US: Does giving antibiotics to animals hurt humans?
Posted: April 22nd, 2012 - 3:52pm
WASHINGTON -- The bacon Americans have for breakfast is at the center of a 35-year debate over antibiotics.
That's because the same life-saving drugs that are prescribed to treat everything from ear infections to tuberculosis in humans also are used to fatten the animals that supply the chicken, beef and pork we eat every day.
Farmers say they have to feed the drugs to animals to keep them healthy and meet America's growing appetite for cheap meat. But public health advocates argue that the practice breeds antibiotic-resistant germs in animals that can cause deadly diseases in humans.
The U.S. government moved to ban the use of some of the drugs in animals in the 1970s, but the rule was never enforced. Then last week, the Food and Drug Administration outlined plans to phase out the use of antibiotics in farm animals for nonmedical purposes over three years.
"Consumers are beginning to understand the cost of eating cheap meat," said Stephen McDonnell, CEO of Applegate Farms, which markets antibiotic-free meats and cheeses. "As people really understand what it takes to create a healthy animal they will probably eat less meat, but they are going to eat better meat."
The FDA approved the use of antibiotics in livestock in the 1950s after studies showed that animals that got the drugs in their feed put on more weight in less time than animals on a traditional diet. For example, pigs that got an antibiotic were shown to need 10 to 15 percent less feed to reach the same weight as pigs on regular diets.
Since feed can account for as much as 70 percent of total animal production costs, the discovery was a windfall for farmers. It meant they could produce more meat for less money, resulting in fatter profits.
But by the 1970s, researchers began warning regulators that routine use of antibiotics was contributing to a surge in drug-resistant germs, or superbugs, that render antibiotics powerless against deadly infections. Professor Stuart Levy of Tufts University conducted the first study in 1976 showing highly-resistant e. coli E. coli bacteria could pass from chickens to farm workers who worked with the animals in just a few weeks.
The study contributed to the FDA's decision to ban nonmedical use of penicillin and tetracycline in farm animals a year later. But farmers and drugmakers pushed back, and the FDA rule was never enforced.
"Why did no one act on it? Because there was a strong lobby," said Levy, who is co-founder and president of the Alliance for Prudent Use of Antibiotics, a nonprofit advocacy group that favors restrictions on the drugs. "They said, 'Well, show us the deaths. Show us the real problem. Otherwise, this isn't so terrible."
"We're pretty darn committed to our cattle, and our goal is to not have them get sick," said Mike Apley, a cattle farmer and professor of veterinary medicine at Kansas State University.
Farmers like Apley also point to a handful of studies that conclude the risk to humans is extremely low. One 2004 estimate conducted by scientists consulting for the meat industry, for instance, placed the likelihood that antibiotic would not work in a human due to animal use at 1 in 82 million.
And, they argue, it's the overuse of antibiotics in humans — not animals — that's causing a rise in drug-resistant bacteria. Indeed, for decades, doctors have prescribed antibiotics for common ailments like the flu and sinus infections that are not caused by bacteria. Studies show doctors often feel pressured to prescribe the drugs.
"The problem is not an animal or human issue per se," said Dr. Tom Chiller, associate director for epidemiologic science at the Centers for Disease Control and Prevention. "It's about using the antibiotics as judiciously as we possibly can in situations where they are needed."