Fighting Infections

Today, patients have as much to fear from hospitals as they do from disease. According to the CDC, health care–associated infections (HAIs)—including both nosocomial infections and those associated with medical intervention in health care facilities—account for an estimated 1.7 million infections in American hospitals, and 99,000 related deaths annually.

These numbers are tragic in light of the fact that the infection might have been prevented if more effective disinfection and control programs had been in place. The CDC infection-control guidelines state that the incidence of HAIs and pseudo-outbreaks can be reduced by using specific measures. These guidelines include the appropriate use of cleaners and disinfectants, the appropriate maintenance of medical equipment, and adherence to certain water-quality and air-quality standards. Though environmental services can bear much of the responsibility for disinfection and sanitation, it is important to be sure that the right tools and methods are in use. Laboratories, like the hospital as a whole, should have a program in place to prevent the introduction or spread of HAIs, recognize outbreaks, and contain risk.

AcryMed’s SilvaGard prevents microorganisms from attaching to the surface with a nanoparticle silver coating.

Simple steps such as hand washing can have a big impact. More complex methods, such as those incorporating microbiological monitoring and software algorithms, can add proactivity. New products and technologies expand effectiveness, attacking and evaluating new organisms more quickly and with better results. Following, CLP looks at some of the latest products to make cleaning up easy.

Guarding Against Microorganisms

AcryMed, Portland, Ore, offers a new coating technology that helps keep coated items from becoming dirty. SilvaGard is made of silver, which possesses natural antimicrobial properties that repel and kill microorganisms including bacteria, viruses, and fungi.

The coating can be applied to a variety of materials without changing the measurable dimensions or characteristics. The silver nanoparticles are microscopic and deposited using a solution dip process, which makes it easy to control the amount applied. “The coating can be tailored for an active time frame from 1 week to years,” says AcryMed President Jack McMaken.

The company has focused its early efforts on coating products used on or in the human body, such as catheters, because they are more likely to develop biofilms, but it can also be applied to lab supplies. “When putting material into the body, bacteria can attach to it and build up,” says McMaken.

According to research cited by the company, biofilms are formed when fast-mutating versions of free-floating bacteria attach to a surface. There they multiply, colonize, and form a polysaccharide-protective covering that becomes extremely difficult to eliminate and can contribute to infection. The silver coating prevents these biofilms from forming by keeping microorganisms from adhering to the surface.

The silver, however, poses no danger to humans and is extremely well tolerated by tissue. “It takes between 1,000 and 10,000 times the concentration of silver needed to kill a bacterium to kill a human cell,” says McMaken. The SilvaGard-coated device must still be sanitized as usual, but that process should be more effective with fewer microorganisms to eliminate.

The coating could eventually be applied to everyday items, such as doorknobs and countertops, and the company works with others to coat new products and license the technology. “If someone wants something treated, we’ll work out the formula and recipe and either produce the product ourselves or provide the client with a license to do it directly,” says McMaken. Materials tested include glass, metal, plastic, and Teflon. Laboratory-treated equipment could include beakers, test tubes, and other reusable items.

Handling Difficult Microorganisms

While SilvaGard helps to prevent microorganisms from taking hold, products from CalTech Industries Inc, Midland, Mich, are intended to eliminate them once they are present. A particularly difficult organism to kill is Clostridium difficile, which is also a very dangerous organism. “C diff can be life threatening, particularly for immunocompromised patients,” says Joan Holtschlag, a research and development chemist with CalTech.

Symptoms of C. difficile–associated disease (CDAD) can cause diarrhea—and even death. According to the CDC, US hospital discharges for which CDAD was listed as a diagnosis doubled from 1996 to 2003, and new strains continue to emerge, often more virulent than their predecessors.

Because patients can carry the bacterium without symptoms, it may not surface until antibiotics permit it to flourish by eliminating other bacteria. C. difficile is therefore difficult to keep out of the health care setting. “I think the best way to eliminate the risk of infection is meticulous cleaning followed by disinfection,” says Holtschlag.

Holtschlag notes there are two forms of C. difficile: vegetative and spore. “There is controversy over which form is more prevalent in the environment, but both need to be killed,” she says. “When the vegetative form is stressed, it can turn into the harder-to-kill spore form and sit around for months.”

Unfortunately, the Environmental Protection Agency does not have products registered to inactivate C. difficile spores. “The agency has no test that can measure a disinfectant’s effectiveness against this organism,” says Holtschlag. It does, however, recommend sodium hypochlorite— aka bleach—as being effective against the vegetative form.

The CDC suggests that health care facilities use the recommended disinfectant, carefully following the manufacturer’s instructions. Each product has its own specific directions for dilution, application, and contact time. “A big mistake people often make is not to read the label. Every product has different contact times—sometimes 1 minute, sometimes 5—you need to know how long to leave it on,” says Holtschlag.

Kimberly-Clark WetTask closed-bucket wipes system improves disinfectant effectiveness by reducing the potential for contamination.

CalTech’s Dispatch Hospital Cleaner Disinfectant with Bleach requires a 1-minute contact time. The detergent and bleach solution (5500 ppm NaOCl) does not need to be diluted and includes stabilization ingredients that give it a 2-year shelf life—bleach alone has a much shorter life cycle and will begin degrading almost immediately. Dispatch is available in three application methods— pour, spray, and towels—to accommodate various environments.

The disinfectant can be used in any health care location, including laboratories, hospitals, physician offices, dental and veterinary clinics, nursing homes, ambulances, and outpatient clinics.

It is also registered to kill more than C. difficile. Other organisms the solution will kill within 1 minute include Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella enterica (formerly known as choleraesuis), Streptococcus pyogenes, Methicillin-resistant Staphylococcus aureus (MRSA), Vancomycin-resistant Enterococcus faecalis, HIV-1, hepatitis A virus, hepatitis B virus, hepatitis C virus, poliovirus type 1, herpes simplex virus, rotavirus, norovirus, avian influenza A, and Trichophyton mentagrophytes (athlete’s foot fungus).

Wiping Out Microorganisms

Kimberly-Clark Professional, Roswell, Ga, offers wiper products that work with disinfectant solutions from other manufacturers to wipe out the intended microorganisms more effectively . Research published by the company indicates that disinfection can be optimized with the right wiping material.

“Some wiping materials actually deactivate disinfectant chemicals in solutions,” says Kimberly MacDougall, a research scientist with Kimberly-Clark Professional. To examine this effect, the company compared its KimTech Prep Wipers for Bleach, Disinfectants, and Sanitizers used with the company’s closed-bucket WetTask Refillable Wiping System to cotton rags and disposable cellulose-based wipers used in an open-bucket system.

The study found that cellulose and cotton fibers showed a decline in the concentration of basic quaternary amine disinfectants delivered from the wiper to the surface being cleaned, and continued to decline throughout usage. “Natural fibers and synthetic fibers are not compatible with disinfectants. However, many synthetic fibers can be enhanced to sustain the active disinfectant concentration throughout the use period,” says MacDougall.

Quaternary amines are a common disinfectant used to protect against a broad range of vegetative bacteria and enveloped viruses. They, too, have specific instructions for effective use. Kimberly-Clark Professional offers a line of wipes designed to work with specific disinfectants and chemicals, such as quaternary amines; bleach; and general solvents, soaps, and cleansers.

If any disinfectant is not applied as required, it may not work. If a wiping material does not deliver the same concentration as measured in the bucket, then it can impede efficacy. Users often assume the two concentrations are the same, but the study showed they may not be.

The initial quaternary amine concentration from the first cotton rag passed through the open bucket was 53% lower than that of the original disinfectant solution A, and nearly 30% lower for disinfectant solution B. In contrast, initial quaternary amine release for KimTech Prep Wipers for Bleach, Disinfectants, and Sanitizers was less than 10% below the original concentration of disinfectant solution A and less than 1% lower for disinfectant solution B. In addition, the KimTech wipes maintained an average of 90% or greater target concentration of quaternary amine actives during a prolonged period of use.

“To optimize disinfectants, you need to be sure your disinfectant chemical is making it to the surface at its target concentration,” says MacDougall. The closed-bucket system may be the ideal way to do this. Advantages include the potential for reduced contamination and sustained contact time, easy portability, and less environmental waste.

In an open-bucket system, if a rag or wipe is returned to the bucket for a second use, it can introduce microorganisms to the cleaning solution. These microorganisms can be killed; but they will also further consume the disinfectant. Using a spray may lead to immediate wiping, and therefore, insufficient contact time; visible debris is removed, but invisible microorganisms remain. “People often work with a dry wipe right after spraying on the disinfectant solution. This results in wiping up the solution before it has been on the surface long enough to disinfect,” says MacDougall.

Wipes and the closed-bucket system may cost more initially than a repurposed cotton towel the hospital has recycled for free, but they are much less expensive in the long run than the cost of an HAI. HAIs increase the cost of care not only through the need for additional procedures and medications, but also in longer hospital stays.

Of course, disinfection alone isn’t the answer; prevention is also key, and Kimberly-Clark Professional offers another product line to reduce the spread of infection, including gloves, masks, eye protection, soaps, towels, tissues, and dispensers. “Our Purple Nitrile exam gloves are extremely popular in laboratory environments,” says MacDougall.

Keeping Microorganisms Off

Gloves are officially required in the lab, as are lab coats, eyewear, and in some instances, face masks. The clothing requirement is less official, but some facilities may have dress codes requiring men in positions of authority—eg, lab directors, physicians, and administrators—to wear ties, which can be a breeding ground for infection. Ties are rarely cleaned, yet dangle throughout the day, touching patients, bedding, and hands.

A study conducted by Steve Nurkin, MD, found that 47.6% of the neckties worn by clinicians harbor potential pathogens, while one in eight neckties harbored well-known hospital-acquired bacteria.

“The British Medical Association released a study in 2006 that evaluated health care–associated infection rates throughout the world and found risks related to hand washing, improper handling of sharps, and [wearing] neckties. They suggested that neckties no longer be worn,” says April Strider, CEO of SafeSmart, St Augustine, Fla.

Although some men may relish the opportunity to leave the tie at home, others may want to consider purchasing a SafetyTie from SafeSmart. These neckties are processed with an antimicrobial coating that repels germs and stains.

“SafetyTies are 100% silk neckties that have been nanotreated to give them superhydrophobicity. Each silk strand is encapsulated to create a barrier that prevents proteins from embedding in the material,” says Strider.

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Lab tests have proven this repellent quality. Cultures completed by an independent lab showed a 99.9% difference in Safety Ties versus conventional silk ties worn in the health care setting. “The regular ties grew a lot of E.coli and salmonella, while our ties grew almost none,” says Strider. New studies showed similar results with MRSA.

The cost of a SafetyTie is comparable to that of some department store ties—$45—and the designs are intended to be as fashionable. Institutions wishing to order in mass quantities can select from more than 300 styles or customize their own; individuals can choose from a line of 24, though Strider says the company is expanding its offerings. SafetyTies are resistant not only to stains and germs, but also to wrinkles.

Renee DiIulio is a contributing writer for CLP.