ing the relationship between food-animal drug use and public health, reviews the rationale and process under which food-animal drugs are developed by industry and approved by the federal government for use, addresses alternative measures that might be considered in food-animal production strategies to lower use of and dependence on drugs—specifically antibiotics—and summarizes the basic strategies and practices used in modern animal production. Risks and benefits to human and animal health and to animal production economics and efficiency are identified but because quantitative information was insufficient or confounding, not objectively ranked.

The committee reviewed the major classes of drugs used in food animals, focusing on the potential effect of drugs used both for human and for animal health. The committee conducted a review of the scientific literature; heard testimony on animal-drug-related issues; and reviewed federal regulations that provide guidelines and list mandatory practices for drug use, monitoring capabilities for drugs and residues in foods, veterinary oversight in prescription drug use, rates of violations, and instances of documented health problems. The committee concluded that most drugs used and most drug residues found in animal-derived foods pose a relatively low risk to the public so long as the drugs are used responsibly and in keeping with label instructions.

There were, however, concerns about the effects of antibiotic use in food animals. Effects on human health were not related to food contamination from the use of antibiotics or from antibiotic residues. Rather, the concern was narrowed to the effect of antibiotic use on the emergence in food animals of populations of microorganisms that become resistant to the biochemical mechanism by which an antibiotic drug kills or severely restricts the proliferative capability of microorganisms. For example, a review of the scientific literature found that studies focused on antibiotic resistance in human health outnumber those related to drug and chemical residues by almost 10 to 1. In addition, there has been a notable increase in reported cases of human illness associated with antibiotic resistance and an increase in documented resistance patterns from veterinary microbiological surveillance data.

Based on that information, the committee decided to focus on the potential for antibiotic resistance as the main food-animal drug issue. The committee updated and consolidated the most recent findings and opinions that address the human health risk or shape perceptions of the risk. It also summarized the science behind the process by which bacteria become resistant to antibiotic drugs and the ramifications for animals and humans.