Disease challenges and AMR-free dairying @AMRForce @davidbarrettvet Prof David Barrett BSc(Hons) BVSc(Hons) DBR DCHP Dip. ECBHM FHEA FRCVS Professor of Bovine Medicine, Production and Reproduction, University of Bristol President of the British Cattle Veterinary Association Member of the RUMA Scientific Advisory Group Board Member of the British Society for Antimicrobial Chemotherapy / Antibiotic Action RCVS Recognised Specialist in Cattle Health and Production European Veterinary Specialist in Bovine Health Management
Emerging disease threats Diseases present in the UK Schmallenberg Psoroptic mange Summer scour syndrome Embolic pneumonia udder cleft dermatitis Exotic disease FMD Bluetongue Besnoitiosis (Besnoitia besnoiti) Many others!
Emerging disease threats Expect the unexpected BSE! Schmallenberg (Tritrichomonas) Endemic diseases remain our greatest threat take your pick! Mastitis, lameness, (infertility), BRD, Parasites, BVDV, TB, Johnes, Mycoplasma bovis
Surveillance https://assets.publishing.service.gov.uk/government/uploads/system/uploa ds/attachment_data/file/755515/bovine-tb-review-2018.pdf https://assets.publishing.service.gov.uk/government/uploads/system/uploa ds/attachment_data/file/717210/pub-survrep-c0118.pdf
Mycoplasma bovis GB data, Mycoplasma bovis as a % of diagnosable submission (Q1 2018) bars indicate 95% confidence limits
What is udder cleft dermatitis (UCD)? A condition that affects the skin cranial to the udder on the ventral body wall. Also known as: ulcerative mammary dermatitis foul udder udder rot or intertrigo Recognised in many countries for a number of years and is sporadically seen by farmers and cattle veterinarians.
Associated problems Non-production limiting Foul smelling Painful welfare implications Reported possible sequalae include: Abscessation and rupture of adjacent milk vein Clinical mastitis in adjacent quarters
Hypothesised causes or risk factors Spirochete bacteria Treponema Fusobacterium necrophorum (opportunistic bacteria) Sarcoptic mange Udder conformation Udder oedema
Other cases: Further 5 similar cases submitted to Langford pathology service from other farms Other similar cases have been reported from other post mortem facilities across the UK First 2 cases published ref: TURNER, A., WOOD, S. & MILLAR, M. (2017) Two cases of embolic pneumonia associated with udder cleft dermatitis in dairy cattle from the same farm. Veterinary Record Case Reports
Conclusions Septic emboli increasingly recognised as being associated with UCD lesions (UK) Increased awareness earlier detection and novel detection / monitoring methods Earlier intervention & appropriate diagnosis and prognosis
Uncertain changes Brexit other changes to the political environment Possible increased disease risk of international trade outside the EU Opportunities for alternate disease control measures? Changing farming practices funding of public good New technology diagnostics, data management, movement data, treatment data, genomics, understanding the microbiome. Climate and environment changes / impacts Veterinary medicine policies veterinary services need to change
Antimicrobial resistance (AMR) What is AMR? Who is AMR likely to affect? How big is the problem we face? What are the main drivers for AMR worldwide? What proportion of the problem is caused by veterinary antibiotic use? Can we have AMR-free dairying? What can we do now to improve the situation?
Antimicrobial resistance is resistance of a microorganism to an antimicrobial that was originally effective for treatment of infections caused by it. WHO
14 Penicillin Alexander Fleming
The evolution of resistant strains is a natural phenomenon that occurs when microorganisms replicate themselves erroneously or when resistant traits are exchanged between them. The use and misuse of antimicrobial drugs accelerates the emergence of drug-resistant strains. Poor infection control practices, inadequate sanitary conditions and inappropriate food-handling encourage the further spread of antimicrobial resistance. WHO
Importance of HP-CIAs The Responsible Use of Medicines in Agriculture (RUMA) Alliance has decided to use the European Medicines Agency (EMA) list of critically important antibiotics (CIAs) setting out which antibiotic groups should only be used in livestock when no other product will be effective. https://veterinaryrecord.bmj.com/content/180/22/532.1
Importance of HP-CIAs Highest Priority Critically Important Antimicrobials Last resort for human treatments where nothing else is effective Which ones are included? Fluoroquinolones Third- and fourth-generation cephalosporins Colistin
The Development of Antibiotics 18 Quinolones Carbapenems Colistin www.nature.com
Which products?
Current trends
Current trends: Sales data HP-CIA s
Current trends: Sales data HP-CIA s
Current trends: Usage data HP-CIA Cattle No 3 rd generation cephalosporin or fluoroquinolone resistance was detected in Salmonella from cattle in 2017 Escherichia coli mainly from calves may show resistance (11% to fluoroquinolones and up to 14% to 3 rd generation cephalosporin)
Set targets
Dairy sector targets Baseline Targets % Subject Figure 2020 Change 1 HP-CIA injectables (mg/pcu) 1.075* 0.538-50% 2 HP-CIA intra-mammary use (DCDVet) 0.332* 0.166-50% Intra-mammary tubes dry cow 3 (DCDVet) 0.842* 0.674-20% Intra-mammary tubes lactating cow 4 (DCDVet) 0.808* 0.727-10% Sealant tube usage (average number of 5 courses per dairy cow) 0.5* 0.7 +40% 6 Total usage (mg/pcu) 26.2** 21.0-20% * Measured using 2015 UK sales data **Measured using FarmVet Systems survey
BCVA statement 2017 BCVA is recommending minimal use of the third and fourth generation cephalosporins, fluoroquinolones and colistin. These drugs should only be used where they have been demonstrated by sensitivity testing to be the only suitable choice to avoid unnecessary suffering. BCVA is recommending that prophylactic use of antibiotics is to be avoided wherever possible without compromising animal welfare. Where it is used it should be regarded as an interim measure whilst alternative management and/or vaccination strategies are implemented.
2010-11: ~ 35% LCTs involved CIAs (~10%mgs) 2015: 0% of LCTs involved CIAs (<0%mgs)
82% reduction in the total use of CIAs 91% reduction in systemic use of CIAs 100% reduction in intramammary use of CIAs No perceived or actual reduction in treatment outcomes or farm animal health
Turner et al. (2018) http://dx.doi.org/10.1136/vr.104702
Turner et al. (2018) http://dx.doi.org/10.1136/vr.104702
Summary of one farm: current data 225 cows 3x milking 305-day yield 11,709 kg / cow (36 kg / cow / day) the yield was less than 10,000 at the start of 2016 Calving to conception interval 84 days, age at first calving 722 days. Bulk milk SCC currently 70,000 cells / ml (rolling average for year c 100,000), 6% cows over >200,000 Lameness 2.5% of herd score 2 and 3
Cow calculated courses per 100 cows Data sample Critically Important Antibiotics - Courses per 100 cows on each Farm 140 124 120 100 80 60 Best 25% of herds use <4 CCC per 100 cows 40 20 3.5 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 Farm Number
Lessons learned It is possible to achieve a total cessation of the use of protected antimicrobials whilst Working with farmers Continuing to improve animal health and welfare and without the need for legislation! The use of CIAs as first line treatments cannot be justified
35 The OH-STAR Project 1.5M to evaluate AMR E. coli in the farm environment and transmission links to humans (dogs, human urinary tract infections) Drivers of AMR and acquisition 80 dairy farms Monitor changing antimicrobial use and track resistance Antimicrobial Resistance Cross Council Initiative supported by the seven research councils
The OH-STAR Project 36 What are the risk factors for AMR E. coli in dairy cows? Do dogs pick up AMR E. coli from the nearfarm environment? Is there a link to human UTIs caused by AMR E. coli? Antimicrobial Resistance Cross Council Initiative supported by the seven research councils
No significant overlap between resistant E. coli in humans and animals in the OH-STAR area 37
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40 Antibiotic dosing has long term effects Ashley Bryce et al. BMJ 2016;352:bmj.i939
41 The driving force behind antibiotic resistance is antibiotic use.
A personal view Unless a veterinary surgeon can clearly demonstrate the only available effective treatment is a HP-CIA they should not be prescribing them. Many practices no longer even hold them in their pharmacies. Has anyone isolated a pathogen that is only sensitive to a HP-CIA and for which no other treatment option is available? The UK cattle industry should be (virtually) HP-CIA free by 2020 we all have a part to play in achieving this.
Acknowledgements 43 University of Bristol, Diagnostic and clinical services Mick Millar, Andrea Turner, Julie MacFarlane, Sarah Wood, Gus Paixao, Heather Marie Niman, Bristol veterinary students University of Bristol, AMR Force research group Matthew Avison, Kristen Reyher, Katy Turner, Tristan Cogan, Andrea Turner, Severine Tasker, Hannah Schubert, Emma Wright, Ginny Gould, Katy Morley, David Tisdall (University of Surrey), all the other practitioners, farmers and others that support our research effort @thebcva @AMRForce @davidbarrettvet