Graphic via the National Academy of Medicine.

A new paper published in Science assesses three major ways to reduce use of antimicrobial drugs in food animals so as to help stem the rise of antimicrobial resistance in pathogens of importance in human medicine. The authors, among them Tim Robinson, of the International Livestock Research Institute (ILRI), find that imposing user fees for such drugs is a plausible policy action to take, if fees can be kept affordable for small-scale livestock keepers. Excerpts from the paper follow.

‘The large and expanding use of antimicrobials in livestock, a consequence of growing global demand for animal protein, is of considerable concern in light of the threat of antimicrobial resistance (AMR). Use of antimicrobials in animals has been linked to drug-resistant infections in animals (1) and humans (2). In September 2016, the United Nations (UN) General Assembly recognized the inappropriate use of antimicrobials in animals as a leading cause of rising AMR. In September 2018, the interagency group established by the UN Secretary General will report on progress in the global response to AMR, including antimicrobial consumption in animals. We provide a baseline to monitor efforts to reduce antimicrobial use and assess how three global policies might curb antimicrobial consumption in food animal production: (i) enforcing global regulations to cap antimicrobial use, (ii) adherence to nutritional guidelines leading to reduced meat consumption, and (iii) imposing a global user fee on veterinary antimicrobial use.

‘The rise of AMR in zoonotic pathogens, including to last-resort drugs such as colistin, is an important challenge for human medicine because it can lead to untreatable infections. Evidence linking AMR between animals and humans is particularly strong for common foodborne pathogens resistant to quinolones, such as Campylobacter spp. and Salmonella spp. AMR is also a threat to the livestock sector and thus to the livelihoods of millions who raise animals for subsistence.

‘The primary driver for the accumulation of harmful resistance genes in the animal reservoir is the large quantity of antimicrobials used in animal production. Antimicrobial use in livestock, which in many countries outweighs human consumption, is primarily associated with the routine use of antimicrobials as growth promoters or their inappropriate use as low-cost substitutes for hygiene measures that could otherwise prevent infections in livestock.

‘In Europe, regulations have been the principal instrument to limit antimicrobial use in animal production. In the United States, consumer preferences have driven companies to reduce antimicrobial use in animals . . . .  A second solution to reduce antimicrobial consumption in animal production may be to promote low-animal-protein diets . . . . A third solution to cut antimicrobial use would be to charge a user fee, paid by veterinary drug users, on sales of antimicrobials for nonhuman use. This approach has recently received support from the World Bank on the basis that the associated revenues could be injected into a global fund to stimulate discovery of new antimicrobials and support efforts to preserve existing drugs. Without further analysis, however, it is unclear whether a user fee policy could achieve a meaningful reduction in the global consumption of veterinary antimicrobials, let alone generate sufficient revenues to support improved livestock rearing practices or the development of new drugs, vaccines, and diagnostics. . . . Imposing a user fee of 50% of the current price on veterinary antimicrobials could reduce global consumption by 31% . . . . However, because user fees could be passed on to individual farmers, these could also have adverse effects . . . [with low- and middle-income countries] disproportionally affected by a user fee. . .

‘Unlike regulations that may be virtually impossible to enforce in [low- and middle-income countries], a user fee policy could be applied immediately, without waiting for costly surveillance networks to put in place. In [low- and middle-income countries], large livestock producers could follow the example from European countries, where drastic reductions in antimicrobial consumption could have potential long-term benefits.

‘In compensation for the reduction in antimicrobial use in [low- and middle-income countries], major investments will be needed to improve farm hygiene and expand veterinary services. We show that these could be partly financed with the revenues of the user fee policy through a global fund.

In parallel, national programs should also ensure that antimicrobials used for treatment by smallholders remain affordable so that a global user fee doesn’t become an obstacle for livestock-driven economic development. . . .

In the long run, this transition to low antimicrobial use could benefit all countries: Phasing out growth that promotes antimicrobials will likely have limited impact on food production but would reduce the risk of emergence of pathogens resistant to last-resort drugs. . . .

Our findings suggest that imposing a user fee on veterinary antimicrobials is a plausible policy option to achieve meaningful reductions in antimicrobial use in the short term while simultaneously raising funds to improve farming practices that will benefit the long-term viability of the livestock industry.

Read the whole paper: Reducing antimicrobial use in food animals, by Thomas Van Boeckel, of the Institute of Integrative Biology (Switzerland); E E Glennon; D Chen; M Gilbert; Tim Robinson, of the International Livestock Research Institute (ILRI) (Kenya) and the Food and Agriculture Organization of the United Nations (FAO) (Italy); B T Grenfell; S A Levin; S Bonhoeffer; and Ramanan Laxminarayan, of the Center for Disease Dynamics, Economics and Policy (CDDEP) (Washington, DC) and Princeton Environmental Institute at Princeton University, 2017, Science, 29 Sep 2017: Vol. 357, Issue 6358, DOI: 10.1126/science.aao1495