Bacteria cut by ‘up to 95%’ in copper trial

Initiated in a single medical ward at the Selly Oak acute hospital in April 2007, the Birmingham trial began following earlier laboratory work by Southampton University scientists, undertaken over the past 2-3 years, which had clearly shown that copper surfaces can inactivate both MRSA microbes and C. difficile bacteria. In laboratory tests in 2006,1 the Southampton team, led by Professor Bill Keevil, showed that “exceptionally high levels” of MRSA bacteria were eliminated within 90 minutes on copper surfaces (Health Estate Journal – April 2007), while the second, in early 2007, demonstrated copper’s effectiveness in destroying C. difficile2 “within one or two days”. In contrast, MRSA pathogens were found to remain on stainless steel surfaces “for days”, while C. difficile bacteria were discovered to still be alive a week later.

Laboratory research

The laboratory research, by a team at Southampton University’s Environmental Healthcare Unit, led subsequently to a year-long evaluation programme, by the United States Environmental Protection Agency (EPA), of the results of independent laboratory tests on 3,000 samples of different copper alloy types for their bacterial-eliminating abilities. So positive were the results that the EPA has since officially registered copper as an anti-microbial agent, reportedly the first and only solid metal so far to receive such an endorsement. Speaking at a lunch in London on 1 October to mark the 75th anniversary of the founding of the Copper Development Association (whose members include leading copper miners and producers, and fabricators of copper-based goods) Professor Tom Elliott, who has led the copper clinical trial at Selly Oak Hospital, gave the first public progress report on the 18-month pilot.

The professor, whose trial team includes microbiologist Dr Anna Casey and associate director, nursing, at the University Hospitals Birmingham NHS Foundation Trust, Lisa Miruszenko, said that, while data on the levels of bacteria reduction achieved so far would not be released in full until a major US conference later in October, replacing items such as stainless steel and plastic push plates and door handles, taps, light switches, sink fittings, and electrical sockets, with copper or copper alloy alternatives, had reduced levels of bacteria by up to 95%.

The consultant microbiologist, and deputy medical director, University Hospitals Birmingham NHS Foundation Trust, explained that, while the Southampton University scientists had achieved excellent success in the lab trials, and indeed copper’s anti-microbial properties had been known for at least 6,000 years, the next logical step was to scientifically verify the metal’s effectiveness in killing organisms such as MRSA and C. difficile in a real-world hospital environment.

CDA member input

Thanks to the help of many CDA members, a number of whom supplied materials, and Antimicrobial Interest Group members, who manufactured copper items for the ward and toilet areas etc specially, within a short time the trial team at Selly Oak Hospital were able to begin fitting copper replacements for items such as door ironmongery, taps, sink fittings and even toilet seats – the latter are known to harbour especially large quantities of bacteria.

The professor said the “size of the hospital-acquired infection problem” in the UK was evident from the fact that, while 10% of patients admitted to UK hospitals have an infection of some kind on admittance, of the 90% who enter infection-free, one in 10 subsequently contract a HAI, equating to some 300,000 cases a year, and costing the NHS around £1 billion.3

Returning to the trial, he explained that one of the things the trial team did early on was to identify which touch surfaces would be most likely to harbour bacteria, and thus prove a potential source of infection. One of the most obvious ones was toilet seats, while others included door handles and taps.

Enhanced cleaning regime

Over a 10-week period the team studied a number of items subject to being touched a good deal by patients and staff, measuring the level of bacteria on both traditional stainless steel and plastic items, and on the copper replacements, twice a day, at 7 am, and at 5 pm. On the trial ward an enhanced cleaning regime was implemented, where all surfaces were cleaned every two hours as part of the “bundle of care”. The professor explained that the various copper items selected for the trial’s early stages were installed gradually, some several months before the trial began, so that patients, and particularly staff, could “get used to the different colours – golds, bronzes etc”. Half way through the trial the team switched a number of the copper items for plastic or stainless steel ones and vice-versa, to dispel any subsequent suggestions that bacteria levels in particular places were high or low simply due to their location.

The full results of the “crossover study” would not, Professor Elliott said, be revealed until the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) in Washington DC in late October, but the initial indications were “incredibly exciting” – with a 90% reduction in the number of organisms present on the copper components and, in some areas, such as on parts of toilet seats, reductions in pathogen levels as high as 95%.

Further items

In the coming months the team expects to take delivery of further copper and copper alloy items for the ward, including bed tables with a top copper sheet (replacing the current melamine-topped tables), flush handles, grab rails, hand towel dispensers, and toilet roll holders. Professor Elliott said he could envisage in future seeing items including copper stethoscopes, blood pressure cuffs and doctors’ pens introduced, as well as catheter drain tubes made of copper or copper alloy. All these items were, he said, known to harbour bacteria. His team was, he told those gathered for the CDA lunch, particularly proud to have beaten researchers elsewhere in Europe and in the US to successful results, noting that it would be fascinating to see the response when the full findings were presented at the ICAAC conference. Associate director of nursing Lisa Miruszenko added that, while the team had anticipated a fair bit of comment from staff, and potentially patients, on the various copper items, it had experienced no real issues, apart from one or two nurses initially mentioning that the copper surfaces did not look “as shiny and clean” as stainless steel. However, she said that everyone had very quickly got used to the items, which can be cleaned with conventional detergent, being “really no different in this respect” to stainless steel or plastic fittings.

The team is now looking forward to installing a range of other items, such as the coppertopped bed tables, in coming months. Dr Anna Casey, who has undertaken much of the bacterial sampling and subsequent laboratory analysis in the trial, added that, without the CDA, and the numerous fabricators who had supplied copper items, the trial could never have gone ahead. Professor Tom Elliott concluded: “While the NHS is doing a great job in reducing HAIs, 300,000 affected patients annually is still way too high, and I genuinely believe copper has the potential to very substantially reduce infection rates in hospitals across the world. With people as far back as the Ancient Egyptians harnessing copper’s anti-bacterial properties – they were known to drink from copper vessels, which helped protect them from the ill-effects of imbibing dirty water – and Hippocrates having used the metal to treat leg ulcers, the only real question it why it has taken so long for the penny to drop?” 

References:

1 Noyce J.O., Michels H. and Keevil C.W. Potential use of copper surfaces to reduce survival of epidemic methicillinresistant Staphylococcus aureus in the healthcare environment. Journal of Hospital Infection. 63: 289-97 (2006).

2 Weaver L. et al. Survival of Clostridium difficile on copper and steel. Futuristic options for hospital hygiene. Journal of Hospital Infection. (2008), doi:10.1016/j.jhin.2007.11.011.

3 The Management and Control of Hospital-Acquired Infection in NHS Acute Trusts in England (HC 230 Session 1999-00). National Audit Office, February 2000.