Kerry McCarthy – 2016 Parliamentary Question to the Department for Environment, Food and Rural Affairs
The below Parliamentary question was asked by Kerry McCarthy on 2016-02-19.
To ask the Secretary of State for Environment, Food and Rural Affairs, what recent assessment her Department has made of the sensitivity of the single intradermal comparative cervical tuberculin test for Bovine TB; and what steps her Department is taking to improve testing for TB.
George Eustice
The single intradermal comparative cervical tuberculin (SICCT) commonly known as the ‘skin test’ is the legal standard approved in the EU legislation for the diagnosis of TB in live cattle in the UK. SICCT has a very high specificity giving on average only one false positive result for every 5,000 or 6,000 uninfected cattle tested, although it is only moderately sensitive (with about one in five to one in four infected cattle potentially missed by the test).
The skin test is a good herd screening test and it is supplemented by post-mortem meat inspection at commercial slaughter of cattle. When one or more infected animals are detected in a cattle herd, we apply a number of strategies to improve the overall sensitivity of TB testing until the infected herd regains officially TB free status. This includes testing the herd every 60 days, lowering the positive cut-off of the skin test (‘severe interpretation’) and supplementing the skin test with the more sensitive interferon-gamma blood test.
We have also increased the number of interferon-gamma blood tests carried out in conjunction with the SICCT to maximise the detection of infected cattle in TB breakdown herds. This number has more than quadrupled since 2009 to reach just over 74,000 blood tests in 2015. The use of this blood test to help remove infected animals from breakdown herds has been compulsory in the Low Risk Area of England since 2006 and in the whole of the Edge Area since January 2014.
My department plans to launch a public consultation that will set out proposals for enhancing the sensitivity of TB testing in TB breakdown herds.
