Wipes are becoming the standard for decontaminating the low-risk patient environment.

Image courtesy of PDI healthcare

Health care-associated infections (HAIs) are a considerable concern in health care facilities, despite continued progress to improve compliance and evidence-based, preventive solutions.

In 2014, for instance, William A. Rutala, Ph.D., MPH, CIC, and David J. Weber, M.D., MPH, concluded that an estimated 20 percent of such infections were attributed to environmental surfaces and medical devices. Contamination of the hands of health care workers could, in turn, result from direct patient contact or indirectly from touching environmental surfaces.

Moreover, Curtis Donskey, M.D., in 2013 reviewed scientific literature and found that improving surface cleaning and disinfection reduces HAIs.

Facilities have a number of disinfectants from which to choose and can opt for different formats, including sprays, aerosols, dilutable concentrates and wipes. Wipes are increasingly becoming the standard for decontaminating low-risk patient equipment and high-touch environmental surfaces because of their ease of use and reduced susceptibility to cross-contamination.

Direction review

Rutala and Weber wrote that disinfectant selection is one of the two components essential for effective disinfection. The other component, the practice, includes thorough application ensuring that the disinfectant contacts all surfaces, as well as proper training of hospital staff and adherence to the manufacturer’s label instructions.

The directions for use are important for the end user to understand, from a safety point of view as well as with respect to compliance with manufacturer instructions, internal policies and the Centers for Medicare & Medicaid Services (CMS). The manufacturer establishes a set of instructions, which is subsequently reviewed by the Environmental Protection Agency (EPA) for compliance.

For most facilities, the label instructions become policy and are held accountable by CMS or other surveying entities such as The Joint Commission or DNV GL. In some instances, internal policies are developed by the facility’s infection-prevention team based on its own scientific studies and research.

Thus, there are differing perspectives:

  • Manufacturer. This is as succinct as possible with clear language. It can be conflicted by a desire for claims and a wide variety of usages to suit the needs of its customers.
  • EPA. This is to protect human health and the environment. It is to ensure consistency and compliance.
  • CMS/The Joint Commission/DNV GL. This is to ensure compliance and to act within the facility’s policies.
  • Facility policy writers. This is to reduce HAIs through the latest research and compliance tools.

A glance at the directions for use of a disinfectant wipe shows how complex they typically are.

Many steps are laid out with various amendments for specific scenarios like blood spills, suspected Clostridium difficile contamination and even varying contact times depending on the organism. It is not surprising that the information can be confusing with a risk of being out of compliance.

Upon review of the commonly used disinfectant wipes currently available, a number of different iterations of contact time directions for use can be observed:

  • “Repeated use of the product may be required to ensure that the surface remains visibly wet.”
  • “Allow surface to remain wet for x minutes(s).”
  • “Allow treated surface to remain wet for x minute(s).”
  • “Allow surface to remain treated for the specific contact time.”
  • “Surface must remain wet for the entire contact time.”

CMS expects that health care facilities strictly follow the label directions for use as written into their infection control worksheet:

  • “2.D.4 Cleaners and disinfectants, including disposable wipes, are used in accordance with manufacturer’s instructions (e.g., dilution, storage, shelf life, contact time).”
  • “4.F.11 Objects and environmental surfaces in patient care areas that are touched frequently (e.g., bed rails, overbed table, bedside commode, lavatory surfaces in patient bathrooms) are cleaned and disinfected with an EPA-registered disinfectant frequently (at least daily) and when visibly soiled.”

How EPA governs wipes

Intermediate and low-level disinfectant performance is governed by the EPA under the guidelines of Series 810. Within are general considerations for use and disinfectants for use on hard, nonporous surfaces. Each EPA-registered disinfectant goes through a rigorous process of approval including, but not limited to, safety and toxicity, chemical stability, claims, antimicrobial efficacy and directions for use, all of which can be found on the product master label.

The master label is an excellent source of information for the end user and can be found easily on the EPA’s website. Infection preventionists should review the master label for each disinfectant used in their facility.

Manufacturers can update the master label when new information is available. Typical updates include additional organisms, reduced contact times, label language changes and/or additional claims. Each update is dated on the website. Due to the logistics of manufacturing, there is often a lag time between the EPA update and the change on the product label itself. Periodic review of the master label is recommended.

The EPA defines its test methodology for wipes based on the AOAC method 961.02, Germicidal Spray Products as Disinfectants. As the title suggests, the method was not originally designed for wipes, but is modified from a ready-to-use (RTU) format perspective. The EPA does not currently have a method specific to disinfectant wipes, although one is under review. The full disinfectant methodology can be found on the EPA’s website under the title “Disinfectant towelette test: Testing of Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella enterica.”

There are also methods for viruses, tuberculosis and C. difficile that differ due to the nature of the microorganisms and how they must be handled in a laboratory environment. None of the aforementioned microorganisms have a specific wipe method and are also a modified approach of other formats, typically RTU sprays. It is important to note that the word “towelette” is used interchangeably with “wipes” to be in keeping with EPA terminology.

The disinfectant towelette test simulates the use of the wipe upon a dried inoculum of the test organisms at a concentration of 106 colony-forming units per milliliter. The surface is exclusively glass and represents a hard, nonporous surface. Wipes are passed across the inoculated surfaces a total of six times. In total, 180 surfaces are tested across three batches of the test product per organism (i.e., 60 per batch). Following the treatment, surfaces are left undisturbed for the remainder of the contact time. The surfaces are not observed for wetness during this time. Any surviving bacteria are recovered by aseptically moving the glass surface into a test tube containing neutralizing growth medium. Efficacy is achieved if each batch of product completely kills the test organisms in 59 of the 60 test tubes.

Typical of all microbiological tests, a standard (and short) list of bacteria is included; however, manufacturers do not limit their studies to just the standard organisms as reflected in their master labels. Again, typical, but the method employs one surface material (glass) as indicative of all hard, nonporous surfaces. It does not reflect all surface types that can be found in a health care setting. A total of 10 glass surfaces are treated with each wipe on a surface area of 1 square inch for a total surface area of 10 square inches, which is much smaller than some applications (e.g., bed tray or stretcher).

It must be noted that manufacturers design their wipes to cover a greater surface area than 10 square inches. Surface pressure applied is not standardized, so there will be variation depending on how much vertical and horizontal pressure is applied by the technician. Robust training and practice is required to reduce this variability. Simulated soil is an option within the test and typically comes in the form of albumin. Despite the inclusion of soil, manufacturers must declare the use of an initial cleaning step where gross/heavy soil is seen. If a manufacturer chooses not to use soil, a preclean step must be included in all situations, not just those with gross/heavy soil.

Most manufacturers suggest that the end user maintain wetness for the duration of the contact time, even suggesting that additional wipes are to be used to maintain wetness. That appears to make sense, but there are flaws in this approach. First, there is the practicality of observing wetness, especially if the contact time is long (i.e., 10 minutes) — no health care worker has time to watch disinfected surfaces dry. Next, there is the subjectivity of wetness; is it thoroughly wet or partially wet? Wetness is truly subjective and, therefore, open to interpretation, which may impact how the product is used.

Then, consider the environmental conditions. Temperature, humidity and air flow all play a role in how long a disinfectant (or any liquid) will remain wet on a surface.

Finally, there is compliance with the antimicrobial test methods. Hospital disinfection tests, as described, do not require that the test surfaces remain wet during the contact time. Indeed, experience of hundreds of studies have demonstrated various levels of wetness throughout the contact time. Despite this, efficacy is assured.

Recommended approaches

The selection of disinfectant wipes is important as infection-prevention efforts may be compromised if a product is not fit for its intended purpose. The selection of an appropriate product can be a complex process that includes the consideration of scientific information and the interpretation of the EPA master label. It is recommended that purchasers and end users alike be familiar with the EPA master label and how the information pertains to their specific need. According to a 2014 publication from Rutala and Weber, there are five components to selecting the ideal disinfectant: relevant kill claims, appropriate wet-contact and kill times, safety, ease of use and other factors like customer support, cost and standardization.

Policymakers should consider the practical usage of disinfectant wipes when writing and defending their procedures to surveyors. Wiping down a surface can come in many forms not considered by the regulatory guidelines. A stretcher that is flat and relatively large in surface area is quite different from an IV pole that is cylindrical and relatively low in surface area. An environmental services professional conducting daily or terminal cleaning will move from one surface to another under the demands of quick turnaround time. Surface curvature, lighting, time and environmental conditions all play a role in whether the end user can comply with the practicality of the product-use directions. It raises the question of how to manage compliance, effectiveness and practicality.

Based on the aforementioned antimicrobial test methods, it’s assured that a disinfectant wipe will perform within the contact time provided by the manufacturer. The surface does not need to remain wet except for specific applications where the regulations differ — C. difficile and the recently emerged Candida auris.

Some common sense

Disinfectant wipes are playing a role in a health care facility’s arsenal against HAIs. Unfortunately, regulations do not accurately reflect how wipes are being used.

Common sense should prevail. Fortunately, the data show that disinfectant wipes are effective and can be used as practice dictates.

James Clayton is director of laboratory sciences at PDI Healthcare, Orangeburg, N.Y. He can be reached at james.clayton@pdipdi.com.