Annex A
Note of a Meeting with Ben Bradshaw MP,
Minister for Local Environment, Marine and Animal Welfare, held
on Monday 24 April 2006
The meeting was held to enable an update and
discussion on current TB policy developments and on the ISG's
presently available scientific evidence. This note provides a
summary of the key points discussed.
In Attendance
| Ben Bradshaw MP |
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| Professor John Bourne | xxx, Defra
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| Professor Christl Donnelly | xxx, Defra
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| Dr Rosie Woodroffe | xxx, Defra
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| Mike Summerskill, ISG Secretary | PS/Ben Bradshaw
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Badger Culling Consultation
Professor Bourne confirmed the ISG's disappointment that
the consultation ignored much of their scientific evidence, and
that it did not fully reflect the ISG's representations made to
the Minister and his officials prior to publication. The ISG had
felt it painful but obligatory for them to subsequently write
to the Minister clarifying the scientific findings. The ISG commented
that aspects of the science need resolution, but they did not
believe that aspects of the proposals in the consultation were
either feasible or tenable. The Minister said he was content with
the way the consultation document presented the evidence, asking
the ISG to understand that any upset that may have been caused
was not intentional.
Professor Bourne asked the Minister to note that between
the mid 1970's and 1990's badger removal policies, based on extended
but localised badger culling over areas up to 10km2, had no impact
on the rising national trend of bovine TB incidence. Evidence
from the reactive element of the RBCT demonstrated that localised
culling benefited an individual farmer, but made no impact on
national trends and indeed made matters worse.
Professor Bourne confirmed that the RoI Four Areas Trial
has helped the ISG interpret its own data, despite differences
in the culling method, badger density, landscape and geography
and compliance. He said Thornbury could not be produced in a national
context, because it required prolonged culling by gassing over
a 7-year period, and was conducted in a geographically isolated
area, and asked the Minister to note that the RBCT results for
TB incidence within proactively culled areas were very similar
to those that emerged from the East Offaly trial.
Professor Bourne said that there was widespread scientific
agreement on the detrimental impacts of localised culling and
re-iterated the ISG's view that to be effective, a cull would
need to be delivered in a co-ordinated manner over a large area,
for a sustained period of time, and would need to be efficient.
Professor Bourne pointed out that badger removal in the RBCT had
been high and substantial, and that—acknowledging that this
was an extrapolation from British and Irish studies—the
ISG doubted if improved badger removal rates would reduce cattle
TB incidence appreciably more than the RBCT had achieved.
Perturbation, the Edge Effect and RBCT Efficiency
Professor Bourne said that the scientific community agreed
with the principle of the ISG's finding regarding perturbation.
This included the Royal Society and all of the independent scientists
who attended a January meeting with Howard Dalton, as well as
the EFRA Select Committee. Dr Woodroffe explained the hypothesis
for badger movements and perturbation related to culling, and
confirmed that if a drastic reduction in local badger population
was achieved in a culling area—more than the RBCT achieved—this
could further reduce the contact rate between badgers, and between
badgers and cattle, and that this might lead to an incremental
reduction in cattle TB incidence inside the culled area. However,
she cautioned that immigration of badgers was inevitable unless
the area to be culled was isolated by features such as major rivers,
roads, or coastline, and hence a detrimental edge effect, like
that seen in the RBCT, was to be expected.
In response to a question from the Minister about whether
it was possible to compare rates of badger removal between the
RBCT and other trials, particularly in RoI, Professor Bourne explained
that it is very difficult to give certainty on the exact removal
rates in any culling exercise. Professor Donnelly urged caution
in making direct comparisons between culling trials in different
countries because the underlying proportion of TB infections in
cattle arising from badgers is likely to differ, meaning that
similar culling policies would have different impacts on TB incidence
in cattle. Dr Woodroffe pointed out that geographical isolation
was an important component in the efficiency of the RoI Four Areas
trial as this impeded badger immigration.
Professors Donnelly and Bourne confirmed that the ISG was
working with CSL to arrive at a more robust culling efficiency
figure for the RBCT, pointing out that the 20-60% efficiency figure
quoted by Defra and Ministers was without scientific basis, and
unhelpful. They said that CSL staff had now suggested that the
RBCT had achieved 50-80% removal of badgers after the first proactive
cull. Professor Bourne commented that, while this figure was subjective
(since it was not possible to obtain an accurate figure for trapping
efficiency) the latest CSL estimate was consistent with the view
of the independent ecological assessment that badger numbers had
been substantially and consistently reduced in proactive areas
as a result of continued systematic culling.
The Minister asked about the balance of benefit, ie would
more intensive culling, possibly using different methods to the
RBCT, reduce the edge effect by removing more badgers and thus
limiting disease incidence in the periphery of the culled area?
Dr Woodroffe said the answer was unknown, but it was assumed that
any changes in the balance would depend on the size of the area
culled. She confirmed, however, that this would require significant
reduction in badger densities over a large area and in a sustained
and controlled manner.
Dr Woodroffe said there were a number of issues to be resolved
regarding the edge effect and perturbation, but confirmed that
the ISG was working on some analyses, which they would make available
as soon as possible.
Area to be Culled
The Minister asked about the scientific basis for calls for
a culling area to be at least 300 km2, and whether there was a
trade-off between the size of area and the level of badger removal.
Professor Donnelly explained that by extrapolating from the RBCT
results, Defra's Science Advisory Council had suggested that 300
km2 might bring benefits, but the ISG might recommend this as
a minimum, and opt for a larger area. As for a trade-off, Professor
Donnelly said that a simple analysis suggested that as the inner
culled area (more than 2 km from the boundary) expanded, the benefit
improved, but this would require sustained effort and comprehensive
coverage. ISG members warned, however, that their experience in
overseeing the RBCT indicated that culling over such extensive
areas would be very difficult to achieve.
A state cull?
The Minister asked why the ISG appeared to be sceptical of
any cull other than one implemented by the state. Professor Bourne
said it would be wrong for the Minister to underestimate the expertise
of Defra's Wildlife Unit staff. He said farmers did not have that
level of expertise and could not be relied upon to work equally
efficiently or effectively, over a long period of time. Professor
Bourne said any cull would need to be systematic and co-ordinated
by a skilled workforce over a long period of time—if a cull
was patchy it would not work. Professor Bourne also asked the
Minister to note that the majority of farms in high incidence
areas do not get TB, and many of those farms see badgers as protective.
xxx outlined the main culling options in the consultation,
and explained that a cost and benefit analysis did not support
a state run cull. Collectively, the ISG said that although this
might be the case, the other options were not supported by the
science, would have no positive impact and would make matters
worse, adding that, clearly, any policy without a positive benefit
could not be cost-effective in any sense. It was the opinion of
the ISG that more could be achieved, in terms of cattle TB control,
by focusing on measures other than badger culling.
Testing
Professor Bourne said that there was clear evidence that
the tuberculin skin test has limitations, which is why the ISG
had been calling for greater use of gamma interferon, as a complementary
test, for a number of years.
Professor Bourne said a recent finding that 85% of cattle
are not tested in their lifetime suggests the testing regime needed
tightening, and that to achieve this (in part) pre-movement testing
required policing if it was to be effective. He added that at
the moment too many undetected infected animals remained in the
national herd resulting in the geographical movement of the disease
into new areas of the country and contributing to persistence
of disease in infected areas. The meeting noted that Defra officials
were to discuss gamma interferon with stakeholders, and with the
ISG later in the week.
The meeting briefly discussed the PCR technique, with the
ISG advising caution on the recent results and announcements emanating
from Warwick University. The ISG pointed out that even if the
test was validated (ie shown to be both sensitive and specific),
any localised culling policy prompted by positive PCR results
would be expected not to yield benefits and could make TB incidence
worse. Professor Bourne agreed to send further details to the
Minister.
What would the ISG do?
The Minister asked what the ISG would do, when presented
with the current situation of increasing TB trends.
Professor Bourne said it would take many years for badger
culling to be effective if carried out efficiently over large
areas. Therefore, a quick reduction in TB herd incidence could
be achieved by focussing on the cattle element, but this would
require farmer co-operation, as Defra cannot tackle this disease
alone. He added that there are a significant number of problem
herds that should not be trading, which should be treated aggressively.
Professor Bourne pointed to the success in reducing TB incidence
in New Zealand and N. Ireland, achieved through improved diagnostics
and herd control measures.
Dr Woodroffe said that the badger TB reservoir would remain,
however, and that the science supported the notion that culling
would make the situation worse. The Minister said that, unfortunately,
the Government did not have farmer co-operation, and this was
less likely if the badger issue was not addressed. The ISG said
this was the conundrum that Government had to resolve but cautioned
that culling was unlikely to achieve control. Ongoing analyses
by ISG should further inform this issue and will be presented
to Ministers shortly.
Chief Scientific Adviser
The Minister said that it would be beneficial for the Government's
Chief Scientific Adviser, Sir David King, to be fully informed
of the science behind the ISG's analyses, and that the ISG should
meet Sir David at the earliest opportunity. The Minister had already
recommended to the Secretary of State that such a meeting should
take place. The ISG confirmed that Sir David had not been in touch,
so the ISG Secretariat agreed to initiate a meeting.
Concluding the meeting, the Minister said that a quick decision
on the policy options might not be possible, although clear actions
would need to be apparent fairly rapidly. A further meeting with
the ISG in June/July 2006 was not ruled out.
ISG Secretariat
May 2006
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