Antibiotic resistance is also a food and climate issue

Originally posted on BMJ Blogs http://blogs.bmj.com/bmj/2016/06/17/david-mccoy-antibiotic-resistance-is-also-a-food-and-climate-issue/

When George Osborne spoke to the IMF in April about antibiotic resistance being a greater threat to mankind than cancer, one might assume that the current government had actually listened to some professional advice from the medical community. Sally Davies, the country’s Chief Medical Officer, has been raising the alarm that the growing emergence of antibiotic resistance is a ticking time bomb of potentially apocalyptic proportions.This impending crisis has been in the making for decades during which time governments across the world have failed to implement the financing arrangements, laws and policies to ensure proper stewardship over the sale and use of antibiotics. Underlying this failure has been the broad trend towards the deregulation and marketization of health systems, and the effects of structural adjustment programmes and public budget cuts in many countries.

The Chancellor’s speech at the IMF, however, did not emphasise the need to strengthen the regulatory capacity of health systems or remove the incentives that encourage irresponsible prescribing. Rather he emphasised the need to finance the development of new antibiotics and diagnostics to assist clinicians to correctly identify the precise microbe responsible for an infection. In reality, there are few prospects for new antibiotics to be developed in the short term and there is therefore an urgent need to preserve the effectiveness of existing antibiotics.

This means doctors only prescribing the right antibiotic, for the right infection, at the right dose and for the right duration; and the public understanding that most common conditions such as mild colds and coughs, sinusitis, earache and sore throats get better without antibiotics. But the same principles must apply for antibiotic use in animals, as evidence mounts to show that antimicrobial resistance in the farming sector can be transferred across to the human sector. This is not surprising given that humans and farm animals occupy a single ecosystem which we also share with pathogenic microbes.

The need for a holistic but also global approach to address antimicrobial resistance (AMR) was clearly outlined in the final recommendations of the O’Neill Review, published in May this year. This was the final outcome of a two year AMR Review, led by economist Jim O’Neill and commissioned by David Cameron and the Wellcome Trust. One of the nine recommendations made was for nationally adopted targets to “reduce unnecessary use of antimicrobials in agriculture and their dissemination to the environment.” Critics have welcomed these recommendations but highlighted that such targets must be ambitious in their scope, set by species, and include a ban on routine, purely preventative (prophylactic) medication of groups of animals.At a conference held a day after Osborne’s IMF speech, the current pattern of antibiotic use in UK farms was discussed. In the spotlight was the practice of prophylactic group treatment which involves treating groups of animals without clinical infection on the grounds that they are or might be at risk of infection. Group treatment is now under question because of concerns about antibiotic resistance.The routine preventative use of antibiotics in animals is not allowed in Sweden, Denmark, the Netherlands and Norway. And a proposal to implement an EU wide ban of routine prophylactic antibiotic use in groups of animals is currently under review. The Netherlands and Sweden also have laws requiring sensitivity testing of pathogens before certain critically important antibiotics such as fluoroquinolones can be used. In contrast, in the UK, fluoroquinolones can still be used for the mass medication of poultry even when no disease has been diagnosed.

Although there is a growing recognition of the need to strengthen stewardship over the use of antibiotics in farm animals, the UK should be moving faster towards a reduction in antibiotic use, particularly in pig farming where use is high. We should also be concerned about the high density factory farming which, when accompanied by poor hygiene or practices such as the early weaning of young animals, facilitates the spread of infection and creates a need for antibiotic use by depressing the immune system of animals.

But the intensive farming of animals, which provides the abundant amounts of cheap meat that we now consume, is at the root of another impending public health crisis: climate change. The livestock industry accounts for 14.5% of human-induced global green house gas emissions (GHG), similar to those produced by the entire transport system, with feed production and processing and methane produced by the digestive process of ruminant animals contributing 84% of this figure. In addition, the livestock industry is a major underlying cause of deforestation, biodiversity loss, water pollution, and soil erosion.

“It is predicted that by 2050, demand for meat and dairy will increase by 73% and 58% … as a result, antibiotic use in livestock is predicted to increase by 67% between 2010 and 2030”

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Globally, the period between 1990 and 2009 saw a 60% increase in the total amount of meat consumed. This has been accompanied by a dramatic shift away from small-scale outdoor farms with mixed feed and forage-based systems, to “concentrated animal feeding operations” where animals are raised intensively in indoor structures, and fed primarily cereal and soy. It is predicted that by 2050, demand for meat and dairy will increase by 73% and 58%, respectively, with growth predominantly occurring in developing countries. As a result, antibiotic use in livestock is predicted to increase by 67% between 2010 and 2030, with growth predominantly expected in developing nations.

On both grounds of preserving our antibiotics and preventing irreversible ecological degradation and further global warming, the message is clear: we need to reverse the trend of increasing meat production and consumption, and limit forms of livestock farming that are ultimately dangerous. None of this will be easy. But the UK, particularly with its medical, veterinary, agricultural and food science expertise can and should play a leading role in fostering the change and international cooperation that is required.

But our potential to make such a vital contribution to global health must begin at home. We can start by banning the treatment of groups of animals where there is no disease diagnosed and restricting further the use of the critically important antibiotics; changing our own farming practices to improve animal health and welfare; and starting a public dialogue about what it means to have a sustainable diet.

David McCoy

Professor of Global Public Health at Queen Mary's, University of London
David is a public health physician and academic, and former Director of Medact.

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