A new trial shows simple air purification devices can significantly reduce viral outbreaks among older Australians.
Installing germicidal ultraviolet appliances in aged care homes can cut viral respiratory infections by more than 12%, an Australian-led study has shown.
Researchers from Flinders Health and Medical Research Institute (FHMRI) and SAHMRI trialled commercially available GUV devices – already commonly used in hospitals – in four residential aged care facilities across South Australia.
The findings, published in JAMA Internal Medicine this week, suggest these UV-C light-based systems could be transformative in protecting some of our most vulnerable citizens, said lead author Dr Andrew Shoubridge from Flinders University and SAHMRI’s Microbiome and Host Health Program.
“When used in conjunction with existing infection control measures, they could be transformative in reducing rates of seasonal respiratory viral infections and protecting residential aged care facilities against emerging pathogens,” he said.
The study’s senior author, Professor Geraint Rogers, said outbreaks of viruses such as covid were “absolutely devasting for older people, significantly increasing the risks of hospitalisation and death”.
“Our study aimed to explore new ways in which to protect aged care residents from harmful outbreaks of viruses, including covid 19, without disrupting their day-to-day activities,” he said.
“Based on our findings, it’s difficult to see why you wouldn’t install these appliances in aged care facilities.”
The trial tested commercially available LAF Technologies GUV appliances that are already used in a wide range of clinical and commercial settings, including hospitals.
The appliances can be mounted to ceilings or walls, fitted into ventilated AC systems, are harmless to people, and are already proven to reduce levels of airborne pathogens in laboratory and hospital settings.
The appliances were installed and tested in four aged care homes across metropolitan and rural South Australia, including Barmera Health Service Residential Aged Care Facility (RACF), Riverland Mallee Coorong Local Health Network (RMCLHN); Allambi Residential Care Home (Eldercare); Lightsview Residential Care Home (Helping Hand); and Golden Grove Residential Care Home (Helping Hand).
The appliances were installed in communal areas that were exposed to high volumes of people where the transmission of airborne viruses is usually greater.
GUV appliances were switched off during control periods and run continuously during intervention periods. Control and intervention arms were run in parallel within each facility. Arm 1 (intervention) involved a six-week GUV intervention period, followed by a two-week washout, while arm 2 (control) involved a six-week control period followed by a two-week washout and crossover.
“We designed a randomised clinical trial to compare the same environments with and without the appliances tracking infection rates over two years,” said Dr Shoubridge.
“While the appliances didn’t seem to lower infection rates during short study periods, they did help reduce overall numbers of respiratory infections by 12.2%, or roughly 0.3 fewer cases per week.
“This means GUV technology could make a noticeable difference in protecting people in aged care facilities, especially when we consider there are 250,000 Australians currently living in them.”
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The researchers said their study estimated the causal effect of the intervention to be an approximately 9% reduction in infections. When applied to the ARI rate in the control arm, such a reduction equates to 92 fewer ARIs per 1000 residents annually.
“While falling short of the 20% benchmark that is often considered a clinically meaningful change for an individual, such a reduction could translate to a very meaningful effect from a public health perspective, for which the aggregate benefit of even small individual improvements becomes substantial,” the researchers wrote in JAMA Internal Medicine.
“This potential was highlighted by the rate of hospitalisation associated with ARIs being three to nine times higher and the mortality rate being nine to 11 times higher in populations of older adults.
“Moreover, the effect of GUV appliances within LTCFs might be further augmented through a refined strategy for retrofitting and use or the integration of GUV technology into ducted heating, ventilation, and air conditioning systems to provide more comprehensive air sterilisation.”
They concluded that while their trial had limitations, it did demonstrate the effectiveness of an adjunct infection control strategy to address airborne pathogen transmission in a healthcare setting. This highlighted the potential of GUV-based strategies, if shown to be cost-effective, in preventing seasonal respiratory infections and protecting vulnerable populations against future outbreaks of novel viral pathogens.
“While this randomized clinical trial found that use of GUV appliances did not reduce the ARI incidence rate within study cycles, it did reduce the total numbers of ARIs by the study conclusion,” they wrote.
“GUV-based strategies are a potential adjunct to existing infection control practices for vulnerable residential populations.”
