Germ-Killing Robots

A study by Duke Health finds a new tool that produces a type of ultraviolet light, which could help hospitals fight drug-resistant bacterial infections.

DURHAM — A 5-foot-tall, black cylinder sits in a metal cart, and is rolled through the hallway of a hospital. 

At first glance, it looks like some type of robot for a new science fiction movie. More down to Earth, perhaps, it’s actually a device for a new surgical procedure or X-ray system. 

The device is then rolled into a recently vacated and cleaned patient room. The technician pulls off the system's side panels, revealing long light tubes along the side. The technician checks the room, plugs the device into a wall socket, leaves the room and remotely turns it on. The side panels are flipped over and positioned outside the room at the door, revealing red, "DO NOT ENTER" signs printed on the undersides. 

The light bulbs lining the device slowly light up and fill the room with a bluish-purple light. 

“And when it turns on, the light bulbs light up and it is irradiating an entire room," says Deverick Anderson, M.D., associate professor of medicine at Duke University Medical Center and the director of the Duke Center for Antimicrobial Stewardship and Infection Prevention. “The machine emits UVC light, which penetrates dangerous bacteria and disrupts the DNA, which kills the bacteria.” 

That’s right, the machine is, essentially, a robot germ killer that uses ultraviolet light. 

You’ve probably heard of ultraviolet light before, especially when doctors talk about sunburn. But in that case, doctors are talking about UV-A and UV-B light. 

UV-C light is a little further down the spectrum. It is a shorter wavelength, which means it doesn’t cause skin cancer in humans. But it does kill bacteria. 

A study by researchers at Duke University Health System hospitals finds the germ-killing machine may help hospitals in their fight to keep drug-resistant bacteria from lingering in patient rooms and causing new infections. 

The study focused on four drug-resistant organisms: methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), C.difficile and Acinetobacter. 

And it turns out those bacteria can live on in the environment even after a patient has left the room and it has been cleaned. For clarification, researchers did find that hospitals are cleaning and using the proper disinfectants. 

“Of course, disinfectants are highly effective, but the issue is more complicated than that,” explains Anderson. “You have to make sure there’s enough time to clean the room, and if you’ve been in a hospital room, you realize there’s a lot more nooks and crannies than you might expect with all the complicated beds and machines. So it's really difficult to clean a hospital room from top to bottom the way we would like, so this adds to the chemical clean.” 

Just think of some of those difficult to clean areas: the TV remote, the light switch or the corner of a room, to name a few. 

It takes about 30 minutes for the germ-killing machine to do its work. The cleaning study found that when UVC light was combined with the traditional cleaning with disinfectants, the overall transmission of superbugs, or bacteria that's become resistant to antibiotics, decreased by 30 percent. 

The technology was born in the midst of bio-terrorism research. Companies are looking for other ways to market the product, and health care was the obvious choice. Researchers continue to look at other ways hospitals can cut infection rates for all pathogens. But the germ-killing robot’s effectiveness in reducing infection risks and reducing costs is catching the eye of hospital administrators. 

“You can’t decide what room you get put into," says Anderson, "so you want to make sure the hospital you are being admitted to is doing everything possible to keep you from being exposed to these pathogens."

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