Antimicrobial use in food animal medicine has become an important political and scientific issue, especially in relation to the contribution that animal sourced antimicrobial resistance might play in human medicine, leading to calls at a political level for national action plans to be developed. Globally, the World Health Organization (WHO) and World Organisation for Animal Health have created critically important antibiotic list for human medicine and veterinary medicine, respectively. The responsible use of antibiotics in food animals and humans is essential to preserve the viability of antibiotics for use in medicine. For animals, maintaining their health is important for the production of safe food for human consumption, to meet the demands of an increasing world population that is seeking more animal sourced affordable protein in their diets.
Sound political policy can be developed based upon the best science and practices considering global experiences and lessons learned. Extensive experiences and learnings globally, including those in the European Union (EU) and the United States (US), can contribute to developing science-based policy and regulations for individual countries. Risk analysis principles and application, which includes risk assessment, risk management and risk communication, can serve to ensure countries incorporate best practices into their ever evolving food animal regulatory processes. Learnings and best practices globally have demonstrated that a strategic approach to addressing antimicrobial resistance is critical. Recognition of existing status and desired goals in a country and then building a process through laws, regulations and practices, that bridges from current state to desired state, is most important to ensure that policy and science can be and are implemented for a successful outcome. Political action without reasoned science and realistic practices will lead to unintended consequences and a waste of limited resources.
Antibiotics are normally regulated as part of a food animal drug approval process. The regulatory approval process includes assessment for safety (human, animal and environment), quality and efficacy (the label claim with approved uses). The regulatory human safety assessment for antibiotics historically considered toxicological and microbiological safety. This assessment provided for the establishment of an acceptable daily intake (ADI) and maximum residue limits (MRLs) to ensure safe use of the product. More recently, the safety assessment is incorporating a risk analysis specific to antimicrobial resistance. This process includes assessing the risk considering exposure, managing the risk through label use directions and communicating the risk to ensure responsible use. The primary focus is to reduce food borne pathogens, and the resistance associated with bacteria, that may contribute to untreatable human illness. Importantly, residues and resistance both need to be addressed through laws and regulations, however, each requires unique policies and practices to meet desired outcomes. Providing for the regulated uses of antibiotic products reduces the uses of unregulated antibiotic products. Regulation with proper enforcement contributes to a safe food supply while preserving the effectiveness of antibiotics for use in human and food animal medicine.
Antibiotic regulations and the associated risk analysis need to consider the indication for use and the categories for use of the compound. Antibiotics are used in food animal medicine either for a therapeutic indication which includes disease treatment, control and prevention.
Global experiences and lessons can provide insights for best practices in developing sound policy and science-based regulation. The European Union and United States both have sought over the past two decades to address antimicrobial resistance by evolving their laws, regulations and responsible use practices. Each advanced different approaches over time and thus with different experiences and lessons learned. Globally, antibiotics continue to be used in all countries in food animal production; no country has eliminated all uses of antibiotics.
The European Union has evolved their antibiotic regulations to provide for uses as injectables, medicated water and medicated feed. Antimicrobial resistance risk analysis is a critical part of the regulatory approval process. Antibiotics can be approved for therapeutic uses of disease treatment, control and prevention. The veterinarian plays a major role as the prescriber of antibiotics.
In the European Union, there has been much debate over the antibiotic growth promotion (AGP) use of antibiotics in veterinary medicine, the European Union banned antibiotic growth promotion use as of 1st January 2006. Importantly, the European Union ban was not a molecule ban but rather an indication of use ban meaning that if a molecule had a therapeutic indication and an antibiotic growth promotion indication the AGP indication was banned however the molecule remained on the market for therapeutic indications. The European Union approach to banning antibiotic growth promotion use has had a negative impact termed the ‘unintended consequences’ which has resulted in an increased incidence of necrotic enteritis in poultry and dysentery in swine which has resulted in increased quantities of antibiotic being used as therapeutic indications. There is an increase in therapeutic use of antibiotics in Denmark after the antibiotic growth promotion ban was implemented in 2000. The increase was mainly due to the extensive use of tetracyclines and penicillin such as ampicillin.
The United States has evolved their antibiotic regulations with antimicrobial resistance risk analysis as a critical part of the regulatory approval process. Antibiotics can be approved for therapeutic uses of disease treatment, control and prevention, and for growth promotion. The veterinarian plays a major role as the prescriber of antibiotics, including for use in feed under a “veterinarian feed directive”.
The US FDA has, in their guideline 213 for industry, divided antibiotics into three classes. Human use only, i. e. classes of antibiotics only used in human medicine, animal use only, i. e. classes of antibiotics only used in animal medicine and shared class use, i. e. classes of antibiotics used in both human and animal medicine. This guideline is requesting veterinary pharmaceutical companies to voluntarily remove antibiotic growth promotion label claims of all shared class antibiotics while allowing the antibiotic growth promotion claim to remain for those antibiotic classes that are animal use only.
A country needs to determine what laws, regulations and responsible uses policies are best for them considering learnings from global experiences. The approach should start fully understanding current policy and practices, the desired goals and then a practical approach that bridges current status to desired status over time.
(Authors Shabbir Simjee is with Elanco Animal Health, Basingstoke, United Kingdom, and Shraman Jha is with Elanco Animal Health, Bangalore, India)