Farm-Animal Prescriptions Urged to Cut Drug Resistance

American farmers would be forced to get prescriptions for livestock antibiotics under a plan developed in Denmark and promoted by infectious disease doctors to stem a rising tide of drug-resistant infections in people.

Healthy livestock routinely get antibiotics in the U.S. to promote growth and prevent illness. The practice, though, allows germs to mutate within their bodies, spreading into meat and swapping DNA with flora in the human gut. That’s a recipe for transferring resistance, said James Johnson, a University of Minnesota researcher at a medical meeting yesterday.

Resistant infections cost the U.S. more than $20 billion annually, according to a 2009 study in the journal Clinical Infectious Diseases. By following a method used in Denmark that tracks data on livestock antibiotics, the U.S. may thwart resistance, said Lindsay Grayson, chief of the Interscience Conference on Antimicrobial Agents and Chemotherapy.

“My main advice for the U.S. is that all antibiotics used on animals should be given only with a prescription,” said Henrik Caspar Wegener, the director of the National Food Institute in Denmark. “That’s not the case at the moment. Antibiotics are medicines. They should be prescribed by someone educated to make that decision.”

Six Times More

Wegener spoke yesterday during a panel session at the conference in Chicago. Though the data is rough, the U.S. uses about six times more antibiotics than Denmark to produce about 2.2 pounds of meat, Wegener said in his presentation.

By requiring prescriptions for all antibiotics, the U.S. Food and Drug Administration can make more-informed decisions about how the drugs are used and lead them to see where their use may be eliminated, he said. Additionally, more data may help officials persuade the U.S. meat-producing industry, which had 2009 sales of $154.8 billion, to change its practices, Wegener said.

Currently, antibiotics are available by prescription, in an animal’s feed with the approval of a veterinarian, and over-the-counter without a prescription, said Bill Flynn, the deputy director for science policy at the FDA’s center for veterinary medicine.

The agency issued draft guidance on June 28, 2010, that would require veterinarian approval for all antibiotics, eliminating over-the-counter availability. The guidance isn’t yet final and the FDA is accepting public comment.

Call for More Surveillance

“That may have implications for tracking, but overall, it provides a level of control that isn’t there right now,” Flynn said in a telephone interview. The agency is scheduled to provide a follow up to its guidance later this year, he said.

While Liz Wagstrom, chief veterinarian at the National Pork Producers Council, echoed the call for more surveillance, she said requiring prescriptions would be more difficult here than in Denmark, a country that’s smaller than the state of Iowa. The U.S.’s larger size and less homogeneous population make tracking efforts more complex, she said.

“Really, until we have data about uses and trends in resistance, we’re talking in generalities,” Wagstrom said in a telephone interview. For smaller producers and those in remote geographic areas, having a veterinarian prescribe every use could be difficult, she said.

Gary Mickelson, a spokesman for Springdale, Arkansas-based Tyson Food Inc., the largest U.S. meat producer, referred questions to the American Meat Institute.

Food infections sickened 48 million Americans last year, leading to 128,000 hospitalizations and 3,000 deaths, according to the Centers for Disease Control and Prevention.

A First Step

The Denmark program, dubbed DENMAP, would only be a first step, Denmark’s Wegener said. The European Union barred any non-therapeutic antibiotic use in livestock in 2006.

A study two years later in the American Journal of Veterinary Research found that mortality rates among the animals didn’t change despite the EU ban on non-therapeutic use, which slashed use of the drugs by half. In 2010, the European Food Safety Authority reported that the prevalence of food-borne illness in Europe dropped in the four years after the ban.

“For us, it is quite clear,” said Awa Aidara-Kane, the leader of the World Health Organization’s antimicrobial resistance group, in an interview. “Special attention should be paid to antimicrobial agents that are critically important for human infection.”

GAO Report

There has been some movement toward more monitoring in the U.S. A Sept. 7 report from the Government Accountability Office gave the issue new prominence, recommending the FDA work with drug companies on a voluntary basis to increase veterinary supervision of antibiotics.

Data collected by the departments of Health and Human Services and Agriculture “lack crucial details necessary to examine trends and understand the relationship between use and resistance,” the report said.

The GAO said the data collected by agencies don’t show what type of animals are getting antibiotics or for what purpose. The agency also said the data are collected in a haphazard manner and “are not representative of food animals and retail meat across the nation.”

“We agree with the GAO’s findings,” said Betsy Booren, the director of scientific affairs for the American Meat Institute Foundation. “We think more data is needed and the report is reasonable, because without it, we can’t look at the trends.”

Healthier animals from antibiotic use may also mean safer food, Booren said.

Data Collection

The FDA currently collects sales and distribution data, which isn’t detailed enough to say what antibiotics go toward what animals, the FDA’s Flynn said. So if an antibiotic is approved for multiple uses in cows and pigs, the FDA doesn’t know what uses it is prescribed for, or even which animal gets the medicine.

Wegener said he met with GAO investigators in Denmark, and the investigators also talked with farmers and veterinarians.

“We had a lengthy discussion about the situation in Demark,” Wegener said. “I just wonder if there is the political will to change anything about antibiotic use in the U.S.”

The GAO endorsed an idea proposed last year by the FDA to work with drugmakers to limit access to antibiotics for animals and increase veterinary supervision. “Except for one $70,400 USDA project,” all other federal programs to educate producers and veterinarians use of antibiotics and alternatives have ended, the report said.

“We all agree there should be greater veterinary oversight on antimicrobials, but logistically it’s a challenge,” said Christine Hoang, the assistant director of scientific activities at the American Veterinary Medical Association.

Regulations for prescriptions and certain over-the-counter medicines vary by state, Hoang said. Veterinary feed directives are federally regulated.

The veterinary association’s steering committee will meet with the FDA tomorrow to discuss the issue, she said.

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