Seema Rai, MD, of North Shore Long Island Jewish Health System in Manhasset, N.Y., and colleagues, investigated the impact of copper surfaces on the bacterial burden found on high-touch surfaces of phlebotomy chairs in an outpatient infectious disease clinic.
Quantitative cultures were obtained from phlebotomy chairs and the results from control (wood/composite) chairs and the copperized therapy chairs were compared. A total of 437 patients used the chairs during the 15-week study period.
All chairs were wiped down at the end of each day with a nonalcohol-based quaternary ammonium compound (QAC) cleanser wipe and the floors of the therapy suites were cleaned once nightly with QAC solution. Chair locations were rotated every three weeks. The number of patients who used each chair was noted. Arm tops, arm sides, and tray tops of each therapy chair were cultured twice per week in midafternoon. Surfaces were wiped with moistened sterile rayon/polyester wipes and placed in sterile containers; bacteria samples were plated and incubated for 48 hours. The microbial burden associated with each surface was expressed as colony-forming units (CFUs) per 100 cm2.
Copper surfaces were found to reduce the bacterial population present on the trays and arm surfaces. An 88 percent median reduction for the total aerobic bacteria of copperized trays and a 90 percent reduction on copperized arms were observed. The majority of microorganisms identified were mannitol-fermenting and nonfermenting staphylococci. The remaining unidentified microbes grew well on TSA blood agar at 37°C. MRSA and VRE were not recovered.
The researchers note, "Despite routine disinfection efforts, high-touch areas can harbor high densities of microorganisms. As proposed by White et al, bacteriological standards for assessing surface hygiene in the hospital environment comprise identification of either an indicator organism (such as MRSA) or a heavy burden of any microbe. In this study, 90 percent of samples from noncopper chairs exceeded 2.5 CFUs/cm2 with routine daily cleaning. Covering high-touch surfaces with antimicrobial copper may provide an adjunctive infection control measure to minimize the spread of bacteria. The microbicidal activity of copper was effective in significantly reducing the total median burden by 90 percent on arm tops and by 88 percent on copperized trays. In addition, the microbicidal properties of copper were able to confer an antimicrobial halo as high as 70 percent next to the copperized arm top."
Reference: Rai S, et al. Evaluation of the Antimicrobial Properties of Copper Surfaces in an Outpatient Infectious Disease Practice. Infect Control Hosp Epidem. Vol. 33, No. 2. February 2012.