Research and Statistics

Could your credit card kill you?


A study reveals that half of all credit cards sampled tested positive for methicillin-resistant Staphylococcus aureus — better known as the deadly MRSA infection

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Did you ever fleetingly rest your credit card between your lips during checkout because your hands were full or the kids were acting up?

After reading this, you’ll never do that again.

A new grant-based study, “Cash or Credit: Spreading the Wealth of Virulence Genes?” conducted by microbiology students at Florida’s St. Petersburg College found that half of all credit cards sampled at local malls, stores and hospitals tested positive for methicillin-resistant Staphylococcus aureus, better known as MRSA. Paper currency scored even worse on the hygiene scale; six in 10 dollar bills tested contained traces of MRSA.

Could your credit card kill you?

It’s the first known study to confirm what biologists have long suspected: under the right circumstances, your credit card could kill you.

“If it has the right type of microbe with the right type of virulence factors in a person who is immuno-compromised, possibly so,” says Shannon McQuaig, the associate professor of natural sciences who devised the study.

You may have heard of MRSA, an aggressive form of staph bacteria discovered in 1961 that laughs off antibiotics, modern medicine’s multipurpose magic bullet. MRSA is spread skin to skin or by contact with portals in the body (mouth, nose, open cuts, etc.). Once inside, MRSA microbes can spread to bones, joints, blood or any organ, including the heart, lungs and brain.

“The problem is, they are antibiotic-resistant, so once an infection is established, you have to use some pretty strong drugs that have some toxicity associated with them to get rid of it,” says McQuaig. “If MRSA is introduced, say through a contaminated credit card touching a cut on the skin, that can lead to a subcutaneous infection that tends to abscess and has to be cut open and drained.”

The Centers for Disease Control and Prevention (CDC) have declared MRSA an epidemic. While hospitals are making progress containing the bug in clinic settings, MRSA continues to threaten the public, notably among high-risk groups: children in day care, athletes who share towels, members of the military and people who sport tattoos.

CDC spokeswoman Melissa Dankel calls credit cards a natural fomite, the medical term for an inanimate object that can transmit disease.

If MRSA is introduced, say through a contaminated credit card touching a cut on the skin, that can lead to a subcutaneous infection that tends to abscess and has to be cut open and drained.

— Shannon McQuaig
Associate professor, St. Petersburg College

“MRSA can survive for months” says Dankel. “They don’t reproduce or grow but they can stay alive on plastic, as can other staph infections or enteric bacteria such as E. coli. There’s no telling what you might find on a credit card.”

McQuaig says the widespread presence of MRSA is one reason cashiers, toll booth workers and TSA agents increasingly wear gloves on the job.

Lisa Holmes, a longtime vendor to the Department of Veterans Affairs, began her one-woman crusade against plastic fomites more than a decade ago after observing commonplace cross-contamination while making her rounds of VA hospitals.

“In one, the woman who registers veterans all day had lesions all over her hands from their plastic ID cards; she couldn’t wear gloves because she couldn’t type with them. In another, a lady caregiver was leaning over a patient with her badge touching his face, then turns and leans over another veteran and does the same thing. I said, ‘whoa, we’ve got to fix this thing,'” she recalls.

Holmes became an industry representative with the American Society for Healthcare Environmental Services (ASHES) and pursued a solution with the help of Thompson Research Group, a building materials pioneer. In 2006, she applied for a patent on antimicrobial plastic that would incorporate antibiotics into the raw plastic used to make credit, debit and ATM cards. But she didn’t stop there; her germ-fighting patent also includes name badges, driver’s licenses, hotel key cards, subway tokens and poker chips.

Holmes says she has received international interest in her antibiotic plastic. India has contacted her regarding its subway tokens and a proposed national health care card; Canada has expressed interest in it after converting to plastic currency; and Russians fancy germ-fighting poker chips. But are U.S. card companies beating down her door? Not so much.

Holmes approached a major U.S. credit card issuer about her product, but its lawyers responded by saying that would presume that something was wrong with the card. “I explained that nothing is wrong with the card as long as you don’t remove it from the pristine envelope in which you sent it; then ‘what’s in your wallet’ really takes on a whole new meaning.”

Holmes says card companies and issuers alike seem to have higher priorities these days than the health of their cardholders. While the additional manufacturing cost would be inconsequential, in the industry’s view, the idea of rolling out a new “cleaner” card just now would open a whole can of public relations worms best left unopened, she says.

There’s one other obstacle as well: the antimicrobial card doesn’t kill germs per se; it simply inhibits their growth.

Holmes insists she’s on the right side of history and that one day her patent will be inside every purse and wallet in America.

“It’s just a matter of getting a credit card company that is willing to develop it. They don’t want to embrace it right now but once they do, everyone will want this thing,” she says. “I’m hoping the plastic badges will catch on, too. You have to fix it all.”

See related:10 flu-fighting credit card tips, Implantable credit card RFID chips: convenient, but creepy

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