TB testing

We have a rigorous, EU Commission approved TB eradication programme that complies with the EU Directive 64/432/EEC (as amended), which enables us to secure €5 million per year towards the costs of our Programme. Directive 64/432 applies to intra-Community trade and requires a system of surveillance networks to be in place.

Our eradication programme, which includes a robust TB testing regime, is vital in safeguarding NI’s £1,000 million plus export-dependent livestock and livestock products industry. As a result, over 90% of our herds are free to engage in that international trade at any time. Securing annual EU approval for our TB eradication programme and compliance with the Trade Directive 64/432/EEC (as amended) will continue to be a priority to ensure our livestock and livestock products industry continues to have access to this important export trade.
In NI, live animal surveillance is undertaken using 4 diagnostic methods:
  • Clinical examination of animals
  • Herds and animals (except for direct export) are tested using the Single Intradermal Comparative Cervical Test (SICCT) – the tuberculin skin test
  • For export certification, the SICCT is carried out, but interpreted as a Single Intradermal Test, i.e. the avian response is ignored
  • Gamma Interferon testing (a blood test) where considered epidemiologically necessary, as a supplementary test to the SICCT

Single Intradermal Comparative Cervical Test (SICCT)

The intradermal tuberculin test is regarded as the definitive indicator of infection with M bovis and is the required test in the EU. It has proved to be a reliable tool for this purpose on a worldwide basis.
The technique of tuberculin testing and the interpretation of reactions are clearly described in Annex B of Council Directive 64/432/EEC (as amended).
The tuberculin test is based on cell-mediated immunity. Like all other biological tests based on the immune response, the reaction to the injection of bovine tuberculin is influenced by many intrinsic and extrinsic factors and is therefore subject to considerable variation according to the individual animal and the environment.

Gamma interferon test (IFNG)

This is a blood test approved since 2002 in the EU to be used as an additional test in certain high risk situations. Can be used as either a serial test (remove animals positive to both tests-improved specificity) or in parallel (remove animals positive to either test-improved sensitivity).It is also based on cell mediated immunity but detects infection earlier than the SICCT.
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