Most people associate stainless steel with food preparation, hospital surfaces, and other places where sterility is desired. I challenge any reader to find an operating room devoid of stainless steel. And for good reason: Stainless steel is a very hard surface that lacks porosity, is easy to clean, and does not tarnish.
The World Health Organization’s definition of a hospital-acquired infection has several components. They include:
- An infection acquired in a hospital by a patient who was admitted for a reason other than that infection, and
- An infection occurring in a patient in a hospital or other health care facility in whom the infection was not present or incubating at the time of admission.
In general, infections occurring more than 48 hours after admission are considered nosocomial.
This burden is enormous. Some estimates suggest that as many as 1 in 10 hospitalized patients will get a hospital-acquired infection. According to the Centers for Disease Control & Prevention (CDC), there are 2 million hospital-acquired infections each year in the United States. Data from 2002 in the United States suggest this adds nearly $7 billion in direct costs.
Many programs have been developed to help prevent nosocomial infections, including hand washing protocols, isolation protocols, and setting cleaning standards for rooms and equipment. But despite nearly four decades of active intervention, these infections continue. So any efforts to cut down on nosocomial infections will be met with enthusiasm by hospitals and managed care.
The most common infections include urinary infections, central line catheter-induced infections, ventilator-associated pneumonias, surgical site infections, and GI illness. The severity of the infection and subsequent costs are highly dependent on the type and resistance patterns of the pathogen involved, but common wisdom suggests that pathogens in the hospital typically are of a higher level of antibiotic resistance than those in outpatient settings. The most feared are MRSA, E.coli, Proteus, Klebsiella, Enterobacter and Pseudomonas, although fecal-oral transmitted Clostridium difficile is also a growing threat.
Stainless steel readily holds all of these bacteria for hours or even weeks with little diminution over time at temperature and humidity conditions found in hospitals.
When copper is mentioned most people will think of water pipes, wiring, and the coin — a penny. Others may recall that brass is an alloy of 70–90 percent copper plus zinc and that bronze is an alloy of copper and tin. Both are found in decorative lighting and door handles. Most would suggest that a key property of all of these copper alloys is the need to polish the tarnish away! Few would relate copper to preventing and treating infection, but the history of using copper for that purpose goes back thousands of years.
Ancient societies, including the Egyptians, Greeks, Romans, and Aztecs, used copper in a variety of ways to prevent or treat disease. Copper was used by the Egyptians to sterilize drinking water. Open wounds were treated with copper by Hippocrates. Boils and eye infections were treated with copper in India and Persia.
Even today copper is used to create fungicides, oral hygiene products, and antiseptics, and to prevent the “spoiling” of paint from mold. But until recently the approach was to use a copper salt or compound to treat a problem. Now, based on research sponsored by the Copper Development Association and the International Copper Association, a much more pervasive use of copper may be on the horizon.
Several years ago, studies demonstrated that placing microorganisms in contact with copper will kill them rather quickly (less than two hours) without the addition of any soap, disinfectant, or sanitizing agent, and the surfaces remain sterile. This property is not associated with stainless steel or chrome-plated surfaces.
The surface does not need to be pure copper, but an alloy of at least 60 percent is needed. The possible alloys can be a brass or bronze type alloy or even a copper-nickel alloy that is a brushed-nickel color and nontarnishing, with a composition very similar to the quarter-dollar coin.
Properties of copper
Incidentally, other surfaces were tested including polyethylene, common in food cutting boards, and silver-coated stainless steel, but none exhibited a significant reduction in bacterial levels over test times as long as six hours.
It also appears that this remarkable property of copper is not diminished by either low or high humidity. While near-freezing temperatures delayed the drop in live organisms on both stainless steel and copper-nickel surfaces, it did not prevent eradication of the microorganisms by copper surfaces. Stainless steel exhibited no killing effect.
The mechanism of action of this toxic affect appears to be the production of hydroperoxide radicals, leading to degradation of nucleic acid, structural and functional proteins, and lipids, and to inhibition of metabolic processes. Studies have indicated a nearly total destruction of DNA of plasmid DNA, suggesting that transmission of resistance patterns between bacteria can be reduced with the use of copper alloy surfaces.
All of these studies have led researchers to propose a major rethinking of the types of surfaces that might be changed to copper alloys in hospitals. These include door handles, IV poles, nurse call buttons, data input devices, bed rails, railings, sink faucet handles, furniture pulls, instrument knobs, work surfaces, hospital bed trays and tables — any surface that is commonly touched by the patient or by hospital personnel.
The copper industry is already gearing up to produce the common surfaces mentioned above, and supply chains are being formed as you read this. If these studies demonstrate what the investigators are postulating, we may soon see an ancient metal taking over even the most modern hospital, demonstrating that Tomorrow’s Medicine may draw heavily from yesterday! -