Copper’s Antimicrobial Properties Help to Reduce Infection, Study Shows

According to the preliminary results of a multisite clinical trial in the United States, antimicrobial copper surfaces in intensive care units (ICU) kill 97 percent of bacteria that can cause hospital-acquired infections. The study, presented recently at the World Health Organization’s 1st International Conference on Prevention and Infection Control (ICPIC) in Geneva, Switzerland, backed what research teams at three U.S. hospitals suggested four years ago: replacing the most heavily contaminated touch surfaces in ICUs with antimicrobial copper will control bacteria growth and cut down on infection rates.

The results also showed a 40 percent reduction in the risk of acquiring an infection.

Previous research has been validated by the U.S. Environmental Protection Agency, which in 2008 registered five copper-alloy products and approved the claim that the metal could kill 99.9 percent of bacteria within two hours.

Hospital-acquired infections (HAIs) are the fourth leading cause of death in the United States behind heart disease, strokes and cancer, according to estimates provided by the Centers of Disease Control and Prevention (CDC). CDC figures claim that nearly one in every 20 hospitalized U.S. patients acquires an HAI, resulting in 100,000 lives lost each year at a cost of $45 billion.

The 97-percent reduction rate in bacteria on antimicrobial copper surfaces is the same as that achieved by “terminal” cleaning—a process that is done after a patient leaves a room.

Dr. Michael Schmidt, professor and vice chairman of microbiology and immunology at the Medical University of South Carolina, who presented the results, said, “Bacteria present on ICU room surfaces are probably responsible for up to 80 percent of patient infections, demonstrating how critical it is to keep hospitals clean.

“The copper objects used in the clinical trial lowered microbial levels and supplemented cleaning protocols.”

Copper releases ions that penetrate the cell walls of microbes, disrupting their ability to function and reproduce. Copper also retains its bacteria-killing effectiveness even when mixed with other metals such as nickel and tin. That has helped ease aesthetic concerns, as many of the current antibacterial copper products are alloys of a lighter color and a finish closer to that of stainless steel.