About 1.7 million Americans each year acquire new infections during hospital stays—and hospital-acquired infections are one of the top five causes of death overall, killing 44,000 to 98,000 people in the U.S. each year.

Nasty Clostridium difficile can lurk on door handles and other surfaces, leading to severe intestinal distress; Acinetobacter can also survive in the open air, threatening to cause pneumonia, urinary tract infections and blood infections; and vancomycin-resistant Enterococci (VRE) is tough to beat with other drugs and can infect wound and catheter sites, as well as the bloodstream. Even a thorough traditional cleaning by staff, with disinfecting sprays, can leave spots untouched—and dangerously contaminated.

A new study finds that a certain frequency of ultraviolet (UV) light can kill almost all of these nasty bugs from at least the surfaces of a hospital room—even when not directly exposed to the light.

A team of researchers sampled five high-contact areas in hospital bedrooms and bathrooms (such as bed rails, toilets and remote controls) where patients with C. difficile, Acinetobacter or VRE infections had been staying. They then brought in a machine outfitted with eight bulbs to emit short-wave UV radiation (UV-C) for 25 to 45 minutes. Afterward, the researchers sampled the same locations for any persisting bacteria or spores.

"We were able to demonstrate that we could achieve well over 90 percent reduction in each of those three bad bugs after using the UV light," Deverick Anderson, co-director of the Duke Infection Control Outreach Network, and study collaborator, said during a media briefing call earlier this week. Even shadowed surfaces that escaped direct UV exposure demonstrated this drastic reduction in bacteria. The findings were presented October 18 at IDWeek, a meeting to highlight progress in the fight against infectious diseases, in San Diego.

UV-C radiation has already been deployed by food processors and utilitiesto kill bugs in food and water, respectively—and it is also used to sterilize some medical equipment. Putting it to use for larger targets—such as hospital rooms—might become a new standard step in healthcare disinfection. The researchers did not, however, compare the light's effectiveness with that of standard cleaning procedures. "We would never propose that the UV light be the only form of room cleaning," Anderson said in a prepared statement. "But in an era of increasing antibiotic resistance, it could become an important addition to hospitals' arsenal."

Previous work had shown that UV-C can also cut down on MRSA (methicillin-resistant Staphylococcus aureus) in hospital rooms. "We have a solid foundation to show that this approach succeeds in both experimental and real-world conditions," Anderson said in a prepared statement. "Now it's time to see if we can demonstrate that it indeed decreases the rate of infections among patients." After all, it would be nice to be rid of our acquired infection risk in a flash.