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More than 50 years ago, the U.S. Food and Drug Administration (FDA) approved the addition of antibiotics to livestock feed to reduce disease that can occur from dense living conditions and high-protein diets. Yesterday, the FDA announced its aim to withdraw that approval and stop all nontherapeutic germ-fighting in chickens, pigs and cows.
The ban would cover seven classes of antibiotics that the FDA considers “highly” or “critically” important components of the human arsenal against bacteria. “Trends toward increasing numbers of infection and increasing drug resistance show no sign of abating,” Joshua Sharfstein, principal deputy commissioner of the FDA explained in written testimony to the House of Representatives' Committee on Rules.
Approximately 90,000 people in the U.S. die every year from bacterial infections—with 70 percent of the offending bacteria “displaying resistance to at least one microbial drug,” according to Sharfstein. Methicillin-resistant Staphylococcus aureus (MRSA) is probably the most notorious.
Boyd H. Parr, the state veterinarian for South Carolina, worries about what such a bill would do for the health and suffering of animals. “A lot of nontherapeutic uses are for disease prevention,” he tells us. “Are we just going to wait for the animals to get sick?”
Stricter standards for antibiotic use will also require more veterinarian involvement. “We have a tremendous shortage of food animal veterinary practitioners in the country,” Parr says. “There’s just not enough manpower.”
Others worry about increased costs for farmers, and consumers, if the rules are changed. Over the last half century, since the advent of antibiotics, average chicken weight has grown 50 percent while the amount of feed required dropped 35 percent, reported The New Republic. It’s not clear how direct this link is, however. After imposing a similar ban, Denmark has found only minor decreases in this efficiency ratio.
But did the ban actually lower rates of antibiotic resistance? “I’m puzzled by reports of similar, if not higher, rates of resistance in Europe, even where stricter rules were adopted,” Parr says. Some suspicion has arisen that off-label, underground antibiotics have actually increased risks in the region.
The farm industry isn’t the only group likely to oppose the bill; the pharmaceutical industry has a lot to lose, too. Seventy percent of all antibiotics in the U.S. are used for livestock, as estimated by the Union of Concerned Scientists.
In her statement yesterday, Rep. Louise M. Slaughter (D–N.Y.), who chairs the Rules Committee, quotes a National Academy of Sciences report: "A decrease in antimicrobial use in human medicine alone will have little effect on the current situation. Substantial efforts must be made to decrease inappropriate overuse in animals and agriculture as well.”
“As a microbiologist, I cannot stress the urgency of this problem enough,” Slaughter said.
Photo by K.Muncie via Flickr