Comparison of the Microbiological Efficacy of Hydrogen Peroxide Vapor and Ultraviolet Light Processes for Room Decontamination

OBJECTIVE. To compare the microbiological efficacy of hydrogen peroxide vapor (HPV) and ultraviolet radiation (UVC) for room decontamination. DESIGN. Prospective observational study. SETTING. 500-bed teaching hospital. METHODS. HPV and UVC processes were performed in 15 patient rooms. Five high-touch sites were sampled before and after the processes and aerobic colony counts (ACCs) were determined. Carrier disks with similar to 10(6) Clostridium difficile (CD) spores and biological indicators (BIs) with 10(4) and 10(6) Geobacillus stearothermophilus spores were placed in 5 sites before decontamination. After decontamination, CD log reductions were determined and BIs were recorded as growth or no growth. RESULTS. 93% of ACC samples that had growth before HPV did not have growth after HPV, whereas 52% of sites that had growth before UVC did not have growth after UVC (P < .0001). The mean CD log reduction was >6 for HPV and similar to 2 for UVC. After HPV 100% of the 10(4) BIs did not grow, and 22% did not grow after UVC, with a range of 7%-53% for the 5 sites. For the 10(6) BIs, 99% did not grow after HPV and 0% did not grow after UVC. Sites out of direct line of sight were significantly more likely to show growth after UVC than after HPV. Mean cycle time was 153 (range, 140-177) min for HPV and 73 (range, 39-100) min for UVC (P < .0001). CONCLUSION. Both HPV and UVC reduce bacterial contamination, including spores, in patient rooms, but HPV is significantly more effective. UVC is significantly less effective for sites that are out of direct line of sight.