Ominous projections for global antibiotic use in food-animal production

Alexander Fleming famously warned that the ignorant may someday misuse his life-saving discovery—penicillin—and select for resistant bacteria (1). This was prescient given the widespread use of subtherapeutic antibiotics by food-animal producers today. According to the findings of Van Boeckel et al. (2) in PNAS, the proliferation of ignorance is only poised to increase. Using global datasets of veterinary antibiotic use, livestock densities, and economic projections of meat demand, Van Boeckel et al. (2) estimate that from 2010 to 2030 antibiotic use in food-animal production will increase by 67%, from 63,151 ± 1,560 tons to 105,596 ± 3,605 tons.

The study by Van Boeckel et al. (2) is the first to estimate global use of antibiotics in livestock production, and to disaggregate that global figure into estimates for each of 228 countries. However, their estimate is based on data from only 32 countries. Using a clear framework and a state-of-the-art Bayesian statistical model, the authors extrapolate from the most reliable data available to arrive at the global sum. This is an admirable approach to a difficult problem, but it raises a question: Why not derive the values more simply, by summing data from all 228 countries, using the actual records of antibiotic use in livestock production? After all, this is how we quantify global fossil fuel use (3), livestock production and trade (4, 5), and the use of fertilizers in agriculture (4). For many assessments of global economic activity, including these, the actual data exist. However, for antibiotics in livestock production, a statistical model is the best option because comprehensive data on the use of antibiotics in livestock production are not available. Most countries do not record the sale and use of antibiotics, in part because practitioners may be reluctant to release those data. Despite this limitation, Van Boeckel et al. (2) provide the first global assessment of antibiotic use in livestock production. Their estimate is important: The figure is large and has been notoriously difficult to extract (6), and it sets the stage for understanding the global impacts of profligate use of these powerful drugs.