SEE THE LIGHT Ultraviolet-C energy kills microbes on the surfaces it illuminates, but multiple cycles might be required to completely illuminate all surfaces.

The first time we trialed whole-room disinfection technology, our hospital was facing a Clostridium difficile outbreak that had caused 3 patient deaths in a month. When heightened precautions failed to decrease the infection rate, our director of epidemiology got in touch with a manufacturer who was planning the U.S. launch of a device that claimed to sterilize rooms with hydrogen peroxide vapor. That was more than a decade ago, when there were few automated surface disinfection systems on the market. The field has since expanded to include ultraviolet light, aerosolized hydrogen peroxide, ozone and even cluster ion technologies (see "Your Options in Whole-Room Disinfection"). If you're seeking to step up your facility's infection prevention efforts with whole-room disinfection, here's how to evaluate your options.

• Microbiological efficacy. This is the best place to start your selection process. It can be difficult to compare technologies, since they work differently. We conducted our own validation studies while trialing manufacturers' equipment. As an emergency response, our hydrogen peroxide trial had real-time stakes in terms of proving its effectiveness. Over the course of a year, we sought to decontaminate as many patient rooms and wards as possible, as quickly as possible, and we saw a major decrease in C. diff. rates.

When ultraviolet light systems entered the market a few years later, though, we conducted another trial, examining the UV light's microbiological efficacy in 25 patient rooms over the course of a year. We cultured 5 high-touch sites (bed rail, over-bed table, TV remote, bathroom grab bar and toilet seat) in each room before and after UV treatment to determine its microbial reduction. We also inoculated small metal disks with consistent amounts of C. diff. spores and stationed them around the rooms (over-bed table, floor beneath bed, chair, toilet seat and shower floor) at different distances from the light source during treatment, to gauge results. Some rooms received a single cycle with the UV unit placed in the middle of the room, while others received 2 cycles, with the unit moved to the bathroom for the second round.

• Cycle time. Some UV systems' cycles are only a few minutes long, short enough to fit between cases, but would the potential need for multiple cycles prove time- and labor-intensive? Would a more thorough treatment at day's end be worth a 3-hour running time? Also, how easy is the device to use? Could it be set up and operated by any nurse or housekeeper, or does it require specialized training?

MARKET SNAPSHOT
Your Options in Whole-Room Disinfection

TAPE JOB Seal doors and ducts before using hydrogen peroxide vapor.

An overview of the decontamination methods that kill the microbes that survive sprays and wipes:

• Ultraviolet light. UV-C energy breaches the cell walls of viruses, bacteria and spores to deactivate their DNA, killing them in the air and on surfaces without contact or chemicals. Two types of devices use UV-C for germicidal irradiation: continuous light systems (1- to 2-hour cycle) and xenon-based pulsed light systems (5- to 10-minute cycle). Both require direct illumination to treat targeted surfaces.
• Hydrogen peroxide vapor. A solution of hydrogen peroxide with or without peracetic acid in purified water, dispersed as an odorless vapor throughout a room over the course of 2½ to 3 hours, delivers a broad-spectrum disinfectant evenly over a room's surfaces. The system, which is safe to use around electronic equipment, consists of vapor generators and aeration units. A room's doors, ducts and other openings must be sealed before the system's use.
• Aerosolized hydrogen peroxide. As a dry mist disinfectant uniformly sprayed within a room, aerosolized hydrogen peroxide is residue-free and won't harm electronic equipment. The process takes about 2 hours in smaller rooms and 3 to 4 hours in larger ones, during which time doors and ventilation ports must be sealed.
• Ozone. Ozone gas rendered through catalytic technology provides a chemical-free disinfectant, and has been applied in conjunction with high-powered air filtration and UV light to rid surfaces and room air of microbe colonization.
• Cluster ions. These air purifiers fight germs on surfaces, carriers and in the air 24 hours a day, 7 days a week. They generate a stream of germicidal balanced ions that actively seek out pathogens through their electromagnetic charge and destroy them on the subatomic level.

— David Bernard

Addition, not a replacement
The extent to which whole-room disinfection systems can reduce the incidence of surgical site infections has not been conclusively demonstrated by evidence-based studies. None of the systems are designed to replace manual cleaning, so your staff is stuck with wiping and mopping.

Many of the technologies also take more time than manual cleaning does, and in addition require staff to vacate the rooms being treated while the disinfection process is underway. Since these factors may put an OR out of commission for several hours, whole-room disinfection isn't generally used for routine between-case turnovers, though end-of-the-day terminal cleanings have surely benefited from it.

Each system's disinfectant agent and its mechanism of action require specific preparations to achieve optimal results, and in one case (hydrogen peroxide vapor) to ensure employee and patient safety. A room's size and shape, the layout of its equipment and fixtures, and the reflectivity of its surfaces can all impact effectiveness.

Ultraviolet light units, for example, kill the microbes on all the surfaces they illuminate. Since this method's effectiveness may be compromised by shadows that occlude a surface or a surface's distance from the light source, the units must be positioned precisely in a room, and perhaps repositioned for a second or third cycle in order to sufficiently illuminate all the surfaces, unless multiple units are used.

In contrast, hydrogen peroxide vapor methods disperse uniformly to sterilize every single solitary surface in a room, without shadows. Some users open cabinets, drawers and closets before activating a hydrogen peroxide unit. However, since the vapor irritates the eyes, nose and throat, staff must seal up the doors and ventilation systems of rooms in which it is operating until its cycle is complete.

While these systems vanquish the same microbial threats that manual cleaning does, they do so automatically, thoroughly, with minimal need for intervention or supervision and with repeatable results. In other words, to quote infectious disease specialist Robert A. Weinstein, MD, of Rush University Medical Center in Chicago, "If given a choice between improving infection control by changing human behavior or new technology, go with new technology every time." OSM