SAN FRANCISCO – The M.D. Anderson Cancer Center is abandoning bleach for cleaning hospital rooms exposed to Clostridium difficile in favor of a new machine that kills the organism using ultraviolet light.
The machine reduced C. difficile counts as much as, or more than, bleach cleaning in a preliminary prospective trial in 30 hospital rooms previously occupied by patients infected with C. difficile. The machine is a bit more expensive than bleach at a cost of approximately $82,000 (or $3,000-$4,000 per month to lease), but it avoids damage to materials and the toxic environment for workers caused by the use of bleach or other corrosive chemicals, Dr. Shashank S. Ghantoji said in an interview at a poster presentation at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.
Courtesy Xenex Healthcare Services
A few minutes of PX-UV treatment in each of three room locations kills most Clostridium difficile.
Bleach treatment reduced the average number of colony-forming units of C. difficile from 2.39 before cleaning to 0.71, a 70% reduction in the contamination level. Treatment with the Pulsed Xenon UV machine (PX-UV) reduced the average number of colony-forming units from 22.97 to 1.10, a 95% reduction.
The postcleaning contamination levels were not statistically different between the bleach and PX-UV rooms, Dr. Ghantoji and his associates found. However, PX-UV decontamination is faster than using bleach, Dr. Ghantoji said. "It takes at least 45 minutes to clean a room with bleach, and it’s not good for the patients or the health care professionals," plus admissions staff usually are clamoring for the room to be ready as soon as possible, he said. Cleaning a room using the PX-UV method takes perhaps 15 minutes.
The PX-UV machine has been available for some time, but its adoption depends on how proactive hospital infection control teams are, he added. He said he is aware of at least two medical centers beyond M.D. Anderson that are also using the machine.
In the study, 298 samples were taken before and after cleaning from high-touch surfaces – the bathroom handrail, the bed control panel, the bed rail, the top of the bedside table, and the IV pole control panel or other equipment control panel – and analyzed for C. difficile endospores. Fifteen rooms were cleaned by the conventional method using a 1:10 solution of sodium hypochlorite (bleach), and 15 underwent a visual, nonbleach cleaning of surfaces followed by 15 minutes of treatment with the PX-UV.
With the PX-UV method, housekeeping workers clean the bathroom and place the remote-operated PX-UV in the bathroom with the door shut while they finish cleaning the rest of the room. Then the machine is placed on each side of the bed for 4 minutes of operation with workers gone. Sensors stop the machine if any movement is detected.
It works by emitting ultraviolet C light, which kills C. difficile. And here’s a bonus – it also kills vancomycin-resistant enterococci and methicillin-resistant Staphylococcus aureus, Dr. Ghantoji of the M.D. Anderson Cancer Center, Houston, said at the meeting, sponsored by the American Society for Microbiology.
Courtesy Xenex Healthcare Services
The round PX-UV machine (foreground) cleans a hospital isolation room.
"The PX-UV method may be a promising alternative to the current standard of decontamination, bleach," he said. Future studies should look at whether the PX-UV method decreases not just endospore counts but transmission of C. difficile, he added.
C. difficile causes more than 300,000 health care–associated infections each year in the United States, incurring $2,500-$3,500 in costs per infection aside from any surgical costs, he estimated. Current guidelines recommend that rooms previously occupied by patients infected with C. difficile be cleaned with a disinfectant registered with the Environmental Protection Agency as effective against the organism.
Xenex Healthcare Services, which markets the PX-UV machine, funded the study, and two of the investigators are employees of the company. Dr. Ghantoji reported having no other relevant financial disclosures.