Steven Roach, Food Safety Program Director, Food Animal Concerns Trust
On September 14, the Food and Drug Administration (FDA) Center for Veterinary Medicine (CVM) released a Five-Year Action Plan to slow the spread of antibiotic resistance by reducing antibiotic overuse on the farm. While it is great that FDA continues to recognize the problem and take steps to address it, the plan does not do enough and does not include concrete goals for success. With the world on the brink of a post-antibiotic era where routine infection will once again kill and the threat of infection makes routine surgery dangerous, the FDA needs to do much more.
The World Health Organization (WHO) recommends much greater action than the FDA on curbing antibiotic overuse. Of the WHO recommendations, the FDA plan fails to include targets for antibiotic use reductions, allows the continued use of antibiotics for routine disease prevention, and does nothing to address the overuse of the drugs that are most important for human health.
FDA’s plan commits to asking makers of medically important antibiotics to set limits on how long an antibiotic can be used and to require that these antibiotics only by used with a prescription. FDA in 2016 completed a previous plan that required drug makers to require prescriptions for medically important antibiotics in feed and water. The new plan extends this to any remaining medically important drugs for animals including those used by injection. Medically important antibiotics are antibiotics that are the same as or related to those used in human medicine that create a risk of spreading resistance to humans when used in animals. The plan also includes goals for improvements in the collection and reporting of data on antibiotic resistance and antibiotic use in food producing animals.
Duration limits
One of the major ways that the FDA plans to address antibiotic overuse in food animals is by adding duration limits on all medically important drugs that do not already have them.
Most antibiotics have a duration limit on them. This tells the user how long they should be taking any particular drug. When antibiotics are used for treatment, the duration should be long enough to treat the disease but no longer. If a patient continues to use an antibiotic after the disease is cured, the drug does not be help the patient but will create resistance. If the duration limit has passed and the animals still have not gotten better, the antibiotic is probably not effective.
Because drug use in animals can spread resistance to humans, the FDA in 2003 put in place new requirements for animal drug makers that limited how long farms could give antibiotics to food animals. FDA recognized that longer durations can create resistance and restricted the use of most new medically important drugs in food animals to less than 21 days.
However, these restrictions do not apply to drugs approved before 2003, so almost 40% of existing medically important antibiotic approvals have no duration limit. Most of these approvals without durations are not to treat disease but are instead given routinely to prevent illness – a practice WHO would like to see eliminated because it creates resistance while not being needed to treat sick animals. The Keep Antibiotics Working Coalition agrees with the WHO and supports improving how animals are raised to prevent disease not giving them routine antibiotics.
Instead of eliminating preventive use of medically important antibiotics, the FDA plan lays out steps to add duration limits to all medically important drugs. This will help reduce the overuse of antibiotics for disease prevention by eliminating continuous use, but does not go far enough. Under the FDA plan, farms can still feed antibiotics to animals that have no signs of illness resulting in many more animals receiving antibiotics and an increased risk of resistance. The Keep Antibiotics Working coalition supports FDA requiring appropriate duration limits, but continues to push for the restriction of the preventive use of medically important antibiotics as recommended by WHO. In addition, FDA has not indicated that it will require duration limits to be short. Longer durations means bacteria are exposed to antibiotics for longer with the result being more resistance. We will continue to ask that FDA keep duration limits shorter than 21 days consistent with the 2003 requirements for new drugs.
Surveillance
The FDA plan is strongest in its expansion of the National Antimicrobial Resistance Monitoring System (NARMS). NARMS is the federal program that tracks antimicrobial resistance in foodborne bacteria in humans, retail meats, and food producing animals. The 5-year plan would expand the number of bacterial and animal species monitored as well as the food products sampled. The FDA plan also has a goal to improve information-sharing systems, and building on research on antimicrobial resistance with new genomic technologies and bioinformatic tools. NARMS is an invaluable resource to help us understand emerging bacterial resistance, and expanding what it already covers would help fill numerous gaps in our knowledge. Keep Antibiotics Working has long supported NARMS and is happy to see it being strengthened.
What is more is needed
In addition to further restricting preventive use of medically important antibiotics, we believe an effective plan would also include antibiotic reduction targets and more detailed and more ambitious goals surrounding collection of antimicrobial use data. Regarding antibiotic use data, the plan contains only limited intermediate steps at a long time scale. One these intermediate steps is to finish the development of a biomass adjustment metric. This would allow the FDA to understand better the antibiotics used per animal, rather than just looking at aggregate sales data. With the biomass adjuster, we'd be able to have a better understanding of trends, and be able to see if we're really getting better at stewardship or not. The European Union already has a functional method for adjusting antimicrobial use data by number of animals. As the FDA develops a more nuanced, us-specific measure, we see no reason why they can't also use this internationally accepted method in the interim. We need better data on antimicrobial usage, and we need it now.
This 5-year plan is all about stewardship, but if we don't have reduction goals or metrics that establish the baseline of where we're at today, then how can we judge our progress on improving our stewardship practices? We need to know if our policies are actually working, and this involves setting targets and the ability to benchmark. It's worth remembering that our ultimate goal is to preserve the effectiveness of antibiotics, because a future without antibiotics is a future where modern medicine is crippled. The FDA five-year plan has many worthy goals, but it does not go far enough to tackle the urgent problem of antibiotics overuse on farm.
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