Memorandum submitted by the Department
for Environment, Food and Rural Affairs
PROGRESS ON CONSIDERING SOLUTIONS TO THE
PROBLEM OF BOVINE TB, INCLUDING PROGRESS MADE TOWARDS DEVELOPING
A VACCINE, THE EXPERIENCE OF IRELAND AND THE ROLE PLAYED BY TRACE
ELEMENTS
1. This report gives an update on progress
on the Government's five-point plan for dealing with bovine tuberculosis
since EFRAC's 7th Report of Session 2002-03 on Badgers and Bovine
TB, published on 9 April 2003. The Government's reply to the Committee's
report was published on 24 June 2003.
2. Ben Bradshaw provided oral evidence to
the main EFRA Committee on 10 December 2003, focussing on the
suspension of the reactive cull element of the badger culling
trial.
3. This submission has been agreed with
the Devolved Administrations.
INTRODUCTION
4. In February 2003 the Secretary of State
announced a review of GB policy on TB. This is an opportunity
to ensure Government's approach on bovine TB is consistent with
the Strategy for Sustainable Farming and Food and the Animal Health
and Welfare Strategy. Government spent £75 million on bovine
TB controls across GB, including research, in 2002-03 and remains
committed to finding a sustainable way forward on bovine TB, based
on best available evidence. Provisional outturn for 2003-04 is
£88 million. A breakdown of expenditure is at Annex A.
5. Defra published on 9 February 2004 a
consultation document that represented the outcome of the first
stage of the review of the TB strategy. Separate but parallel
consultations have been issued in Scotland and Wales.
6. The consultation closes on 4 June, having
been extended by 1 month to allow stakeholders to take into account
the recommendations of the Independent Scientific Review of the
Randomised Badger Culling Trial and associated epidemiological
research that was published on 6 April.
7. A robust, fair and cost-effective settlement
on bovine TB is required, one that sets out where Government and
stakeholders hope to be in 10 years time and reconciles the contending
perspectives of stakeholder groups. Achieving everybody's aspirations
is unlikely. Challenging but realistic targets and indicators
of success need to be developed which recognise the regional distribution
of the disease and scientific uncertainty around the effectiveness
of TB control tools including wildlife interventions. The consultation
document asks questions covering all of these issues.
8. Defra is also committed to action in
the short term to address some of the immediate problems of bovine
TB. A number of policy options were set out in Defra's submission
to EFRAC on 24 February 2003 (see Annex B) and progress is reported
below. The remainder are set out in the consultation document
as proposals for action to:
— Reduce the risk of spreading TB from
high to low incidence areas through cattle movements;
— Ensure early detection and prevention
of developing TB hotspots;
— Increase efficiency and transparency
of TB surveillance and alignment with EU Directive 64/432/EC.
9. A key proposal is the introduction of
a legal requirement for the pre-movement testing of cattle moving
from one and two year tested herds to other herds, for which farmers
will pay. Government for some time has advised this as best practice.
10. The written consultation has been complemented
with regional meetings to discuss the issues raised with a wide
range of stakeholders. After closure of the consultation Government
will work to implement the short-term measures as soon as is practicable,
and develop draft proposals for the longer term.
PROGRESS UNDER
THE FIVE-POINT
PLAN
Protecting human health
11. Public health protection measures (ie
pasteurisation of milk and post-mortem inspection of carcases)
continue. The threat to public health remains low and the disease
is treatable. The Government is not complacent however and continues
to work in liaison with the Department of Health to monitor the
situation.
Continued regular testing of cattle herds for
TB and slaughter of suspect animals, and where possible strengthening
of these controls
12. There have been a number of developments
since Defra's last written submission to EFRAC in early 2003:
— With the co-operation of Local Veterinary
Inspectors and farmers, the number of overdue TB herd tests built
up during the Foot and Mouth Disease (FMD) outbreak in 2001 has
been reduced to pre-FMD levels. There were nearly 27,000 overdue
tests at the end of 2001. This had been reduced to 7,000 at the
beginning of 2003 and now stands at under 4,000.
— Automatic restrictions were imposed
on herds with TB tests overdue by more than three months from
the start of October 2003, to reduce the risk of spreading bovine
TB. This has acted as a powerful incentive for farmers to get
tests done promptly. At the end of March 2004 84% of overdue herd
tests were less than three months overdue.
— Mycobacterial culture capacity at
the Veterinary Laboratories Agency has been trebled. By the end
of 2003 the additional culture facilities had resulted in the
elimination of the backlog of bovine tissue samples awaiting culture.
— A field pilot of the gamma-interferon
blood test, begun in autumn 2002, has continued. The pilot was
set up to determine whether the gamma-interferon test, used in
tandem with the skin test, significantly improves the detection
of infected cattle and shortens the duration of confirmed TB incidents.
Up to the end of April, 108 herds had been recruited into the
pilot. Consideration is being given to ways to improve recruitment.
In addition, since November 2003 the State Veterinary Service
has allowed ad-hoc gamma-interferon testing in specific situations.
Details are at Annex C.
— General movement licences were introduced
in October 2003 for clear testing cattle destined for slaughter
from herds under TB restrictions, significantly streamlining procedures
and reducing paperwork.
— In spring 2004, research carried
out by Reading University into the economic impacts of bovine
TB and alternative control policies, showed whilst most farmers
suffered a loss due to TB some farms (20% of dairy, 35% of beef
herds surveyed) made a net gain from the breakdown. Net losses
ranged from £37 to £17,021.
— A survey of badgers (killed in road
traffic accidents) and deer (culled or found dead) in South West
Cumbria was announced in December 2003. The objective of the survey
is to determine whether or not there are badgers and deer infected
with TB in this part of Cumbria. The results of the survey will
be used along with the results of two cycles of cattle testing
at six- to 12-month intervals, to determine the future herd testing
frequency in the area.
13. The following developments describe
progress on a number of the short-term policy options flagged
to EFRAC in February 2003. The remainder are being taken forward
as part of the current TB consultation (see para 10):
— Increasing the pool of people trained
to test for TB has been taken forward in the consultation on a
proposal to introduce an Exemption Order, under the Veterinary
Surgeons Act 1966, to permit suitably trained and competent non-veterinarians
to administer the tuberculin skin test, read and record the results.
Consideration is now being given to how best to proceed.
— A National Audit Office report on
TB compensation in Wales was published in 2003 which noted that
compensation payments in 2002 were on average 50% higher, and
in some cases over 100% above the underlying market price. An
internal Defra audit in summer 2003 similarly found that TB valuations
appeared to be significantly higher than market prices. A number
of changes have been introduced to help ensure valuations are
a fair reflection of market price, including improved data handling
procedures, provision of market price information to valuers to
act as a benchmark for valuations, and a letter to valuers reminding
them of the conditions under which valuations should be carried
out. In October 2003 Defra consulted on proposals to rationalise
compensation for animals slaughtered for all notifiable disease
including TB. The aim is to strike a balance between practical
disease control and responsiveness to individual circumstances.
It is hoped that reviewing the compensation procedures will help
speed up removal of reactor cattle from farms. This was flagged
to EFRAC as one of the short-term policy options in February 2003.
Next steps are being considered.
— On-farm management to reduce TB risk
to cattle was another of the options identified. Under the Animal
Health and Welfare Strategy, Defra is working closely with Devolved
Administrations and interested parties, particularly vets and
the different livestock sectors, to take forward a number of initiatives
to promote farm health planning and improve training and advice.
— The State Veterinary Service (SVS)
is developing improved guidance, training and contractual arrangements
for Local Veterinary Inspectors, including TB testers, and enhancing
its quality assurance procedures. The timing of implementation
is dependent on negotiation with the British Veterinary Association.
— The SVS has also developed an IT
system for Veterinary e-Business (VeBus). This allows Local Veterinary
Inspectors and SVS staff to receive worklists and submit completed
forms electronically. Full rollout is scheduled to be completed
by October 2003.
— The SVS Business Reform Programme
is re-engineering business processes and improving the delivery
of field services between 2004 and 2008. TB is the primary focus
and initial efficiency gains will be implemented in 2004 through
improved data handling.
Research to develop an M.bovis vaccine
14. The timetable for producing an effective
vaccine against bovine tuberculosis remains broadly in line with
that set out in the Krebs Report.
15. In January 2002, the Independent Scientific
Group on Cattle TB established a Vaccine Scoping Study Sub-Committee
(VSSSC) to advise Defra Ministers on whether a TB vaccination
strategy for either cattle or wildlife would be feasible. The
VSSSC reported to Ministers in July 2003 (published December 2003).
This advised on research requirements, but cautioned that a vaccine
(for cattle or badgers) remains a long-term policy option. Many
obstacles still have to be overcome.
16. An Inter-Departmental Vaccine Steering
Group, chaired by the Chief Veterinary Officer, is working to
identify administrative and legal procedures to allow a potential
vaccine to be authorised for use in both badgers and cattle. A
new Vaccine Programme Advisory Group (following on from the VSSSC)
provides advice on the science needed to progress towards a vaccine
for use in the field.
17. The Vaccine Advisory Group has recommended
developing options for a field experiment using BCG in badgers
and a series of transmission and vaccination studies (BCG and
heterologous prime boost) in cattle. The Vaccine Steering Group
has agreed in principle that these proposals should be investigated
further.
18. In 2002-03, Defra spent £1.5 million
on vaccine research. Exploiting the sequencing of the M.bovis
genome has led to the development of a test that distinguishes
between vaccinated and infected cattle for experimental use. However,
more work is needed before the test can be used for wide scale
application in the event that a vaccine based on BCG is introduced.
48 possible vaccine candidates have been tested in small animal
models. These include two live attenuated M. bovis vaccines, subunit
recombinant protein and DNA vaccines. Concurrent work to determine
the best adjuvant/vaccine combination for use in cattle is in
place. Diagnostic reagents and vaccines are being tested in collaboration
with New Zealand as well as in the UK.
19. Researchers at the Veterinary Laboratories
Agency are collaborating with the Republic of Ireland in conducting
challenge studies using BCG in badgers.
20. A review of the ecological implications
of a vaccination strategy for badgers covering the various aspects
of badger ecology that must be considered has been published.
21. At the end of April 2004 a workshop
was held with the animal pharmaceutical industry to discuss how
Defra, working in partnership with industry, might take BCG vaccine
forward for use in badgers. The aim of the workshop was to identify
the most suitable plan for complying with the many regulatory
obstacles for use of a vaccine in the field.
Other research to improve knowledge of the disease
and its transmission to and between cattle and other species
22. The Committee will consider the possible
role of trace elements. There is anecdotal evidence that trace
element deficiencies in soils are related to susceptibility to
tuberculosis in cattle. At present this link is scientifically
unproven. The ISG have not dismissed the possibility of a nutritional
link. However, they have advised that given the available resources,
and the difficulty in devising informative experimental protocols,
this area of research should be given low priority. Preliminary
data from the TB99 survey may help to shed some light on nutritional
issues.
23. There have been a number of recent developments
in the wide-ranging research programme supported by Defra (full
details of which are on Defra's website):
— Studies on the virulence and pathogenesis
of M.bovis have found that certain strains are found in
specific geographic locations. Different molecular typing methods
are currently being evaluated to better understand the development
of different M.bovis strains in the UK. Additionally a
Polymerase Chain Reaction (PCR) detection system for M.bovis
has been developed that could be used as part of the routine strain
identification process.
— Recently published work highlights
that the use of farm buildings and cattle troughs by badgers can
constitute a TB risk to cattle. A study of possible badger/cattle
interactions and how cattle husbandry methods may limit these
is underway.
— Other work looks at the effects of
removing badgers from an ecosystem, both in terms of the possible
perturbation effects on the local badger population and the effect
of removing badgers on the wider ecosystem and associated species.
Nearing completion are two research projects investigating the
risk to cattle from wildlife species other than cattle in areas
of high herd breakdown risk.
— A cattle pathogenesis programme is
providing information on how TB develops in cattle and is looking
at cattle-cattle transmission. Results have shown that, in laboratory
conditions, the route of M.bovis challenge has implications
for the shedding pattern of bacteria subsequently seen and that
some infected but skin test negative animals could be identified
that would not be detected by current tests. Work has shown that
the effect of repeated skin testing prior to infection with M.bovis
does not invalidate the use of the skin test.
A BADGER CULLING
TRIAL TO
TEST THE
EFFECTIVENESS OF
BADGER CULLING
IN REDUCING
TB IN CATTLE
Randomised Badger Culling Trial (RBCT)
24. All 10 triplets were enrolled into the
Randomised Badger Culling Trial (RBCT) by the end of 2002. All
10 proactive areas have been culled at least twice and culling
had taken place in all but one of the reactive areas before the
suspension of operations in November last year.
25. Ministers suspended culling operations
in reactive areas on 4 November 2003 following advice from the
Independent Scientific Group on Cattle TB (ISG) that their latest
interim analysis, of data collected up to the end of August 2003,
indicated that, after appropriate statistical adjustments, the
incidence of herd breakdowns in reactively culled areas was consistently
greater than expected. This increase, compared with the survey
only areas, was estimated by the ISG to be 27%, with 95% confidence
that the increase lay between 4.8% and 53%. A more conservative
analysis would give confidence limits of between a 2.4% decrease
and a 65% increase. The ISG's most recent analysis of data collected
to mid-February 2004 indicated an increase of 28% with confidence
limits of between 1.1% and 62% using the wider confidence limits
recommended by the Independent Review panel.
26. Following the suspension of culling
in reactive areas, the ISG considered whether to convert some
of the reactive areas to proactive areas. They advised that data
on cattle breakdowns in at least six reactive areas should continue
to be collected and analysed, along with data from the proactive
and survey only areas, at six monthly intervals. Proactive data
from the remaining areas would add little value to the dataset,
as there would be insufficient time to see an effect in these
areas before the end of the trial; the resource could be better
used to carry out culling operations in the existing proactive
areas at the most advantageous times of the year.
TB99 Epidemiological Survey
27. The first analysis, of data collected
from the survey before the FMD outbreak, has been completed. A
report on this is expected very shortly. An analysis of more recent
data collected is ongoing.
28. The structure of the TB99 questionnaire
is being revised for 2005, to focus on those aspects which, from
the analyses undertaken so far, seem to be the most significant.
The revised form will also be shorter and easier to complete in
the field. Additional data sources, such as the Cattle Tracing
System, will be used to remove time consuming parts of the questionnaire
and standardise the data collected across the study area. In the
meantime, collection of TB99 data during 2004 is focussed on the
completion of 100 datasets, each comprising a case and three controls
(if available), across three of the 10 triplets.
Road Traffic Accident (RTA) Survey
29. At 31 March 2004, 1,744 carcases had
been collected from the seven counties covered by the survey (Cornwall,
Devon, Dorset, Gloucestershire, Worcestershire, Herefordshire
and Shropshire). An analysis of the results from the post-mortems
of these is underway and will be finalised shortly.
Independent Scientific Review of the Randomised
Badger Culling Trial and associated epidemiological research
30. As part of a wider review of Defra Science,
Elliot Morley announced in April the 2003 establishment of an
independent scientific panel to review the randomised badger culling
trial and related research. This work is being overseen by the
ISG, which has been providing guidance and monitoring the RBCT
since its establishment in 1998.
31. The Review was chaired by Professor
Charles Godfray FRS, director of the Natural Environment Research
Council's Centre for Population Biology at Imperial College London.
The panel comprised experts from the fields of veterinary and
wildlife population epidemiology, applied statistics and population
biology. Their report, the ISG's response and comments from Professor
Mollison, the statistical auditor of the RBCT, were published
on 6 April 2004.
32. The review's conclusions will inform
Defra's wider review of TB strategy. The recommendations are complex
and have potentially far reaching consequences for TB policy.
There are also areas of disagreement between the Review Group
and the ISG. This often occurs when challenging science is being
undertaken and Defra will be considering carefully how to move
forward.
The "four area" badger culling trial
in the Republic of Ireland
33. The results of the "four area trial"
in the Republic of Ireland have not yet been published. We will
look closely at the methods and results once published to establish
what we can learn and apply in GB.
Department for Environment, Food and Rural Affairs
May 2004
Annex A
BREAKDOWN OF GOVERNMENT EXPENDITURE IN GREAT
BRITAIN ON BOVINE TB
(£ million)
Activity
| Outturn
1999-2000 | Outturn
2000-01
| Outturn
2001-02 | Outturn
2002-03
| Provisional
2003-04 |
Cattle Testing | 17.6
| 13.3 | 5.4 | 24.7
| 33.0 |
| Compensation | 5.3 | 6.6
| 9.2 | 31.9 | 33.3
|
| Culling Trial | 4.6 | 6.6
| 6.0 | 6.5 | 8.5
|
| Other Research | 3.8 | 5.3
| 6.1 | 6.8 | 7.1
|
| Veterinary Laboratory Agency | 2.4
| 3.5 | 3.7 | 4.1
| 5.3 |
| Headquarters/Overheads | 4.5 |
0.9 | 0.1 | 0.7 |
1.0 |
Totals | 38.2 |
36.2 | 30.5 | 74.7
| 88.2 |
| |
| | | |
Annex B
THE SHORT-TERM POLICY OPTIONS FLAGGED TO EFRAC IN FEBRUARY
2003
The 10 options were:
— clearer implementation of EU legislative requirements;
— a review of test frequencies to ensure compliance
with the EU;
— tailoring TB controls according to TB risk by
area and/or herd health history;
— the introduction of pre-movement testing;
— requiring on-farm management action to reduce
TB risk to cattle;
— review to identify possible need for test frequencies
above the EU requirements in certain areas;
— improvements in delivery of TB controls which
might be made through the development of a new relationship between
the State Veterinary Service and Local Veterinary Inspectors;
— increasing the pool of people trained to test
for TB and available to deliver testing;
— streamlining service delivery processes within
the SVS in order to improve efficiency and reduce administrative
delays; and
— speeding up removal off farms of cattle that react
to the tuberculin test.
Annex C
AD-HOC USE OF THE GAMMA-INTERFERON TEST
In addition to the gamma-interferon field pilot, since November
2003 the State Veterinary Service (SVS) has conducted ad hoc gamma-interferon
testing in specific situations, namely:
— as an aid to decision making in relation to whole
or partial herd slaughter in severe TB breakdowns;
— as a "parallel" (ie adjunct) test for
non-reactor cattle in ongoing, confirmed TB incidents that do
not qualify for the field trial, but have a chronic TB problem;
and
— as a "serial" (ie confirmatory) test,
to resolve skin test reactors or inconclusive reactors in prolonged
unconfirmed TB incidents within low TB prevalence areas, where
there is a suspicion of non-specific reactivity to the skin test.
In the first two instances, the blood test is used to enhance
the overall sensitivity of TB testing. In the third, the blood
test complements the skin test results to achieve better specificity.
In 2003, almost 1,000 cattle in 12 non-trial herds in England
(6), Wales (5) and Scotland (1) were gamma-interferon tested by
the SVS under one of the three scenarios described above.
Department for Environment, Food and Rural Affairs
May 2004
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