UV-C reduces infection with MDROs in hospitalized patients

Issue: November 2015

SAN DIEGO — Enhanced terminal room disinfection strategies that utilized shortwave ultraviolet light significantly reduced patients’ risk for acquiring infections caused by multidrug-resistant organisms, according to the results of a cluster-randomized crossover study.

“The hospital environment is an important component to patient care,” Deverick J. Anderson, MD, MPH, from Duke University Medical Center, said during a presentation. “For example, several studies have demonstrated that risk of acquisition is higher in patients who enter rooms recently vacated by a patient with [multidrug-resistant organisms (MDROs)]. This risk likely comes from two important factors: first, these organisms can persist in the environment and second, these organisms are often allowed to persist in the environment, as the status quo of room cleaning is often inadequate.”

Deverick J. Anderson

Several enhanced strategies for hospital room disinfection have been developed over the years, but these strategies have not yet been evaluated in a multicenter, randomized controlled trial, Anderson said.

The BETR-Disinfection study was conducted at nine hospitals in North Carolina and Virginia between April 2012 and July 2014. The hospitals randomly employed four strategies, each of which lasted 7 months. These included:

standard cleaning with the use of quaternary ammonium, except bleach for C. difficile;
quaternary ammonium plus ultraviolet-C (UV-C), except bleach plus UV-C for C. difficile;
bleach; and
bleach plus UV-C.

The four cleaning protocols were employed in “seed rooms” — defined as rooms containing patients on contact precautions for infection or colonization due to MRSA, vancomycin-resistant Enterococcus (VRE), Clostridium difficile or multidrug-resistant Acinetobacter. The study’s primary outcome was the clinical incidence of any of these MDROs in the next patient to occupy the room for at least 24 hours after disinfection.

Results showed that the three enhanced terminal room disinfection strategies decreased the incidence of MDROs by 10 to 30%, and the largest decreases were seen when a UV-C emitting device was added to the standard cleaning strategy.

Anderson said the median cleaning cycle lasted just over 30 minutes, and the turnover time increased by 5 to 10 minutes with the use of the UV-C emitter device.

The largest impact of enhanced terminal room disinfection was seen in the incidence of vegetative bacteria. However, there was no change in the rate of C. difficile, which may be due to the fact that bleach was already being used in rooms of patients with suspected or confirmed C. difficile. “Thus, it is conceivable that if bleach is indeed applied to 90% of surfaces of a room, then there may not be many spores remaining for UV light to kill,” Anderson said.

Compliance with hand hygiene and cleaning protocols was high in the study, “with median compliance rates for both potential confounders observed around 90%,” Anderson said. Hospital staff used the correct chemical agent more than 95% of the time, and the UV-C device was employed in 89% of eligible rooms.

“Frankly, given the high bar set with our high rates of room cleaning and hand hygiene, we believe the differences we observed likely represent minimum changes that occur with the use of enhanced terminal room disinfection strategies,” Anderson concluded.

In another study presented at IDWeek, David A. Pegues, MD, professor of medicine at the Hospital of the University of Pennsylvania, and colleagues examined the impact of UV-C germicidal irradiation on C. difficile infection (CDI) rates in three adult hematology-oncology units at a 695-bed tertiary care hospital. According to Pegues, rates of CDI were five time higher in these units than in all inpatient units at Penn combined.

David A. Pegues

Over the course of a year, UV-C was used to disinfect 75 private and seven semiprivate rooms upon discharge of patients with CDI or on contact precautions.

During the 52-week study period, UV-C was used for 21.1% of all patient discharges from the three hospital units. The researchers found that rates of CDI declined 25%, compared with 16% in units in which UV-C was not utilized. The IRR for the three study units was 0.49 (95% CI, 0.26-0.94; P = 0.03).

Moreover, an estimated $150,000 in direct annual medical costs was saved by preventing CDI using this technology.

Pegues was a coauthor of a study recently published in the Annals of Internal Medicine that found a lack of evidence of the effectiveness of various disinfection strategies for hospital rooms.

“There weren’t a lot of studies showing the efficacy of UV lights to clean hospital rooms,” Pegues said in a press release. “These results help fill that gap. This is a cost-saving measure that showed a sizeable reduction in infections for a high-risk group of patients — and set the stage for further implementation of the technology at our hospitals.” – by John Schoen

Reference:

Anderson D, et al. Abstract 1280. Presented at: IDWeek; Oct. 7-11, 2015; San Diego.

Han JH, et al. Ann Intern Med. 2015;doi:10.7326/M15-1192.

Pegues DA, et al. Abstract 1715. Presented at: IDWeek; Oct. 7-11, 2015; San Diego.

Disclosure: Anderson reports receiving royalties from UpToDate. Another researcher is a consultant for Clorox, Inc. Pegues reports no relevant financial disclosures.