bovine tb - bva parliamentary briefing
TRANSCRIPT
Bovine TBBVA Parliamentary briefing
Tuesday 27 October 2015
Sean Wensley BVSc MSc Grad DMS MRCVS BVA President
John Blackwell BVSc MRCVS
BVA Senior Vice-President
Overview
• Bovine TB: what is the problem?• How bTB spreads• Controls:
• cattle• badgers• other species• Government approaches across the UK
• BVA position• Questions
What is bovine TB?
• A complex infectious zoonotic disease of animals and humans
• Caused by the bacterium Mycobacterium bovis
• Maintenance hosts: cattle, badgers• Spillover hosts: various mammals inc humans,
deer, camelids, goats, pigs, dogs, cats
• Direct effects on cattle • Production efficiency
• Indirect effects of disease• Business viability in face of control measures• Trade within and beyond the European
Union
What is the problem?
bTB: the problem
All herds tested
3y Scot & Wal, 2y Eng
M bovis tuberculin replaces M tuberculosis
4 yr testing
FMD
120,000 herds 80,000 herds
Badgers Act 1973
bTB: the problem
bTB: the problem
Regions of England• High Risk Area (HRA)• Edge Area (EA)• Low Risk Area (LRA)
How does bTB spread?The Randomised Badger Culling Trial report (2007) established:•that badgers “contribute significantly to the disease in cattle” and •that “cattle-to-cattle transmission is also very important in high incidence areas and is the main cause of disease spread to new areas”.
How does bTB spread?
• Transmission• Cattle to cattle
• Badger to cattle (& vice versa)
• Translocation• Locally
• Greater distance
• Amplification
Spoligotype translocation
Post FMD 2001
How does bTB spread?Critical control points
• Translocation• Transmission• Amplification
• Transmission• Amplification
Controls in cattleTB Testing•Routine•Pre-movement•Post-movement
Risk based trading
Surveillance
Biosecurity
Farm Health
Planning
Questions around TB testing
• Accuracy of the test• Frequency• Quality assurance
Controls in cattle• Cattle vaccination?
• BCG (vaccine) does not fully protect any species• Differentiating Infected from Vaccinated Animals
(DIVA) test is not yet validated• Currently illegal in EU
European Commission (2013): “Possible EU rules on vaccinated animals… to enter intra-Union trade…. [2023]”
Controls in badgers
• Biosecurity• Culling• Vaccination• Other?
Badger control: Culling
• Randomised Badger Culling Trial (1998-2006)• Proactive culling of badgers reduces the incidence
of bTB in cattle herds• Net benefit 4.5 years post culling = 16% (Key
conclusions from a meeting of scientific experts held at Defra on 4th April 2011)
Badger control: Vaccination• Injectable BCG• Not proven to protect from infection• Reduces the severity of the disease in infected
animals• Test to differentiate is unreliable • No evidence of impact on bTB in cattle• Oral vaccine?
Badger control: OtherResearch:•Contraception•Oral vaccine•Humane whole sett culling methods•Trap- and sett-side diagnostics
Control in other species
• Spillover hosts, eg:• Deer• Camelids (llamas and alpacas)• Goats• Pigs• Dogs• Cats
• Control measures inc biosecurity, testing, notification, and compulsory slaughter
A comprehensive approachTB Testing•Routine•Pre-movement•Post-movement
Risk based trading
SurveillanceBiosecurity
Farm Health Planning
Vaccination
Culling•Targeted•Humane
Research•Cattle vaccine•Oral badger vaccine•Badger contraception•Improved diagnostics
Policy approaches across the UK:England
Regionalisation• High Risk Area (HRA)• Edge Area (EA)• Low Risk Area (LRA)
Policy approaches across the UK:England
Cattle controls•High risk = Annual herd testing•Edge = Annual herd testing•Low risk = Four yearly testing•High & edge = Routine pre-movement tests•Post-movement tests•Targeted use of interferon-gamma assay (IFN-γ)•Defra consultation on increased cattle controls (Oct 2015)
Badger controls•Two pilot cull areas (from 2013) to test method of culling•Independent Expert Group assessment of safety, efficacy and humaneness•New cull area in Dorset (from 2015)•Badger Vaccine Deployment Project to test deliverability
Policy approaches across the UKScotland•Officially tuberculosis free
• Decision Sept 2009
• Implementation Feb 2010
•Risk-based testing
Wales•“Intensive Action Area”•Badger vaccination deployment•Cattle testing: Check Test Wales
NI•Separate epidemiological unit•Cattle testing•Modelling a “TVR” policy = Test and vaccinate or remove badgers
BVA position: the ethics of cullingEthical review process•Ethically justifiable?•Scientific basis?•Feasible and deliverable?•Exit strategy?•Area of cull?•Cost benefit analysis?•Ecological impact?Ethical framework – the 3 Rs (reduce, refine, replace)
Targeted, effective and humane
BVA position: Badger culling• We support badger culling as part of a comprehensive
strategy provided it is targeted, effective and humane
• We have withdrawn support for the use of controlled shooting BUT acknowledge there are different views with the veterinary profession
• We have called for the wider roll-out of culling using cage trapping and shooting only, in carefully selected areas
BVA position: A comprehensive approach
TB Testing•Routine•Pre-movement•Post-movement
Risk based trading
SurveillanceBiosecurity
Farm Health Planning
Vaccination
Culling•Targeted•Humane
Research•Cattle vaccine•Oral badger vaccine•Badger contraception•Improved diagnostics
