Common Metal May Prevent Spread of Stomach Bug
July 10, 2015
An illness does not have to be deadly to be a major problem. Norovirus, for example, has been the bane of humans living in close quarters for a long time.
Complete with associated diarrhea, vomiting, nausea and stomach pain, noroviruses can make life plenty unpleasant for a few days, but according to the CDC, only a few hundred of the roughly 20 million Americans that contract norovirus every year die from it.
What norovirus lacks in lethality, however, it possesses in contagiousness. Norovirus can pass through food, on surfaces and silverware, and through contact with an infected person. As such, in places where people are crammed into close quarters like day cares and cruise ships, norovirus spreads very quickly.
There is no real vaccine or treatment for noroviruses — the CDC advises drinking lots of fluids and seeing the doctor if dehydration gets really bad — so doctors and public health agencies are focused on prevention.
The best thing to do, according to the CDC and other organizations, is to wash your hands — thoroughly and often. But new research from NC State University has shown that something almost as common as hand-washing can also help stop norovirus.
That something is copper and NC State doctoral researcher Clyde Manuel found that copper and copper alloys can quickly break down norovirus particles: no fancy delivery methods required. A piece of copper metal will tear up norovirus like sunlight will tear up a vampire.
The secret to this virus destruction is how copper metal and copper ions react. Because of how the electrons on copper ions are arranged, they can create what are called free radicals from water, oxygen and amino acids. Free radicals are solo electrons. They sit on molecules looking for other electrons to pair up with, and they will rip other molecules apart to find those electrons.
In several experiments, Manuel found that a copper or copper alloy surface will damge and destroy both the human receptor binding-portions — the piece of the virus that attaches to and infects human cells — of the virus shell and the virus genome in just ten minutes. It must be copper though. Manuel found that stainless steel had no effect on the virus.
Unfortunately, copper will not become a quick and easy cure for norovirus. The free radicals copper creates will chew through human DNA and proteins as quickly as those of the norovirus. That is why copper cookware is always lined with a chemical coating to keep it separate from food.
Manuel says, however, that placing it on “high-touch” surfaces like doorknobs, railings and countertops could prevent the spread of the disease. Previous studies have shown that hospitals that replaced these surfaces with copper were able to reduce the rate of infections — all infections, not just norovirus. One intensive care unit even managed to cut their infection rate in half.
Manuel says this research suggests that installing copper railings and doorknobs in high-risk areas — like cruise ships, day cares, nursing homes and restaurants — could potentially reduce the rate at which norovirus infections spread.
Copper surfaces are not a replacement for washing your hands, but together they might spare many people a few exceedingly unpleasant days.
A paper describing Manuel’s research was published in the journal Applied and Environmental Microbiology.
— Daniel Lane
Daniel Lane covers science, engineering, medicine and the environment in North Carolina.