Infection Control & Hospital Epidemiology

Original Articles

The Antimicrobial Efficacy of Copper Alloy Furnishing in the Clinical Environment: A Crossover Study

T. J. Karpanena1, A. L. Caseya1, P. A. Lamberta2, B. D. Cooksona3, P. Nightingalea4, L. Miruszenkoa5 and T. S. J. Elliotta5 c1

a1 Department of Clinical Microbiology, University Hospitals Birmingham National Health Service Foundation Trust, Birmingham, United Kingdom

a2 Life and Health Sciences, Aston University, Birmingham, United Kingdom

a3 Laboratory of Healthcare Associated Infection, Health Protection Agency, London, United Kingdom

a4 Wolfson Computer Laboratory, University Hospitals Birmingham National Health Service Foundation Trust, Birmingham, United Kingdom

a5 Corporate Division, University Hospitals Birmingham National Health Service Foundation Trust, Birmingham, United Kingdom

Abstract

Objective. To determine whether copper incorporated into hospital ward furnishings and equipment can reduce their surface microbial load.

Design. A crossover study.

Setting. Acute care medical ward with 19 beds at a large university hospital.

Methods. Fourteen types of frequent-touch items made of copper alloy were installed in various locations on an acute care medical ward. These included door handles and push plates, toilet seats and flush handles, grab rails, light switches and pull cord toggles, sockets, overbed tables, dressing trolleys, commodes, taps, and sink fittings. Their surfaces and those of equivalent standard items on the same ward were sampled once weekly for 24 weeks. The copper and standard items were switched over after 12 weeks of sampling to reduce bias in usage patterns. The total aerobic microbial counts and the presence of indicator microorganisms were determined.

Results. Eight of the 14 copper item types had microbial counts on their surfaces that were significantly lower than counts on standard materials. The other 6 copper item types had reduced microbial numbers on their surfaces, compared with microbial counts on standard items, but the reduction did not reach statistical significance. Indicator microorganisms were recovered from both types of surfaces; however, significantly fewer copper surfaces were contaminated with vancomycin-resistant enterococci, methicillin-susceptible Staphylococcus aureus, and coliforms, compared with standard surfaces.

Conclusions. Copper alloys (greater than or equal to 58% copper), when incorporated into various hospital furnishings and fittings, reduce the surface microorganisms. The use of copper in combination with optimal infection-prevention strategies may therefore further reduce the risk that patients will acquire infection in healthcare environments.

Infect Control Hosp Epidemiol 2012;33(1):3-9

(Received April 21 2011)

(Accepted September 20 2011)

Correspondence

c1 Corporate Division, Queen Elizabeth Hospital, University Hospitals Birmingham National Health Service Foundation Trust, Edgbaston, Birmingham B15 2TH, United Kingdom (tom.elliott@uhb.nhs.uk)