Microbial contamination of surfaces in patient rooms has been well documented in numerous studies, including those that have demonstrated patients admitted to a room in which the previous occupant was colonized or infected with a pathogen requiring contact precautions have been shown to have an increase in the risk of acquiring that pathogen. Mark Stibich, PhD, MHS, of Xenex Healthcare Services in Austin, Texas and colleagues, report on their evaluation of pulsed-xenon ultraviolet (PX-UV) room disinfection by sampling frequently touched surfaces in vancomycin-resistant enterococci (VRE) isolation rooms. The researchers say that the PX-UV system showed a statistically significant reduction in microbial load and eliminated VRE on sampled surfaces when using a 12-minute multi-position treatment cycle.
Stibich, et al. sought to compare the use of a PX-UV disinfection system to the standard room terminal cleaning process in a large medical facility and to assess the level of room microbial contamination before and after applying each method and the degree to which room turnaround time were affected by the use of each approach.
At the time of terminal cleaning, a research team went into 12 rooms in which a patient had been under contact isolation for VRE infection or colonization for at least two days before discharge, and took environmental surface samples. These samples were tested to determine bacterial heterotrophic plate counts (HPCs) and the presence of VRE. The high-touch surfaces sampled included bed rails, tray tables, chair arms, telephones, cabinets, intravenous infusion poles, door handles, remote controls, toilet seats, bathroom handrails and computers.
The researchers explain that three sampling strata of high-touch surfaces were used in four rooms each to determine the effectiveness of PX-UV in uncleaned and cleaned environments: (1) 14 samples from high-touch surfaces were obtained before manual cleaning and after PX-UV treatment, (2) 14 samples from high-touch surfaces were obtained after standard terminal room cleaning was completed, and (3) seven samples from high-touch surfaces were obtained before cleaning, after standard terminal cleaning, and after UV treatment. The standard terminal cleaning for VRE isolation rooms was performed according to hospital guidelines, took approximately 30 minutes, and included the use of a germicide. The PX-UV device was placed in three positions in the room and was run for four minutes in each position.
Stibich, et al. report that 239 samples were obtained from 21 surfaces from 12 rooms; the average HPC for before cleaning, after cleaning, and after UV treatment was 33.0, 27.4, and 1.2 CFU/cm2, and the number of VRE-positive surfaces was 17 (23.3%), 4 (8.2%), and 0 (0%), respectively. Of the 18 VRE samples that were analyzed quantitatively, the mean VRE count was 19.5 CFU/cm2 (range, 0.3155.0; median, 40 [interquartile range, 0.827.1]). The Wilcoxon-Mann-Whitney test showed that if HPC was used as an outcome, each disinfection stage showed a statistically significantly improvement over the prior stage.
The researchers conclude that use of PX-UV is more effective than standard manual room terminal cleaning in reducing the rooms microbial burden and reducing levels of known pathogens. They say they found statistically significantly lower HPCs and no VRE in rooms after PX-UV treatment, suggesting that the risk to the next occupant from environmental contamination is correspondingly lower.
Reference: Stibich M, Stachowiak J, Tanner B, Berkheiser M, Moore L, Raad I and Chemaly RF. Evaluation of a Pulsed-Xenon Ultraviolet Room Disinfection Device for Impact on Hospital Operations and Microbial Reduction. Infect Control Hosp Epidem. Vol. 32, No. 3. March 2011.