The U.S. healthcare system is burdened with 3.2 billion dollars of added cost each year to battle multi-drug-resistant organisms (MDROs). The two primary organisms are methicillin-resistant Staphylococcus aureus (MRSA) and Vancomycin-resistant Enterococcus (VRE), which account for about 63 percent of hospital reported infections.1 To battle these so-called superbugs, disinfectants with residual killing properties are essential. Hospitals would be able to effectively attack these bacteria by proactively treating environmental surfaces with anti-microbial technology products. These products would work on a molecular level with inanimate objects to provide a barrier where viruses, bacteria, fungi and spores could not attach to the surface and could not contaminate the surface. Disinfectants with residual activity will be the answer and prove to be a valuable weapon against MRSA and VRE. Proactive measures of focusing on the environmental components in patient-care areas will enhance the effectiveness of infection control programs.
These superbugs can cause outbreaks of infections that increase mortality rates four-fold. One method to attack these superbugs is through enhanced environmental measures. The Centers for Disease Control and Prevention (CDC) states, Clean and disinfect surfaces and equipment that may be contaminated with pathogens, including those that are in close proximity to the patient and frequently-touched surfaces in the patient care environment.2
A successful six-month study at Glasgow Royal Infirmary reports that treatment of high-contact surfaces such as door handles, patient contact systems and bed rails account for a 75 percent reduction in MRSA throughout the ward; total elimination of MRSA was noted for several weeks during the trial.3 The anti-microbial technology product that this study tested was found to provide residual disinfecting properties to surfaces that may become contaminated by MDROs. This product uses polymer technology to entrap added biocides and adhere them to surfaces at a molecular level. Anti-microbial disinfectants work at two levels: initial kill on contact and formation of a monolayer when wet and dry killing viral and bacterial cells, spores, fungi and algae. This product inhibits bio-film formation by interference with and disruption of microbial attachment. Some characteristics of anti-microbial disinfectants are: ongoing protection from microorganisms by preventing attachment; broad-spectrum efficacy; no induction of MDRO resistance; low in toxicity; easy to use; and require no specialized capital equipment.
Infection control practitioners (ICPs) and epidemiologists have often been in a reactive mode due to incubation periods and identification processes. There is agreement that proactive factors to a successful infection control program should include appropriate antibiotic usage, physician and staff education, pre-treated medical supplies, effective handwashing programs and appropriate usage of isolation precautions. The most overlooked component of an effective infection control program is switching from a reactive state to a proactive state. Prevention is the primary component to hardwire efficacy into any infection control program.
Environmental condition is one measure on which to focus while trying to implement an effective program. Inanimate objects in the healthcare setting are a major source of transmission of MDROs. Although it is true that healthcare workers are the primary mode of transmission, the objects that become contaminated in and around the patient care setting are the source for the transmission. Eradication must occur at the source to control or prevent transmission. The Association of Professionals in Infection Control and Epidemiology (APIC) indicates in a 2006 report that 70 percent of patient rooms had MRSA recovered from the environment. Sources where MRSA recovery occurred include the patients gown, the floor, bed linens, blood pressure cuffs, over-the-bed tables, stethoscopes and door handles.4 Various national reports indicate that super-bugs are found on the television remote control, patient bed controls, door handles, light switches, curtains, commodes and patient room chairs. These environmental sources of MDROs require action in order to prevent the healthcare worker from contaminating him/herself every time he/she enters a patient-care area.
Proactive measures include appropriate use of disinfectants, scheduled and frequent environmental cleaning, appropriate use of isolation and the inclusion of disinfectants with residual killing properties. If disinfectants could create a barrier on the surface of the inanimate object that prevented the microorganism from being able to attach, then transmission would not be possible. Even if this disinfectant only produced a residual effect for a day, the object would not instantly be re-contaminated after cleaning. There are currently two products on the market with claims of residual disinfecting properties.
One product is a silver-based liquid designed to add a protective coating to inanimate surfaces and the other focuses on antimicrobial treatment designed to work at the molecular level on the surface on an object.
Certainly, residual disinfectants sound like a win-win solution to the MDRO problem, but are they really? To determine if a residual disinfectant would be an effective component to a proactive preventive program this product requires testing, and clinicians should ask, Do either one of these products really work? That is the question posed to the laboratorys microbiology department and environmental services director.
Our environmental services director, Katrina Bardsley, provided the following test methodology on Feb. 1, 2007: the silver-based product was tested in a patient room on the medical/surgical nursing unit. While using this product per manufacturers recommendations, a white film surfaced on the items being cleaned. This film represented a dirty appearance on the furnishings and it was decided not to test this product any further.
The antimicrobial product was mixed per manufacturers recommendations of three ounces to five gallons of water. All surfaces were soaked and allowed to dry for the recommended ten minute time frame. Glass and mirror surfaces were wiped down and allowed to air dry and the result was no streaks with this product. The surfaces that were treated included the patient bed, remote control, patient bedside table, microfiber chair, nurse call hand-held device, light switches, bathroom fixtures, curtains and wooden closet panels. All surfaces in the patient rooms were allowed to air dry and the result was no residual film, no appearance of the product and no discoloration to the furnishings. It was decided to test the residual properties of the disinfectant in the laboratory based on these results. The test was conducted in the microbiology section of the hospital laboratory. The project plan was to test for a three-day consecutive residual study of the disinfectant.
Our microbiology technician, Chuck Grimmett, MLT (AMT), provided the following results on Feb. 22, 2007: Throughout the project life cycle, for three consecutive days, this antimicrobial disinfectant was tested for residual performance against VRE and MRSA. Utilizing a hard, non-porous environmental surface measuring 3 inches by 3 inches, the product was evaluated at manufacturers recommended concentration of three ounces of product to five gallons of water (18 ml per gallon). Surfaces were treated with disinfectant and remained wet for 10 minutes per the manufacturers specifications. Quality control was performed using the same hard nonpworous environmental surface moistened with sterile water and no disinfectant. All surfaces were inoculated using either MRSA or VRE with sterile swabs. For three consecutive days, these surfaces were streaked with sterile swabs and then inoculated to blood agar plates to check for either growth or no growth. All results were recorded (see Table 1).
The objective of this report was to gather all relevant information for better disinfectant use, to improve implementation of product usage and to prevent or minimize risks for HAIs. This study concluded that the antimicrobial product had a residual effectiveness for at least three consecutive days when applied according to the manufacturers recommendations.
Since VRE and MRSA are both MDROs, if this product can kill VRE then it can be extrapolated that MRSA can also be killed. The laboratory results prove to be in favor of the antimicrobials residual disinfecting properties. Residual activity was documented, killing VRE and MRSA on the tested inanimate objects for at least three days. With this knowledge, a proactive infection control program can now attack the environmental factors that aid in the transmission of MRDOs. Along with appropriate antibiotic usage, handwashing effectiveness and isolation precautions, residual disinfectants can additionally increase a facilitys chance of decreasing the transmission of MRSA and VRE. A follow-up study is underway that will test the products effectiveness when applying multiple layers and will test for the effectiveness of residual kill properties greater than three days.
James Ballard, MBA, is the infection and performance improvement manager at Monroe Hospital in Bloomington, Ind.
1. Battling superbugs in the environment of care. The Joint Commission Environment of Care News. Vol 10. No. 2. Pg 1-4. February 2007.
2. Seigel JD, Rhinehart E, Jackson M, Chiarello L, et al. Management of multi-drug-resistant organisms in healthcare settings. Centers for Disease Control and Prevention. Sect V.A.6. Pg 40. 2006.
3. Study shows cleaning agent reduces MRSA by half. Infection Control Today. Accessed Dec. 7, 2006 from http://www.vpico.com/articlemanager/printerfriendly.aspx?article=129508
4. Muto CA. Controlling MRSA: Designing a program to eliminate MRSA transmission part I: Making the clinical case. Association for Professionals in Infection Control and Epidemiology (APIC). December 2006.