Reservoirs of Antimicrobial Resistance

20 Feb 2019 01:42 PM

The widespread use of antimicrobials, particularly antibiotics, has accelerated the spread of antimicrobial resistance (AMR) in microbes. A recent report by the Health and Social Care Committee called for AMR to be a ‘top five policy priority’. This POSTnote evaluates the main reservoirs of AMR microbes arising from the use of antimicrobials in both humans and animals.

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Resistance to antimicrobials is a natural phenomenon but is exacerbated by their inappropriate use in human and animal medicine. Antimicrobial resistance (AMR) becomes a public health concern when disease-causing organisms evolve ways to survive treatments. This is a particular concern with antibiotics. AMR is present in humans, animals and the environment, with evidence of transfer between these ‘reservoirs’. Current surveillance data on AMR are not coordinated across reservoirs to the extent needed to inform more targeted interventions, beyond simply reducing antibiotic use. A strengthened joined-up ‘One Health’ approach across human health, agrifood and environmental sectors is central to the Government's new action plan for AMR 2019-2024.

Key points

• Antimicrobial resistance (AMR) is a natural phenomenon but the spread of antimicrobial resistance is exacerbated by the widespread, and sometimes inappropriate, use of antimicrobials in both human and veterinary medicine.
• Antimicrobial resistance arises when disease-causing organisms evolve to become resistant and survive the medicines used to treat them. This is a particular concern with antibiotics, on which we are heavily reliant to reduce the risk of infection associated with treatments such as organ transplantation and cancer chemotherapy, and even routine operations such as caesarean sections and hip replacements. 
• Antibiotic resistance is a global problem. Infections caused by drug-resistant bacteria have an increased risk of severe outcomes and patient death, and place a higher burden on health-care resources than non-resistant strains of the same bacteria. 
• Some bacterial infections are becoming untreatable. Treatment failure to the medicine of last resort for gonorrhoea has been confirmed in at least 10 countries, including the United Kingdom. Several countries have also reported resistance to the last resort treatment of life-threatening infections caused by Enterobacteriaceae.
• Antimicrobial resistant-microbes are found in humans, animals and the environment, so each can be considered as a ‘reservoir’ of antimicrobial resistance. These resistant-microbes can transfer within and between each of the reservoirs, for example through person-to-person contact, spreading of manure onto fields, the preparation and consumption of food. 
• Many interconnected factors drive the spread of antimicrobial resistance, which makes it a complex problem to tackle. The new UK 5-year national action plan to tackle AMR makes a commitment to ‘explore how to coordinate and harmonise surveillance schemes across the different sectors (human, animal, food and environment), taking a One-Health approach to provide a more complete picture of antimicrobial use and AMR that will enable analysis of trends over time and across sectors.

Acknowledgements

POSTnotes are based on literature reviews and interviews with a range of stakeholders, and are externally peer reviewed. POST would like to thank interviewees and peer reviewers for kindly giving up their time during the preparation of this briefing, including:

• OH-STAR - One Health Selection and Transmission of Antimicrobial Resistance project
• NAMRIP - Network for Anti-Microbial Resistance and Infection Prevention
• NOAH - National Office of Animal Health*
• BVA - British Veterinary Association
• Quadram Institute Bioscience* 
• VMD - Veterinary Medicines Directorate*
• APHA - Animal and Plant Health Agency 
• NPA - National Pig Association*
• Dr Chris Brown, SfAM - Society for Applied Microbiology
• Professor Willem van Schaik, Institute of Microbiology and Infection, University of Birmingham*
• Dr Emily Rousham, Centre for Global Health and Human Development, Loughborough University
• Dr Liam Shaw, Nuffield Department of Clinical Medicine, University of Oxford
• Nichola Naylor, Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine (LSHTM)*
• Dr Andrew Edwards, Department of Medicine, Imperial College London
• Professor Roberto La Ragione, Head of Department of Pathology and Infectious Diseases, University of Surrey*
• Dr Jessica Boname, Programme Manager for Antimicrobial Resistance, MRC – Medical Research Council*
• Professor William Gaze, European Centre for Environment and Human Health, University of Exeter Medical school* 
• Professor Jodi Lindsay, Institute of Infection and Immunity, St George's, University of London
• Dr Barbara Haesler, Veterinary Epidemiology, Economics and Public Health, The Royal Veterinary College*
• Dr Lisa Boden, Global Academy of Agriculture and Food Security, The University of Edinburgh*
• The Professor Lord Trees, House of Lords*
• Dr Gabrielle Laing, Veterinary Parliamentary Intern to the Professor Lord Trees
• Sir Patrick Vallance, Government Chief Scientific Adviser*
• Sir Bernard Silverman FRS, board member, Parliamentary Office of Science and Technology (POST)*

*Denotes those who acted as external reviewers of the briefing.