Using a certain type of ultraviolet (UV) light while disinfecting hospital rooms can cut down on transmission of antibiotic-resistant bacteria by as much as 30 percent.

The study, led by Duke University researchers and published in The Lancet, involved more than 21,000 patients at nine hospitals, including three Duke Health hospitals and a VA facility. Researchers focused on four organisms known to be resistant to drugs: methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), C. difficile and Acinetobacter.

After a patient with a confirmed infection was discharged from a room, it was cleaned using one of four strategies: the reference group of ammonium (or bleach for C. difficile), ammonium plus ultraviolet-C (UVC) light, bleach or bleach with UVC.

The UVC methods involved using a portable machine which emits UVC light into the infected room for about 30 minutes. According to the Duke press release, the light waves “kill bacteria by disrupting their DNA,” getting into less accessible areas like open drawers or between cabinets.

“Some of these germs can live on the environment so long that even after a patient with the organism has left the room and it has been cleaned, the next patient in the room could potentially be exposed,” said Deverick J. Anderson, MD, an infectious disease specialist at Duke Health and lead author of the study. “Infections from one of these bugs are tough and expensive to treat and can be truly debilitating for a patient.”

The reference group had 115 patients out of more than 4,900 become infected with one of the targeted organisms. The incidence was “significantly lower” among the UVC group, with 76 patients out of nearly 5,200 becoming infected.

None of the cleaning methods reduced C. difficile infections, even UVC was used along with bleach. For VRE infections, however, that regimen cut transmission by 64 percent.

What may hold hospitals back from implementing these strategies are two cost concerns: the $90,000 price tag for UVC machines and the lost revenue from keep a room vacant for an extra 30 minutes.

“There is such a push in the hospital environment to turn rooms over that really any amount of added time is viewed as a potential issue,” Anderson said. “In a large hospital, you might have 100 rooms that are vacated and turned over in one day.”

Anderson said he plans on looking into other, less time-consuming methods at stopping the spread of so-called superbugs, like hand-washing policies or non-UV lights which can be used in occupied rooms.