by Steve Hinchliffe
The emergence and transmission of microbes that are resistant to available medicines are major threats to medical practice and public health. The use of antibiotics and other antimicrobial treatments in food production adds to the risks of resistance. Food and farming account for the majority of the world’s consumption of those products.
Producing food in ponds and coastal waters, or aquaculture, is the fastest growing food production sector worldwide. In many parts of the world, production relies on various treatments, including antibiotics. Pond conditions, the use of feed, detergents and fertilisers may provide an ideal setting for resistance to develop and spread.
In Bangladesh, aquaculture has contributed to improvements in nutrition levels and rural livelihoods. But widespread disease and falling profits threaten production. So how can farmers maintain and improve production without using antibiotics?
Earlier this year, we brought together farmers from various parts of Bangladesh, Government officials, NGOs and others from the shellfish and finfish value chain, along with people with expertise in biosciences, epidemiology, anthropology and geography to understand current disease challenges and assess possible strategies for change.
Forming a number of ‘competency groups’, participants considered all the materials and processes that make a pond work. The diagrams produced by each group were used to generate a composite ‘pond system’ model which included everything from seed to monsoon rains, the addition of feed to the role of local markets for produce.
Participants then considered the main sources and drivers of disease – from the unstable mud banks that are built up around the gher (former rice production fields), to the financial banks that offer little credit, farmers mapped out a wide range of social as well as biological risks. The lack of credit is one reason why farmers stock their ponds frequently, a practice that increases the risk of disease transfers.
After presentations from microbiologists and representatives from the United Nations Food and Agricultural Organisation (FAO), groups added resistance risks to their diagrams, such as:
- Antibiotics used in seed hatcheries are suspected of bringing resistant bacteria to the ponds
- Medicines that farmers use aren’t clearly labelled and may be difficult to understand or contain banned medicines
- Companies are keen to sell them new medicines
- Commercial feed is suspected of containing antimicrobial compounds, and locally made feed and fertilisers can contain poultry waste (in poultry production, antibiotics are used on a regular basis).
Participants ranked these and other risks and generated a collective model of disease and resistance risks.
The session ended with groups discussing possible actions. For example, would accredited seed improve production? The composite model, with its numerous disease pathways and stressors, suggested that disease could come from many sources.
Despite the added risks of transmission, farmers were reluctant to abandon frequent stocking practices, as these were a means of adapting to frequent disease risks – for the farmers, frequent stocking spreads the risk of crop failure.
Paradoxically, moving to best practice pond management, and single stocking, would make antimicrobial use more likely. Frequent stocking means that farmers can tolerate losses, whereas single stocking would increase the stakes and make farmers more likely to attempt to rescue stock with available treatments.
Eliminating a disease risk is therefore not always the best way to reduce resistance risks, and solutions are likely to come from further adaptations to these open pond systems. For example, along with better and more available seed, improved farmer clustering to share disease knowledge, and local acclimatisation ponds to help juvenile stock to adjust to local conditions, would improve production success.
These methods for generating shared or transdisciplinary understandings of practice are vital to improve rural livelihoods and food production without generating the need for more antimicrobial uses and increasing resistance risks.
Steve Hinchliffe is a Fellow of the Academy of Social Sciences and Professor of Geography and Deputy Director of the Wellcome Centre for Cultures and Environments of Health at the University of Exeter. He is author of the book Pathological Lives (Wiley), and sits on the UK Department of Environment, Food and Rural Affairs (DEFRA) Social Science Expert Group, and the Scientific Advisory Committee on Exotic Diseases.
This week (12-19 November 2018) is World Antibiotic Awareness Week.