The European Union has banned the use of four additional antimicrobials as growth promoters in animal feed. As of Jan. 1, the antimicrobials monensin sodium, salinomycin sodium, avilamycin, and flavophospholipol may not be marketed or used for nonmedicinal purposes. The antimicrobials may only be added to animal feed for veterinary purposes.
As a result of the emergence of microbes resistant to antimicrobials that are used to treat human and animal infections, the EU stated, the Commission of the European Communities decided to phase out, and ultimately ban, the marketing and use of antimicrobials as growth promoters in animal feed. The Jan. 1 ban was the final step in the phaseout. The EU previously banned antimicrobials such as avoparcin and virginiamycin, used in human medicine, from being added to animal feed to promote growth.
Similar to the EU ban but more extensive, legislation was proposed in the United States to amend the Federal Food, Drug, and Cosmetic Act. Called the Preservation of Antibiotics for Medical Treatment Act of 2005 (S. 742/H.R. 2562), the bill is more restrictive than the EU ban because it proposes to eliminate antimicrobial uses in feed and water for undefined routine disease prevention and other routine purposes, in addition to growth-promotant uses.
In June 2005, the AVMA Executive Board approved "nonsupport of passage" of the Preservation of Antibiotics for Medical Treatment Act. The AVMA Legislative Advisory Committee recommended nonsupport of passage because it believes the ban on antimicrobial uses for routine disease prevention and other routine purposes presents risks to the health and welfare of animals without reasonable assurance that the bill will protect or improve human health. Instead, the AVMA believes the availability and effectiveness of antimicrobials are important for maintaining the health and welfare of food-producing animals and ensuring food safety. The AVMA stated that there is not enough evidence to justify legislative or regulatory prohibition of classes of use, such as uses to prevent diseases, of antimicrobials in animal feed or water.
The AVMA proposes that the proper strategy is to perform risk analysis of the specific uses of individual drugs to assess health risks and benefits to humans, to communicate any identified health risks or benefits, and to decide on appropriate risk-management procedures, said Dr. Lyle Vogel, director of the AVMA Scientific Activities Division. The risk management options can range from no change, to a change from an over-the-counter approval to a veterinary feed directive approval, or to a ban on the use, if needed to protect human health, he said.
"The many different drugs and the many ways of using drugs do not create uniform risks of antimicrobial resistance affecting human or animal health," Dr. Vogel said. "Therefore, general overarching bans on classes of use are not appropriate." The AVMA believes that the Food and Drug Administration has adequate authority to perform these evaluations. The FDA has demonstrated its authority with the recent ban on the use of enrofloxacin in water to treat disease in poultry (see JAVMA, Sept. 1, 2005). Additional legislation is not necessary, Dr. Vogel said.
"Reportedly, the FDA is reevaluating the currently approved uses of penicillins and tetracyclines in feed," Dr. Vogel said. "The FDA has performed a risk assessment of the use of virginiamycin in feed. The AVMA believes that the U.S. Congress should ensure that the FDA has the resources necessary to prioritize and complete the risk-based determinations."