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Preparing for a new GB strategy on bovine tuberculosis

PART TWO

5. Short term measures

5.1 Background

5.1.1 A memorandum submitted to the Environment, Food and Rural Affairs Committee set out a number of policy options to address the problem of bovine TB. These were:

5.1.2 Some of these measures were dependent on the availability of SVS resources.

5.1.3 The European Directive 64/432/EEC, which governs intra-Community trade in bovine animals, sets out the rules for trading of bovines and avoidance of a number of diseases, such as bovine TB, being transferred between Member States. The Directive also sets out rules for the control of these diseases within the Member State. The GB TB surveillance and control regime aligns very closely with the requirements of the Directive but is not an exact fit. Some of the proposals described below give an opportunity to align ourselves better with the requirements of the Directive. The Directive allows for extra controls within Member States to improve surveillance or management of disease. Examples include pre and post movement testing.

5.1.4 The proposals in this part of the consultation document cover the first 6 points above and fall into two groups: the first three points set out how we might align ourselves better with the Directive by adjusting basic TB testing frequencies and by imposing movement restrictions immediately routine TB tests become overdue; we would continue to cull inconclusive reactors at third rather than second tuberculin test. Points 4 to 6 aim to reduce the risk of geographic spread of bovine TB from high to low incidence areas. This part of the document should be read in conjunction with the draft partial Regulatory Impact Assessment (RIA) at Annex A, which sets out the costs and benefits of the proposals.

5.1.5 The last four points in 5.1.1 describe activities that are being considered separately by others within Defra and the Environment and Rural Affairs Departments of Scotland and Wales and are not further described here. There have already been consultations on new contracts between SVS and LVI's and on lay testing (points vii and viii). Work is going on in SVS to improve efficiency (point ix). A consultation on the rationalisation of compensation was issued in October 2003 (point x).

5.2 Increasing the efficiency and transparency of TB surveillance and alignment with directive 64/432/EEC

5.2.1 The EU Directive 64/432/EEC (as amended) sets out the method of calculating routine tuberculin testing frequencies according to disease incidence. We propose to align ourselves with this part of the Directive, as we are required to do. This will place us in a better position if and when we seek to export live bovine animals to other Member States.

5.2.2 The Directive does not define the unit area to which testing frequencies are to apply. In Scotland we propose to use the whole country as our base unit. We have looked at the affects of using parish, country and region. In each case the low cattle density in Scotland, the relatively high risks from imported cattle and the Directive requirement to base calculations on the pervious 8 years (two testing periods) would mean imposing epidemiologically unsound annual testing on a significant number of Scottish parishes. Over and above the Directive requirements, Divisional Veterinary Managers (DVMs) may increase testing frequencies for parishes adjacent to areas of high TB incidence and for individual herds posing a high animal or public health risk as a risk management measure.

5.2.3 The basis of the EU testing regime is set out in Table 2. All herds are tested annually unless the low incidence of TB in a given area warrants otherwise. This annual frequency can be gradually relaxed as shown in the table below. Averages are determined at 31 December of each year.

Table 2:-

5.2.4 Analysis of historical data shows that provided testing intervals are reviewed frequently the use of the whole of Scotland to set testing intervals is an effective way of detecting most infection in cattle. However, it may be necessary to use a much smaller area if there was a significant change in TB frequency in Scotland. This is an issue which we would wish to keep under review. In light of the above, there would need to be a clear additional benefit to make significant changes to the current testing arrangements.

5.2.5 This proposal aims to ensure that we get the maximum benefit from routine herd TB testing as a surveillance mechanism. Our veterinary advisers stress the importance of regular testing in all parishes to maximise our chances of identifying new infected areas as early as is possible. By dividing up the total number of herds in a parish to be tested by four we can ensure that balanced numbers are tested in each year. Thus we are as sure as we can be that we are carrying out adequate surveillance. This measure is especially important in 4 yearly testing areas like Scotland.

5.2.6 Implementation of this measure in practice may call for some herds to be tested in advance of the due date for their 4 yearly test.

5.2.7 If we do not proceed with this proposal we face an increased risk of missing new hotspots. For instance, if the majority of herds in a parish are tested in the same year then there are three years for most of the herds in the parish where active surveillance is not being done. By equalisation of testing within relatively small areas (such as parishes) we stand a better chance of detecting TB incidents, either through testing of the index case or, indirectly, when routinely testing neighbouring herds infected following lateral spread from the index herd.

5.2.8 At present herds with overdue routine tuberculin tests are not immediately placed under restriction. Current GB policy is to issue a written warning to the herd owner if a test has not been completed by the day after its due date and then impose movement restrictions if that test remains overdue three months later. In contrast, the Directive prescribes that a herd should have its officially TB free status suspended if not tested at the appropriate interval for its area. This effectively calls for movement restrictions to come into force when the test is only one day overdue.

5.2.9 We propose to adopt the Directive standard. The benefits are two fold. Firstly, we cut down on the risk inherent in allowing testing intervals to expand. Secondly, we become better aligned with European requirements.

5.2.10 In relation to testing dates we recognise that some flexibility is essential and in some cases farmers might wish to undertake a test earlier than the due date. Thus we propose that herd owners be allowed to advance tests by three months. From then on the routine test date will be calculated from the advanced date.

5.2.11 There is also the question of responsibility for initiating and carrying out a routine herd test. At present this is not clear. We propose that both the farmer and LVI are informed of the routine test date. The notification to the farmer will place the onus on him or her to arrange for the test to be carried out by the LVI. The notification will contain a cattle movement restriction notice that automatically comes into force the day after the test is due, if the test has not been carried out by then and the results reported to the DVM. Evidence of a completed test, i.e. clear test results received at the animal health office will cause the restriction to be lifted on the occasion that a test has become overdue.

5.2.12 An IR is an animal with a positive reaction to bovine tuberculin, where the swelling caused by injection of bovine tuberculin is between 1 and 4mm greater than the swelling at the site where avian tuberculin has been injected. A more stringent interpretation of this rule is applied in herds with confirmed infection.

5.2.13 At present, when an IR is disclosed by a routine tuberculin test or any of the check tests following a disease incident, we allow the animal to undergo up to two further tests at 42 day intervals. If the animal remains inconclusive after the third consecutive test, it is slaughtered as a reactor. Directive 64/432/EEC, in contrast, calls for IRs to be slaughtered if they are not negative to the second test.

5.2.14 Looking back to GB TB surveillance data for the year 2000 we can see that a significant number of herds (some 574 herds out of 2805 disclosing IRs only) still had one or more IRs at the second test and would have become reactor herds under a strict implementation of the Directive's rule on IRs. Of these 574 herds, 571 were subjected to a third test and 52 incidents were confirmed in these herds in the following 220 days. Thus for every incident that was confirmed in the next 220 days there were nine that were not and many animals that were IRs at the second test went clear on the third test. Veterinary advice is that there is little to be gained in disease control terms from reducing the number of re-tests of IRs from two to one. There would clearly be an extra cost to the taxpayer in slaughtering large numbers of IRs that would have resolved to clear status at the third test. Also a large number of extra herds would be put under restrictions causing extra costs to the farmer and Government because of the testing required. In relation to alignment with the Directive, switching to take IRs at second test could be easily and simply done when the prospect of exporting live bovines comes nearer. Our proposal is not to change our present policy but to be prepared for the change once it becomes necessary if it becomes necessary for wider reasons.

5.2.15 At present we have different check testing regimes depending on whether a herd is re-formed after FMD, newly formed, or formed after complete herd slaughter due to TB. We propose that all new and re-formed cattle herds outside annual testing parishes undergo three check tests at 12 month intervals before reverting to the normal routine test frequency for the parish. This would align our current policy for herds restocked post FMD with that of herds restocked for any other reason. This proposal would ensure that we have adequate surveillance of all newly formed and reformed herds against a background of increasing disease incidence and therefore higher risk from buying in stock.

5.2.16 Question

( QUESTION 13 ) We have proposed five measures (below) that are aimed to improve our surveillance testing and make the system more transparent. Are these measures appropriate, should any be changed and if so what should the changes be?

The five measures are:

• Use the Directive 64/432/EEC method of calculating base herd testing frequencies on a Scotland, and allow local discretion to increase testing.
• Equalise the numbers of herds that are tested each year in 2, 3, and 4 yearly testing parishes.
• Impose movement restrictions immediately routine tuberculin tests become overdue (aligns us with Directive 64/432/EEC).
• To retain our present system for inconclusive reactors, that is to allow up to three tuberculin tests before compulsory slaughter.
• To carry out three check tests at 12 monthly intervals on all new or reformed herds.

5.3 Reduction of the risk of spreading TB from high to low incidence areas through the movements of undisclosed infected cattle and minimisation of risks due to cattle movements in general.

5.3.1 Examining the maps of disease spread over recent years indicates that controlling geographic spread of bovine TB within GB must be one of our most important targets and we propose to introduce measures to strengthen surveillance to help ensure that Scotland is protected from imported disease from known high TB incidence areas. This is particularly important given the history of TB in Scotland arriving mainly from the movement of cattle from high risk areas.

5.3.2 The introduction or pre and/or post movement tuberculin testing of animals will reduce the risk of transferring disease from high to low TB incidence areas. SEERAD has for a number of years advised herd owners to isolate incoming stock and to have them tuberculin tested to avoid bringing disease onto the farm in areas of low incidence. This will continue to be our advice. The history of bovine TB over the past 20 years shows that there are frequently cases of TB outside the areas of high incidence, some of which can be attributed to movements of infected cattle. Others are unexplained, perhaps caused by wildlife vectors. The Staffordshire / Derbyshire area of high incidence started as a single outbreak in the late 80s and has subsequently yielded a cumulative total of 6000 reactors from the two counties. Given the development of the disease, we think the time is right to introduce a statutory requirement to help prevent cattle to cattle spread, specially when they move from areas of high incidence to areas of low incidence. We recognise we cannot be certain that we can prevent new areas of high incidence developing if wildlife is the underlying cause.

5.3.3 We have considered 6 options on a GB basis:

i. zoning - banning all cattle movements from areas of high TB incidence to areas of low TB incidence (such as Scotland) without some form of risk assessment and assurance testing;

ii. pre movement testing for all cattle moving from 1 and 2 year testing herds to any other herd;

iii. post movement testing for all cattle moving from 1 and 2 year testing herds moving to 3 and 4 year testing herds;

iv. pre movement testing for all cattle moving from 1 and 2 year testing herds and subsequent post movement testing at all 3 and 4 year testing receiving herds;

v. pre and post movement testing for all cattle sold for breeding and production regardless of herd of origin and destination; and

vi. a pre movement testing system based upon herd TB history, cattle to be tested that come from herds that have experienced an outbreak in the past five years.

(Note: In all options (i) - (vi) above the cattle to be tested are animals sold for breeding and production, meaning all animals that are not going immediately to slaughter. Thus calves (over six weeks old) or store animals for subsequent growing, breeding and fattening and cows for continued beef or dairy production fall within the definition.)

Veterinary advice

5.3.4 No measures other than a complete ban on movements will eliminate the risk of disease spread from cattle movements. However, less stringent intervention will reduce the risk of spreading disease. The option likely to yield greatest benefits is option (v) - pre and post movement testing all animals sold for breeding and production. A more targeted approach would be to require pre and/or post movement testing for animals moving from high risk to low risk areas. Alternatively a farm risk based approach could be used, where pre-movement testing is applied to animals coming from herds which had experienced a breakdown in the past five years, except where the incident was caused by a purchased animal.

5.3.5 Veterinary advice is that controls should apply to all cattle moving off from 1 and 2 year testing herds, irrespective of type, intended purpose or age except calves under six weeks old and those animals being sold direct for slaughter. An animal should be permitted to move for a period of 60 days after the pre-movement test. If it has not been moved from the home herd during this period then a new test should be conducted before the animal can be moved to another farm.

Discussion

5.3.6 Any option selected must be simple to administer, be proportionate to risk and confer disease control benefits. We consider zoning (option (i)) to be impossibly complex and expensive to deliver and a disproportionate response, bearing in mind the costs and benefits and scientific uncertainty about the spread of bovine TB. To make it work England and Wales would need to be divided along a North West to South East axis and any movements across the line would need to be managed. Departments would need to adjust zone boundaries if new hotspots developed and consider how we would treat small areas of endemic disease in otherwise clear areas. The high risk zone in England and Wales would also include a large number of 3 and 4 yearly testing parishes with presently stable TB status.

5.3.7 The options that involve pre movement testing together with post movement testing or the post movement testing option on its own (Options, ii-vi) represent a more targeted approach.

5.3.8 Pre movement testing of all cattle moving from 1 and 2 year testing herds (option (ii)) is the most simple to deliver and therefore likely to have an impact in the short term. Management of risk by both pre and post movement testing is likely to be a complex process, however, our veterinary advice is that option (iv) provides more complete protection for Scotland. This option is targeted to the herds at most risk of spreading TB and to those most at risk of receiving it.

5.3.9 In all options the expectation is that herd owners will pay for these tests to be conducted. The benefits of buying or selling cattle with some degree of disease free assurance fall to the farmer. We expect to hold detailed discussions with stakeholders during the consultation period on how any new requirement would be delivered and enforced.

5.3.10 We envisage that pre and post movement testing would be delivered by Local Veterinary Inspectors (LVIs) or private veterinarians where they have been trained as TB testers. In practice, when a herd owner wished to market some animals he/she would contact his/her LVI arrange for the pre movement test to be done, the LVI would certificate that the test had been carried out listing the animals tested. Animals would then be certificated, or assured as TB tested and can be sold from the home farm within a 60 day period. If an animal has not been moved from the farm during that period it will have to be tested again prior to being moved.

5.3.11 Any post movement testing would also be delivered by LVIs. The test would be administered between 60 and 120 days after movement as a general rule. Knowledge of when a pre movement test had been carried out would allow the timing of a post movement test to be better targeted. It is strongly recommended that animals brought on to a farm should be isolated from the herd in appropriate accommodation until the test is carried out. If the animal/s have been isolated and on post movement testing are found to be reactors they can then be removed without the herd being placed under general restriction. If isolation requirements have not been met or the animals have been incorporated in the herd and when tested are found to be reactors, then the whole herd would have to be placed under restriction and a herd testing regime implemented before restrictions can be lifted.

Preferred option

5.3.12 For the reasons outlined above, we have a strong preference for pre and post movement testing (option (iv)) to be introduced. However, if the complexities that attach to delivery cannot be addressed, then, as a minimum, pre movement testing (option (ii)) should be adopted. We would, in any case, continue strongly to advise farmers for their own benefit to subscribe to option (iii).

Costs and Benefits of the options

5.3.13 These are set out in detail in the Partial Regulatory Impact Assessment at Annex A. The main potential benefit is fewer movements of infected animals into low risk areas. Picking up disease in animals that have already moved, through post movement testing, is a further benefit. This beneficial effect is multiplied if the infected animals that are caught by this process were to be the nucleii of new disease hotspots. Looking at pre movement testing alone, the cost to the farmer will be variable. For those who seek to market their stock immediately after their routine annual TB test (currently paid for by Government) there will be no cost. For those who need to, or seek to sell animals for breeding or production at other times of the year and those on two yearly testing we estimate the cost would be up to about £7 per head.

5.3.14 This is a precautionary measure that we would expect to reduce new incidents occurring in low risk areas and consequently reduce new "hotspots" (new areas of escalating disease). For illustration if we could have prevented the source cases in the Staffordshire/Derbyshire area in the mid to late 1980's then we might have been able to prevent a hotspot developing that has yielded over 6000 reactors to date at a cost to industry and Government of probably over £10m. Because of the outstanding uncertainties around the role of wildlife in geographical spread of disease, we cannot be certain about the extent of the disease control benefit of this option in advance of deploying it. However, evidence from Ireland shows that pre and post movement testing does reveal reactors not found by the routine testing programme.

Implementation

5.3.15 Any of these options requires a regulatory framework and detailed negotiations with interested parties on the most efficient means of delivery. We envisage that the regulatory framework will be put in place by a revised TB Order stemming from the Animal Health Act 1981.

5.3.16 Issues we need to clarify with stakeholders including delivery agents include:

• how to notify farmers as to the routine testing frequency which applies to their herd;
• how an obligation to pre and post movement test might be effected by different ways of marketing animals (i.e. through markets or through dealers);
• whether DVM's should have an element of discretion as to which animals should be pre movement tested, and the factors which would influence the exercise of that discretion e.g. animals going direct to slaughter; and
• how the enforcement authorities should be informed when an animal movement takes place in order to allow efficient enforcement.

5.3.17 Once we have clarified these issues, we will be able to amend the TB Order accordingly. We envisage that the amendments would be along the following lines:

• All herd owners and keepers will be notified as to the testing frequency which applies to their herd from time to time.
• Where a herd is subject to testing every 1 or 2 years then no person shall allow a bovine animal aged 6 weeks or more to move off the premises on which it is kept unless within 60 days prior to movement

• Other herds subject to different testing frequencies may be required to pre movement test if the DVM considers on reasonable grounds that this is necessary.
• Where a bovine animal is moved off the premises without being pre movement tested when it should have been, then the owner and/or keeper would be guilty of an offence.
• Where a bovine animal enters a herd without having been pre movement tested when it should have been then the receiving herd will be placed under movement restrictions.

5.3.18 In addition to a requirement for pre movement testing, we wish to impose a requirement to post movement test the same animals before they can be introduced into the receiving herd.

5.3.19 If adopted this provision would require a statutory obligation to isolate incoming animals until they have been satisfactorily tested. There will need to be appropriate sanctions, and, again, if there is a failure to comply, the receiving herd will be put under movement restriction.

5.3.20 The obligation to post movement test would apply to animals from high risk herds (i.e. those subject to 1 and 2 yearly testing) and also where other animals have been mixed with those from high risk herds.

5.3.21 Questions

) What are your views on our proposal to reduce the risk of spreading TB from high to low incidence areas by requiring pre and post movement testing of all cattle moving from 1-2 year testing herds?QUESTION 14(

) What are your views on our advice that farmers should themselves apply post movement testing in order to minimise the risk of transfer of disease from high to low incidence areas ?QUESTION 15(

) What are your views on the other options we have considered ?QUESTION 16(

i. zoning - banning all cattle movements from areas of high TB incidence to areas of low TB incidence without some form of risk assessment and assurance testing;

ii. pre-movement testing for all cattle moving from 1 and 2 year testing herds to any other herd;

iii. post movement testing for all cattle moving from 1 and 2 year testing herds moving to 3 and 4 year testing herds;

iv. pre-movement testing for all cattle moving from 1 and 2 year testing herds and subsequent post movement testing at all 3 and 4 year testing receiving herds;

v. pre and post movement testing for all cattle sold for breeding and production regardless of herd of origin and destination; and

vi. a pre movement testing system based upon herd TB history, cattle to be tested that come from herds that have experienced an outbreak in the past five years.

5.4 Clarification and strengthening of the powers of veterinary inspectors for dealing with TB incidents and overdue tests under the TB Order

5.4.1 Three main measures were identified in the consultation in 2001 on a revised TB Order. We have added one further change (amendement 4). Due to the FMD outbreak, the Order was not subsequently revised. We propose now to implement these changes along with a number of other minor changes also covered in the previous consultation. A revised draft TB Order 2003 (Scotland) is at Annex D. Similar revised Orders will be made in England and Wales.

Main changes proposed

5.4.2 The three main changes are as follows:

• introduction (in Article 17) of a duty to notify the isolation of the organism M. bovis when found in a sample in a laboratory ("Amendment 1");
• clarification (in Article 8(3)) of the Minister's power to impose movement restrictions on herds where an official tuberculin test has not been carried out by the due date ("Amendment 2"),
• prohibition (in Article 8(5)) of the movement of a bovine animal between the first and second stages of an official tuberculin test ("Amendment 3"), and
• extension (in Article 8(2)) of the role of Scottish Ministers in relation to the use, and results of, any diagnostic test for TB ("Amendment 4").

5.4.3 The purpose of Amendment 1 is to improve current surveillance of cattle TB by enabling to follow up cases where bovine TB is found in other species. This might occur when, for example, a private veterinary practitioner suspects the presence of TB in a domestic pet such as a cat and sends a sample for culture to a commercial laboratory. The proposed amendment would require laboratories to notify Defra's Veterinary Laboratories Agency of any such cases, unless the organism had been deliberately introduced, for example as part of a scientific research programme. This will provide Defra with additional information about the presence of infection which may help in establishing links to outbreaks of TB in cattle while also improving understanding of the epidemiology of the disease.

5.4.4 The purpose of Amendment 2 is to clarify the Minister's power to impose movement restrictions when a routine TB herd test has not taken place by the due date because of the herd owner's refusal to undertake testing. Movement restrictions are imposed as a disease control measure to ensure that such animals are not moved off the holding, thereby missing the test altogether and possibly spreading infection to other cattle. The aim would be to ensure that all cattle are tested for TB at the appropriate time.

5.4.5 The purpose of Amendment 3 is to prevent cattle injected with tuberculin at the first stage of the test being moved off the holding before the test is read 72 hours later. Animals in this category could pose a risk of infection to other cattle. Furthermore, such animals have to be traced and tested if TB is confirmed in the herd of origin. The amendment would restrict the movement of cattle between the first and second stages of the test, except under licence, for example to slaughter. The aim would be to allow the efficient functioning of the routine TB testing programme.

5.4.6 The purpose of Amendment 4 is to manage the process of TB diagnostic testing and to enable the SVS to have records of the use and results of these tests for TB in the event of alternatives to the tuberculin test, such as gamma interferon, becoming available in the future and used as part of the official surveillance or control programme.

Other changes proposed

5.4.7 Other more minor changes to the Order are set out below. In most cases these involve clarification, routine updating or changes to layout intended to make the legislation clearer.

• It is proposed to remove the text of Forms A ( notice requiring detention and isolation or prohibiting movement of animals) and B ( notice of intended slaughter) which currently appears in the Schedule to the 1984 Order. The substance of the two forms is incorporated into the body of the draft Order in Articles 7(2) and 10 respectively. This does not represent any change in policy, but is intended to make the legislation easier to follow. It would also mean that the forms can be updated to incorporate administrative changes without the need to amend the Order.
• For clarity, the definition of "bovine animals" will be amended by making specific reference to Asiatic water buffalo ( Bubalus bubalis) and North American bison ( Bison bison).
• The definition of "premises" will be amended to remove a provision in the 1984 Order which excluded from its application "any part or parts of premises used for the temporary detention of animals, as a market, sale-yard, fairground, slaughterhouse lair or place of exhibition". The effect of this change would be that if the presence of TB was suspected in a bovine animal held on such premises, this would be covered by the disease notification requirement in Article 5. However, the revised drafting of Article 7(2) incorporating wording that was in the Schedule (Form A) allows for movement restrictions to be applied only to a specified part of such premises.
• Article 3 of the proposed new Order on the issuing of notices and licences would be new. This does not represent any change in policy. It brings together requirements previously appearing in different parts of the Order and is intended to make the legislation easier to follow.
• Cross-references to pre-single market legislation on the import of animals which is no longer in force (in Article 4 of the 1984 Order) would be deleted.
• References to reporting the suspicion of disease to a constable of the police force for the area (in Article 5 of the 1984 Order) have been deleted.

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