Testing for TB
Changes to cattle measures
Information on changes to cattle measures brought in from 1 July 2012 and changes to be introduced from 1 January 2013 are available in the TB Information Notes.
The underlying principle of our bovine TB test and slaughter programme is to identify infected cattle as early as possible and minimise the risk of the transmission of the disease within and between cattle herds.
The primary screening test for TB in cattle in Great Britain is the single intradermal comparative cervical tuberculin (SICCT) test, commonly known as the tuberculin “skin test”. The skin test is used throughout the world to screen cattle, other animals and people for TB, and is the internationally accepted standard for detection of Mycobacterium bovis (M. bovis) infection, and is considered the best test currently available for detecting TB in live animals.
Cattle TB testing and movement restrictions are administered by AHVLA – see their website for further information including their Dealing with TB in your herd publications, which detail how the skin test is carried out.
There are a number of strands to this testing programme, which include:
Routine herd surveillance testing
This is carried out at the Government’s expense using the tuberculin skin test.
As of 1 January 2013, England is divided into two cattle TB testing frequency areas. Farms in counties in the south-west, west of the country and East Sussex where the majority of TB cases are found are to be tested for TB annually. The rest of England is on four-yearly testing, although higher risk herds in these areas will be tested annually.
Cattle that react to the skin test (or any other diagnostic TB test) are removed for slaughter and the cattle owner compensated. The herd is placed under movement restrictions (its Officially Tuberculosis-Free (OTF) status is suspended, or withdrawn if disease is confirmed) until all remaining cattle in the herd have cleared two further short interval tests (at 60 days apart). Movement restrictions are then lifted but the herd has further tests 6 and 12 months later. If the herd remains clear, testing reverts to the routine test frequency set for the area.
- Further information on area testing intervals can be found on the AHVLA website
- TB Information Note 04/12 on changes to Bovine TB Surveillance (PDF)
Gamma Interferon blood testing
Since 2006, the more sensitive gamma interferon blood test has been used alongside the tuberculin skin test in certain prescribed circumstances, to improve the sensitivity of the testing regime and identify more infected animals more quickly.
- Further information can be found on the gamma interferon page
Statutory pre-movement testing of cattle requires all cattle 42 days old and over, moving from a 1 yearly tested herd, to have tested negative to a TB test within 60 days prior to movement, unless the herd or movement meets one or more of the exemptions laid down in the relevant legislation (the Tuberculosis (England) (Amendment) Order 2012).
As of 1 July 2012 changes were implemented to tighten up the pre-movement testing requirements by removing or revising some of the exemptions. These changes are in line with the package of TB control measures announced by the Secretary of State in 2011. This follows a review of pre-movement testing, which made recommendations for amendments to the policy.
- Details of the 1 July 2012 changes to exemptions are in our Information Note (PDF)
- Information on pre-movement and post-movement testing in your herd (PDF AHVLA website)
- TB pre-movement testing statistics monitoring data for England and Wales are updated quarterly and available via our TB statistics section
- Report on Phase 1 of the review of pre-movement testing (PDF)
Post mortem testing
All cattle carcases are inspected by the Food Standards Agency for suspect bovine TB lesions, with TB cases identified traced back to the herd of origin.
Contact your local Animal Health office for further practical advice and guidance or visit the AHVLA website