The meat you buy could be contaminated with drug-resistant MRSA
By Stephanie Woodard
July 15, 2009
Prevention
About two years ago, dozens of workers at a large chicken hatchery in Arkansas began experiencing mysterious skin rashes, with painful lumps scattered over their hands, arms, and legs.
"They hurt real bad," says Joyce Long, 48, a 32-year veteran of the hatchery, where until recently, workers handled eggs and chicks with bare hands. "When we went and got cultured, doctors told us we had a superbug."
Its name, she learned, was MRSA, or methicillin-resistant Staphylococcus aureus. This form of staph bacteria developed a mutation that resists antibiotics (including methicillin), making it hard to treat, even lethal. According to the CDC, certain types of MRSA infections kill 18,000 Americans a year — more than die from AIDS.
Soon co-workers at the nearby processing plant, where hundreds of thousands of chicken carcasses are prepped daily for sale, began finding the lumps. Dean Reeves, 50, an 11-year employee, went to the hospital with an excruciating bump on her thigh she thought was a spider bite.
It wasn't: She, too, had contracted MRSA, as had her husband, Bill, 46, who also works at the facility. Since late 2007, Dean has had monthly relapses. Even the safety glasses, gloves, and smocks workers wear (along with upgraded regular cleaning of equipment) aren't enough to protect them, says Bill. "We work so fast, we often stick ourselves with knives or scissors and get blood on us from head to foot." When a swelling rose over one of his eyes, he was told he might go blind; if the infection progressed to his brain, he'd die.
Did any food safety agency test for MRSA in this plant's chickens, which were then sold to the public and served on American dinner tables? Did any government organization determine the source of the outbreak? Calls to the USDA, CDC, and Arkansas Department of Health yielded a no to both questions; the poultry company that owns the operation did not respond to multiple requests for a comment from Prevention. Yet in recent years, studies have found MRSA in retail cuts of pork, chicken, beef, and other meats in the United States, Europe, and Asia.
To get answers, we investigated how MRSA has entered
our food supply with limited government response; we considered the massive use
of antibiotics in agriculture and its role in creating resistant microbes like
MRSA; and we examined the safety of supermarket meat. Here, we offer our
findings and expert advice to
protect you and your family.
Are you at risk?
You've probably heard of people contracting certain strains of MRSA in
hospitals, where it causes many illnesses: postsurgical infections, pneumonia,
bacteremia, and more. Others encounter different types of the bug in community
centers such as gyms, where skin contact occurs and items like sports equipment
are shared; this form causes skin infections that may become systemic and turn
lethal.
Then in 2008, a new source and strain of MRSA emerged
in the United States. Researcher Tara Smith, PhD, an assistant professor of
epidemiology at the University of Iowa, studied two large Midwestern hog farms
and found the strain, ST398, in 45 percent of farmers and 49 percent of pigs.
The startling discovery — and the close connection between animal health and our
own that it implied — caused widespread publicity and much official
hand-wringing. To date, though, the government has yet to put a comprehensive
MRSA inspection process in place, let alone fix our problematic meat-production
system.
You may not have the same close contact with meat that a processing plant worker
has, but scientists warn there is reason for concern: Most of us handle meat
daily, as we bread chicken cutlets, trim fat from pork, or form chopped beef
into burgers. Cooking does kill the microbe, but MRSA thrives on skin, so you
can contract it by touching infected raw meat when you have a cut on your hand,
explains Stuart Levy, MD, a Tufts University professor of microbiology and
medicine. MRSA also flourishes in nasal passages, so touching your nose after
touching meat gives the bug another way into your body, adds Smith.
Tainted meat exposed
Extensive research in Europe and Asia has found MRSA in many food
animal species, and in the past year, US researchers have begun testing meat
sold here. Scientists at Louisiana State University Agricultural Center tested
120 cuts of locally purchased meat and found MRSA in 4 percent of the pork and 1
percent of the beef. A University of Maryland scientist found it in 1 out of 300
pork samples from the Washington, DC, area. And a study in Canada (from which we
import thousands of tons of meat annually) found MRSA in 9 percent of 212 pork
samples. The percentages may be small, but according to the USDA, Americans eat
more than 180 million pounds of meat every day. "When you consider the tiny size
of the meat studies, the fact that they found any contamination at all is
amazing," says Steven Roach, public health program director for Food Animal
Concerns Trust.
In some cases, the tainted meat probably came from infected animals; in others,
already infected humans could have passed on MRSA to the meat during processing.
Regardless of where it originated, even a small proportion of contaminated meat
could mean a tremendous amount of MRSA out there. "We need more US research to
figure out what's going on," says Roach.
MRSA is so common in the United States that it accounts for more than half of
all soft-tissue and skin infections in ERs. The CDC estimates that invasive MRSA
infections (those that entered the bloodstream) number more than 94,000 a year.
Even more troubling, if you add up the other types of illnesses MRSA can cause,
including urinary tract infections, pneumonia, and inpatient skin infections,
the total could be 8 to 11 times more than that, reports a study by
epidemiologist William Jarvis, MD, of the Association for Professionals in
Infection Control and Epidemiology. The numbers are high and rising: From 1996
to 2005, MRSA-related hospitalizations increased nearly tenfold.
People who get MRSA need ever more powerful medication. "Staph-related infections have become serious illnesses that can require hospitalization and stronger drugs," says Georges C. Benjamin, MD, executive director of the American Public Health Association (APHA). For hatchery worker Long, doctors went through several antibiotics, with little success. The swellings would subside, then reappear. "Every time I went back to work, I got it again, for a total of 10 times," she says.
Antibiotics in animals
Scientists know that antibiotic overuse in humans caused ordinary staph
to become resistant, says Levy. And they know the large amounts of meds used by
agriculture caused other bacteria, such as E. coli and salmonella, to develop
resistance. "Now we're looking at the relationship between antibiotic use on
farms and MRSA," he says.
It's an important mission, as industrial agriculture is the country's largest antibiotic user: Animals consume nearly 70 percent of these meds, perhaps more than 24 million pounds a year, says the Union of Concerned Scientists. The drugs compensate for the often unsanitary conditions in the country's 19,000 factory farms — also called concentrated animal feeding operations, or CAFOs — where about half our meat is produced. Long gone are many family farms with animals grazing on pastureland, says Bob Martin, senior officer of the Pew Environment Group. "Instead, they're packed into cramped quarters, never going outdoors, living in their waste." A swine CAFO may house thousands of hogs; a poultry operation, hundreds of thousands of chickens. "As a result, you need to suppress infection," he says.
The large amounts of antibiotics used in CAFOs include
drugs critical to curing human illnesses, he says. Premixed animal feed can
contain medications you may have taken, such as tetracycline and cephalosporin (Keflex
is a familiar brand); you can also buy a 50-pound bag of antibiotics at a feed
store to add to your animals' chow — no prescription necessary, confirms Amy
Meyer, executive director of the Missouri Farmers Union.
Most of the antibiotics given to CAFO animals are not only used to fight
infection, but also to stimulate growth, says David Wallinga, MD, Food and
Health Program director at the Institute for Agriculture and Trade Policy. The
near constant exposure to less-than-therapeutic levels of antibiotics allows the
resistant bacteria to survive; they can then be transferred to people, he says.
This needless use of medication is what docs try to avoid when they don't
prescribe antibiotics for a simple cold. "These operations are reservoirs of
antibiotic resistance," says researcher Smith.
In the areas surrounding CAFOs, docs see firsthand how MRSA impacts the
community. Philip McClure, DO, practices in Trenton, MO, which is home to many
hog farms. MRSA infections have risen as the number of pigs has grown, he says.
"Both CAFO workers and others get them," says McClure, who treats a MRSA-related
skin problem every month. That may be because you can pick up MRSA and not show
symptoms for years. Meanwhile, you can pass it to others by something as simple
as sharing a towel. Kim Howland, 44, a former hog CAFO worker in Oklahoma, fears
she did just that, when in 2007, her husband and daughter developed MRSA skin
infections. "My co-workers told me about lumps they had and I realized I could
have become a carrier," she says. Howland, who left her job, wasn't tested at
the time, so she'll never know if she gave MRSA to her family.
Concerned about the risks of CAFOs (including increased antibiotic resistance,
pollution, and disease in nearby areas), the APHA back in 2003 called for a
moratorium on building new ones.
Who's watching out for you?
Until recently, the CDC has acknowledged the presence of MRSA in meat
but downplayed the danger. In 2008, then CDC director Julie Louise Gerberding,
MD, MPH, wrote that foodborne transmission of MRSA is "possible" but, if it
happens, "likely accounts for a very small proportion of human infections in the
US." Liz Wagstrom, DVM, assistant vice president of science and technology for
the National Pork Board, agrees, saying that this kind of transmission would be
extremely rare. Neither group could provide an estimate when queried by
Prevention, but considering the high numbers of MRSA infections, even a tiny
percentage could be a lot of people.
One reason the CDC and the National Pork Board must guess about transmission
rates — and why we don't know exactly how many MRSA-related infections occur —
is that the federal government doesn't collect data on MRSA outbreaks, says
Karen Steuer, director of government operations for the Pew Environment Group.
According to the US Government Accountability Office, there's no testing for
MRSA on farms. And the National Antimicrobial Resistance Monitoring System tests
just 400 retail cuts of meat each month for four drug-resistant bacteria — which
don't include MRSA.
"These gaps in data keep us in the dark," says Steuer. Without farm-to-fork
surveillance, it's difficult to connect problems at a certain farm to MRSA
outbreaks. "If we don't fix this, mortality rates will go much higher," she
says. "We have an impending crisis."
A rising tide of concern is firing up health care
activists and congressional policy makers to contain the MRSA threat. Several
ideas are on the government's table. Keep Antibiotics Working, a national
coalition of health and science organizations, calls for more federal research
on MRSA and meat. In Congress, Representative Rosa L. DeLauro suggests giving
all supervision of food — now split among many agencies — to just one, which may
improve oversight. And Representative Louise Slaughter, MSPH, reportedly
Congress's only microbiologist, wants to trim agriculture's use of antibiotics
only to those drugs that are not essential for human use. Earlier this year, she
reintroduced the Preservation of Antibiotics for Medical Treatment Act, and
Senator Edward Kennedy submitted a related bill in the Senate.
Bottom line, says Roach of Food Animal Concerns Trust, we need to think of ways
to raise animals that prevent them from getting sick in the first place. And we
must move quickly, adds Slaughter: "As a scientist and mother, I cannot
overstate the urgency. We should be able to buy food without worrying about
exposing our family to potentially deadly bacteria that no longer responds to
medical treatment."
URL: http://www.msnbc.msn.com/id/31766160/ns/health-food_safety/