New clinical research highlights the risk of bacterial transmission via stethoscopes between patients and healthcare workers and shows how antimicrobial copper components can help address the problem.
19 April 2017
Published in the American Journal of Infection Control, the two-centre study aimed to assess the efficacy of antimicrobial copper surfaces in reducing bacterial concentration on stethoscope surfaces in busy clinical environments.
Stethoscopes come into frequent contact with the skin of patients and the skin and clothing of healthcare workers, yet routine cleaning and disinfection is not consistent, posing a risk of bacterial transmission between patients and staff.
Copper is a powerful antimicrobial with broad-spectrum efficacy against bacteria and viruses, proven to rapidly destroy pathogens including influenza A, E.coli and norovirus, and resistant bacteria such as MRSA. It shares this benefit with a range of copper alloys—such as brasses and bronzes—forming a family of solid materials called ‘antimicrobial copper’.
The trial involved 21 healthcare practitioners and was carried out in departments across two hospitals: a paediatric emergency department in a large speciality hospital—attached to the Medical University of South Carolina—and adult medical and surgical intensive care units in North Shore University Hospital, Manhasset, New York.
The study stethoscopes were identical in design to the control devices, but incorporated touch components—chest pieces, ear tubes, braiding over PVC binaural tubing, and diaphragms—made from antimicrobial copper. The number of bacteria on different parts of the copper and control stethoscope surfaces were counted and compared after one week of use on four separate occasions.
The results showed levels of bacteria routinely exceeding the proposed hospital hygiene standard—5 colony-forming units (CFU) per cm2— on the urethane rims of all stethoscopes tested (copper and control), with levels exceeding 300 CFU/cm2 on the paediatric emergency department samples.
The total number of bacteria recovered from all the copper stethoscope surfaces was significantly lower than the control equivalents (127.1 CFU/cm2, P < .00001). This equates to a 91% reduction.
Instances of a complete absence of recoverable bacteria were also significantly higher on copper than the control surfaces. The paper notes this observation was independent of healthcare provider or infection control practices.
Trial leader Dr Michael Schmidt, Vice Chairman of Microbiology and Immunology at the Medical University of South Carolina, said of the research: ‘Based on these trial results, we can say that adding antimicrobial copper stethoscopes to a healthcare facility’s bundle of infection control measures would likely limit the spread of infectious agents. Antimicrobial copper touch surfaces can work in concert with existing hygiene procedures where it will likely have a positive impact on infection rates.’
Antimicrobial copper comprises familiar engineering materials that perform their primary function—delivering hard-wearing surfaces that meet the demands of a busy clinical environment—with the additional benefit of continuously reducing bioburden and thus reducing the risk of infections spreading.
For more information on antimicrobial copper, visit www.antimicrobialcopper.org.
Antimicrobial copper alloys decreased bacteria on stethoscope surfaces
Schmidt, Michael G. et al. American Journal of Infection Control , Volume 45 , Issue 6 , 642 – 647
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Copper Development Association
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.