Study discovers halo effect of antimicrobial copper

Surfaces adjacent to those treated with antimicrobial copper show reduced contamination

The results of a pilot study at an outpatient clinic at North Shore-Long Island Jewish Health System in the US show that, as well as reducing surface microbial contamination by 90%, antimicrobial copper surfaces extend a ‘halo effect’ to nearby, non-copper surfaces, also reducing their contamination levels.

The study was performed in an Infectious Disease outpatient practice. Phlebotomy chairs at the clinic were fitted with copper trays and arms and surface contamination measured, which showed a 90% reduction in contamination compared with that on standard surfaces. In addition, a microbiocidal ‘halo effect’ was discovered, equating to a 70% reduction in contamination on the adjacent, non-copper surfaces of the chairs, compared with controls.

Antimicrobial copper arms and tray on a phlebotomy chair

The majority of samples from the chairs with copper components were below a level thought to represent a risk to the patient (5cfu/cm2), while the majority collected from the non-copper chairs were above this level.

Using this data alongside patient numbers, the researchers extrapolated a 17-fold lower risk of exposure to environmental microbes when using the copperised armrests, and a 15-fold lower risk with the copperised trays compared with standard ones.

Close-up of antimicrobial copper tray and arms

It is well known that micro-organisms can survive for extended periods of time on bed rails, call buttons and overbed tables in the patient environment. This study approached the problem in an environment that is often overlooked: an outpatient facility, where the high volume of potentially infected people with much more mobility than hospital patients increases the opportunity for cross-contamination.

The findings were presented at the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) in Boston, Massachusetts, this month.