LED lighting system kills hospital superbugs

A lighting system that kills bacteria, including superbugs such as MRSA and C difficile, has completed trials at a Glasgow hospital.

The LED technology, which can be used alongside or instead of traditional lighting, continually disinfects the air and exposed surfaces with certain violet wavelengths of visible light.

A two-year trial at Glasgow Royal Infirmary showed that the high-intensity narrow-spectrum (HINS) light was around 60 per cent more effective in killing bacteria and fungi than cleaning alone but was harmless to staff and patients.

‘There are very few disinfectant technologies that are dangerous to microbes but benign to humans,’ said Prof John Anderson of Strathclyde University in Glasgow, where the technology was developed.

Several studies over the last few years have shown that parts of the visible light spectrum can damage pathogens in a similar way to ultraviolet light, which also causes cancer in humans.

‘The challenge was to take the small-scale experimental observations to a larger system by working out the intensities needed to give the right level of decontamination,’ said Anderson.

The HINS light is blended with light from white LEDs to make it suitable for environmental lighting. It was used alongside normal lightbulbs in the trial but could potentially replace them.

The system was effective against all bacteria that were tested, including meticillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile (C difficile), but is less likely to be effective against viruses.

This is because of the way the light works – exciting certain molecules in the bacteria, which produces lethally toxic chemicals and effectively causes the microbe to self-destruct.

‘But this isn’t a replacement for traditional cleaning or hand-disinfection methods – it’s another greater level of decontamination,’ said Anderson.

‘The NHS wants further trials but it’s true to say it is quite excited by this.’

Commercialisation could begin after another six months of tests, he added.

The technology was developed by Anderson along with fellow microbiologist Dr Michelle Maclean, electrical engineer Prof Scott MacGregor, and optical physicist Prof Gerry Woolsey, who have published their study in the Journal of Hospital Infection.

The team were based at Strathclyde’s Robertson Trust Laboratory for Electronic Sterilisation Technologies (ROLEST) and supported by funds from the Scottish Enterprise Proof of Concept Programme.

From scanning to surgery and superbug control, UK hospitals are trialling potentially revolutionary medical technologies. Click here to read more (subscription required).