November 28, 2011
Voicing Concerns Over Antimicrobial Use in Food Animals to the Interagency Task Force on Antimicrobial Resistance
Also contributing to this post is Patrick Baron, CLF Doctoral Fellow and PhD student in Environmental Health Sciences.
For the first time in 13 years, the Interagency Task Force on Antimicrobial Resistance* (ITFAR) heard from the public on antimicrobial resistance. We presented a strong argument for why surveillance, environmental antimicrobial pollution, and veterinary oversight should be given more attention by ITFAR. We were not alone in our concerns about antimicrobials and resistance; representatives from the Infectious Diseases Society of America (IDSA) and the coalition to Keep Antibiotics Working (KAW) also provided input to 14 representatives from over 10 agencies that are members of ITFAR.
The war on antimicrobial resistance centers around the presence of environmental antimicrobials, which creates the selective pressure that drives the evolution and dissemination of drug-resistant pathogens. Federal agencies have largely focused on the use of antimicrobials in human medicine and hospital environments. The majority (80%) of antimicrobial use, however, occurs in food animals, FDA reports. In our ITFAR presentation, we called for expanding efforts to address antimicrobial use in food animal production, highlighting three key areas of need:
- Harmonization and expansion of surveillance for drug use and drug-resistant pathogens
- Greater focus on environmental pathways for movement of antimicrobial drugs and drug-resistant pathogens from farms to human populations
- Improved veterinary oversight of antimicrobial use in food animals
“I was brought up to believe that the only thing worth doing was to add to the sum of accurate information in the world.”
—Margaret Mead, an American cultural anthropologist
Accurate information on antimicrobial use in food animals is difficult to obtain, but worth doing! At the ITFAR public comment hearing, we reiterated points we made during the previous week at an FDA public meeting on reauthorization of the Animal Drug User Fee Act (ADUFA), calling for better refinement of data on how, where, and for what species these drugs are being sold for use. (Read IFTAR comment, Meghan Davis.) We urged ITFAR member agencies to expand data collection through ADUFA and other monitoring programs to include non-antimicrobial drugs that may select for or induce resistance.** We also emphasized the need to harmonize data collection and reporting among the various surveillance programs that address antimicrobial resistance, and to make more of these data available to the public. Key programs include the FDA’s sales and distribution data from ADUFA, the National Antimicrobial Resistance Monitoring System (NARMS), and the National Healthcare Safety Network (NHSN). Expansion of all programs to include data collection and reporting at the state or county level would improve the ability of researchers, agencies, and state and local public health departments to evaluate geographic trends in resistance.
Antimicrobial drugs, whether administered to a human or an animal, or inadvertently released to the environment, can exert selective pressure to expand the population of organisms resistant to these drugs. However, little agency work has focused on environmental pollution with these drugs—that is, on drug contamination of water, air and soil through direct spillage or indirect release of active drugs in manure, which is often applied directly and without any pre-treatment to crops as fertilizer. We urged the Task Force to go beyond its current action plan and expand surveillance, research, and prevention efforts to address the presence and persistence of antimicrobial drug chemicals in the environment.
Antimicrobial drugs for food animals are available over-the-counter, meaning that veterinarians may not be involved in decisions related to their use. In fact, the USDA Animal and Plant Health Inspection Service published findings from the National Animal Health Monitoring System that dairy farmers reported consulting a veterinarian only 46 percent of the time before choosing an antimicrobial drug.*** Just as judicious use is a key component of antimicrobial stewardship programs in human medicine, we urged the Task Force to ensure judicious use of antimicrobials in food animals through increased veterinary oversight.
In the next two years, the Task Force will publish updates on progress toward their goals and consider revisions to their Action Plan to Combat Antimicrobial Resistance. We look forward to working further with federal agencies to enhance efforts to combat the urgent, global problem of antimicrobial resistance.
Acknowledgments: Keeve Nachman, Dave Love, Tyler Smith, & Sally Ann Iverson for assistance in development of the public comment.
*The Task Force was created in 1999 to address Congressional concerns regarding the rise of pathogens resistant to antimicrobial drugs. Led by the Centers for Disease Control and Prevention (CDC), the Food and Drug Administration (FDA), and the National Institutes of Health (NIH), the Task Force also includes members of many other agencies, including the U.S. Department of Agriculture (USDA) and the Environmental Protection Agency (EPA). The main purpose of this group is to enhance communication among agencies and to harmonize and direct efforts to address antimicrobial resistance. The Task Force organized the November 15, 2011 meeting to solicit public comments regarding the progress and future direction of the coalition.
** Lina M. Cavaco et al., Zinc Resistance of Staphylococcus aureus of Animal Origin is Strongly Associated with Methicillin Resistance, 150 VETERINARY MICROBIOLOGY 344 (2011). Zhangqi Shen et al., Salicylate Functions as an Efflux Pump Inducer and Promotes the Emergence of Fluoroquinolone-Resistant Mutants in Campylobacter jejuni, APPLIED & ENVTL. MICROBIOLOGY (accessed ahead-of-print, 2011).
*** Animal & Plant Health Inspection Serv., U.S. Dep’t Agric., Dairy 2007 Part III: Reference of Dairy Cattle Health and Management Practices in the United States (2008)