Drug overuse in cattle imperils human health
12/11/2012 6:36 AM
08/05/2014 10:27 PM
Two kids seriously injured in the Joplin, Mo., tornado in May 2011 showed up at Children’s Mercy Hospital in Kansas City suffering from antibiotic-resistant infections from dirt and debris blown into their wounds.
Physicians tried different drugs, but at first nothing seemed to work.
Blame the overuse of antibiotics in livestock, according to the doctors familiar with their cases.
“These kids had some really highly resistant bacteria that they clearly had not picked up in a hospital,” said Jason Newland, director of the Children Mercy’s antibiotic stewardship program.
Newland and other doctors believe those infections are part of the price we are paying for a half-century of overusing antibiotics in cattle and other meat animals in the United States.
“If you look at tonnage, 80 percent of the total of all the antibiotics we use in the states is used in meat animals,” Newland said.
As in humans, bacteria growing inside animals that are given antibiotics can develop a resistance to the medicines, Newland explained. That resistant bacteria can then be transferred to the soil through animal waste.
During severe storms, such as the EF5 tornado which killed 161 people in Joplin, that contaminated soil can end up in open wounds, and even modern medicine is challenged in combating the serious infections that can occur.
“We are increasingly treating kids with antibiotic-resistant infections who were at the last antibiotic we could possibly use on them,” Newland said. “In the next 20 years will we see antibiotics resistant to everything?”
A yearlong investigation by The Kansas City Star found a multimillion-dollar-a-year pharmaceutical arms race in the beef industry is not just about curing sick cows.
It’s also about fattening cattle cheaply and quickly, driven in part by efforts to maximize profits, according to food safety advocates. In fact, the same number of cattle today are producing twice as much meat as they did in the 1950s because of genetics, drugs and more efficient processing.
Despite decades of warnings, the federal government has failed to pass meaningful regulation of animal drug use, failed to adequately monitor the harmful residues they leave behind, and failed to stop the consumption of meat contaminated with such substances.
Last year, an Arizona lab discovered a strain of antibiotic-resistant MRSA in meat that can infect humans. MRSA is the potentially fatal staph infection that sometimes races through hospitals.
Mexico rejected contaminated meat that U.S. rules allow Americans to eat. A shipment of U.S. beef in 2008 contained high levels of copper, a byproduct of industry and antibiotics, which can damage kidneys. The U.S. Department of Agriculture, which hasn’t set allowable amounts of copper in meat, couldn’t stop it from distribution in the United States.
Until it tightened monitoring this year, the government couldn’t even stop the sale of meat containing arsenic, one of the residues found in cattle treated with antibiotics. High levels of the poison can cause vascular disease and hypertension in humans. Many U.S. veterinarians who specialize in treating cattle said in a recent survey that they were concerned about the overuse and improper use of antibiotics and other drugs. Some blamed salesmen intent on making more money. Based on sales data alone, the amount of drugs used in livestock is increasing, and beef samples are showing greater numbers of antibiotic-resistant pathogens.
In its investigation, The Star examined the largest beef packers including the big four — Tyson Foods of Arkansas, Cargill Meat Solutions of Wichita, National Beef of Kansas City, Mo., and JBS of Brazil — as well as the intertwined network of feedlots, processing plants, animal drug companies and lobbyists who make up the behemoth known as Big Beef.
Today’s ever-larger feedlots use an intensive antibiotic regimen, even though the USDA reports that such practices contribute to antibiotic-resistant bacteria in humans.
But Big Beef maintains that concerns about antibiotic overuse in livestock are overblown. The Animal Health Institute, the lobbying arm of the animal pharmaceutical industry, said there’s not enough data to compare antibiotic use in animals and humans, citing a Food and Drug Administration statement that said it is “difficult to draw definite conclusions.”
The industry said antibiotics are needed for the humane treatment of sick and suffering animals and added that there is no “provable connection” between the cases in Joplin and livestock antibiotic use.
Before cattle are slaughtered, they’ve been fed, tagged and injected with millions of dollars of hormones, growth promoters and antibiotics.
Every year, about 29 million pounds of antimicrobial drugs are used on cattle, pigs and poultry, government data show.
But the government doesn’t make public how much of those drugs are used in cattle, or any other meat animals, because it considers that information a “trade secret” and its release might give one meat producer a competitive advantage over another.
A public interest group, however, sued the FDA on Wednesday to force the release of additional data on antibiotics used in food animals.
“How can we truly know the extent to which these drugs are causing harm if we can’t even access the information?” said Amanda Hitt, director of the food integrity campaign at the Government Accountability Project, a whistle-blower protection group.
GAP sued when FDA refused to release the data under a Freedom of Information Act request.
The Animal Health Institute said that data it collected until 2007 showed that about one-third of the compounds used in food animals are not used in humans and therefore “cannot in any way contribute to the burden of antibiotic resistance in humans.”
Which means two-thirds of those used in food animals are used in humans. So why does Big Beef keep using them?
Cattlemen have known for decades that antibiotics cause digestive changes in cattle that help them efficiently convert corn into added weight.
And that saves money.
Before the 1950s, most cattle primarily ate grass until they were slaughtered. But after World War II, farmers learned they could feed large numbers of cattle on less acreage by using more corn instead of grass.
However, there were unintended consequences.
Animals in confined spaces spread diseases. Cattle on high rations of corn develop acid buildup, which can deteriorate the gut lining — similar to an ulcer in humans — and cause gas, bloating and lameness.
Corn can eat away part of a cow’s stomach, said Allen Williams, a former feedlot owner and cattle specialist at Mississippi State University.
Big Beef soon discovered antibiotics controlled both problems.
Not only do such drugs help control diseases among closely confined cattle, they also counteract the acid buildup from corn. They relieve bloating, allowing cattle to eat more.
Beef industry officials said they had no research to back up that claim. But Cargill acknowledged that antibiotics are used in part to treat liver abscesses in cattle that result from high concentrations of corn they are fed.
Williams, who now consults with grass fed beef producers, said pressure to keep using higher levels of antibiotics and other drugs on cattle is all about bigger profits.
“It’s pressure from pharmaceutical companies. They are making money … and they don’t want it to stop,” he said.
That’s inaccurate, industry officials contend. “Farmers and ranchers have complete freedom to purchase or not purchase products based on animal needs,” according to the Animal Health Institute.
Improved genetics along with antibiotics, hormones and growth promoters allow the beef industry to raise a calf to slaughter weight in a little more than a year, half the time it used to take. Studies also show that animal drug residues in the beef people eat, and in cattle waste runoff that occasionally enters public water systems, can cause human illnesses.
Yet both sides in the debate over limiting the use of animal antibiotics remain entrenched and cite scientific studies to back up their point of view.
“There’s no question that routinely administering non-therapeutic doses of antibiotics to food animals contributes to antibiotic resistance,” said Donald Kennedy, former commissioner of the FDA and president emeritus at Stanford University.
Not true, said Mike Apley, a veterinarian and Kansas State University professor.
“We have zero data to say that growth-promoting uses of antibiotics in animals is a major contributor to the overall problem of antibiotic-resistant bacteria,” said Apley, who acknowledged that some of his studies are funded by pharmaceutical companies.
Study raises worries
Today, there is overwhelming evidence that non-therapeutic use of antibiotics in food animals contributes to antibiotic resistance, according to Stuart Levy, a world-renowned expert who co-authored a study last year at Tufts University.
The World Health Organization also is worried, warning that the speed at which antibiotics are becoming ineffective outpaces the development of replacement drugs.
“One of the most powerful measures globally to prevent antimicrobial resistance has been the ban of the use of antibiotics as growth promoters in livestock in the 27 European Union countries since 2006,” the WHO said last year.
Numerous strains of antibiotic-resistant bacteria already have begun cropping up. Earlier this year, a lab in Arizona discovered a strain of antibiotic-resistant MRSA in retail meat. MRSA, a staph infection, can cause abscesses and lesions.
The lab, the Translation Genomics Research Institute, published a study that showed that bacteria jumped from humans to livestock and back.
“Our findings underscore the potential public health risks of widespread antibiotic use in food animal production,” the study noted.