Tackling Antimicrobial Resistance - the Role of Antimicrobial Copper

Antimicrobial-resistant organisms are a major threat to global health

The O'Neill Report—Tackling Drug-Resistant Infections Globally: Final Report and Recommendationssponsored by the UK Government and the Wellcome Trust, was published last week (on 19th May) and sets out the Review of Antimicrobial Resistance's final recommendations for a global approach to addressing antimicrobial resistance (AMR). With an estimated 700,000 people dying every year from drug-resistant strains of common bacterial infections, it warns that the problem is already severe and, without action, will only worsen, taking a heavy toll on lives and economies across the world.

24th May 2016

Decreasing demand for antibiotics—so currently-available drugs last longer—and increasing the number of effective antimicrobial drugs to treat resistant infections are the two main areas for attention proposed. Improving hygiene and preventing the spread of infection is one of the steps indicated to reduce the demand for antibiotics and one of the most fundamental steps is to break the chain of transmission. The healthcare setting is deemed high risk for the spread of bacterial infections and the report urges a return to the pre-antibiotic era, when infection prevention was recognised as a priority as cures were limited.

In a new interview in the World Alliance Against Antimicrobial Resistance's AMR times newsletter, Professor Bill Keevil—Chair in Environmental Science at the University of Southampton—discusses the challenges of infection prevention and control, and the contribution that can be made by antimicrobial copper touch surfaces.
 

As an expert in IPC and member of the NAMRIP, the Network for Anti-Microbial Resistance and Infection Prevention,could you give me your thoughts on why countries are weak on IPC?

'In many cases countries have limited resources to fight infections and do not spend enough on IPC, particularly simple things like regular cleaning of healthcare facilities focusing on touch surfaces such as door handles, push plates, chair arms and bed rails. Some countries rely on simple hand washing as an important preventative measure for IPC but compliance with regular hand washing is still far from ideal for staff and visitors to healthcare facilities, despite the efforts of WHO to promote a handwashing programme.'
 
The impression is that health systems leadership doesn't grasp very well the role of 'amplifiers' in drug resistant infections spread?

'The situation is slowly changing due to WHO education programmes, and government officials and politicians realising that IPC reduces morbidity and mortality, prolonged stays in hospitals causing “bed blocking” and the high costs to taxpayers. A major problem which must be resolved quickly is the excessive use of antibiotics in intensive animal farming leading to rapid evolution of resistant pathogens, with infected persons using modern air transportation systems to spread the infection around in the world in a day or less.

'Our own work has shown that antibiotic resistance genes are rapidly transferred from one superbug to another species on touch surfaces such as stainless steel, meaning that an infected traveller with poor hand hygiene can fly into an airport, touch various surfaces leaving his superbug behind and then another person from another part of the world can add their bacteria to the same surface to create an even greater superbug threat.

'Cleaning these touch surfaces every hour is impracticable. This is where measures affording 24/7 protection become an important adjunct to regular cleaning. Indeed, our work has shown that copper alloys used for touch surfaces quickly kill bacteria, viruses and fungi, and just as importantly prevent antibiotic resistance gene transfer on touch surfaces. The bacteria include the superbugs MRSA, C. difficile, Acinetobacter baumanii, extended spectrum beta-lactamase (ESBL) producing E. coli and carbapenamase producing Klebsiella pneumonia (KPC), which are now causing many outbreaks worldwide. The viruses include influenza, adenovirus, human coronavirus (a close relative of SARS and MERS) and the highly robust norovirus, which suggests that antimicrobial copper surfaces should be efficacious against Ebola etc.'
 
You advocate copper. The efficiency of copper to reduce bacterial spread on door handles has been well studied?

'The beneficial health properties of copper to cure infections were well known to ancient civilisations, such as 5000 years ago in Egypt, India and China, and more recently in Greece, South America and Medieval Europe. These properties were forgotten as we moved into our current age of using contemporary materials such as stainless steel, aluminium and plastics for touch surfaces like door handles. We started our antimicrobial studies of copper in the late 1980s, investigating control of biofilms, Legionella pneumophila and E. coli O157 in copper plumbing systems, before working on touch surfaces in food processing factories and hospitals.'

So you undertook to study these properties?

'Subsequently, we and several other groups have shown in the laboratory that dry (from hand contact) or wet (from bodily fluids such as coughs and sneezes etc) copper alloy touch surfaces kill bacterial, viral and fungal pathogens.  We have also described the mechanisms involved, including direct attack of released copper ions on cell respiration and bacterial membranes, affecting their integrity, and destruction of their DNA so that no resistance mutation can occur. A second reaction also occurs when bacteria release small amounts of hydrogen peroxide from their metabolism which copper converts to highly reactive oxygen species such as hydroxyl radicals which accelerate the kill mechanisms.

'So, in effect, bacteria commit “metabolic suicide” on copper. These lab studies have been successfully translated into clinical practice.  Initial studies in the UK andUSA were quickly followed by studies around the world showing that hospital wards had up to 90% reduction in bacterial numbers on common touch surfaces compared to other materials such as stainless steel.

'Moreover, an important study involving two hospitals in New York and one in Charleston, USA demonstrated a 58% reduction in infection rate when even modest amounts of copper alloys were used as touch surfaces close to patient beds, such as bed rails, overbed tables and the arms of visitors chairs.
It was only latterly that we discovered that an American physician,Dr Phyllis Kuhn, had warned in 1983 about the risk of increased rates of infection when brass doorknobs were being replaced with stainless steel in her hospital in Philadelphia. This was prescient but her warning was unfortunately overlooked.'

Question: Cost Efficiency?

'The principle of “prevention is better than cure” is never truer than now, not least when our antibiotic “cures” are failing due to widespread emergence of resistance. There is little difference in the cost of stainless steel versus various antimicrobial copper alloys, so it is advantageous when building new healthcare facilities to install copper alloy touch surfaces. Even for a retrofit of hospitals, replacing contemporary materials with copper alloys is cost effective. This was shown by a cost-benefit analysis by the University of York which revealed that when including the savings obtained from reduced morbidity and mortality, reduced patient stay and reduced antibiotic therapy the payback time to retrofit copper alloy touch surfaces was only two months.'
 

Click here to see the newsletter in full, and here to subscribe to the electronic edition of AMR Times.

Copper and copper alloys are engineering materials that are durable, colourful and recyclable and are widely available in various product forms suitable for a range of manufacturing purposes. Copper and its alloys offer a suite of materials for designers of functional, sustainable and cost-effective products.

Copper and certain copper alloys have intrinsic antimicrobial properties (so-called ‘Antimicrobial Copper’) and products made from these materials have an additional, secondary benefit of contributing to hygienic design. Products made from Antimicrobial Copper are a supplement to, not a substitute for standard infection control practices. It is essential that current hygiene practices are continued, including those related to the cleaning and disinfection of environmental surfaces.

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