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Infection Control

Steam Vapor: A Green Disinfectant

September 19, 2010
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We live in an era of increasing antibiotic resistance.

The proximate causes of most antibiotic-resistant infections are invasive medical devices and compromised immunity, but how do the bacteria spread from one person to the next?

Obviously, environmental surfaces play a major role.

Infected patients and colonized staff interact with the hospital environment in hundreds of ways every day: An infected patient contaminates his bedding, which, in turn, contaminates his bedrail; a colonized nurse removes a difficult bandage, stopping to adjust the room lighting; a rushed doctor grabs a doorknob, then remembers she forgot to wash her hands after checking on a problematic catheter.

Beyond the widely publicized need for handwashing, prevention and control of surface-transmitted infections begins and ends with disinfection.

However, traditional disinfection technologies have drawbacks that limit effectiveness when it comes to controlling the spread of germs.

"What?" you ask. "I thought that disinfectants registered with the U.S. Environmental Protection Agency (EPA) were very efficacious!"

EPA-registered disinfectants are efficacious — when used in accordance with label instructions.

Use instructions for disinfection found on common U.S. hospital disinfectants read like this: "Pre-clean the surface to remove gross filth — spray and then wipe clean. Then, thoroughly wet the surface and let the product stand for 10 minutes."

Pre-cleaning followed by disinfection for the full contact time specified on the label is how surfaces in a hospital should be disinfected.

Anyone who aspires to improve hospital infection control will benefit from assessing the actual state of compliance.

All too often, cleaning staff do not pre-clean or thoroughly wet surfaces, and many hospital surfaces do not stay wet for the full contact time specified on the label.

The frequency of surface disinfection is also important.

A critical question in any hospital is, "How often does a given high-touch surface actually get disinfected?"

The truth is that there is a great difference between how we hope hospital surfaces are disinfected and how they are actually disinfected in most hospitals.

Choosing The Right Tool

A few measures can improve compliance with best practice surface disinfection procedures.

First, the organization can be restructured so cleaning staff can report directly to trained infection prevention; at the least, environmental services staffs can begin a direct dialog with infection prevention specialists to determine how to achieve a more cooperative, interdependent relationship.

Second, the cleaning staff can learn about the strengths and weaknesses of the different products they use, especially with respect to disinfection.

Cleaning staffs should know enough to avoid common pitfalls of surface disinfection like the overuse of properly prepared disinfectant solutions.

Research shows that the resulting depletion of the active ingredient leads to cross-contamination of adjacent surfaces.

The final, and probably easiest, way to increase compliance is to provide the cleaning staff with a tool that makes foolproof surface disinfection easy.

The optimal surface disinfectant for the hospital environment would have these qualities: Easy to use, quick disinfection, broad kill range, reduces potential of cross-contamination, non-toxic and will not damage surfaces.

A commercial steam vapor system outfitted specifically for surface disinfection provides all of these qualities and more.

Commercial steam vapor systems provide many advantages, but they must be individually validated for surface disinfection because a steam vapor system''s germ-killing power depends on many factors: The moisture content of the steam, its temperature at the tool-surface interface and tool surface area.

A leading manufacturer of commercial steam vapor systems recently completed extensive surface disinfection efficacy testing at three established, independent laboratories.

A realistic test system was designed for all studies — many of which were done entirely in duplicate.

High initial microbial concentrations that were dried onto a mix of porous and non-porous surfaces were used.

Study results show that the system rapidly kills viruses, fungi and antibiotic-resistant bacteria, providing a sanitizing benefit within two seconds of surface contact and disinfecting surfaces within five seconds.

In the hands of trained cleaning staff, commercial steam vapor systems have many advantages.

Most systems are chemical-free, safe to use around patients, quiet and portable.

Since targeted heat, not chemicals, is the "active ingredient," disinfection is exceedingly fast and broad-spectrum.

There is no specter of chemical cross-resistance to antibiotics, surfaces do not become sticky, stain or discolor over time and staff can disinfect as frequently as necessary without long-term chemical exposure concerns.

Since pre-cleaning is not required and the contact times necessary for disinfection are on the order of seconds rather than minutes, staff compliance is naturally less of an issue for the commercial steam vapor system.

Additionally, commercial steam vapor systems afford a key advantage: The steam cleaning tool remains very hot, so the potential for cross-contamination from surface to surface or room to room is greatly reduced.

This is in sharp contrast to the traditional "spray and wipe" approach, which recent studies suggest can actually spread pathogens from one surface to the next if the disinfectant becomes overused or is inadvertently inactivated.

Visualizing The Change

Just as there is no breakthrough cure for multi-drug resistant infections in sight, there is no disinfectant likely to be developed soon that will provide the unique benefits of a steam vapor system.

The optimal plan will be determined through careful scientific research, but it will certainly capitalize on the ability of commercial steam vapor systems to be used seamlessly around patients and frequently on high-touch, often vertical surfaces.

In one scenario, a member of the hospital cleaning staff would be tasked with ongoing "hot spot" disinfection while another would be responsible for terminal cleaning and disinfection with a commercial steam vapor system.

The first staff member would move in a cyclical fashion from wing to wing or floor to floor on an ongoing basis.

This person would focus on disinfecting surfaces such as doorknobs, light switches, bedrails in patient rooms and other high-touch surfaces.

Meanwhile, the second staff member would focus on deep cleaning and disinfection of a broader group of surfaces between room changeovers.

There would be many advantages to such an approach.

Foremost, the repetitive disinfection of the high-touch surfaces would dramatically decrease transmission of pathogens throughout the hospital.

Traditionally, such surfaces are cleaned once a day or once a week and, considering the rate at which these surfaces are touched, once a day or week is wholly inadequate.

By using a steam vapor system, high-touch surfaces can be disinfected on an hourly basis without damage to the surface, chemical irritation to sensitive populations or long-term risks to staff.

Time To Take Action

It is time to take action, to be open with respect to how we think about preventing pathogen transmission by hospital surfaces.

Hospital surfaces are cleaned to enhance appearance and preserve functionality; they''re disinfected to prevent infections.

Chemical disinfectants have surely prevented many infections, but they can be irritating to patients and dangerous to staff.

In addition, they are not used in hospitals as intended.

As such, chemical disinfectants may not provide the kind of disinfection that is needed in this era of increasing antibiotic resistance.

Commercial steam vapor systems represent a new approach to infection control that is environmentally friendly, chemical-free, broadly active and rapidly efficacious.

If you are interested in infection control, you doubtless enjoy opportunities to evaluate new technologies as they become available.

Consider steam vapor from an objective, scientific perspective: It is a new technology with the potential to reduce pathogen transmission within your facility.

The impact to human health may well be worth the time and contemplation invested.


Dr. Benjamin Tanner is the principal of Antimicrobial Test Laboratories, an independent testing facility specializing in the research and development of antimicrobials, including disinfectants. Dr. Tanner holds a B.S. in Molecular Biology and a Ph.D. in Microbiology and Immunology from the University of Arizona, where he studied environmentally mediated disease transmission and assessed infection risks for workers.

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