Superbugs spread through the air in hospital wards

(Medical Xpress)—Hospital superbugs can float on air currents and contaminate surfaces far from infected patients' beds, according to University of Leeds researchers.

The results of the study, which was funded by the Engineering and Physical Sciences Research Council (EPSRC), may explain why, despite strict cleaning regimes and hygiene controls, some hospitals still struggle to prevent bacteria moving from patient to patient.

It is already recognised that hospital , such as and C-difficile, can be spread through contact. Patients, visitors or even can inadvertently touch surfaces contaminated with bacteria and then pass the infection on to others, resulting in a great stress in hospitals on keeping hands and surfaces clean.

But the University of Leeds research showed that coughing, sneezing or simply shaking the bedclothes can send superbugs into flight, allowing them to contaminate recently-cleaned surfaces.

PhD student Marco-Felipe King used a biological chamber, one of a handful in the world, to replicate conditions in one- and two-bedded hospital rooms. He released tiny aerosol containing Staphyloccus aureus, a bacteria related to MRSA, from a heated mannequin simulating the heat emitted by a human body. He placed open where other patients' beds, bedside tables, chairs and washbasins might be and then checked where the bacteria landed and grew.

The results confirmed that contamination can spread to surfaces across a ward. "The level of contamination immediately around the patient's bed was high but you would expect that. Hospitals keep beds clean and disinfect the tables and surfaces next to beds," said Dr Cath Noakes, from the University's School of Civil Engineering, who supervised the work. "However, we also captured significant quantities of bacteria right across the room, up to 3.5 metres away and especially along the route of the airflows in the room."

"We now need to find out whether this airborne dispersion is an important route of spreading infection," added co-supervisor Dr Andy Sleigh.

The researchers are hoping that computer modelling will help them determine the risk. The findings have been compared to airflow simulations of the mock-up hospital rooms and the research team have shown that they are able to accurately predict how airborne particles can be deposited on surfaces.

"Using our understanding of airflow dynamics, we can now use these models to investigate how different ward layouts and different positions of windows, doors and air vents could help prevent microorganisms being deposited on accessible surfaces," said Mr King.

The international design and engineering firm Arup, which designs hospitals, part sponsored the study.

Phil Nedin, director and global healthcare business leader at Arup, said: "We are looking at healthcare facilities of the future and it is important that we look at key issues such as infection control. Being involved in microbiological studies that inform airflow modelling in potentially infectious environments allows us to get a clear understanding of the risks in these particular environments."

The paper "Bioaerosol Deposition in Single and Two-Bed Hospital Rooms: A Numerical and Experimental Study" is published in the journal Building and Environment.

More information: M.F. King, C.J. Noakes, P.A. Sleigh, M.A. Camargo-Valero, 'Bioaerosol Deposition in Single and Two-Bed Hospital Rooms: A Numerical and Experimental Study' Building and Environment (2012). DOI 10.1016/j.buildenv.2012.09.011

Related Stories

Can we 'wipe out' MRSA?

Jun 03, 2008

Three basic principles is all it could take to reduce the incidence of MRSA in hospitals according to a new research by Cardiff University.

Copper reduces infection risk by more than 40 percent

Jul 01, 2011

Professor Bill Keevil, Head of the Microbiology Group and Director of the Environmental Healthcare Unit at the University of Southampton, has presented research into the mechanism by which copper exerts its ...

MRSA eliminated by copper in live global broadcast

Apr 04, 2011

A live broadcast from the University of Southampton today (4 April 2011) highlighted the effectiveness of antimicrobial copper in preventing the spread of antibiotic-resistant organisms, such as MRSA, in hospitals.

Recommended for you

US looking past Ebola to prepare for next outbreak

6 hours ago

The next Ebola or the next SARS. Maybe even the next HIV. Even before the Ebola epidemic in West Africa is brought under control, U.S. public health officials are girding for the next health disaster.

Can robots help stop the Ebola outbreak?

15 hours ago

The US military has enlisted a new germ-killing weapon in the fight against Ebola—a four-wheeled robot that can disinfect a room in minutes with pulses of ultraviolet light.

New bird flu case in Germany

15 hours ago

A worrying new strain of bird flu has been observed for the first time in a wild bird in northern Germany, the agriculture ministry said Saturday.

Mali announces new Ebola case

Nov 22, 2014

Mali announced Saturday a new case of Ebola in a man who is fighting for his life in an intensive care unit in the capital Bamako.

Plague outbreak kills 40 in Madagascar: WHO

Nov 22, 2014

An outbreak of plague has killed 40 people in Madagascar, the World Health Organization said, warning that the disease could spread rapidly in the country's densely populated capital Antananarivo.

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.