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Bovine Tb

Volume 409: debated on Friday 18 July 2003

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To ask the Secretary of State for Environment, Food and Rural Affairs how many cattle were slaughtered owing to bovine TB in each of the last 10 years; how many were subsequently found to be negative; and what the cost was to the Government of compensating farmers for the slaughter of cattle subsequently found to be negative in each year. [126335]

Information on compensation is held only for overall expenditure, not in the form requested. The remaining information requested is shown in the following table:

Number of cattle slaughtered in GB under bovine TB control measures and compensation paid 1993–2002
(a) Number of animals slaughtered under TB Control Measures (Reactors plus direct contacts)(b) Cases where TB was not confirmed(c) Total amount of compensation paid (£)


  • 1. Columns (a) & (c) are compiled from data published in the Chief Veterinary Officer's annual reports on Animal Health.
  • 2. Column (b) is compiled from data available from Defra's computer systems. Base data for 1993 and 1994 cannot be validated, and figures for all years cannot be reconciled with published data and have therefore been rounded. The figures show the number of cases where TB was not confirmed (rather than 'negative' cases). Post mortem examinations are less than 100% sensitive so failure to detect visible lesions or culture Mycobacterium bovis (M. bovis) from samples does not confirm the absence of infection or that the animal has not been exposed to M. bovis. The figures also include cases where culture results are still outstanding and where samples were not taken.
  • 3. In 2001, the TB testing and control programme was largely suspended due to the foot and mouth disease (FMD) outbreak. Since testing resumed in 2002, resources have been concentrated on herds with overdue TB tests that would have had a longer period in which to contract the disease. Also the proportion of high risk herds being tested post-FMD is greater than that prior to the outbreak. As a result, the numbers of TB reactors identified and slaughtered in 2001 and 2002 are not comparable with previous years.
  • To ask the Secretary of State for Environment, Food and Rural Affairs what recent discussions she has had on the efficacy of skin tests for bovine TB; and what assessment she has made of the benefits of blood tests for bovine TB. [126336]

    The single intradermal comparative cervical test (SICCT) is the only skin test currently used in Great Britain for the detection of TB in cattle. This test and the less specific single intradermal test (SIT) were, until recently, the only TB tests officially recognised by the European Union for use in cattle. The skin tests, along with the application of disease control principles, have achieved TB eradication in many countries.Last October, we begun a field evaluation of the gamma-interferon test, an in-vitro assay that measures the immune response to M. bovis of T-cells in cattle blood. This laboratory-based blood test was officially recognised by the EU in July 2002, but only for use as a supplement to the SICCT in TB affected herds. The test is considered more sensitive than the SICCT, but less specific, meaning that it results in a higher probability of false positives. For this reason, the gamma interferon test cannot be used as a screening test for TB for the time being.Diagnostic tests are never 100 per cent. accurate and there is often a trade-off between sensitivity and specificity. Although the gamma interferon test is not sufficiently specific to replace the SICCT, the use of the two tests in parallel has the potential to significantly increase the detection of infected cattle in herds where TB has been confirmed.I discussed the issue of TB diagnosis, particularly in relation to the progress of the gamma interferon trial, at a recent meeting with Professor Bourne, Chairman of the Independent Scientific Group on Cattle TB.