Draft Disease Control Policy Statement
In agreement with a core group of industry stakeholders, the UK remains
committed to a disease control approach which aims to contain disease until
vaccination is an available disease control option, in line with ‘Phase 1’ of the
UK Bluetongue Control Strategy. This is taking into account:
·the epidemiological situation (i.e. cases of Bluetongue (BTV8) currently
remain contained to the East and South Eastern parts of England);
·the time of year (i.e. in advance of the 2008 vector season);
·cost benefit analysis of disease control measures and its likely
economic impacts; and
·the development (and order) of BTV 8 vaccine for England.
This assessment remains under constant review, and recognises that the
disease situation could change at any time (e.g. in advance of vaccine
becoming available to use). Further cases of Bluetongue a significant
distance from the existing Protection Zone may lead to a change in strategy.
Annex A sets out more detail on the rationale behind specific controls.
We are currently in the “seasonally vector free period” as set out in EU
legislation – a period during which midge activity, and therefore transmission
of disease, are greatly reduced, or stopped, and movement controls are
adjusted to allow some moves out of zones under specific pre-movement
Historical data suggests such a period may run into March, but this is
dependent upon meteorological conditions and midge activity. More
information will be published shortly on the likely criteria and process for
declaring an end to this year’s vector free period.
The winter period provides a vital opportunity in which to review the disease
situation and the control strategy for 2008. Disease surveillance work is
therefore being undertaken to evaluate the full extent of disease spread in
2007, alongside data from reports of disease from farmers.
n the meantime, this statement sets out the broad aims and intentions of the
control policy for the Spring and Summer of 2008.
Pre-Vaccination Policy (Winter – Spring)
A suitable inactivated vaccine for BTV8 has only very recently been
developed. Defra placed a firm order of 22.5 million doses (2.5 million of
which are reserved for potential use in Wales) from Intervet in December,
after a detailed competitive tender process designed to ensure best value,
that vaccine is currently being manufactured. This is a lengthy process which
is not expected to be fully completed before May 2008 at the earliest. Until
this vaccine is available, tight controls will be maintained to contain disease
within existing zones as much as is possible. In the meantime, we have been
developing a detailed plan as to how that vaccination will be delivered which
will shortly be published and submitted to the European Commission for
approval and consideration of funding.
Once the vector free period ends (and we enter the 2008 vector season),
movement controls will revert to the strictest default regime, with movement
out of zones permitted only in very limited circumstances. This will be
reviewed as the disease situation develops.
Vaccination Policy (Spring – Summer)
Once a vaccine bank has been delivered, livestock keepers will be given the
opportunity to purchase from this bank.
There are a number of constraints as far as the implementation of vaccine is
·Intervet aim to start delivering vaccine in stages from May 2008,
although it will take time for the whole amount to be delivered;
·Based on experience on the continent, disease could begin reemerging
and circulating before then;
·Vaccination is only allowed under EU rules in the Protection Zone (PZ);
·The PZ would need to be extended to allow people currently outside
the PZ to vaccinate.
n agreement with the core group, the vaccination plan and wider control
policy will therefore have the following aims:
·A simple mass vaccination programme, with farmers purchasing
vaccine and using it voluntarily;
·To prioritise the initial availability of vaccine to the existing PZ.
·To make vaccine available as widely as possible, and rapidly, after
those in the existing PZ have been given sufficient opportunity to
purchase, and as vaccine is delivered by Intervet.
·To expand the PZ as soon as possible to facilitate vaccine availability
(to the extent of the SZ boundary as soon as vaccine delivery allows,
possibly staged with some further prioritisation on a risk basis if
vaccine is not delivered quickly enough).
·To expand the PZ to the whole of England as soon as sufficient
vaccine is available to allow opportunity to vaccinate across this area.
·To implement an industry-led campaign to promote the benefits of
vaccination and encourage pre-ordering, to increase uptake.
To achieve the above aims, assessment of the location of zone boundaries
will be carried out throughout the period with the core group, taking into
account vaccine uptake and availability; disease situation and movement
risks; economic impact etc.
Current disease control strategy - rationale
The current strategy is being delivered using disease control measures such
as controlling the movements of susceptible animals, as set out in EU
legislation. The rationale for this approach is set out below:
oBluetongue is spread between animals by a midge vector (Culicoides
spp.). Infected midges have the potential to spread disease in a local
area (up to 1.5-2km a day in some cases)
oIt is neither possible nor proportionate to attempt to eradicate or control
populations to an extent that would mitigate against or have a desired
controlling effect on the spread of Bluetongue.
oSusceptible animals (i.e. all ruminants and camelids) potentially are a
‘reservoir’ for disease for up to 60 days when infected. Movements of
infected animals has the potential to spread disease a much further
distance than midges.
oIt is extremely difficult/impractical to completely protect an infected
animal from attack by midges. Therefore an infected animal provides a
source of virus for a local midge population wherever it is located (and
potentially further disease transmission in that local area)
oWhile it is not possible to stop the local spread of disease through
movement of midges. It is possible to control the spread of disease
through the control of movements of infected and potentially infected
Disease control measures
oA Protection zone is established in order to try to contain disease within
an area around an infected premises. The Protection zone boundary
should always be at least 20km away from any infected premises.
oMovements of animals and midges may still spread disease within the
zone, however, sufficient surveillance and reporting of signs of disease
should monitor the levels of spread, and new infected premises are
most likely to be found within this zone.
oEven so, given the nature of the disease, it can be assumed that there
will always be a level of undetected infection in the Protection Zone i.e.
as clinical signs of disease are not always apparent.
oTherefore, any movement of susceptible animals out of the Protection
zone has the potential to spread disease to a new and previously
uninfected part of the country.
oAnimals can move freely within a PZ, so any decision to extend a PZ
geographically (e.g. to allow vaccination in a wider area) must be
balanced against the risk of wider movement of potentially infected
oA Surveillance zone is established in order to maintain a buffer area
around the Protection zone. This size of the zone is set in EU
legislation at at least 150km radius from any infected premises.
oDue to the nature of the spread of Bluetongue, new cases can be
found outside of the Protection Zone.
oAny movement of susceptible animals out of the Surveillance zone
(although a lesser risk than the Protection zone) has the potential to
spread disease to a new and previously uninfected part of the country.
oTherefore the zone, and the movement restrictions within provide a
vital buffer against further, and wider spread of disease.
Moves to Slaughter
oGiven the nature of the UK farming industry, there is an economic need
to allow moves to slaughter, potentially long distances and moving out
oAs infected animals (showing no symptoms) can potentially move to
slaughter out of the restricted zones, there is potential for midges at the
abattoir of destination to bite them and become infected. This can
potentially lead to the creation of a local infection in a previously
oTherefore there is a need to mitigate against the risk of midges biting
potentially infectious animals in abattoirs, through licence conditions.
As such the following measures are required for moves to slaughter
(outside the “vector free period”, VFP).
oA requirement for animals to arrive at abattoirs after dawn, and
slaughter animals of the before dusk each day. This minimises
the risk of potentially infectious animals being bitten at abattoirs
during peak times of midge activity i.e. dawn and dusk.
oSimilarly, potentially infectious animals should not be present in
abattoirs overnight, as midges are still fairly active at night, and
would be particularly attracted by lighting at the abattoirs (as
opposed to during the day)
oVehicles used to transport animals should be treated with
authorised insecticides prior to the movement. This will reduce
the likelihood of potentially infected midges entering the vehicles
and moving with the animals out of the zones.
oInsecticide treatment of the animals to mitigate the same risk is
not possible due to the withdrawal periods.
oDuring the period of low vector activity is has been possible to relax
these time constraints and allow movements of livestock to slaughter
from the restricted areas through dedicated slaughter markets.
Moves to Live
oDue to the nature of the disease, all animals in the Protection and
Surveillance Zones must be considered as potentially infected
(although there is a higher risk in the PZ).
oTherefore, any moves of animals outside of the Restricted Zones can
potentially lead to the creation of a local infection in a previously
oIn the current period of low vector activity moves to live are being
allowed out of the current Restricted Zone, providing the livestock
meets specific criteria and has a pre-movement test, but such moves
will only be allowed after the VFP ends under very specific criteria (e.g.
naturally immune animals). Moves out of zones to slaughter will
however be allowed (see above).
oAll movements of animals from and to a lower risk area through a
higher risk area provide a level of risk to the transiting animals of being
bitten by potentially infected midges while in transit, and transferring
infection to a previously uninfected area.
oTherefore conditions are required for such moves (outside the VFP) to
mitigate against the risk of animals being bitten in transit.
oMoves from free area to free area through a SZ, are subject to
the vehicle and animals being treated with insecticides prior to
entering the SZ. No stops, apart from required rest periods or
for welfare reasons are permitted.