Defra today announced a new trial using gamma interferon as a back up to the Intradermal skin test from October 2006. Emphasising that the skin test - an internationally recognised diagnostic tool - will still remain the primary test, (even though his CVO implies retraining is necessary to make sure they all do it properly) Ben Bradshaw announced further specific and limited use of gamma interferon as back up.
The announcement describes the proposed use of gamma interferon in England and Wales, as follows;
"Under this new policy the g-IFN test will be applied mainly in 3 and 4 yearly testing parishes in an attempt to ensure that infection in such areas does not become established in cattle or wildlife. The test will also continue to be available to use as a disease control tool in TB hotspot areas.
From October 2006 the use of g-IFN test will be mandatory, to enhance sensitivity and detection of infected cases, in the following prescribed circumstances:
*All confirmed new incidents (CNI) in 3 or 4 year parish testing intervals (PTIs), including those that fail to resolve through repeated skin tests or where complete or partial de-population is contemplated .
*Confirmed incidents failing to resolve (with Visible Lesions), despite taking bio-security precautions in 1 and 2 year PTIs, including those herds where a complete or partial de-population is contemplated
*Used at the first Inconclusive Reactor (IR) retest in unresolved IRs in herds in 1 and 2 year PTIs.
Additionally, the test will be used occasionally to enhance specificity in the following limited circumstances:
*Non-specific reactor procedure for unconfirmed breakdowns in 2, 3, or 4 year PTIs
*Suspected fraudulent reactors
More information on these prescribed circumstances is detailed below.
As set out in the Government strategic framework for the sustainable control of bovine tuberculosis (bTB) in Great Britain, the Government will continue to develop a sound scientific evidence base by supporting research to improve our understanding of the disease and generate new tools, particularly in relation to diagnostics and vaccines."