ˇ Introduction
4.1 The Committee recognises that an understanding of the history and development of OJD programs is important. That is not to suggest that history can be rewritten, or that it is useful to dwell on the past. Rather, the Committee has sought to understand what has happened in order to learn lessons for the future.
4.2 In this chapter the Committee attempts to document briefly what is known about the history of OJD, internationally and in Australia. Responses to the disease within Australia are important aspects of this history. The Committee outlines these responses and the stages now reached at both national and State levels.
4.3 In the early 1800s, a chronic debilitating intestinal disease of cattle that had different symptoms from other known disorders was recognised in Europe.1 In 1894 Drs H. A. Johne and L. Frothingham examined the intestines of a cow that had died from this disorder in Oldenberd, Germany. They described the thickening of the intestinal walls and abnormal lymph nodes now typically associated with Johne's disease. They discovered abundant rod-shaped bacteria in the inflamed tissue of the intestines and concluded that the disease they were observing was caused by an infection similar to tuberculosis.
4.4 By the early 1900s Johne's disease in cattle (then called pseusotuberculosis enteritis) was recognised as being widespread.2 Considerable research on the disease followed. By the 1940s paratuberculosis had been described in Africa, Asia and the Americas as well as Europe.
4.5 The first confirmed case of Johne's disease among sheep that the Committee is aware of was diagnosed in the late 1930s in Iceland.3 It was apparently introduced into Iceland with imports of sheep from Germany in 1933. The disease spread to 20-30 per cent of the nation's farms and losses from OJD reached more than 100,000 -in a country of 450,000 sheep. Authors of a paper on the introduction of the disease conclude that the experience in Iceland should act as a stimulus to all countries to exercise the utmost caution when introducing animals.4Johne's disease in sheep was subsequently considered to be a separate strain of the disease known as ovine Johne's disease (OJD) and has been diagnosed in sheep throughout Europe. However, the sheep (that is ovine) strain of the bacteria was very difficult to culture and it was not until the late 1980s that it was successfully cultured in the laboratory.
4.6 OJD was first reported in New Zealand sheep in 1952 in the Canterbury district of the South Island.5 Evidence soon emerged that this was caused by a different strain of M. paratuberculosis from the one responsible for BJD. For the next ten years incidence of clinical symptoms within flocks remained low - 0.5 to 4 per cent. Not until 1970 was the disease recognised outside the Canterbury district. Losses in flocks were still low, except for two farms, where they were such as to lead to the use of vaccination. The first case of OJD in the North Island was reported in 1972. The rate of identifying more infected flocks increased exponentially. By 1995, 1,500 flocks were known to be infected - that is, 6.4 per cent of all flocks. How many are actually infected is not known as there is no systematic surveillance or testing. Some claim that the actual level may be as high as 70 per cent.6 However, clinical disease generally remains low - usually 0-1 per cent in individual flocks.7
4.7 Generally New Zealand flocks are self-replacing, with only rams introduced. Consequently the OJD status of ram breeding flocks is critical to the spread of infection.8 This may have been a factor in the slow initial spread of the disease, and also the high prevalence and mortality in a few flocks.
4.8 Australian quarantine requirements on the importation of sheep have been very strict. However, since the 1950s it has been permissible to import sheep from New Zealand, subject to nationally agreed health protocols. These protocols required sheep to be accompanied by certification from New Zealand veterinary authorities that OJD was not known to occur in the flock of origin and that each sheep for import had been tested.9
4.9 OJD was first diagnosed in Australia on the NSW Central Tablelands in 1980, by veterinarians Dr Chris Dent and Dr John Seaman.10 There had been no report in Australia of Johne's disease in sheep prior to this, though it had been diagnosed in cattle and goats for many decades.11 Further investigations of the distribution of the disease suggested that it had been in the district for some years.12 While the origin of the Australian outbreak is not categorically known, trade with New Zealand makes that country a likely source.13 During the 1980s the protocols for importing sheep from New Zealand were tightened. 14Finding 4.1
That quarantine protocols have been inadequate to protect Australia's sheep flocks from diseases introduced from overseas.
4.10 Some submissions to the Inquiry suggested that OJD has been in Victoria for many decades, since the early 20th century and possibly even arrived with the First Fleet.15 The Committee has not, however, found any evidence to support such assertions.
4.11 On the other hand, Dr D. H. Pemberton, former research pathologist with the regional veterinary laboratories in Hamilton and Bairnsdale from 1971 to 1979, provided evidence that OJD is reasonably new to the Victorian sheep flock.16 According to Dr Pemberton, he undertook a research project during this time on the diagnosis of Johne's disease in cattle. He and his colleagues were very familiar with the symptoms and diagnosis of OJD. At the regional laboratories Dr Pemberton "was directly or indirectly involved in the autopsies of thousands of sheep during that time, most of which [he] examined histopathologically [microscopically]. Not a single sheep showed pathological changes suggestive of OJD." Dr Pemberton considers that, had OJD been present, it would certainly not have been missed.
4.12 Similar conclusions were made by Dr Kit Button, a government veterinarian who managed the government veterinary laboratory from 1986 to 1994. In this time, according to Dr Button, the laboratory screened many hundreds of livestock, including sheep. While his laboratory fairly regularly picked up bovine Johne's disease, it only picked up OJD once - in 1989.17This diagnosis of OJD in Victoria in 1989 was in a single ewe introduced from Flinders Island.18 Extensive testing at that time revealed no further evidence of infection. An earlier diagnosis of OJD, the first recorded in Victoria, was made in 1980 at the Bairnsdale Veterinary Laboratories, in sheep that had lived at the laboratory for some time.19 There was no evidence of any spread of the disease from these sheep. There are no other confirmed records of OJD in Victoria until 1995, when it was identified in several flocks in the Ensay area (although one witness to the inquiry stated that OJD had been identified in goats at Malden in 1975).20In the 1970s and 1980s the regional government veterinary laboratories provided a complimentary autopsy service. While sheep submitted for autopsy were not obtained evenly across the State,21it would have meant that a larger number of sheep that died on farms would have been autopsied routinely than in the 1990s - given the introduction of a fee for service policy in September 1990. The 1995 outbreak was not picked up by routine laboratory screening. Indeed, the first testing of what was subsequently known to be an OJD-infected sheep returned an "open finding".22 A couple of years prior to this another farmer was experiencing heavy lambing losses and had two very sick sheep. A local veterinarian couldn't identify the problem, even after post mortem of one of the sick sheep. The flock was later identified as being OJD affected.23 The ability to pick up the disease was thus perhaps not as effective as the government veterinarians had indicated.
4.13 The origin of the infection in East Gippsland is uncertain. The Committee was not able to obtain any direct evidence, although the owner of a property visited by the Committee in Ensay thought rams he obtained from NSW may have been the source. A farmer from Gelantipy gave evidence that he thought his flock may have become infected from a ram imported from new Zealand in 1982.24 Dr Pemberton believes that it is likely to have been the reliance on an inadequate blood test as the screening procedure for importation of a stud ram from New Zealand in 1984 that allowed OJD into Victoria.25 Certainly in the 1980s both NSW and New Zealand were known to have OJD and were selling sheep into Victoria.
4.14 If the source of infection was introduced in the mid-1980s, this would have meant that the level of infection would have been increasing and possibly spreading for around a decade. That the disease only became conspicuous in the mid-1990s is consistent with what is now known about the behaviour of the disease - see Chapter 7. It is also consistent with the observation of a shearer operating in the Ensay area for some 14 years, that he particularly noticed the presence of the disease only in the last few years.26The flocks involved in the 1995 outbreak were experiencing significant disease by this time, with progressive emaciation and high mortality rates.27 Mr and Mrs Evan Newcomen described the circumstances faced by the producers who were living with clinical symptoms of the disease:
We lived with the disease, knowing our sheep programme was finished, continually watching them die, one by one.28According to Dr Hugh Millar, Acting Chief Veterinary Officer, this experience of severe disease "was central to the subsequent development during 1996 of the industry's preferred position on how to deal with OJD on a state-wide basis".29SPREAD OF OJD
4.15 Reported distribution and prevalence of OJD may reflect, in part, the diligence with which veterinarians and stock owners have looked for the disease, as well as its actual presence.30 Consequently the disease may be more widespread in some countries than present information indicates.
4.16 Johne's disease has been reported from all continents and from almost all countries in the world. OJD, in particular, is found in temperate sheep-growing countries, but may be capable of spreading further into the sub-tropics and tropics than has previously been assumed.31 Some of these regions have mild climates due to their elevation and carry quite high stock densities - factors that are generally considered to encourage perpetuation of the disease.
4.17 However, prevalence varies greatly from one region to another. A comprehensive effort to evaluate prevalence in north-eastern Spain showed that up to 50 per cent of flocks were infected. The estimate for Greece is 61 per cent and for Germany is 10 per cent.32 Variation in incidence has been attributed to differences in soil, breed susceptibility and, most of all, to differences in management factors. Internationally, information on prevalence of OJD is scarce.33
4.18 Increasing concern over the disease and the growing pace of research led to the organisation, in 1983, of the First International Colloquium on Paratuberculosis in Ames, USA.34 These colloquia have become a triennial forum for sharing of information on Johne's disease. The Sixth Colloquium was held in Melbourne in 1999.35 At the conclusion it was stated that no country has yet provided evidence of freedom from M. paratuberculosis and the disease continues to spread between and within nations.36Spread in Australia
4.19 For more than a decade infection appeared confined to the Central Highlands of NSW. This appears to have been due to the fortuitous consequences of the trading patterns of the region. Sheep from this area are traditionally sold to slaughter or, for a much smaller proportion, for local restocking. That is, the region is not a sheep-exporting locality.37 Spread of OJD into other areas of NSW was identified in 1994.38By mid-1997 OJD had been confirmed in 170 flocks in NSW, as well as some on Kangaroo Island and Flinders Island.39 In Victoria some 33 infected flocks had been identified by the start of the OJD control program in January 1997.
4.20 At the end of March 2000 a total of 748 flocks had been identified as infected since 1980, with 511 flocks still infected. These figures were 0.9 per cent and 0.6 per cent respectively of the estimated total of 84,362 sheep flocks in Australia.40By the end of 1999, 30 infected properties had been detected on Kangaroo Island (South Australia) with a further 50 under investigation.41 In NSW a total of 494 infected flocks had been identified. A further 575 flocks were suspect and under investigation for various reasons. An additional 1,298 flocks were under surveillance. Recent abattoir surveillance indicates that 7 per cent of NSW flocks contain infected sheep.42
4.21 OJD was found on one property in mainland South Australia in late 1997, following the introduction of an infected sheep earlier in the year.43 This property was destocked and there is no evidence of the disease having spread from it.
4.22 No further infected flocks have been identified in mainland South Australia, and none on the main island of Tasmania nor in Queensland.44 No infected sheep have been identified in Western Australia, although one infected goat has been found in that State.45In Victoria, other nodes of infected flocks were identified in East Gippsland (in the Tambo and Buchan River valleys), in the Giffard, Darriman and Woodside area from mid-1996, around Kyneton in 1997 and Yea in 1999. By mid-2000, 188 infected flocks had been detected. Most have been destocked or are in the process of destocking.46 As at March 2000, there were 16 known infected properties in the State (and 66 suspect flocks and 394 flocks under investigation).
4.23 The situation now, according to Dr W. Sykes, former National Co-ordinator, OJD Research and Development, is that some 90 per cent of Australia's flocks are believed to be free of OJD.47 Its prevalence is low, other than in the Central Tablelands of NSW and parts of the Southern Tablelands.
4.24 Distribution of OJD-infected properties in NSW, as known at December 1999, is shown in Figure 4.1.
4.25 Distribution of OJD-infected properties in Victoria as identified at the same date is shown in Figure 4.2. Note, however, that most of the identified flocks have subsequently been destocked.
The spread of OJD both internationally and between regions of Australia has been by the introduction of infected sheep.
Source: Prowse (2000), p. 13.
Finding 4.3Most identified cases of OJD infection in Australia are in New South Wales and Victoria. |
4.26 It was recognised shortly after OJD was identified in New Zealand (in 1952), that control of the disease would be difficult because of the long incubation period, its length of survival in the environment and difficulties with diagnosis.48 The temperate New Zealand climate also favours survival of the infective agent.49 For these, and possibly other reasons, the control of OJD has been left essentially in the hands of individual producers. No regulatory control or eradication program has been attempted and national monitoring is not undertaken, although New Zealand is undertaking research and development in relation to OJD.50 The disease has continued to spread over the last 30 years and is now widespread through out New Zealand and essentially endemic.51
Source: Prowse (2000), p. 11.
4.27 Since 1987 a killed vaccine has been in use. It is found to produce some damage to the injection site.52Europe
4.28 Vaccination programs mounted against OJD in Cyprus, Iceland and Spain, and against Johne's disease in goats in Norway, appear to have been successful in reducing the incidence of the disease.53 Cyprus claims to have eradicated OJD using a live vaccine.54In Iceland, early extensive efforts to control spread of OJD included fencing to restrict sheep movement, testing and slaughter of individuals and destocking.55 All these approaches failed. Cattle retained on properties appear to have been responsible for reinfecting sheep after restocking.56 Experimentation showed that vaccination could reduce mortalities by 94 per cent. Lambs are vaccinated once with a killed vaccine. Vaccination in endemic regions became compulsory in 1966. This has led to considerable reduction in losses. Sheep are kept within one specific region during the eradication campaign.57 Serological testing is used as well, to detect infection in `non-infected' regions. OJD is reported to have been eradicated from some regions. Vaccination is to be stopped in those regions and abattoir surveillance undertaken for the next ten years.58Norway failed to eradicate Johne's disease from goats using hygiene as well as isolation and slaughter of diseased animals. A compulsory vaccination program on kids, started in 1967, using live vaccine, reduced infection rate from 53 per cent to 1 per cent, as evidenced by post-mortem surveys. Those infected had missed timely vaccination.59Mexico
4.29 In Mexico test-and-cull is used to reduce prevalence of Johne's disease in goat flocks.60South Africa
4.30 The first case of OJD in South Africa was diagnosed in a merino sheep imported from Germany in 1967.61 The presence of OJD in 1993 in a flock in the Western Cape Province marked the beginning of its identification in commercial flocks. In 1996, at the urging of farmers, it was decided to assess the spread of the disease, first in two provinces and then on a national basis. This is to be a precursor to a control program. These actions are seen as needed to prevent further spread of the disease. As at 1999, no integrated control measures appear to have been initiated.
4.31 A Market Assurance Program has been introduced in the United States and there is considerable commitment to research and development.62Poor results from control programs for Johne's disease have been attributed mainly to an inadequate understanding of the disease by livestock owners and veterinarians.63Application of Overseas Programs to Australia
4.32 It is difficult to draw conclusions from these overseas programs that are useful in Victoria. Among other things, as previously indicated, the strain of OJD may be different. While New Zealand appears to have the same strain, the characteristics of the New Zealand flock and its environmental conditions are very different from those in Australia. For instance, the New Zealand flock is dominated by meat breeds, whereas in Australia the merino is the dominant breed. New Zealand also has a more reliable climate that is cool and damp and sheep are less likely to suffer from shortage of fodder due to drought.
4.33 Of the many countries afflicted with Johne's disease, only a few have compulsory eradication programs; most depend on voluntary participation in programs.64 It seems, however, that the only successful control programs in endemic areas are those that have used compulsory vaccination.
In many other overseas countries OJD is endemic and control programs largely voluntary. Long-term compulsory vaccination programs appear to be successful, but there is no consistent pattern of control.
4.34 The spread of OJD from its original focus in central NSW led concerned producers to initiate a steering committee in 1995 to co-ordinate policy.65 Representatives of peak national and NSW sheep industry organisations and relevant government agencies met in Sydney and resolved to form a Johne's Disease Sheep Industry Steering Committee to plan the "control and ultimate eradication of Johne's disease from Australia".66 A wide cross-section of producer groups, as well as government and research organisations, were represented on this Committee.
4.35 A complex political process followed.67 At the time, the necessary funding and support from government and industry for a national OJD control program was not forthcoming.68 Individual States were also setting up their own programs. In October 1996, the NSW Government began implementation of its Sheep Johne's Disease Strategic Plan 1996-2005.69 In December 1996, Victoria initiated an OJD control program based on eradication by destocking allied with compensation (this was the only State with such a program). At around this time there was a desire to establish a national program to share costs, on the basis that all would share the long-term benefits.70
4.36 Though the National OJD Program was only formalised in 1998, development of a national response to OJD had been in progress since 1997. Animal Health Australia (Animal Health Council of Australia Ltd) played a pivotal role in these responses.
4.37 Animal Health Australia is a non-profit company with funding coming from State, Territory and Commonwealth governments, key primary industry groups and other interested organisations.71 It has, since 1996, undertaken the facilitation and co-ordination of a national approach to animal health services and standards.72 There are currently seven non-executive directors and nine full-time support staff.
4.38 In early 1997 Animal Health Australia was asked to implement a national OJD program. Initial efforts to control OJD at a national level centred on implementation of a Market Assurance Program and development of a set of Standard Definitions and Rules.73 The latter were published in January 1998 and are currently being updated.
4.39 At that stage eradication by destocking was still the intention, but it stalled over funding issues.74 In an effort to move forward, the Commonwealth Minister for Primary Industry and Energy commissioned a study by Dr Denis Hussey and Prof. Roger Morris to provide guidance on a national approach to OJD.75 Recommendations contained in the resulting report, widely known as the `Hussey and Morris Report', were accepted by the Agricultural and Resources Council of Australia and New Zealand in February 1998. The report focused largely on the need to obtain better information on which to build a rational and effective control program and, in the interim, to contain the disease.
4.40 In the period before the national program was established (between 1 April and the 30 September 1998) an Interim Surveillance Program was set up to clarify the distribution of OJD. During this period funds were supplied for farmers to undertake testing.76During 1998 Animal Health Australia commenced preparation of a detailed six-year business plan for a National Johne's Disease Control and Evaluation Program (commonly referred to as the National OJD Program). This put in place a program to fulfil the recommendations of the Hussey and Morris Report. Details of this program are given in a later section.
4.41 The National OJD Program is intended to run for six years from 1998.77 Under the program the States, federal government and industry groups involved have agreed to an integrated national approach to the control of OJD.78The defined purposes of the National OJD Program are to:
a) provide, through an effective research program, sufficient information to allow an informed decision to be made on the national management of OJD, including particularly the feasibility and cost-effectiveness of eradication; and
b) control OJD during the research period.
4.42 The estimated cost of the program is $40.1 million, with $10.5 million being allocated to research, $18 million to surveillance, $0.6 million to communication and $7.5 million to restocking incentives.79 The program is funded equally by the federal government, the State governments and industry.
4.43 The National OJD Control and Evaluation Business Plan was prepared in 1998-99.80 Since then there has been a series of meetings to deal with implementation and reporting procedures.
4.44 The Plan is comprised of the following five distinct parts:81a Research and Development Program;
a) an Operational Program to contain OJD;
b) a Management Program to ensure appropriate funding arrangements and achievement of objectives;
c) a Communications Program; and
d) Assistance Measures delivered by the States to provide the financial incentives necessary for the implementation of programs (a) and (b).
4.45 The aim of the Research and Development Program is to fill key gaps in information relevant to the detection, control and possible elimination of M. paratuberculosis.82 It includes:
a) extensive on-farm trials to evaluate and optimise disease reduction and elimination strategies and to develop a better understanding of the epidemiology of OJD;
b) basic and applied research needed to underpin on-farm work;
c) specific further diagnostic test development;
d) support for the development of an effective sheep identification system;
e) further evaluation of surveillance and testing strategies and payment of producers to assist them to become involved in the Research and Development trials.
4.46 The Operations Program is conducted by the States. It comprises a strategy to contain OJD during the evaluation period, including a surveillance program to define the current and potential extent of OJD infection in Australia.83 Key tasks include:
a) defining area and property disease status and developing appropriate criteria for monitoring;
b) reporting and more adequately predicting the extent of the disease and identifying risk factors associated with the spread of the disease;
c) implementing an ongoing monitoring of zones for disease-control purposes; and
d) reviewing and promoting laboratory quality-control procedures.
4.47 As part of the Communications Program, Animal Health Australia publishes regular surveillance reports.84
4.48 A Deed of Agreement, executed in March 1999, sets out the contractual relationships between Animal Health Australia, the Commonwealth, State and ACT governments and the Sheepmeat and Wool Councils of Australia for funding and implementation of the six-year National OJD Program.85The Deed reiterates the objectives of the Business Plan and commits the parties to it to its financial support of the Program, as well as other actions. For State governments these actions include:86effective control of OJD within the State in accordance with the Standard Definitions and Rules;
a) the efficient management of the surveillance component of the National OJD Program and provision of information as required to Animal Health Australia; and
b) assessment and approval, as appropriate, of flock owners, sheep and properties for Property Disease Eradication Plans and participation in research projects under the National OJD Project.
4.49 As signatory to this Deed, the Victorian Government is bound by these obligations.
4.50 The nationally agreed Standard Definitions and Rules - Ovine Johne's Disease was developed by the Veterinary Committee of the Standing Committee on Agriculture and Resource Management.87 This committee comprises the Chief Veterinary Officers of each State. The purpose of the document is to assist control of OJD in a nationally co-ordinated manner. It sets out minimum standards for activities aimed at containment and property-level eradication of OJD.88Rules contained within the document deal with such matters as:
a) testing flocks for OJD;
b) defining flock status;
c) establishing zones related to the extent of the disease and conditions controlling movement of sheep within and between zones;
d) destocking and decontamination of land; and
e) disposal of infected stock.
4.51 The provisions of the document are given effect through State legislation and administrative policy. The document itself was not, however, subject to any form of public comment prior to adoption. While prescribing an agreed minimum approach, the Standards Definitions and Rules none the less provide considerable scope for variation between States. For instance, in certain circumstances it requires flocks to be subject to "control measures over the movement of animals", to have an "advisory program in place" or that "eradication measures be enforced". There is no prescriptive definition of a control measure, advisory program or eradication measure. The document does not prescribe whether compensation should or should not be paid or what other form of support program should be provided. All such aspects of OJD programs are determined by the individual States.
4.52 A revision of the Standard Definitions and Rules is due to be completed in October 2000.89 Appendix 4 of these revisions, which has been made available to the Committee, details procedures for `trace-forward' and `trace-back' to determine whether properties that have bought sheep from, or sold sheep to, known infected properties are also infected. Restrictions that are placed on such `suspect' properties are given, as are conditions under which the `suspect' status can be removed.90
4.53 The object of zoning is to stem the spread of infection from high-risk areas - that is, it forms a `containment' approach.91 Zones defined in the Standard Definitions and Rules are `free', `protected', `control', `residual' and `infected'.92 In both `residual' and `infected' zones OJD is considered endemic. Sheep can be traded into these zones from other zones provided that they are not from an infected flock. However, restrictions apply to sheep traded out of these zones to a `control' or `free' zone. For a `control' zone restrictions apply to the introduction of sheep from a `residual' zone and to a `free' zone. While the boundaries of the zones are drawn up by the individual States, the Veterinary Committee needs to be satisfied that all requirements for a particular zone have been met or, in the instance of the `free' zone, be declared by the Standing Committee in Agriculture and Resource Management.93
4.54 The requirements that need to be met for each zone are summarised in Table 4.1.
4.55 Current zones are large. The whole of Victoria is a `control' zone, as are Queensland, mainland South Australia and much of NSW. No region in Australia has been zoned `infected', within which there would be minimal regulations enforced to control OJD. The Central Tablelands and part of the Southern Tablelands of NSW and Flinders Island (Tasmania) are in a `residual' zone, while Western Australia is a `free' zone. Queensland and South Australia are seeking upgrading from `control' to `protected' status.94 The boundaries of all of these zones are shown in Figure 4.3.
4.56 The boundaries of the zones are drawn up by the individual States in accordance with the agreed criteria defined in the Standard Definitions and Rules, with restrictions enforced under State legislation.
|
Requirement |
Infected |
Residual |
Control |
Protected |
Free |
|---|---|---|---|---|---|
|
OJD infection is endemic. |
_ |
_ |
|||
|
OJD may be present in a manageable number of defined foci, or in flocks where the infection has been recently introduced. |
_ |
||||
|
OJD occurs only sporadically. |
_ |
||||
|
No flocks are infected or `suspect' and the population of susceptible species has been assessed. |
_ |
||||
|
No or minimal regulatory measures are enforced. |
_ |
||||
|
OJD is notifiable and movement restrictions on susceptible species are enforced for infected flocks. |
_ |
||||
|
OJD is notifiable. |
_ |
_ |
_ |
||
|
An approved monitoring plan is in place. |
_ |
||||
|
An approved monitoring plan is in place and operating and there is ongoing evidence to justify the zone's status. |
_ |
_ |
|||
|
Reports of activities and outcomes are presented annually (or as otherwise agreed) to Veterinary Committee. |
_ |
_ |
|||
|
Thorough tracing and investigation of all known or suspected infection is undertaken. |
_ |
_ |
_ |
||
|
No restrictions on movement into the zone. |
_ |
_ |
|||
|
There will be restrictions on movement into the zone from an infected or residual zone. |
_ |
||||
|
Movements into the zone from zones of lower status must meet prescribed health standards for OJD. |
_ |
_ |
|||
|
All infected or `suspect' flocks are subject to control measures over the movement of susceptible animals, including control measures to minimise the risk of spread to neighbours. |
_ |
||||
|
All infected flocks (or `break downs' in the free zone) or `suspect' flocks are placed in quarantine. Eradication measures are enforced in infected flocks, and `suspect' flocks are actively investigated to determine whether infection is present. |
_ |
_ |
|||
|
Vendor/owner declarations may be used for voluntary movement controls. |
_ |
_ |
|||
|
Vendor/owner declarations are encouraged for voluntary movement within the zone. |
_ |
||||
|
An advisory program is in place to ensure there is producer awareness about the disease and its prevention, and that there are requirements for introducing sheep into the zone. |
_ |
_ |
|||
|
Vaccination may be approved by the Chief Veterinary Officer. |
_ |
_ |
|||
|
There are no vaccinated animals. |
_ |
_ |
4.57 The Committee was told, while on its inspection tour of NSW, that trade restrictions imposed by zoning can cause considerable hardship to producers. It has also been suggested that Victoria has only escaped the greater restrictions of `residual' zoning because of its program of eradication with compensation.95 If Queensland and South Australia were successful in achieving `protected' status this would impact on Victoria's ability to trade with these States.
Finding 4.5Under the current nationally agreed rules, trading restrictions apply according to the OJD status of the State or a region within the State. Zones with the highest level of OJD have the highest level of trading restrictions imposed. These are in addition to trading restrictions on individual properties under quarantine. |
4.58 The Market Assurance Program for OJD, known as `SheepMAP', has been running since May 1997.96 It is based on concepts of risk management - that is, providing a high level of probability, rather than certainty, that the flock is free of OJD. The level of probability is set at 95 per cent or higher. The declared level of risk applies to the whole flock - that is, the probability that no animal within the flock is infected. The risk that any individual animal is infected will be much lower.
4.59 SheepMAP is a voluntary program.97 It depends on biennial testing and flocks are given an `assessed' status based on how many times they have been tested.98 After the completion of the first negative test they are rated as `Monitored Negative' level 1, or MN1. A second negative test gives MN2 status and a third negative test results in MN3 status. The program is supported by published Rules and Guidelines. Under these, testing has to be undertaken by an approved veterinarian and the producer has to enter into an agreement to implement an approved management plan. Private veterinarians are `approved' through a training program run by the State veterinary authorities.
4.60 By December 1998 there were 548 assessed flocks under the program in Australia, mainly in NSW, Victoria and South Australia.99 At this stage three of these flocks, of MN1 status, had been shown to have OJD. 100Stud livestock shows and sales are increasingly demanding that sheep presented have been assessed under SheepMAP.101 According to staff of Animal Health Australia, interest in buying from assessed flocks is increasing. The Committee has no evidence that this is being translated into higher prices for assessed flocks at this stage.
4.61 NSW is using regional zoning in line with prevalence of disease in the region and restriction of trading between zones. Infected properties are quarantined, with sales of stock permitted only to slaughter. Similar restrictions are also placed on `suspect' properties until sufficient testing has been done to clear them of suspicion. Testing and abattoir surveillance are being used to define the distribution and prevalence of infection.
4.62 Sale of sheep from infected properties is only permitted under the following conditions:
a) direct to the abattoir for slaughter;
b) by auction on the property for slaughter; and
c) with special permission, live to another infected property.102In addition to meeting the requirements of the National Program, NSW Agriculture introduced the notion of Property Disease Eradication Plans some years ago. These were applied, for example, in the footrot eradication program described in Chapter 3. This approach has been used for OJD for several years, but now has been extended to allow development of property disease control plans where eradication is not seen as appropriate.103 The idea has now been extended in NSW to more general control and containment of OJD, rather than only eradication.104According to NSW Agriculture, there have been a number of instances of civil litigation where vendors of sheep have been sued for damages following the introduction of OJD into another flock. Damages are potentially "many times greater than the value of the stock that was sold".105 No case has, as yet, been successful.106NSW Agriculture has produced a range of fact sheets on M. paratuberculosis and OJD. These provide useful information in easily readable form. This information includes guidance for farmers running a variety of types of sheep enterprises on ways to minimise the impacts of OJD on their properties and also sources of further information. Fact sheets encourage co-operation between farmers, particularly neighbours. There is recognition in them of financial, social and emotional impacts of OJD. Information is offered on ways to deal with these aspects of the disease as well as purely animal health management.107Queensland, Western Australia and Mainland South Australia
4.63 Queensland and Western Australia have instituted restrictions on movement of sheep from other States across their borders to prevent the introduction of OJD.108
4.64 Since 1986, authorities in Western Australia have required a declaration from vendors of sheep in other States before sheep may be imported to Western Australia.109 The vendor must be able to state that their sheep are free of OJD and have been free of the disease for the preceding five years.110 In August 1996 further requirements were put in place to protect the Western Australian flock. All sheep to be imported now have to be blood tested and show a negative result. They must also come from a tested-negative flock - MN2 for sheep from a `residual' or `control' zone and MN1 for a `protected' zone.111 Nine to eighteen months after the sheep enter Western Australia they are further tested and must test negative. A major extension campaign has been undertaken to inform intending importers about OJD and import requirements.
4.65 Continuing surveillance in Western Australia identified one case of OJD - in mid-2000 - in a cashmere goat imported into Western Australia from an infected flock in New South Wales. Investigations into the possible spread of this infection are in progress.112 To maintain the OJD-free status of Western Australia the property concerned is to be destocked and decontaminated. Consideration is being given to a one-off compensation package for the affected producer.113The South Australian Government has reached an agreement with its sheep industry on a destocking program with compensation for producers with OJD-infected flocks on Kangaroo Island.114 Property destocking in stages is allowed on Kangaroo Island.115 The South Australian Government will contribute to the compensation fund. Mainland South Australia has applied for the State (apart from Kangaroo Island) to be declared a `protected' zone under the National OJD Program in 2002. This application has been strengthened by the recent clearing of the one `suspect' flock in the State from suspicion of infection.116The Tasmanian Government has yet to announce an approach to OJD control for Flinders Island, over and above the required quarantine.
Finding 4.6In NSW, the State with the highest levels of recorded OJD infection, control approaches include `minimisation' as well as quarantine between zones and voluntary eradication by destocking. Other States, being those with mostly low levels of identified OJD, have control approaches based on exclusion, quarantine and eradication by destocking. |
1 Johne's Information Centre (1997b).
2 Johne's Information Centre (1997b).
3 Fridriksdottir, Gunnarsson, Sigurdarson and Gudmundsdottir (1999).
4 Fridriksdottir, Gunnarsson, Sigurdarson and Gudmundsdottir (1999).
5 West (1997).
6 Brett, 1995 quoted by Prowse (2000), p. 27.
7 Prowse (2000), p. 27.
8 West (1997).
9 Department of Natural Resources and Environment (2000), Written Submissions, OJD 087.
10 NSW Agriculture (1999b).
11 Denholm, Ottaway, Cornish and Merton (1997).
12 NSW Agriculture (1999a).
13 NSW Agriculture (1999a).
14 Department of Natural Resources and Environment (2000), Written Submissions, OJD 087.
15 For example Layton, L. (2000), Minutes of Evidence, 14 June 2000 and Esson, C. (2000) Written Submissions, OJD 025.
16 Pemberton, D. H. (2000), Written Submissions, OJD 042.
17 Button, C, (2000), personal communication, 17 May 2000.
18 Millar, H. (2000).
19 Galvin, J. (2000), Manager, Animal Health Operations, Department of Natural Resources and Environment, Minutes of Evidence, 7 August 2000.
20 Hartigan, K. (2000), Minutes of Evidence, 14 June 2000.
21 Kefford, K. (2000), Executive Director, Agriculture, Department of Natural Resources and Environment, correspondence to the Committee, 22 September 2000.
22 Newcomen, E. O. (1998), Senate Proof Committee Hansard, Rural and Regional Affairs and Transport References Committee, Reference: Prevalence and Incidence of Ovine Johne's Disease, Wednesday, 11 February 1998.
23 Bryce, E. (2000), Minutes of Evidence, 17 May 2000.
24 Hodge, N. (2000), Minutes of Evidence, 18 May 2000.
25 Pemberton, D. H. (2000), Written Submissions, OJD 042.
26 Lloyd, C. R., (2000), Minutes of Evidence, 17 May 2000.
27 Millar, H. (2000), p. 1; and also Newcomen, E. and D. (2000), Written Submissions, OJD 058.
28 Newcomen, E. and D. (2000), Written Submissions, OJD 058.
29 Millar, H. (2000), p.1. The reference to industry, presumably means as represented by the Pastoral Group of the Victorian Farmers' Federation.
30 Johne's Information Centre (1997b).
31 Denholmn, L. (2000), NSW Agriculture, personal communication, 25 May 2000.
32 Juste (1997).
33 Juste (1997).
34 Johne's Information Centre (1997b).
35 Manning and Collins (1999).
36 Meat and Livestock Australia (1999), pp. 17-19.
37 Eppleston and Simpson (1999).
38 Nicholls (1999).
39 Links, Sergeant, Moloney and Reddacliff (1999).
40 National Ovine Johne's Disease Control and Evaluation Program (2000), p. 3.
41 Rayner (2000).
42 Anon. (2000c)
43 Allworth and Kennedy (1999).
44 Australian Animal Health Council Ltd. (2000b); and also Allworth and Kennedy (1999).
45 Boylen (2000).
46 Kefford, B. (2000), Executive Director, Agriculture, Department of Natural Resources and Environment, Minutes of Evidence, 7 August 2000.
47 Sykes, W. (2000), Animal Health and Research Consultant, Minutes of Evidence, 24 July 2000.
48 West (1997).
49 West (1997).
50 Meat and Livestock Australia (1999), p. 4.
51 Prowse (2000)
52 West (1997).
53 Meat and Livestock Australia (1999), p. 6.
54 Benedictus, Verhoeff, Schukken and Hesselink (1999).
55 Fridriksdottir, Gunnarsson, Sigurdarson and Gudmundsdottir (1999).
56 Meat and Livestock Australia (1999), p. 23.
57 Benedictus, Verhoeff, Schukken, and Hesselink (1999).
58 Meat and Livestock Australia (1999), pp. 4-5.
59 Benedictus, Verhoeff, Schukken, and Hesselink (1999).
60 Vélez Herández, Domínguez Punaro, del Río Alfaro, F., Suárez Guemes and Chávez Gris (1999).
61 Michel and Bastianello (1999).
62 Meat and Livestock Australia (1999), pp. 4-5.
63 Meat and Livestock Australia (1999), p. 12.
64 Gee (1999a).
65 Nicholls (1999).
66 Denholm, Ottaway, Cornish and Merton (1997).
67 Denholm, Ottaway, Cornish and Merton (1997).
68 Nicholls (1999).
69 Denholm, Ottaway, Cornish and Merton (1997).
70 Nicholls (1999).
71 Australian Animal Health Council Ltd. (2000a).
72 Australian Animal Health Council Ltd. (2000a).
73 Veterinary Committee (1998); and also Allworth and Kennedy (1999).
74 Nicholls (1999).
75 Hussey and Morris (1998).
76 Allworth and Kennedy (1999).
77 Australian Animal Health Council Ltd. (1998a).
78 National Ovine Johne's Disease Deed of Agreement (March 1999), Recital A
79 Allworth and Kennedy (1999).
80 Australian Animal Health Council Ltd. (2000b)
81 Australian Animal Health Council Ltd. (2000b).
82 Australian Animal Health Council Ltd. (2000b).
83 Australian Animal Health Council Ltd. (2000b).
84 For example - Australian Animal Health Council Ltd. (2000c).
85 National Ovine Johne's Disease Program Deed of Agreement (March 1999); and also Australian Animal Health Council Ltd. (2000b).
86 National Ovine Johne's Disease Program Deed of Agreement (March 1999), S 6.4.
87 Veterinary Committee (1998).
88 Allworth and Kennedy (1999).
89 Millar, H. (2000), Acting Chief Veterinary Officer, Department of Natural Resources and Environment, personal communication 11 August 2000.
90 Usually a single negative flock sample is now taken as adequate to remove suspect status, in spite of the long development time of the disease. However the sheep introduced from the infected farm are required to be included in the sample.
91 Kennedy and Harkin (1998).
92 Veterinary Committee (1998).
93 Veterinary Committee (1998).
94 Millar, H. (2000), Acting Chief Veterinary Officer, Department of Natural Resources and Environment, personal communication, 14 March 2000.
95 Millar, H. (2000), Acting Chief Veterinary Officer, Department of Natural Resources and Environment, personal communication, 14 March 2000; and also Shea, D. (2000), Ararat Branch, Victorian Farmers Federation, Written Submissions, OJD 029.
96 Allworth and Kennedy (1999).
97 Allworth and Kennedy (1999).
98 Allworth and Kennedy (1999).
99 Allworth and Kennedy (1999).
100 Allworth and Kennedy (1999).
101 Allworth and Kennedy (1999).
102 NSW Agriculture (1997b), Johne's Disease in Sheep, Agfact A3.9.44, NSW Agriculture, Orange NSW.
103 Roth, I. (2000), Program Manager Wool and Sheep Meat Services, NSW Agriculture, personal communication, 3 July 2000.
104 NSW Agriculture (1999a), and also Roth, I. (2000), Program Manager Wool and Sheep Meat Services, NSW Agriculture, personal communication, 3 July 2000.
105 NSW Agriculture (1997b).
106 Denholmn, L. (2000), NSW Agriculture, personal communication, 8 July 2000.
107 For example NSW Agriculture (1999b).
108 Millar, H. (2000), Acting Chief Veterinary Officer, Department of Natural Resources and Environment, personal communication, 14 March 2000.
109 Higgs (1997).
110 Higgs (1997).
111 Hodgen (2000).
112 Boylen (2000).
113 Anon. (2000b).
114 Smart (2000).
115 Anon. (2000b).
116 Rayner (2000).
