Approaches and issues related to measurement of antibiotic use (ABU) data in the US swine industry

The urgency to address antibiotic resistance in human medicine is echoed among health groups at globally. ABU in all arenas (human, food animal, companion animal, aquaculture, agriculture) contributes to the phenomenon of resistance, albeit with variable clinical consequences. Improving antibiotic stewardship is a cornerstone of efforts to combat the emergence of clinical resistance, and measurement of both ABU and resistance is needed. In most countries, current national data based on gross weight of products sold across multiple species lack sufficient granularity to provide meaningful support for stewardship activities.

A review of existing systems for measuring ABU was conducted to evaluate potential models for the US industry. This included in person meetings with groups involved with development systems in some European countries, and reviews of published materials in other countries. In parallel, information is being gathered on ABU data kept by US producers, to understand the scope of archived data and the opportunities and barriers to sharing data within the industry and to external stakeholders.

Key issues arising include: 1) Clear definition of the core purpose for measuring ABU (obtaining meaningful and representative data on trends at an industry level vs. monitoring ABU at an individual user level for benchmarking and interventions) and 2) Definition of appropriate metrics for measurement, including the scope of compounds to include (e.g. ‘medically important’ vs. not). Weight based measures for ABU are essentially meaningless and adjustment for potency is necessary and done in some countries. However, adjusted measures are also problematic and population-based measures are not consistently applied across existing programs. There also is a need to differentiate ABU by stage of production. In the highly consolidated US industry, considerable data on ABU is kept privately for cost accounting purposes. Such data are biased towards larger systems, but may represent a large part of commercial production. Efforts are now being directed to design a framework for confidential data sharing and analysis, including the potential of within industry benchmarking and contributing another data stream to national surveillance initiatives.

There is concern that ABU reduction is seen as synonymous with judicious use. Reduction should not be pursued or mandated independent of efforts to assess resistance in human pathogens or without concurrent assessment of the appropriateness of use, and impact on clinical outcomes, and animal health and well-being. Appropriate practices that most benefit animal health need to be defined based on evidence not opinion.

Disclosure of Interest: None Declared.