Hydrogen Peroxide Vapor Found Effective in Decontamination

A comparison of two novel hospital-room decontamination methods, hydrogen peroxide (HP) vapor and an ultraviolet C (UVC) light process, shows that HP is more effective in eradicating bacteria than UVC, according to a new study.

Researchers at the Hospital of Saint Raphael (New Haven, CT, USA) decontaminated 15 patient rooms of varying shapes and sizes twice, with at least two months passing between decontamination sessions. The rooms were decontaminated once using HP vapor and once using UVC light. Five high-touch sites were tested for the presence of bacteria before and after each decontamination process, and aerobic colony counts were determined for each site. In addition, Clostridium difficile and Geobacillus stearothermophilus were placed in discs at five sites in the patient rooms prior to decontamination.

The results showed that of the 75 sites sampled, 70 yielded aerobic growth in rooms prior to HP vapor decontamination; after decontamination, 65 of 70 were negative. In the rooms treated with UVC light, all 68 sites yielded aerobic growth prior to treatment; after treatment, 35 of 68 were negative. Areas in the rooms that were not fully lit were less likely to be decontaminated with UVC light. HP vapor treatment yielded a 6-log reduction for all 5 discs placed, compared with the median 2-log reduction after UVC light treatment. After HP vapor treatment, none of the biological indicators grew; after UVC treatment, 71% - 100% grew, depending on the density of bacterial growth in the discs at placement. The study was presented at the 21st European Congress of Clinical Microbiology and Infectious Diseases, held during June 2011 in Milan (Italy).

"With the UVC mobile unit, you just wheel it into the room and close the door. There's a wireless unit that lets you turn on the device from outside the room. The machine delivers a preset amount of UVC light to the room's surfaces, and turns itself off when its sensors indicate that it has delivered the required amount of decontamination," said study coauthor John Boyce, MD, chief of the infectious diseases section at the Hospital of Saint Raphael. "The HP vapor system, in contrast, requires that users seal the door and air vents in the room, and it might require more training for the operators. Both systems appear to offer improvement over conventional decontamination methods, which most hospitals need."

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