Antimicrobial copper alloys decreased bacteria on stethoscope surfaces (original) (raw)

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Major Article

Antimicrobial copper alloys decreased bacteria on stethoscope surfaces

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Highlights

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Stethoscopes may transmit bacteria among patients and health care workers.
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Stethoscope surfaces fabricated with antimicrobial copper alloys harbored significantly fewer bacteria.
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Of the antimicrobial copper alloys surfaces sampled, 66.3% were free of microbes; 22.4% of control surfaces met this mark.

Background

Stethoscopes may serve as vehicles for transmission of bacteria among patients. The aim of this study was to assess the efficacy of antimicrobial copper surfaces to reduce the bacterial concentration associated with stethoscope surfaces.

Methods

A structured prospective trial involving 21 health care providers was conducted at a pediatric emergency division (ED) (n = 14) and an adult medical intensive care unit located in tertiary care facilities (n = 7). Four surfaces common to a stethoscope and a facsimile instrument fabricated from U.S. Environmental Protection Agency–registered antimicrobial copper alloys (AMCus) were assessed for total aerobic colony counts (ACCs), methicillin-resistant Staphylococcus aureus, gram-negative bacteria, and vancomycin-resistant enterococci for 90 days.

Results

The mean ACCs collectively recovered from all stethoscope surfaces fabricated from the AMCus were found to carry significantly lower concentrations of bacteria (pediatric ED, 11.7 vs 127.1 colony forming units [CFU]/cm2, P < .00001) than their control equivalents. This observation was independent of health care provider or infection control practices. Absence of recovery of bacteria from the AMCu surfaces (66.3%) was significantly higher (P < .00001) than the control surfaces (22.4%). The urethane rim common to the stethoscopes was the most heavily burdened surface; mean concentrations exceeded the health care–associated infection acquisition concentration (5 CFU/cm2) by at least 25×, supporting that the stethoscope warrants consideration in plans mitigating microbial cross-transmission during patient care.

Conclusions

Stethoscope surfaces fabricated with AMCus were consistently found to harbor fewer bacteria.

Graphical abstract

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Stethoscope surfaces fabricated with AMCu were consistently found to harbor fewer bacteria: the collective mean concentration for all surfaces measured was 11.7 versus 127.1 ACC/cm2 (P < .00001).
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Absence of bacteria from the AMCu surfaces (66.3%) was significantly higher (P < .00001) than the control surfaces measured (22.4%).

Values are associated with stethoscopes from pediatric arm of the trial.

ACC, aerobic colony count; Al, aluminum; AMCu, antimicrobial copper alloy; PVC, polyvinyl chloride; SS, stainless steel.

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Key Words

Antimicrobial copper

Stethoscopes

Infection control

Health care–associated infections

Cited by (0)

Funding/support: Supported by of an unrestricted research grant from the Copper Development Association.

Conflicts of interest: None to report.