Key takeaways
- A large share of surgical site infections are thought to come from bacteria in the air settling on the wound during surgery.
- Drug-resistant bacteria such as MRSA are a growing part of the problem.
- UV light has been used in operating rooms since the 1930s, and modern studies continue to support its role.
- Far-UVC is being studied as a way to keep disinfecting the air during surgery itself.
The size of the problem
Surgical site infections (SSIs) are one of the most common and serious complications after an operation. They lengthen hospital stays, lead to further surgery and increase the risk of death. A 2023 review from the University of St Andrews highlights how often these infections now involve drug-resistant bacteria. Staphylococcus aureus is among the most common causes, and in one study cited in the review, around 39% of S. aureus isolates from surgical wounds were resistant to methicillin (MRSA).
The environment matters more than it seems
Much of the attention on SSIs goes to the patient and the surgical technique. But researchers at Columbia University note that most surgical site infections are believed to be caused by airborne bacteria landing on the wound during the procedure. Surfaces and equipment that are not fully disinfected between cases add further risk. A chapter on UV disinfection in Advances in Experimental Medicine and Biology describes the operating room environment as a surprisingly understudied part of the SSI story.
A long history of UV in surgery
UV light in the operating room is not new. In the 1930s, after an outbreak of infections at Duke University Hospital, surgeon Deryl Hart introduced UV lamps in the operating theatre. The reported infection rate fell from 11.62% to 0.24%. Although this was an early, uncontrolled observation, it led many surgeons to adopt the practice. Today, portable UV systems are used between cases and for terminal cleaning, and newer studies continue to look at how often, how much and where UV should be applied to lower infection rates.
What far-UVC adds
Conventional UV-C can only be used when the operating room is empty. Far-UVC at 222 nm is being studied because it may be able to keep disinfecting the air and surfaces while surgery is under way.
In a 2018 study in mice, Columbia University researchers spread MRSA on the skin, exposed it to either 222 nm or 254 nm light, and then made a small surgical incision. The 222 nm light killed the bacteria just as well as 254 nm light, but without the skin damage caused by 254 nm. In people, a clinical trial in Japan found that 222 nm light significantly reduced bacteria on the skin of healthy volunteers without causing redness. A pilot study in Singapore found that 222 nm light reduced bacteria in pressure ulcers, including MRSA, Pseudomonas aeruginosa and Klebsiella pneumoniae, with no adverse events.
A layered approach works best
No single technology prevents every infection. The strongest protection comes from combining measures:
- Good ventilation and filtered air in the operating room.
- Thorough manual cleaning of surfaces and equipment.
- UV-C disinfection between cases and at the end of the day.
- Continuous far-UVC where appropriate, to reduce microbes during procedures.
- Traceable records, so infection control teams can link practice to outcomes.
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References
- Panzures A. 222-nm UVC light as a skin-safe solution to antimicrobial resistance in acute hospital settings with a particular focus on MRSA and surgical site infections: a review. Journal of Applied Microbiology. 2023;134(3):lxad046.
- Simmons S, Dale C, Holt J, Velasquez K, Stibich M. Role of ultraviolet disinfection in the prevention of surgical site infections. In: Ultraviolet Light in Human Health, Diseases and Environment. Advances in Experimental Medicine and Biology, vol 996. Springer; 2017.
- Ponnaiya B, Buonanno M, Welch D, et al. Far-UVC light prevents MRSA infection of superficial wounds in vivo. PLOS ONE. 2018;13(2):e0192053.
- Fukui T, Niikura T, Oda T, et al. Exploratory clinical trial on the safety and bactericidal effect of 222-nm ultraviolet C irradiation in healthy humans. PLOS ONE. 2020;15(8):e0235948.
- Goh JC, Fisher D, Hing ECH, et al. Disinfection capabilities of a 222 nm wavelength ultraviolet lighting device: a pilot study. Journal of Wound Care. 2021;30(2).
This article summarises published research for general information and is not medical advice. Selection and use of disinfection devices should follow the manufacturer's instructions and local regulations.