Study: Copper kills bacteria better than plastics

Antimicrobial plastics are facing competition in hospital applications from an old competitor-copper.

In research reported in part by the copper industry, researchers say that copper surfaces are an effective way to cut risk of infections in operating rooms and other medical environments because of their inherent antimicrobial activity.

"The use of antimicrobial copper surfaces in intensive care unit rooms resulted in a 97 percent reduction of bacteria that cause hospital acquired infections and reduces the risk of acquiring an infection by 40 percent," according to a multi-site study.

Tom Elliott, a consultant microbiologist in the United Kingdom, commented: "The findings of a 90 to 100% killing of those organisms, even after a busy day on a medical ward with items being touched by numerous people, is remarkable. So it may well offer us another mechanism for trying to defeat the spread of infection."

Six objects studied

The study focused on six objects commonly found in hospitals: bed rails, overbed tray tables, chairs, call buttons, data devices, and intravenous  poles. Versions were tested in copper, plastic, wood or another type of metal.  The report states that the copper surfaces had 98% less bacteria than the noncopper surfaces. The authors didn't indicate if the plastics tested had antimicrobial treatments.

The results were presented at a hospital association meeting held in San Diego by authors from the Copper Development Association, the University of South Carolina, the Ralph H. Johnson Veterans Medical Center in Charleston, SC, and Memorial Sloan Kettering Cancer Center in  New York City. The work was underwritten by the Department of the Defense.

Surging infection rates coupled with new Medicare payment rules are triggering a wave of interest in hospital applications from materials producers. New antimicrobial treatments have been a major theme in medical conferences held in the USA this year.

It's not clear how copper would fare against plastics with newly developed antimicrobial treatments. Data for the copper study were collected from 2006 through earlier this year.

The economics for copper don't stack up well. Copper is averaging about $3.50 per pound while plastics prices are significantly lower. For example, high-impact polystyrene is under $1 per pound. Plastics also have the advantage of being formed into complex shapes in high-volume equipment.

Results were presented again last month at the Infectious Diseases Society of America annual meeting in Boston.