Read the second paragraph,
understand that this work has been continually confirmed and that simple
changes in feed protocols equal any benefit from the actual use of antibiotics
at all. The danger from the practice can
not be any starker.
The attempt to blame a single
source in the EU for the sudden appearance of a new E coli infection is
obviously misplaced. Its existence is
possible only because of the practice of using antibiotics. Ending the practice as we must do sooner or
later and better sooner is our only real option.
Must we wait for a real nasty
problem to get out there like the SARS event which may also have been an
agriculture derived problem?
There are plenty of concerns with
factory farming to start with. Ending
the risk of disease generation is surely a good decision.
E-I-E-I-Oh no: Decades of antibiotics in farm animals lead to deadly
superbugs 3
2 JUN 2011 2:34 PM
Stuart Levy once kept a flock of chickens on a farm in the rolling
countryside west of Boston .
No ordinary farmer, Levy is a professor of molecular biology and microbiology
and of medicine at Tufts
University School
of Medicine. This was decades ago, and his chickens were taking part in a
never-before-conducted study. Half the birds received feed laced with a low
dose of antibiotics, which U.S.
farmers routinely administer to healthy livestock -- not to cure illness, but
merely to increase the animals' rates of growth. The other half of Levy's flock
received drug-free food.
Results started showing up almost instantly. Within two days, the
treated animals began excreting feces containing E. coli bacteria
that were resistant to tetracycline, the antibiotic in their feed. (E. Coli,
most of which are harmless, normally live in the guts of chickens and other
warm-blooded animals, including humans.) After three months, the chickens
were also excreting bacteria resistant to such potent antibiotics as
ampicillin, streptomycin, carbenacillin, and sulfonamides. Even though Levy had
added only tetracycline to the feed, his chickens had somehow developed what
scientists now call "multi-drug resistance" to a host of antibiotics
that play important roles in treating infections in people. More
frightening, although none of the members of the farm family tending the
flock were taking antibiotics, they, too, soon began excreting drug-resistant
strains of E. coli.
When Levy's study was published in The New
England Journal of Medicine in 1976, it was met with skepticism.
"The other side -- industry -- could not believe that this would have
happened. The mood at the time was that what happens in animals does not happen
in people," said Levy, who serves as president of the Alliance for the
Prudent Use of Antibiotics, in a telephone interview from his office at Tufts.
"But we had the data. It was obvious to us even then that using
antibiotics this way was an error and should be stopped."
During the intervening 35 years, study after study has confirmed Levy's
findings and shown that the problem of antibiotic-resistant
"superbugs" is even worse than anyone could have imagined. Each year,
70,000 Americans in U.S.
hospitals die from bacterial infections that drugs are unable to kill. And even
as the number of infectious diseases is on the rise, more antibiotics are
administered to livestock than ever before, from 17.8 million pounds per year
in 1999 according to the Animal
Health Institute (a trade organization of companies, like Bayer,
Novartis, and Pfizer, that manufacture livestock drugs) to 29.8 million pounds
in 2009, according to the U.S. Food and Drug Administration (FDA). Fully 80
percent of the antibiotics used in the United States are given to
livestock, and the vast majority are administered to promote growth and stave
off potential infections, not to treat illness.
From his perspective of more than three decades as a resistant-microbe
watcher, Levy sounded almost weary when he said, "Proponents of growth
promotion keep asking for more data, and we scientists provide them. But then
the findings have never led to removal of the practice."
Getting serious
Last month, the Natural Resources Defense Council, Center for Science
in the Public Interest, Food Animal Concerns Trust, Public Citizen, and the Union of Concerned Scientists joined forces to file
a lawsuit against the FDA. The groups want the agency to withdraw its
approval for most non-therapeutic uses of penicillin and tetracycline in animal
feed. They say that it's something regulatorsshould have
done decades ago.
The FDA first approved the use of low-dose antibiotics in the 1950s.
Concerns about the drugs began appearing within a decade, and by the time
Levy's paper was published, the FDA was aware the practice posed a serious risk
to human health. The agency proposed to withdraw its approval in 1977, saying
that new evidence showed that penicillin- and tetracycline-containing products
had not been "shown safe for widespread, sub-therapeutic use."
The proposal drew howls of outrage from two of the most powerful
lobbying groups in Washington, agribusinesses and drug manufacturers. Both the
House and Senate ordered the FDA to "hold in abeyance any and all
implementation of the proposal" until further studies had been conducted.
"It was the power of the lobby and the money behind that lobby," Levy
recalled.
As requested by Congress, the FDA commissioned three studies during the
1980s, all of which supported initial concerns about the risks of feeding farm
animals antibiotics on a daily basis. The FDA received petitions urging it to
act from coalitions of scientific and environmental groups in 1999 and 2005.
Such respected bodies as the American Academy of Pediatrics, the Centers for Disease
Control and Prevention, the National Academy of Sciences, the U.S. Department
of Agriculture, and the World Health Organization all identified low-dose
antibiotics as the reason antibiotic-resistant bacteria were proliferating in
humans and animals. And the FDA -- which is charged with protecting the health
of Americans -- failed to act, only going so far as to issue a "Draft
Guidance" [PDF] report and a draft "Action Plan" proposing
voluntary guidelines. These suggestions have done nothing to stem the deluge of
unnecessary antibiotics through the spigot of agribusiness.
"We've been fighting the non-therapeutic use of antibiotics in
livestock for more than 30 years," Margaret Mellon, director of the food
and environment program at the Union of
Concerned Scientists, said in a press release announcing the lawsuit.
"And over those decades the problem has steadily worsened. We hope this
lawsuit will finally compel the FDA to act with an urgency commensurate with
the magnitude of the problem." (Siobhan Delancey, a spokeswoman for the
FDA, declined to comment on the suit.)
The trouble with antibiotics
Bacteria are evolutionary dynamos. Untold trillions of them can live in
one confined animal feeding operation, or CAFO -- the technical term for a
factory farm. They breed rapidly and mutate readily. Exposure to even miniscule
levels of drugs equips bacteria with the genetic resilience to fend off higher
levels of the same drugs.
From the dawn of modern antibiotics, researchers have been aware that
the seeds of the wonder drugs' destruction had already been sown. In his 1945 Nobel acceptance speech for his discoveries
related to penicillin, Sir Alexander Fleming said, "There is a danger that
the ignorant man may easily under-dose himself and by exposing his microbes to
non-lethal quantities of the drug make them resistant." Fleming's
prediction was prescient -- except the problem wasn't an "ignorant
man" but politicians and business executives whose priorities lay
elsewhere.
During the decades that the FDA dithered, a mountain of scientific
research accumulated showing that antibiotic-resistant bacteria can not only
evolve in the guts of farm animals, but can spread from animals to the humans
who tend them, and then be passed on to people who have never been anywhere
near a chicken house or hog barn.
In 2004, Dutch doctors discovered a strain of
methicillin-resistant Staphylococcus aureus (MRSA)
in a 6-month-old baby. Often fatal, MRSA is the original "superbug"
because it can survive treatment by the most powerful antibiotics in modern
medicine's arsenal. At first, the doctors were puzzled. MRSA was primarily
known as a hospital-acquired infection. But the child, who carried the germs
but never became sick, as is often the case with the asymptomatic carriers of
bacteria, had never been in a hospital. Her parents were pig farmers, and
subsequent investigations showed that the MRSA had been passed from the pigs to
the parents and on to the baby. (Most bacteria are non-infectious, although
they may carry resistance genes. The problem is that they can pass their
resistance traits to infectious bacteria.)
Three years later, J. Scott Weese, a professor at the Ontario Veterinary
College at the University
of Guelph near Toronto , found an identical strain of MRSA in
Canadian pigs and their owners. The superbug had somehow leapt over the Atlantic Ocean . Further research by Weese revealed that
the swapping of resistant bacteria between animals and humans can be a two-way
street. Not only were the farmers affected by MRSA that had originated in pigs,
but the pigs carried MRSA that until then had only been found in humans.
For a year or so, American agribusiness continued to claim that MRSA
was a problem that couldn't happen here -- a myth they were able to perpetrate
because no government agency was routinely testing hogs for MRSA. But during
the summer of 2008, Tara Smith, a microbiologist at the University of Iowa and
the deputy director of the university's Center for Emerging Infectious
Diseases, found that seven out of 10 pigs she and her students tested on farms
in Illinois and Iowa carried MRSA.
A graduate student working with Smith recently uncovered a strain
of S. aureus associated with hogs and the people who tend them in a
day-care worker who had never been near a hog farm. Fortunately, that
particular strain was not antibiotic resistant. But the discovery showed that
humans do not have to work with infected animals to pick up the bacteria they
carry. "Whether the pig bacterium was passed on via another human or via
contaminated food products, we can't tell right now," Smith said in an
email.
Making the case
In fact, there are any number of ways antibiotic-resistant bacteria can
spread from farm to fork. A recently published study in the
journal Clinical Infectious Diseases found that 47 percent of the
beef, chicken, pork, and turkey sampled from grocery stores in five U.S. cities
carried drug-resistant S. aureus. Superbugs are literally blowing in the
wind. According to a 2006 report in the journal Environmental Health
Perspectives, multi-drug-resistant bacteria were found in the air downwind
of a confined hog operation. Nearly 90 percent of the E. coli in
liquid manure pits associated with pig farms are resistant to drugs, according
to Kellogg Schwab, the director of the Johns Hopkins
Center for Water and
Health. Manure ponds frequently burst their banks and contaminate nearby
streams, rivers, and wells.
Pharmaceutical companies dispute the assertion that treating animals
with low-dose antibiotics is dangerous to humans. "A lot of people want to
talk about antibiotic resistance as if it is a big amorphous issue," said
Ron Phillips of the Animal Health Institute, in an interview. "It is, in
fact, a series of discrete issues where you have to look at specific bug/drug
combinations and figure out what are the potential pathways for
antibiotic-resistant material to transfer from animals to humans. Studies have
been done, and have come to the conclusion that there is a vanishingly small
level of risk."
Smith of the University
of Iowa says that the
specific studies that the industry suggests are necessary simply cannot be done
-- it would be the equivalent of having to have an eyewitness to prosecute any
crime. "But we have DNA from the crime scene that matches that of the
suspect. At some point you have to accept that he is responsible. The bulk of
evidence is overwhelming."
One area where solid scientific evidence is lacking, astonishingly, is
on whether changing the industry-wide practice of giving low doses of
antibiotics to livestock would actually make that much of a difference. The
experience of farmers in the European Union, where dosing animals with
sub-therapeutic levels of antibiotics was banned in 1998, suggests otherwise.
Denmark is the world's largest pork exporting country, and most of its hogs are
raised in large confined operations much like those used by the U.S.
pork industry. In that country, the overall use of antibiotics fell
by 37 percent [PDF] between 1994 and 2009, according to a study by
Denmark's National Food Institute. Correspondingly, levels of resistant
bacteria in animals and people plummeted, but production levels of meat either
stayed the same or increased: The average daily weight gain per pig was
actually higher in 2008 than in 1992 when antibiotics were routinely
administered.
It's easy to understand why drug companies react so forcefully to any
attempts to cut back on sub-therapeutic antibiotic use -- FDA figures show that
60 percent of the antimicrobial drugs they sell are fed to farm animals to
promote growth, an enormous chunk of their business -- but given the success of
farmers in Europe who've stopped using antibiotics to promote growth, why is
the farm lobby so vehemently against change? Would it spell the end of the huge
CAFOs upon which American agribusiness has come to depend? Steven Roach, the
public health program director for the Food Animal Concerns
Trust (FACT), one of the plaintiffs in the lawsuit against the FDA,
has a straightforward answer to that question: No, CAFOs would not go away.
European pig farms are as large as those in the U.S., according to Roach. Some
of the E.U.'s chicken operations are even larger than those in this country.
(And if American farmers feel uncomfortable with examples from foreign
countries, he suggests that they look at Tyson, one of the United States'
largest poultry producers, which had no problems raising chickens without
antibiotics in ways that the suit aims to stop.)
"There are two parts of production where there are small economic
benefits to using low-dose antibiotics," Roach said in an interview.
"Particularly on young pigs. The challenge for the beef cattle industry is
that when you feed a high-corn diet, cattle have some heath problems, and one
way they manage that is using the antibiotics in the feed. But even so, some
producers are raising them without antibiotics in feedlots now." Roach
said that European farmers have gotten around these problem areas by weaning
piglets later. Barns are kept cleaner for all animals. And altering diets
allows CAFOs to raise cattle without antibiotics. Of course, says Roach,
some farmers simply won't want to change. He believes they are afraid that if
they allow outside forces to impose even small changes, then other changes are
bound to come.
After 35 years on the frontlines in the battle to keep antibiotics
effective, though, Levy believes there's cause for optimism. "The mood is
now 180 degrees better than it was for getting rid of this practice," he
said. "There are more and more scientists and lay people who are urgently
asking for an end to this use of antibiotics."
It helps that one of those "science people" is also a
representative. Louise
Slaughter, a Democrat who represents upstate New York, was a microbiologist
before going into politics. In 2009, she introduced a bill called the Preservation
of Antibiotics for Medical Treatment Act, which calls for the FDA to
withdraw its approval of the practice within two years unless there is
reasonable certainty that the low-dose antibiotics cause no harm to human
health. "We are witnessing a looming public health crisis that is moving
from farms to grocery stores to dinner tables around the country," she
said in an email. "As the only microbiologist in Congress, I feel it's my
duty to bring public attention to this."
Although Slaughter's bill has yet to pass, it had 127 cosponsors in the
last congressional session, more than double its support in the previous
Congress. It looks as though even more legislators will sign on this time, and
many are hopeful that the combined forces of looming legislation and an active
lawsuit will finally lead the FDA to act. "If we don't address
it," Slaughter continued, "we risk setting ourselves back to the time
before antibiotics, when even common infections could kill a person. That's not
any kind of world I want my children and their children to inherit."
A former contributing editor to Gourmet magazine, Barry
Estabrook is the author of Tomatoland:
How Modern Industrial Agriculture Destroyed Our Most Alluring Fruit and
blogs at politicsoftheplate.com.
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