An international team of researchers say a combination of regulatory caps, user fees, and reductions in global meat consumption could significantly reduce the use of antibiotics in food-producing animals over the coming years.
In a paper today in Science, the researchers estimate that the global consumption of antibiotics in livestock and poultry will climb to 200,235 tons by 2030, up from 131,109 tons in 2013, if the livestock sector continues to grow and antibiotic consumption is left unchecked. That kind of increase in the routine use of antibiotics in food animals, whether for growth promotion or disease prevention, they argue, is unsustainable and will have a devastating impact on efforts to fight antimicrobial resistance (AMR) in animals and humans.
Their proposal to reduce antibiotic use in food animals includes three interventions: capping antibiotic use in animals at 50 mg per population correction unit (PCU), which is the current global average; limiting global meat intake to 40 grams a day (the equivalent of one fast-food hamburger per person); and imposing a 50% user fee on veterinary antibiotics, paid by veterinary drug users. The researchers estimate that the interventions on their own could reduce global food animal antibiotic consumption by 64%, 66%, and 31%, respectively, by 2030. A combination of all three could cut consumption by 80%, they say.
The widespread use of antibiotics to boost growth and prevent disease in livestock and poultry is widely recognized by experts and global leaders as contributing to the emergence and spread of AMR. According to the paper, global antibiotic use in food animals outweighs human antibiotic consumption by nearly three times. And with a growing demand for protein in many low- and middle-income countries, antibiotic use in food animals is expected to explode.
Under a September 2016 pledge by the United Nations General Assembly to combat AMR, world leaders agreed to create national action plans to promote antibiotic stewardship in human and animal health. But many experts believe that targets for reduced use of antibiotics in humans and animals are necessary.
While the suggested interventions are bold, lead author Ramanan Laxminarayan of the Center for Disease Dynamics, Economics & Policy says global regulations might be the only way of achieving meaningful reductions. "We have made essentially no progress on this front and we are losing time with respect to development of resistance," he said in an interview. "When the AMR problem gets worse, and that's only a matter of time, policy ideas that seem unreasonable today suddenly seem absolutely necessary."
A question of enforcement
The question is how such policies would be enforced, and whether they can be enforced, say other experts. "In my mind, it [the interventions suggested] is a good way to get the conversation started, but there's no real consideration in the paper of how you would go about implementing these policies," Gail Hansen, DVM, a public health and animal medicine consultant, told CIDRAP News.
Take the cap on veterinary antibiotic use, for instance. As Laxaminarayan and his colleagues note, current consumption levels vary considerably between countries. European countries such as Denmark have stopped using antibiotics for growth purposes and use less than the current global average of 50 mg/PCU. The United States, which recently banned the use of medically important antibiotics for growth promotion, uses just over 100 mg/PCU. China, the largest consumer of veterinary antibiotics, uses 318 mg/PCU.
But China is also the world's most populous country, with growing consumer demand for meat. And other large, developing nations like Brazil and India are heading in the same direction, with projected increases in veterinary antibiotic consumption of 41% and 82%, respectively. Would these countries agree to a cap that might hamper food animal production?
The same question can be asked about limiting meat consumption, which also varies widely. In the United States, according to the paper, average meat consumption per person is 260 g/day. But in many developing nations, average meat consumption is well below the 40 g/day limit recommended in the paper. And, as pointed out by Hansen, rising meat consumption is one of the metrics low-income nations use to determine progress. Asking those countries to limit meat consumption in order to reduce antibiotic use in food animals could be a tough sell.
"At the UN they agreed to a general set of principles on antibiotic use, but not how to get there," Hansen said. "I'm not sure these ideas will have the same universal appeal."
Timothy Johnson, DVM, a professor of veterinary medicine at the University of Minnesota, agrees. "There's not any democracy in the free world that's going to limit the amount of meat that their constituents can eat," he said in an interview.
But Laxminarayan points to recent efforts by China to revise its nutritional guidelines for meat intake to 40 to 70 g/day—nearly half the country's current consumption level—as proof that countries recognize the public health value of limiting meat consumption. "This does not mean that people who are protein deficient should not be eating meat," he said.
Laxminarayan and his colleagues also explore other options in the paper that would place lesser burdens on low- and middle-income countries. For example, limiting the cap on veterinary antibiotic use to China and the countries of the Organization for Economic Cooperation and Development could still reduce global consumption of antibiotics by 60% by 2030. A less restrictive meat intake limit of 165 g/day, they argue, could cut antibiotic consumption by 22%.
Laxminarayan said the policies would need to be agreed upon globally, in principle, but that enforcement would have to be a national effort, or even subnational in some countries.
Can user fees change behavior?
For Hansen, the user fee is the most intriguing and workable idea. "A user fee really does get to those countries that are using antibiotics at a high rate," she said. "We know from other public health interventions that, whether you call it a user fee or a tax, it will change behaviors."
That's the hope, Laxminarayan said. "As farmers switch to farming with more modern methods, better hygiene, and improved animal nutrition, the need for antibiotics will go away."
Among the advantages of the user fee is that it could be applied immediately at the point of manufacture or wholesale purchase and would be much easier to enforce than the caps on veterinary antibiotic use and consumer meat consumption. In addition, the revenues could go into a global fund to stimulate development of new antibiotics or into projects to improve farm hygiene and expand veterinary services, which would be needed to compensate for the reduction in antimicrobial use.
"Of the three ideas, I think this is the most feasible," Johnson said. But he is concerned that if fewer antibiotics are used and producers don't make the necessary adjustments to more modern farming methods, then the health and welfare of the animals might suffer. Johnson also said he thinks targeted antibiotic reduction strategies, such as limiting certain uses and particular drugs that are more prone to resistance, may be a better way of solving the problem of resistance in animals.
While Johnson said he is skeptical of the particular proposals put forth in the paper, he ultimately thinks global initiatives are going to be a big part of reducing antibiotic use in food animals, and he applauds the authors for starting the discussion. "We need to have these conversations and get these opinions out there so that they can be discussed," he said.
Sep 28 Science study