi:10.3390/app13031426

Maclean M, McKenzie K, Anderson J, Gettinby G, MacGregor S. 405 nm light technology for the inactivation of pathogens and its potential role for environmental disinfection and infection control. J Hosp Infect 2014;88(1):1-11. doi:10.1016/j.jhin.2014.06.004

Cabral J, Ag R. Blue light disinfection in hospital infection control: advantages, drawbacks, and pitfalls. Antibiotics 2019;8(2):58. doi:10.3390/antibiotics8020058