Pulsed Xenon Ultraviolet Light Goes Where Housekeepers Can't

MD Anderson Study Shows Device Helps Purge Common Pathogens in Patient Rooms

MD Anderson News Release 02/11/11

HOUSTON - Hospital room floors, walls, tray tables, sinks, telephones and handrails can be sanctuaries for infection-causing bacteria and pathogens, but a study at The University of Texas MD Anderson Cancer Center has found that a device that pulses xenon ultraviolet light significantly reduces the number of bacteria - even after the housekeeping staff does its most thorough cleaning possible.

Published online this week in Infection Control and Hospital Epidemiology, the study found that the ultraviolet device reduced contamination found on 75 surfaces in 12 inpatient rooms and eliminated a type of bacteria known as VRE, or Vancomycin-Resistant Enterococci, an organism which is resistant to a wide range of antibiotics. The study was conducted in a number of patient rooms, including many in MD Anderson's Stem Cell Transplant Unit where it is vital that the area stay disinfected and free of these multi-drug resistant organisms (MDROs) because of the immuno-compromised patients treated there.

For the study, MD Anderson incorporated the device into its bed turnover process that begins once a patient is discharged from the hospital. The housekeeper thoroughly cleans the room, wheels the device into the room and remotely turns it on after stepping into the hallway and closing the room door. When turned on, the unit's small lamp emits flashes of xenon ultra-violet light like a strobe. The cleaning process takes less than 10 minutes, reaching surfaces that are difficult for a housekeeper to reach and where bacteria or pathogens can linger. Developed by Xenex Healthcare Services in Austin, the Xenex PX-UV device - which is about the size of a vacuum cleaner - can be moved to disinfect the immediate patient bed area, the adjoining bathroom and guest sitting area.

Outside laboratory specialists took surface swabs before the housekeeper cleaned the room, after the room was scrubbed down and then again after using the device. With more than 230 samples taken, researchers found the device further reduced contamination even after a thorough room cleaning by the housekeeping staff. According to the study, researchers "found significantly lower heterotrophic plate counts (HPC) and VRE" after using the device.

Roy F. Chemaly, M.D., M.P.H., associate professor in the Department of Infectious Diseases, Infection Control and Employee Health, led the study, and said the device can help reduce the number of bacteria - VRE in this study - in patient rooms which may help prevent the spread of VRE to an incoming patient.

"This study shows that the device can disinfect a room and eliminate or reduce many sources of this pathogen in hospital rooms. What we need to further study, however, is if it can truly reduce the infection acquired from these organisms in patients in our transplant unit," said Chemaly. "The study shows that this device can enhance the good work of a housekeeping staff, but what will make this an exceptional weapon in infection control, is if we ultimately see fewer patients getting sick from hospital-borne infections, mainly caused by drug resistant organisms like VRE."

Mark Stibich, Ph.D., chief scientific officer of Xenex and a collaborator on the study said, "We are very encouraged by the results of this study, which demonstrated that our Xenex room disinfection system is 20 times more effective in killing dangerous pathogens like VRE and may have the same effect on MRSA and C.Diff in patient rooms than traditional cleaning methods. We hope we can provide patients at MD Anderson and other healthcare institutions around the United States with a safer patient environment by reducing the number of microorganisms which cause healthcare associated infections - and that's a big step towards patient safety."

Chemaly said that in addition to a study looking at infection rates among patients whose rooms have been disinfected with the Xenex device, future research may explore use of the device in the Critical Care Unit or on floors where there may be sudden outbreaks of a particular infection.

"MD Anderson constantly looks for new ways to reduce infection rates and enhance patient safety," said Chemaly. "This includes studying and looking closely at any new device or process that would help us achieve that goal. We will continue our study of the Xenex device."

Xenex Healthcare Services sponsored the MD Anderson study. Collaborating with Chemaly and Stibich on the study were Julie Stachowiak, Ph.D., Xenex; Benjamin Tanner, PhD, Antimicrobial Test Laboratories; Issam Raad, M.D., Matthew Berkheiser and Linette Moore, MD Anderson.