Review into Bovine Tuberculosis
Date: 19 November 2012
ISBN: 978-0339-60448-3 - 978-0339-60449-0 - 978-0339-60450-6
Mandate Number: 2011/15
1. Bovine TB is a highly infectious disease that presents a problem for herd health in Northern Ireland. While in recent years there has been a very welcomed downward trend in infection rates, in the last 18 months there has been a sharp and as yet unexplained and unprecedented increase. There is serious concern amongst Committee Members, that unless this is tackled the disease could take a much firmer hold in Northern Ireland proving more difficult to eradicate in the longer term.
2. Statutory responsibility for control of the disease lies with the Department of Agriculture and Rural Development (DARD) who operates a programme based around compulsory testing and slaughter of infected animals, cattle surveillance, movement restrictions and disinfection. While DARD maintains that its programme is one of eradication, some witnesses questioned whether the DARD strategy is more about containment and control than eradication.
3. In this context, the Committee continues to express its disappointment that the Programme for Government has no explicit target for the eradication of bovine TB, finds the rationale for this omission to be weak and emphasises the need for this to be reconsidered by DARD.
4. The disease has cost Northern Ireland around £317m over the 15 years up to March 2011. This is a substantial amount of money, the bulk of which is spend on the testing regime and on compensation payments for the slaughter of infected animals. However, this has to be put in context in that the bovine TB programme enables an export trade in livestock and livestock products which is valued at around £1000m per year. But the cost of bovine TB cannot be measured solely in financial terms. Account has also to be taken of the personal stress and emotional distress that herd breakdowns brings for many farming families.
5. Under the Tuberculosis Control Order, compensation is paid out at 100% of the market value of the reactor or in contact animal. This arrangement has come under some criticism by external bodies. DARD has been considering revisions to this arrangement and while scrutiny of these revisions has not formed part of this inquiry the Committee remains to be convinced that they will be an effective tool in the plan to eradicate bovine TB. The focus on revised compensation arrangements must not however overshadow attempts to control costs elsewhere such as on lay testing arrangements and on more cost effective blood testing. Indeed, the fact that DARD has now addressed a failure to secure around €5million per annum from the EU Commission towards its eradication plan is particularly welcomed in this context.
6. The Committee does consider the current testing and surveillance regime to be one of the most robust in Europe but at its heart is a reliance on a skin test to identify the disease. This inquiry has shown that the skin test has limitations around its sensitivity. In a best case scenario, the skin test could be missing one in four infected animals. Other witnesses put its sensitivity at around 50 - 60%. Furthermore, according to emerging research, the effect of liver fluke and Johnnes Disease could be masking bovine TB further. The blood test used in Northern Ireland to sometimes supplement the skin test is the Gamma Interferon test and while it cannot replace the skin test it may help to address some of its limitations. While it is expensive, the Committee does welcome research being conducted by the Department on its use while recommending that issues around its performance and cost are addressed. The testing regime is central, therefore ensuring it is conducted properly and to the highest standards is of vital importance, be that by a private veterinary or a DARD employed veterinary. The Committee did examine, in some detail, supposed differences in testing results between private and DARD veterinaries and is glad to see that efforts are being made by all to ensure that the testing is to the highest possible standards.
7. What became clear during the course of the inquiry was that while much is still unknown about bovine TB, there is a wealth of information available within Northern Ireland that, in the opinion of the Committee, is not being interrogated and used to its fullest extent. For example, there is very detailed data available on the various strains of bovine TB but little information or knowledge on whether certain strains are more virulent or whether some can evade skin testing. Another example is that bovine TB displays a distinct pattern whereby around 80% of reactors are in 20% of herds. Yet until recently there appears to be no urgency to discover why this pattern is occurring or how it can be broken, nor indeed is there any clear definition of what constitutes a chronic herd or repeat breakdown herd. The Committee believes that better use of existing data can and will pay dividends for Northern Ireland in its fight against bovine TB.
8. Regarding the recently announced Wildlife Intervention Study (test, vaccinate or remove), while the Committee welcomes the movement by the Minister on addressing the role of wildlife in bovine TB, it does consider that this is late in coming. There has been concern in the farming industry that for too long the wildlife factor has been ignored by the Department. There are still concerns around the practicalities of the chosen approach and around the fact that it could take years to conduct the study, analyse the results and, assuming it was successful, roll it out across Northern Ireland. In the meantime, the Committee does applaud the work being done by many wildlife organisations on badger vaccination within their land and estates in England and would welcome schemes to encourage such activity within Northern Ireland.
9. Finally, there appears to be substantial and promising movement on the long awaited cattle vaccine (and associated DIVA test). But there is still extensive work to be done before the vaccine is acceptable under EU law. There is an active role for the Minister, the Committee and for the industry in lobbying for the necessary changes to allow for cattle to be vaccinated. But, as clearly pointed out to the Committee, the vaccine is not and is likely never to be the whole answer. It will not prevent infection and therefore, even if successfully introduced, other measures are always likely to be needed.
 Sensitivity is the ability of a test to correctly identify an infected animal or to not identify an infected animal as uninfected (false negative). Specificity is the ability of a test to correctly identify an animal that is free from disease or infection or not to identify uninfected animals as infected (false positive).
Please note: This is a large PDF file (approx 79MB). You can download this file by right-clicking on the link above and selecting 'Save Target As...' or 'Save Link As...' and saving the document to your desired location. It may take several minutes to download.