Preventing healthcare acquired infections remains a key concern for institutions globally. Bill O’Neill, vp of Infection Control Applications, PurThead, looks at the role of antimicrobial surfaces in hospitals today.
Healthcare associated infections (HAIs) pose a major threat to patient safety worldwide, with hundreds of millions of patients affected each year. These infections lead to significant and preventable morbidity and mortality, not to mention huge financial costs borne by governments, health systems and patients. Studies have tied HAI rates to contamination in the patient environment, making the reduction of bioburden contamination a top priority. This is leading hospitals and companies to explore antimicrobial surfaces as a novel approach to bioburden reduction.
In the UK, a 2011 survey conducted by the Health Protection Agency (HPA) found that out of 52,443 NHS hospital patients surveyed, a total of 3,360 were diagnosed with an active HAI, while 135 patients had more than one infection.1
In the United States, hospitals report more than 1.7 million HAIs annually, causing approximately 100,000 deaths a year.2 The US Centers for Disease Control and Prevention (CDC) estimates that HAIs cost US hospitals at least $28bn (€21.5bn) annually.3 Additionally, the World Health Organisation (WHO) found that in high-income countries, 30% of patients in intensive care units (ICUs) are affected by at least one HAI. In low- and middle-income countries that frequency is at least two to three times higher.4
In Europe HAI rates dropped 2 percentage points between 2006–2011, a significant movement considering the number of facilities, patients and staff involved. US data for that time period remains less clear. However, in the US health system more and more procedures are being handled on an outpatient basis, leaving the most critical and perhaps most immune-suppressed patients being treated in hospitals overnight. Considering this, the fact that the HAI rates in the US have held steady is a testament to current infection control protocols. With recent decisions by Medicare, Medicaid and many private insurers to discontinue reimbursement to hospitals for the treatment of HAIs, US hospitals are under increased pressure to reduce rates.
In the past decade, critical hand hygiene methods have been implemented across the board. Results from a 2009, 12-month hand hygiene study5 found compliance had a baseline of 26% for ICUs and 36% for non-ICUs. After 12 months of measuring product usage and providing feedback, compliance increased to 37% for ICUs and 51% for non-ICUs. While compliance increased when people knew they were being monitored, the report’s authors note, “[Hand hygiene] still occur(ed) at or below 50% compliance for both ICUs and non-ICUs”.
Hospitals have also been effective at implementing vertical strategies to prevent the contamination of specific instruments such as ventilators or catheters. Programmes targeting specific bacteria, such as Clostridium difficile or methicillin-resistant Staphylococcus aureus (MRSA) have been implemented with much success. Vertical strategies make the data-tracking of HAI rates simpler by focusing on specific pathogen types or infections tied to medical devices or interventions. However, with HAI rates still high across the board, more horizontal strategies to combat the prevalence of contamination in the patient environment are gaining increased attention.
With HAI rates still high across the board, more horizontal strategies to combat the prevalence of contamination in the patient environment are gaining increased attention
Horizontal strategies are universal in that they focus on reducing the risk of all preventable infections through interventions that are consistently applied throughout the patient environment. Examples include hand hygiene and the general reduction of bioburden on all surfaces within the patient environment.
Environmental contamination
A consistent, rigorous focus on hand hygiene is the foundation of a well-planned infection prevention programme. However, due to the high level of bioburden entering and circulating through the patient environment, it may not be enough. Environmental contamination can originate from anywhere and be carried throughout the hospital by anyone, including staff, patients, visitors and even get-well-soon gift deliveries. This ‘revolving door’ of contamination makes it all too easy for a freshly washed hand to become contaminated before reaching the patient.
In the patient environment, clean hands can inadvertently touch contaminated bed rails, curtains, clipboards, blankets or scrubs. To that point, a 2012 study at the University of Iowa examined privacy curtains in ICUs and medical wards. Investigators swabbed the high touch areas of the curtains twice a week for three weeks to determine their level of contamination. The study found 92% of the 43 freshly hung privacy curtains monitored over a three-week period in a medical ward, surgical ICU and a medical ICU were contaminated within one week, including nine with MRSA and 18 with vancomycin-resistant enterococcus (VRE).6
There is an increasing body of evidence that cleaning or disinfection of the environment can reduce transmission of healthcare-associated pathogens. In 2007, Dr John M Boyce from the US Hospital of Saint Raphael in New Haven, Connecticut, wrote, “because routine cleaning of equipment items and other high-touch surfaces does not always remove pathogens from contaminated surfaces, improved methods of disinfecting the hospital environment are needed.”7
Beyond hand hygiene
It is clear that hand washing is essential for good patient care and for reducing microbial bioburden in the patient environment. However, 100% hand hygiene compliance, and hand washing after touching every surface before touching a patient is impractical, time-consuming and very difficult to enforce.
Cleaning patient rooms more frequently than every 24 hours is also not enough to combat HAIs. Environmental cleaning processes often cannot guarantee the complete removal of pathogens and methods may inadvertently transport pathogens from one room to the other. Besides this, most cleaning routines emphasise hard surfaces, such as counters and bed rails, while putting less emphasis on soft surfaces, such as privacy curtains and other fabrics such as furniture upholstery. Hard surfaces are relatively easy to clean with a cloth and disinfectant, while cleaning fabrics presents a more difficult challenge.
Soft surfaces make up a large portion of the patient environment and most cannot be cleaned using portable antiseptics. For some applications, such as privacy curtains, frequent laundering might seem like a reasonable solution.
Soft surfaces make up a large portion of the patient environment and most cannot be cleaned using portable antiseptics
However, removing, laundering, and re-hanging these curtains is historically difficult and time-consuming. As a result, it is not uncommon at many hospitals for curtains to hang for as long as six months before they are laundered. Unfortunately, these overlooked sources of contamination are often the last item touched by a healthcare worker before touching a patient.
MRSA and VRE can survive in the environment for weeks, particularly on soft surfaces.8 The study Survival of enterococci and staphylococci on hospital fabrics and plastic9 researched 22 gram-positive bacteria on five common hospital materials, including scrubs, lab coats and splash aprons. The study found all isolates, including vancomycin-sensitive and resistant enterococci and methicillin-sensitive and resistant staphylococci survived for at least one day, while some survived for more than 90 days on the various materials. The authors reported that: “The long survival of these bacteria, including MRSA and VRE, on commonly used hospital fabrics, such as scrub suits, lab coats, and hospital privacy drapes, underscores the need for meticulous contact control procedures and careful disinfection to limit the spread of these bacteria.”
These studies highlight the role of conventional fabrics as potential reservoirs of contamination. As healthcare institutions recognise the need for clean rooms and equipment as well as clean hands, a new look at novel surface materials may be warranted.
Continuously active surfaces
Hospitals are beginning to examine the potential role of hard and soft surfaces that incorporate continuously active antimicrobial materials. These materials actively reduce the level of microbial bioburden on surfaces within the patient environment. In the realm of hard surfaces, investigators revealed that copper coatings on objects formerly covered in plastic or stainless steel have shown an 83% reduction10 in the average microbial bioburden found on the objects. Other novel approaches include door handles that automatically dispense sanitising gel, like those from PureHold and Altitude Medical.
Textiles that act as continuously active surfaces with antimicrobial properties are providing healthcare institutions with a potentially effective method for further reducing bioburden in the patient environment. While some examples of antimicrobial textiles rely on chemical coatings and topical treatments, another approach is to incorporate active ingredients into the core of the fibres themselves.
Textiles that act as continuously active surfaces with antimicrobial properties are providing healthcare institutions with a potentially effective method for further reducing bioburden in the patient environment
One company pursuing this “imbedded” technique is PurThread Technologies. It has developed a method to incorporate the company’s proprietary Complex Element Compound (CEC) into every fibre of its fabric products at the raw material stage, leaving the fabrics soft, supple, and pliable. PurThread’s textiles have shown a reduction in bioburden of 99% within 60 minutes in the lab. A study at the University of Iowa (publication pending) suggests that PurThread curtains could have measurable benefits relative to the control in a real world clinical environment. PurThread’s textiles are currently undergoing federal review in the United States.
PurThread is targeting surfaces that are not only easily contaminated but also infrequently laundered, such as privacy curtains and lab coats. The company’s proprietary Complex Element Compound is integrated into each individual fibre so that it provides an evenly distributed level of activity throughout the fabric. Because the CEC is not a coating, it cannot wash off or wear out.
Inevitably patients will contract infections in healthcare settings due to the large bioburden and an increasing number of patients with compromised immune systems. However, research indicates a cleaner patient environment correlates with a reduced number of infections. While soft surfaces are an often-overlooked source of contamination, these fabrics may hold the potential to play a key yet unobtrusive role in infection control efforts.
To stay ahead of the curve, healthcare institutions must explore horizontal infection control approaches and continuously active soft surfaces, to support the reduction of HAIs that affect hundreds of millions of people every year around the world.
References
1. Susan Hopkins (HPA), et al. English National Point Prevalence Survey on Healthcare Associated Infections and Antimicrobial Use, 2011: Preliminary Data. Health Protection Agency. 2012.
2. R. Monina Klevens, DDS, MPH, et al. Estimating Health Care-Associated Infections and Deaths in US Hospitals. Public Health Reports. March – April 2007. Vol 122.
3. R. Douglas Scott II, Economist. The Direct Medical Cost of Healthcare-Associated Infections in US Hospitals and the Benefits of Prevention. Centers for Disease Control and Prevention. March 2009.
4. Benedetta Allegranzi, WHO Patient Safety Programme, Geneva, Switzerland. Report on the Burden of Endemic Health Care-Associated Infection Worldwide. World Health Organisation. 2011.
5. Maryanne McGuckin, ScEd, MT et al. American Journal of Medical Quality. March 2009.
6. Michael Ohl et al. American Journal of Infection Control. April 2012
7. John M. Boyce, M.D. The Journal of Hospital Infection. June 2007.
8. Michael G. Schmidt, et al. Journal of Clinical Microbiology. May, 2012.
9. Alice N. Neely et al. Journal of Clinical Microbiology. February 2000.
10. Michael G. Schmidt, et al. Journal of Clinical Microbiology. May, 2012