Healthcare Acquired Infections
Healthcare Acquired Infections (HAIs) or “nosocomial” infections are infections that patients acquire while receiving medical treatment in the continuum of settings where persons receive health care (e.g., long-term care, home care, ambulatory surgical centers, dialysis facilities, outpatient care). HAIs are among the most common complications of hospital care, causing an estimated 1.7 million infections each year in the United States alone. HAIs can be caused by bacteria, fungi, viruses, or other, less common pathogens. HAIs are a significant cause of illness and death and they can have devastating emotional, financial, and medical consequences.
The environment, in which a patient is treated, can be a repository for pathogenic microorganisms, which can survive the most rigorous disinfection practices. Organisms can be transmitted to a patient via their environment, their caregiver or from a patient’s own skin. The occurrence of HAIs continues to escalate at an alarming rate. On any given day, about one in 25 hospital patients acquires at least one HAI, meaning that nearly 650,000 patients contract one of these infections annually.
By aggressively treating HAIs and misusing antibiotics, hospitals must now combat costly multidrug resistant organisms (MDROs). MDROs lead to unnecessary tests on newly admitted patients, longer lengths of patient stay and higher patient mortality rates.
There are 4 types of HAIs associated with invasive devices and procedures:
Central Line Associated Bloodstream Infection (CLABSI)
A central venous catheter, also known as a central line, is a tube that doctors place in a large vein in the neck, chest, groin, or arm to give fluids, blood, or medications or to do medical tests quickly. These long, flexible catheters empty out in or near the heart, allowing the catheter to give the needed treatment within seconds. When this tube is not put in correctly or kept clean, it can become an easy way for pathogens to enter the body leading to deadly infections in the blood. CLABSIs result in thousands of deaths per year and billions of dollars to the US healthcare system.
Catheter-Associated Urinary Tract Infections (CAUTI)
A UTI infection is an infection involving any part of the urinary system, including urethra, bladder, ureters and kidneys. These are the most common HAIs. When the urinary catheter is not put in correctly, not kept clean, or left in the patient for too long, pathogens can travel through the catheter and infect the bladder or kidneys. Catheters should be removed as soon as they are no longer required, to prevent CAUTIs.
Surgical Site Infection (SSI)
A SSI is an infection that occurs within 30 days after surgery in the part of the body where the surgery took place. SSIs can sometimes be superficial, infecting only the skin. Other SSIs can be more serious and involve deep tissue under skin, organs or the implanted materials.
Ventilator Associated Pneumonia (VAP)
A VAP is a lung infection that develops in a person who is on a ventilator. A ventilator assists a patient with their breathing through a tube placed in patient’s mouth or nose, or through a hole in the front of the neck. An infection may occur if germs enter the tube and enter the patient’s lungs.
HAIs impose significant economic consequences on the nation’s healthcare system. HAIs continue to be an important patient safety problem and the financial and social costs of treating them are staggering. Indirectly, HAIs lead to a considerable financial burden and even bankruptcy for many patient families, as well as exorbitant costs for medical malpractice cases and hospital liability. The overall direct cost of HAIs to hospitals ranges from $28B to $45B US, annually.
Steps can be taken to control and prevent HAIs in a variety of settings. Research shows that when healthcare facilities, care teams, and individual doctors and nurses, are aware of infection problems and take specific steps to prevent them, rates of some targeted HAIs (e.g., CLABSI) can decrease by more than 70 percent.
Despite significant prevention success through improved central line insertion practices, there is still a need to expand prevention through improved maintenance of central lines and other strategies. Continued prevention efforts, employing strategies to both reduce the risk of CAUTIs per good catheter care and careful CAUTI diagnosis and reduction of unnecessary catheter use, will be needed in the ICUs and hospital wards. Future declines in SSI will require collaborative efforts with the surgical community to develop innovative prevention strategies directed at specific patient procedures. New prevention strategies for preventing non-CLABSI Methicillin-resistant Staphyloccus aureus (MRSA) bacteremia are needed, as well as strategies for preventing community-associated MRSA bacteremia. Additionally, there is a considerable need for antibiotic stewardship in adult ambulatory settings as well as the development of other prevention strategies directed at these infections.
Biofilms in Medicine and the Environment
A biofilm comprises any group of microorganisms in which the individual cells stick to each other and often also to a surface. These cells produce a protective extracellular slimy polymeric matrix that plays a crucial role in allowing them to grow and thrive. Because they have three-dimensional structure and represent a community lifestyle for microorganisms, biofilms are frequently described metaphorically as “cities for microbes”.
Biofilms can form on living or non-living surfaces and can be prevalent in natural, industrial and hospital settings. Their formation begins with the attachment of free-floating microorganisms to a surface. The development of a biofilm may allow for an aggregate cell colony to be increasingly resistant to antibiotics.
In the case of marine vessels, biofilm formation results from the proliferation of marine bacterial biofilms that ultimately lead to macro-fouling. The accumulation of biomass below the waterline of ships can lead to significant increases in “drag” thus requiring the expenditure of more fuel for transporting goods. With this increase in fuel consumption, concomitant increases in the cost of goods and the emission of greenhouse gases follow.
At Iasis Molecular Sciences, we have developed a family of antimicrobial polymer fillers that can be incorporated into many different materials and subsequently processed using well-accepted methods such as molding, extrusion, and lacquer coating. Polymer modification of the polymer to incorporate the antimicrobial filler yields materials with surface properties inhospitable to microorganisms thus diminishing the likelihood of proliferation in the form of biofilm.
Examples of how biofilms impact everyday life
Non-healing wounds can, in part, be slow to heal because of the presence of tissue-adherent biofilms. These biofilms result in prolonged and exacerbated inflammation, excessive proteolysis, increased oxidative stress, destruction of crucial growth factors, and important cell-surface receptors needed for wound repair and resolution. As such, removing of the biofilm debridement and subsequent dressing with antimicrobial dressings is warranted.
The lumens of a urinary (Foley) catheter can be overrun with mineral-rich biofilms formed in the presence of urease-producing bacteria such as Proteus mirabilis. Urea, a waste product that is excreted by the kidneys when you urinate, is hydrolysed in the presence of urease, an enzyme produced by some bacteria. The hydrolysis product of urea is ammonia. Ammonia in the lumen effectively increases the pH of the urine stream thus precipitating otherwise soluble polyvalent calcium phosphate carbonate salts. This precipitation into the lumen entraps the bacteria which grow into biofilm thus further occluding the flow of urine and creating a dangerous situation for the infected patient.
Examples of How Biofilms Impact Industry
Biofouling is the accumulation of microorganisms, plants, algae, or animals on wetted surfaces. The buildup of biofouling on marine vessels poses a significant problem. In some instances, the hull structure and propulsion systems can be damaged. The accumulation of biofoulers on hulls can increase both the hydrodynamic volume of a vessel and the hydrodynamic friction, leading to increased drag of up to 60%. The drag increase has been seen to decrease speeds by up to 10%, which can require up to a 40% increase in fuel to compensate. With fuel typically comprising up to half of marine transport costs, antifouling methods are estimated to save the shipping industry around $60 billion per year Increased fuel use due to biofouling contributes to adverse environmental effects and is predicted to increase emissions of carbon dioxide and sulfur dioxide between 38% and 72% by 2020.
Crude Pipelines Fouling and Corrosion
A significant portion of “internal” pipeline corrosion results from the microbial-induced corrosion (MIC). Many organisms can contribute to the corrosion as the primary cause with the main types being sulfate-reducing bacteria (SRB), sulfur oxidizing bacteria, iron oxidizing and reducing bacterial, manganese- oxidizing bacteria, and acid producing bacteria (APB). Bacteria also promote external corrosion by depolarization via hydrogen consumption formed at the pipe surface by cathodic protection. While difficult to determine exact percentages, it is believed that MIC is believed to be one of the leading causes of pipeline corrosion.
According to the National Association of Corrosion Engineers (NACE), the oil and gas industries spend ~7B annually on direct corrosion and repair for oil and gas transmission pipelines and the industries spend ~1.4B each year to protect or restore production and exploration of infrastructure and equipment.
High Touch Surfaces
A multifaceted approach to preventing infection is critical to reducing the risk for HAIs, including hand hygiene practices, antimicrobial stewardship, and environmental cleaning and disinfecting. Several studies demonstrate that health care-associated pathogens frequently contaminate the patient environment, including both porous surfaces, such as curtains and hard, nonporous surfaces, such as bed rails and medical equipment.
Contaminated surfaces are a reservoir for transmission of pathogens directly through patient contact with the environment or indirectly through contamination of health care workers’ hands and gloves. Hospital room surfaces are known to be unsanitary even after terminal disinfection with bleach, quaternary ammonium compounds, UV light or hydrogen peroxide vapor. Surfaces of copper metal have been well accepted as protective against most microorganisms, including viruses. Although copper handrails and table tops are known to effectively reduce the transmission of infectious organisms, there are no examples of larger copper surfaces in the clinical environment.
At Iasis Molecular Sciences, modified epoxies and acrylics incorporating copper II modified cation exchange resins have yielded decorative coatings that have demonstrated high level disinfection properties against gram-positive and gram-negative organisms and fungi.
Also, Iasis Molecular Sciences have demonstrated that acrylic latex enamel paints modified with copper II cation exchange resins yield decorative surfaces that possess high level disinfection qualities. These surfaces are effective against a variety of microorganisms including gram-negative and gram-positive bacteria, and fungi.
Walls and flooring represent the largest surface areas susceptible to contamination within the interiors of hospitals, nursing homes, daycare centers, and cruise ships, where pathogens can be a cause for concern. Copper II is widely known to inactivate a variety of bacteria, fungi, and viruses, including Norovirus. Iasis Molecular Sciences’ self-disinfecting surfaces will mitigate the high level of pathogens living on surfaces in these establishments.