Press Release - Unversity of Leeds

2 January 2003

New weapon to fight hospital infections

A potential new weapon in the fight against hospital acquired infections has been discovered by researchers at the University of Leeds.

The scientists studied the effect of negative air ionisers on infections caused by acinetobacter; a pathogen responsible for increasing numbers of sometimes fatal infections amongst hospital patients. The ionisers, manufactured by Hampshire-based Air Ion Technologies, were placed in the intensive care unit at St James's University Hospital, which, like similar wards across the UK, has had recurrent problems with infections caused by acinetobacter.

For the first six months the researchers, from the aerobiological research group in the University’s school of civil engineering, monitored the normal situation in the unit, taking samples from surfaces, patients and from the air to monitor bacteria levels, and logging the number of patient infections. During the second half of the year-long trial, the ionisers were switched on, and the results were impressive: infections due to acinetobacter reduced dramatically.

Lead researcher Dr Clive Beggs said: "This is the first epidemiological study of its kind into the use of ionisers in hospital wards and the initial results are very promising. We believe that the negative air ions are removing the bacteria from the air, so stopping the transmission of infection. Our tests have focused solely on acinetobacter, but it’s possible the ionisers may have had an effect on other airborne bacteria. We now need to carry out further research to determine exactly how the ions work and how widespread their effects could be."

Even without further research, the fact the ionisers are already making a difference is good enough for lead consultant at St James's intensive care unit, Dr Stephen Dean. "We wanted to be involved in the trial as infections are a major issue for units such as ours, where many patients are already very vulnerable," he said. "The results have been fantastic - so much so that we asked the University to leave the ionisers with us. Since the trial finished in May, we've kept them in operation, and have continued to see greatly reduced acinetobacter infections on the ward."

Dr Kevin Kerr, lead clinical microbiologist on the project, said: “Acinetobacter infections are very difficult to treat as the bacterium is resistant to nearly all antibiotics, so prevention of these infections is of key importance. Ionisers may become a powerful weapon in the fight against hospital-acquired infection.”

The researchers have compiled their report for NHS Estates who funded the study, and will be publishing a paper on the research. They are continuing their work on negative air ions and are conducting further trials and experiments at the University of Leeds.

For more information, contact

Abigail Chard. University of Leeds press office 0113 343 6699 Email a.chard@leeds.ac.uk

Ionisers and ion measurement instruments designed and manufactured by Air Ion Technologies Ltd, PO Box 6367, New Milton, Hants BH25 5RL. 01425 638169. www.airiontechnologies.com

Notes to editors:

The trial was funded by a NHS Estates grant of £101,000 and carried out by a team led by senior lecturer Dr Clive Beggs and including Dr Andrew Sleigh of the University of Leeds, Dr Kevin Kerr, formerly of the University of Leeds and now consultant microbiologist at Harrogate Health Care Trust, Dr Neil Todd, consultant microbiologist at York General Hospital and Dr Stephen Dean, lead consultant on the intensive care unit at St James's University Hospital.

The Aerobiological Research Group at the University of Leeds is a leading group investigating the behaviour of airborne micro-organisms and the use of engineering measures to control infection. The group is part of the school of civil engineering – rated 5 in the recent research assessment exercise – and benefits from a newly created aerosol test facility, funded through the University and the EPSRC. The group’s website is at http://www.efm.leeds.ac.uk/CIVE/aerobiology

Acinetobacter is a bacterium found naturally in the environment. It can survive drying, and can persist in dust and on inanimate surfaces for extended periods. While it poses no real threat to healthy humans, when the body’s defences are weakened it can cause serious infections. For these reasons it has become a significant problem in hospitals, particularly in intensive care units where patients are already critically ill. While there are few national data on numbers of infections from specific bacteria, acinetobacter is acknowledged alongside MRSA as a significant cause of hospital-acquired infections. Acinetobacter can cause infections of the lung (pneumonia), blood stream (septicaemia) and infections of surgical wounds and burns as well as urine infections. Such infections are difficult to treat as many strains of the bacterium are resistant to more than one antibiotic, with the most resistant strains only treatable by one or two drugs, and fully resistant strains are expected to develop in the near future. Attention is therefore being focused on preventative strategies.