Johne’s disease and the Queensland beef industry: frequently asked questions

These frequently asked questions about Johne’s disease and the Queensland beef industry are current as of 1 July 2018, they are subject to change. Please check with your local veterinarian or Animal Health Australia for the most recent information and to discuss Johne’s disease in more detail. A list of contacts and references for more information is available on the ‘More resources, references and links’ tab below.

You may also like to read the Johne’s disease update and watch the Johne’s disease and maintaining market access post June 2017 webinar (19 April 2017) with Rachael O’Brien from the Livestock Biosecurity Network.

  • Johne’s disease management is now an industry program, developed by the national cattle industries (dairy and beef). The national industry program does not support regulatory controls by governments – this includes zoning, interstate movement restrictions, quarantines, regulatory tracing and regulatory testing.
  • The national industry program is based on voluntary, market-driven participation. Producers can decide how they manage JD risks according to their own property management objectives and market demands.
  • The program has developed tools to assist producers to assess and declare JD risks in line with voluntary producer management. These tools include:
    • Cattle Health Declaration
    • J-BAS (Johne’s disease – Beef Assurance Score)
    • JD Checklist of key elements to consider in planning
    • Biosecurity plan templates
  • J-BAS is a simplified assessment too for the beef industryl; it is not the only one, nor the most comprehensive, but it provides an acceptable standardised method of describing risk management.
  • A J-BAS score of 7 or higher indicates that the property is actively managing to prevent infection entering or being spread from the property. A score of 6 or less indicates that the property’s focus for JD management is to minimise the impact of clinical disease.
  • Note that a J-BAS score is not an indicator of management skills, competence or even quality. A low or zero J-BAS score does not necessarily mean that producers are negligent or irresponsible.  Some properties will best meet their production, trading and economic objectives by holding a low or zero J-BAS score; others may prefer a higher score.
  • J-BAS has been adopted as a regulated standard by WA & NT in response to their own jurisdictions’ industries’ demands.
  • Biosecurity was added as a module to the Livestock production Assurance (LPA) program from 1 October 2017.
  • LPA accredited producers must have a Farm Biosecurity Plan and implement best-practice biosecurity practices in their on-farm management. Biosecurity practices will be audited as part of the LPA audit.  In effect, this applies to all producers who market livestock.
  • LPA is the Australian livestock industry’s on-farm assurance program. It provides customers and consumers with an assurance that Australian red meat is produced ethically, safely and in a biosecure way.
  • The range of recommended farm biosecurity plan templates for Johne’s disease will satisfy the LPA requirement. These include templates available from Livestock Biosecurity Network, Animal Health Australia, Australian Cattle Veterinarians, and some breed societies.
  • There was a transitional arrangement for beef herds in Queensland to claim a J-BAS score of 7, but that ceased on 30 June 2018.
  • Under the transitional arrangement, Queensland herds could retain J-BAS score 7 by:
    • Having in place a property biosecurity plan which:
      • Addresses the elements of the JD checklist (available on the AHA website) and
      • Is endorsed by a veterinary advisor, and
    • Undergo Check testing (50 animals) with negative results before 30 June 2018, and repeated every three years.
  • Queensland herds which have a biosecurity plan in place (whether or not the plan is endorsed by a veterinary advisor) but have not undertaken a Check test with negative results in the three years before 30 June 2018, are eligible for J-BAS score 6 (unless their herd has had clinical JD in the past 5 years).
  • Note that LPA requires a biosecurity plan for accreditation. To support a J-BAS score, a biosecurity plan should address the elements of the Johne’s disease in Cattle Biosecurity Checklist.
  • From 1 July 2018, any beef herd which wants to progress or regain J-BAS score 7 must have a biosecurity plan agreed with a veterinary advisor and must undergo a sample test (210-300 samples, depending on herd size).
  • Note that J-BAS is a tool for both declaring your own risk status and for assessing the risk status of stock that you might buy in or agist with.
  • J-BAS applies nationally, so a J-BAS score has the same pre-requisites whether the herd is located in a previous low-risk area such as Queensland or in a previous high-risk area.
  • A J-BAS score of 6 provides significantly less biosecurity assurance against a property becoming infected or cattle being low risk for spreading infection than does a J-BAS score of 7. J-BAS 6 indicates that the disease impacts of infection are being managed, J-BAS 7 (and J-BAS 8to a greater extent) shows the property is unlikely to be infected.
  • At J-BAS 6, a herd can be infected just as long as it has not had (or at least reported) a clinical case in the preceding 5 years.  There is no quality management of Johne’s disease by veterinary oversight of the biosecurity plan at score 6, and no differentiation of risk according to zones. A J-BAS 6 herd which is bringing in other J-BAS 6 animals is accepting that level of risk across Australia.
  • A J-BAS score of 6 is at odds with protecting against entry of infection to retain the same level of low risk previously enjoyed by Non-Assessed herds in Queensland.
  • It is possible to bring in cattle of lower status and still actively manage the JD risk. See the FAQ, “Will I lose my J-BAS score if I bring in cattle of lower status?”
  • If you want to protect against JD you need to actively manage JD through a quality biosecurity plan subject to veterinary advice and testing every three years (J-BAS 7); or accept a higher level of risk of infection at J-BAS 6.
  • JD management for Queensland commercial producers will be largely a balance between keeping their herds closed (to prevent the entry of infection) and introducing livestock (bulls, breeders, steers and bullocks, sheep, goats) to sustain production. (There are some other elements to managing JD, such as keeping sound boundary fences, having a biosecurity plan, and testing.)
  • Think about who buys your cattle (in the recent past and in the foreseeable future) and what level of assurance against Johne’s disease your market will demand. You may wish to consult your buyers or agent for their views.
  • Think also about how much you want to protect your property and herd against becoming infected with Johne’s disease.
  • These two factors will guide you towards your preferred J-BAS score:
  1. Maintain low-risk status (J-BAS 7) that you achieved before 30 June 2018
    • Farm biosecurity plan to protect against entry of infection and monitor for infection, supported by a veterinarian.
    • Check Test before 30 June 2018, and repeated every three years to show infection has probably not occurred.
  2. Regain low risk status (J-BAS 7)
    • Farm biosecurity plan to protect against entry of infection and monitor for infection, supported by a veterinarian.
    • Sample Test after 1 July 2018 to progress from J-BAS 6.
    • Check Test every three years to show infection has probably not occurred.
  3. Minimal management of risk (J-BAS 6)
    • Farm biosecurity plan that addresses JD risk factors which are identified in the JD Cattle Checklist.
    • Veterinary support is not required; it might be considered, at least for drafting the biosecurity plan.
    • Testing is not required.
  • The two key actions that commercial producers should do are:
    • Draw up a biosecurity plan that addresses JD risks; this will help you identify why, how, and how much you want to manage JD risks.
    • Use a National Cattle Health Declaration for every cattle transaction from now on (buying, selling, showing or agisting).

The national BJD program defines a biosecurity plan as a herd-specific management protocol for protecting a herd against the introduction or transmission of ptb. and other diseases.

Many resources:

  • BJD checklist on AHA cattle tools webpage to identify key elements that address JD in cattle
  • Templates available from:
  • You do not have to use any particular template, just as long as:
    • it addresses the minimum standards set by the National Farm Biosecurity Reference Manual for Grazing Livestock production, and
    • the elements of the JD in Cattle Checklist are considered.

Keep it simple:

  • Identify your own farm’s objective for managing JD and other biosecurity issues
  • Use AHA JA in Cattle Checklist to identify which factors apply to your farm and objectives for JD
  • For most Queensland beef properties that wish to manage the adverse impacts of JD, the key elements of a biosecurity plan will be to ensure:
    • Secure boundaries
    • All livestock entering the property come from properties that have J-BAS score of 6 or preferably of scores 7 or 8, declared on a Cattle Health Declaration and supported by evidence.
    • Buyers should ensure that they assess the Cattle Health Declaration before bidding or buying cattle.  To enable this, you should seek a copy from the vendor or selling agent well before the sale; do not allow yourself to be bullied into not getting the declaration.  You may also wish to ask to see supporting evidence, such as the property biosecurity plan and/or test results, and lifetime NLIS property history of declared animals.
    • The biosecurity plan should also consider the property’s history of livestock introductions, to identify and appropriately monitor high risks.
  • For Queensland beef properties that wish to prevent the entry of JD, the biosecurity plan should also specify:
    • All livestock entering the property come from properties that have J-BAS scores of 7 or 8, declared on a Cattle Health Declaration and supported by evidence. This is particularly important for livestock sourced from areas of higher prevalence (south eastern Australia) and from properties where there has been co-grazing with high-risk sectors (sheep and dairy cattle of south eastern Australia). Over the long term, a property owner could not credibly claim a J-BAS score of 7, nor could a veterinary advisor credibly endorse a biosecurity plan, if lower-status cattle are still allowed entry.
  • The plan should also address other biosecurity issues, such as other diseases, pest animals, weeds.
  • List the actions to meet that objective that:
    • You do already and will continue
    • You need to do (in a specified timeframe) within the next 12 months
    • Are aspirational, that you would like to do over a longer period.

Get help from

  • Your JD-trained vet
  • LBN.
  • Biosecurity plans for JD should be based on ‘herds’ according to risk of spread of infection. Cattle on different blocks within an enterprise, or agistment cattle on a property, may or may not be considered part of a single ‘herd’ depending on the level of co-grazing, animal exchange, and use of shared facilities.
  • A simple guide should be to only amalgamate cattle into one biosecurity plan if they contact each other or each other’s grazing land at all within a twelve months period, and to only separate cattle into more than one plan if they have no contact with each other or each other’s grazing land for at least 12 months.
  • A JD-trained veterinary advisor should definitely be engaged to develop a complex plan where more than one ‘herd’ might be involved.
  • There is no central register of biosecurity plans to lodge or notify.
  • The plan is useful to you:
    • It can help you to meet the Johne’s disease arrangements, if you want to claim a J-BAS score (score 2-6 requires a plan, score 7-8 requires a plan which is endorsed by a veterinary advisor)
    • It can help you to identify and appropriately manage risks of animal diseases (including but not limited to Johne’s disease), crop and plant diseases, pest animals and weeds
    • It is evidence that you meet the LPA requirement for a biosecurity plan.
  • You should keep the plan secure and readily accessible.  You can then use it regularly to guide your approach to diseases and pests and also to demonstrate compliance with LPA and support your marketing.  If you are satisfied with your plan, you should be OK with showing it to an interested buyer who seeks evidence that your claim of having a plan is valid.
  • You should also be prepared to review and amend the plan as you learn more about biosecurity or your risks and management change.
  • Possibly; there are exceptions.
  • The simple answer is that cattle should assume the status of the lowest-score animal in the herd. So introduced cattle of lower status would lower the J-BAS score for the property.
  • However, there are ways that small numbers of lower-score cattle may be introduced and managed without affecting the J-BAS score:
    • Lower-score bulls may be isolated and collected for artificial insemination (AI) without exposing at-risk animals to their higher risk. This option is not likely to be practical for commercial properties which want an introduced bull to be out working in the breeder paddocks, but may be applied for studs.
    • Isolate lower-score females as a separate herd (including progeny).
    • Test introduced lower-score bulls or females at regular intervals by faecal testing (not ELISA blood testing). Although this testing can never show that the animals are not infected, consistently negative results can show that the animals are unlikely to have been excreting to spread infection, and so co-grazing breeders and progeny have not been exposed.  The cost and inconvenience of this monitoring should be part of the cost-benefit assessment that you make before embarking on this strategy.  Also, it does carry a risk of detection of excretion in the lower-status animals, in which case the J-BAS score of the in-contact herd would be affected.
    • Introduce only a small number of lower-score cattle (maximum of 5% of the herd) and specifically include them in the regular Check Testing. This strategy was acceptable practice in the former CattleMAP.
  • Any strategy for introducing and managing lower-status animals should be, and for J-BAS 7 and 8 herds must be, considered and endorsed by the veterinary advisor, clearly written into the property biosecurity plan, and monitored to ensure that it operates successfully.
  • There is no central listing.
  • Buyers will need to ask vendors or agents for information as part of a transaction.
  • The industry management system relies on the integrity of producers, especially as presented in health declarations. If you’re concerned about the correctness or completeness of a declared status, you can ask for evidence to support the claim.
  • The endorsement of a biosecurity plan by a veterinary advisor is the primary quality check, but applies only to J-BAS scores of 7, 8.
  • Veterinary advice and endorsement is even more credible if provided by JD-trained, preferably CVO-approved vet.
  • Queensland herds which want to attain J-BAS 8 must:
    • Implement a property biosecurity plan which addresses the JD checklist and is endorsed by a veterinary advisor; and
    • Undertake two successive Sample Tests (210-300 samples) with negative results, two years apart.
  • Previous Check Testing done for trade access to Western Australia will not count as a Sample Test for this purpose, unless the number of adult cattle in the herd has been 50 or less.
  • J-BAS score of 7
  • No co-grazing with dairy or dairy-cross cattle (other than MN3 or Dairy Score 8) in previous two years
  • Check Test within previous 12 months (i.e. every year for those consigning each year)
  • No subsequent contact with cattle of lower score
  • Further information is available from WA website: www.agric.wa.gov.au/livestock-movement-identification/documentation-importing-ruminants-western-australia See pages 7-8 of WA Form LB1 for JD entry requirements
  • Note that these requirements are correct at the date of this document, but they are specified by WA and subject to change; you are advised to check the WA website for updates.
  • Health certificate requires declaration by owner
  • Health certificate requires inspection and certification by veterinarian or inspector
  • Border inspection
  • J-BAS score of 6 or higher which requires a biosecurity plan.
  • Free of Johne’s disease for the preceding 5 years
  • This standard applies whether the cattle are consigned to a grazing property, abattoir, or transit for export
  • NVD/Waybill
    • No change
    • Still a requirement for a “movement record” for movements within, into or from Qld – NVD serves this purpose
    • Now available as a paper form (LPA NVD), electronic version for printing (eDec), or electronic platform for storage and sharing (eNVD).
  • Cattle Health Declaration
    • Tool for declaring health status across a range of health issues including JD
    • You can add to the information on the form; for example, tick zone or property status or treatments, weeds status.
    • Not required by law; use according to market demand (except for some interstate movements)
    • Will become accepted and used only if you demand (and assess) them for your own protection
    • Available as form for downloading and printing, and now also as an add-on to the eNVD
  • Health certificates for WA, NT
    • As per WA & NT websites
  • Beef cattle, dairy cattle, sheep, goats, deer, alpaca and other camelids, and buffalo are all susceptible to JD.
  • The other industries will be watching the new arrangements for cattle to see whether they have wider application.
  • At this stage, SheepMAP, GoatMAP and AlpacaMAP are being retained.
  • The sheep industry is essentially ahead of cattle, in terms of industry management having replaced regulatory programs in 2013 (except for some areas which established their own Regional Biosecurity Plans).
  • In recognition of the susceptibility of all species to all strains of JD, the distinction between ovine Johne’s disease (OJD) and bovine Johne’s disease (BJD) is now based on affected host species rather than strain of infection.
  • For people who co-graze multiple susceptible species, the status for all species must be taken into account when assessing and declaring risk. Depending on the degree and duration of exposure between species, either the non-cattle species may need to be assessed and tested, or the management and testing of the cattle may be regarded as sufficient monitoring of risk across the whole property. A veterinary assessment of the need and protocol for testing sheep or other species is recommended.
  • The entry requirement should be determined by the Show/Sale organisers or committee, in consultation with exhibitors, vendors, buyers and agents. They should also take into account the impacts of other species and breeds at the venue.  Ultimately, the entry standard should reflect the demands if the stakeholders and the industry standards.
  • A low-risk standard might be considered J-BAS score 7, but this is not prescribed by government.
  • The new arrangements allow for flexibility; e.g. lower risk from young cattle, irrespective of score
  • On-site risk management is at least as important as entry standards: site hygiene, clean bedding, separation of stock of differing scores, etc.
  • In Queensland, most beef properties will be J-BAS score 6, with many studs especially those consigning to WA being J-BAS 7.  There are no herds of score 8, and only very few properties with a score of 0, 2 or 4.
  • Saleyard operators may wish to protect the score 6 and 7 cattle from risk from score 0, 2 and 4 cattle, such as by requiring a Cattle Health Declaration for all cattle and isolating 0, 2 and 4 cattle and afterwards cleaning their pens.  Very few consignments of these low-score cattle would be expected, except possibly cattle from the southern states.
  • The risk of spread of infection at saleyards between scores 6 and 7 in Queensland at present is low (although this may change over time if score 6 herds allow entry of infection).
  • Under the new arrangements, individual property owners can take responsibility for dealing with JD risk according to their own needs.  Owners of score 7 properties will want to take more care to protect against entry of infection than those of score 6 properties.
  • The major risk of JD to a Queensland beef property is the deliberate introduction of cattle which seem to be healthy but are in fact infected.  Score 7 properties must manage this risk in their biosecurity plan by not bringing in animals of lower score (unless they are isolated and managed separately).  This should include cattle which mix as calves with adult cattle of lower score at a saleyard or elsewhere.
  • Special arrangements will have to be put in place for some stud sales to maintain separation from lower-score cattle for those eligible for entry to WA.
  • I strongly urge that that veterinarians engaged in JD work are only those who have completed the JD training which is available free of charge on the Animal Health Australia website, and preferably have proceeded to have that training and APAV accreditation recognised through State Chief Veterinary Officer approval.
  • The roles for veterinarians under the new industry arrangements are to supervise and endorse the property biosecurity plans, collect and submit samples for laboratory testing for Check Tests and Sample Tests, and provide technical advice such as interpreting test results and assessing risks.
  • There is no requirement under the new industry arrangements for veterinarians to have undertaken training in JD or to be approved as was previously required by CattleMAP; however the training and CVO approval are the best ways of demonstrating competency.
  • A Check Test is a test of 50 adult animals in the herd (or all eligible animals in a herd of less than 50 adult animals) biased to increase the probability of detecting infection, tested by ELISA on blood samples or culture or HT-J PCR on pooled faecal samples.
  • In Queensland, ELISA testing should be avoided for Check Testing or Sample Testing due to the risk of false positive results; use faecal testing in preference.
  • Eligible animals are cattle over two years of age.
  • If the herd has fewer than 50 adult cattle (older than 2 years), a Check Test is based on sampling and testing all adults in the herd.
  • All testing of live animals for JD is affected by the slow growth of the causative bacteria, and the resultant slow onsets of the body’s immune response and of disease progression. This means that testing for antibodies in the blood (ELISA) or for the excretion of the bacteria in the faeces (culture or HT-J PCR) may commonly fail to detect early infection.  For this reason, testing for JD should routinely be done only at the herd level and not for individual animals.  Used in this way, the test provides meaningful accuracy.
  • Note that both a Check Test and a Sample Test should be representative of the whole herd, biased to include higher-risk animals such as introductions and especially those from high-risk sectors and wasting animals.  A sampling veterinarian should examine the herd for wasting animals, identify high-risk introductions, and sample the remainder proportionally from each mob according to mob size.  They should not simply sample the first 50 animals presented by the producer.
  • For all JD assurance testing in Queensland, faecal testing (preferably by HT-J PCR) rather than ELISA blood testing is strongly recommended.
  • Under the new national program, assurance testing (Sample Test or Check Test) for JD in cattle may be performed by ELISA testing of blood samples, individual or pooled faecal culture on faecal samples, or individual or pooled HT-J PCR on faecal samples.
  • Although ELISA testing of blood samples is the cheapest option, past experience has shown a significantly higher risk of false positive results for such testing in Queensland and the Northern Territory than in the southern states. With a cost of approximately $1000 and a delay of 6 months for resolution testing if any cattle give a positive result, using the ELISA test in Queensland to save money or convenience is probably false economy.
  • There have been several recent cases of positive ELISA test results for assurance testing in Queensland that have created anxiety, direct costs for resolution testing, and lost market opportunity or legal liability for affected producers.
  • As testing by pooled faecal culture requires 4 months of laboratory procedures before a result whereas HT-J PCR testing provides accurate test results after 2-3 weeks of laboratory processing, HT-J faecal PCR is recommended as the preferred assurance test for JD in Queensland.
  • JD training is available free of charge on the AHA website
  • Recommendation to use only trained and preferably CVO-approved vets
  • Refer to Definitions & Guidelines for animal selection. The sampled animals should be representative of the herd, biased towards animals of highest risk (such as older age groups) and including introduced animals especially from higher-risk regions or sectors.  No animals aged less than 24 months should be included in the sample.
  • Check Test = 50 animals sampled. Sample Test = 210 – 300 animals (depending on herd size; refer to definitions & guidelines for exact number) sampled.
  • The size of individual faecal samples should be a minimum of 30g (70ml srew top container, 1/2 – 3/4 full).
  • Do not pool cattle faecal samples on-farm, pooling (where appropriate) will be done at the laboratory, (sheep and goat pellets may be pooled on-farm).
  • For ELISA serology, collect 10ml clotted blood from individual animals. Turnaround time for ELISA testing depends on prior notice, as kits are ordered by the laboratory as required.
  • Individual animal identification and sampling records should be kept so that reactors can be identified for further testing if required.
  • Refer to laboratory for advice on sample preparation, handling, transport, submission, costs.
  • In Queensland, the Biosecurity Science Laboratory of the Department of Agriculture and Fisheries is accredited to provide the full suite of tests for JD. Other laboratories are available, but you should check that they hold NATA accreditation for the requested tests and their testing costs.
  • An important consideration is the specification for culture and HT-J PCR testing that the samples are chilled as quickly as possible and frozen to -80OC within 48 hours of collection.
  • In short, Queensland producers should use a veterinarian for taking and submitting samples for JD testing, and should not accept a claimed J-BAS score if the producer rather than a veterinarian has collected samples for testing.
  • The national framework was drafted with an expectation that sampling would be undertaken by a veterinarian, but presently specifies only that animals for sampling must be selected by a veterinarian.
  • Taking and submitting samples for JD can be complex and prone to error. If you or others are to rely on test results for a herd assessment or J-BAS score, for your own animals or for a herd you might be considering buying from, you will want to be confident of the standard.
  • Sampling animals for JD testing involves the processes of selecting the appropriate test, selecting appropriate animals for sampling, having the right equipment, undertaking the sampling and identification of selected animals, maintaining sample integrity and security, identifying an approved laboratory, arranging consignment, submitting to the lab, receiving results, and interpreting results. Veterinarians are overseen by a registration authority to ensure the quality standards of these and other veterinary activities.
  • The Biosecurity Sciences Laboratory will not accept samples for JD testing unless they are submitted by a veterinarian. You would need to consult your own veterinarian, but most vets concerned for their credibility would be reluctant to submit to the laboratory samples which they have not collected themselves.
  • In summary, you must use a vet for animal selection, you must use a vet for laboratory submission; you should use a vet for the other sampling activities especially sample collection and interpretation of test results.

Two components:

  • Veterinary sampling and submission
    • Costs determined by practitioner
    • Depend on time, travel distance, facilities, samples (blood and/or faeces), transport of samples to lab
    • Necessary to factor in veterinary selection of cattle for sampling; selection should not be made by producer
  • Laboratory testing
    • Depends on laboratory
    • Depends on test (ELISA on blood, faecal culture, faecal HT-J PCR)
    • For Queensland, HT-J is recommended as the routine test: cost-competitive, negligible risk of ‘false positive’, rapid turn-around, scope for bulking testing at laboratory to reduce price
    • HT-J cost of ~ $1265 for Check Test at Biosecurity Sciences Laboratory (DAF).
  • Johne’s disease is no longer specifically regulated in Queensland, except that:
    • JD is still notifiable: suspicion or confirmation of JD must be reported to Biosecurity Queensland.
    • All people have a ‘general biosecurity obligation’ to do what is reasonable and practical to minimise the likelihood and impacts of spread of infection. With the tools available through the national industry program, what is “reasonable and practical” in the Queensland context of low prevalence could be considered as having a biosecurity plan in place, using a Cattle Health Declaration and J-BAS score to assess and declare the JD risks of all transactions, and securely containing high-risk animals within a property.
  • The purpose of notifications is for the government to monitor infection to be able to credibly certify exports and to ensure that property owners are aware of their biosecurity obligations. There will be no quarantines applied in response to notification of JD.
  • Use of the Cattle Health Declaration or J-BAS assessment tool is not mandatory for Queensland, but their routine use is strongly encouraged both to maintain trade access such as to WA and NT and also to protect against the risk of entry and spread of infection. The use is not mandatory because:
    • Industry has asked government to be able to manage JD without regulatory impost; and
    • It is more important that producers learn to assess and manage JD risks (which are shown through J-BAS and the Declaration) according to their own objectives, rather than just complying with a requirement to get a piece of paper.
  • The entry requirements of WA and NT are laid out under their own legislation.
  • ELISA testing looks for antibodies (part of the body’s immune system) in the blood which have been produced in response to specific infection, in this case infection with JD.  A positive result to ELISA testing usually indicates infection.
  • In some relatively rare cases, a positive result may be due to the immune system producing antibodies to some other non-JD infection which the test matches with antibodies to JD. These are called ‘false positive’ results.  Historically, false positive results occur more frequently in Queensland than in other areas of Australia.
  • In Queensland, ELISA testing is not recommended due to the higher risk of a positive result. For herd assurance testing, faecal testing (preferably HT-J PCR, or pooled faecal culture) avoids this risk.
  • A positive ELISA result raises suspicion of JD. Until it is further investigated, it cannot be presumed to be a false positive. The property owner has three options, and should consider these carefully in consultation with a veterinary advisor:
    • Undertake further investigation to determine whether the result is due to infection or is a false positive;
    • Undertake a program of destocking and decontamination to eliminate the risk of infection; or
    • Refrain from further investigation, accept or ignore the suspicion of infection, accept a J-BAS score of 0, and manage risks to the property and trading partners accordingly.
  • Under the program of industry management of JD since mid-2016, there is no regulatory requirement for further investigation or any other specific on-farm actions. The only regulatory requirements are that producers will meet their general biosecurity obligation to do what is reasonable and practical to minimise the likelihood and impacts of JD, and that any further evidence or cases of infection be notified to Biosecurity Queensland.
  • If the property owner elects to refrain from further investigation to resolve the suspicion, the herd should be retained behind secure boundaries and potential receivers of cattle from the property (except abattoirs) should be notified of the risk of unresolved suspicion.
  • The national program’s Definitions and Guidelines recommends two elements to investigating reactors:
    • Assessment of the herd history, including location, previous disease and testing histories, movements of animals into the herd, and the health and origins of reactors
    • Testing the reactor by either faecal culture testing (although HT-J might be considered instead), twice, on samples collected 3-6 months apart; or by histopathology of samples collected from the reactor animal at slaughter.
  • This assessment will result in a definitive assessment of whether the reactor is infected or not.
  • The impact of a positive ELISA result on J-BAS score will be:
    • If testing for a J-BAS score of 7 and proceeding with resolution within a reasonable timeframe, the herd can retain score 7 pending the outcome of the investigation
    • If testing for a J-BAS score of 7 and then deciding not to proceed with resolution investigation, the herd’s J-BAS score will be score 0
    • If testing for J-BAS score of 7 and investigation confirms infection in an animal but with no clinical JD, the herd’s J-BAS score will be score 6, provided the property has a biosecurity plan that appropriately addresses the (now changed) JD risks. The herd would be eligible to retest to progress to score 7 two years after the last high risk animal(s) has been removed
    • If clinical JD occurs, the herd’s J-BAS score will be score 0 initially, and score 2 once all clinical cases are removed and the property has a biosecurity plan that appropriately addresses the (now changed) JD risks, with further progression along the J-BAS scale over time.
  • As above, suspicion or confirmation of JD must be reported to Biosecurity Queensland (Telephone 13 25 23).
  • There will be no quarantines or other regulatory consequence applied in response to notification of JD.
  • The property’s J-BAS score will be affected, according to subsequent management decisions and occurrence of clinical cases.
    • If clinical Johne’s disease (wasting, scouring, unresponsive to treatment) occurs, the J-BAS score will be 0 if there is no biosecurity plan appropriate to the occurrence of disease, or 2 if there is a biosecurity plan that addresses the clinical disease.
    • If infection without clinical disease is detected, such as by testing of a J-BAS 7 herd, the J-BAS score will be 6 if an appropriate biosecurity plan is in place.
    • If a positive result to a screening test (such as ELISA) is not investigated and resolved, the J-BAS score will be 0.
  • Biosecurity Queensland will ensure that the property owner has access to information to understand their general biosecurity obligation and how they might meet that obligation. Biosecurity Queensland can also provide technical support to the property’s consulting veterinary practitioner to develop a cost-effective approach to managing the disease risk.
  • Properties which have previously consigned cattle as low-risk may consider advising recipients of those cattle of the revised risk status, so that the recipients can make informed assessment and management decisions.

Department of Agriculture and Fisheries, Queensland

FutureBeef

Animal Health Australia

National industry’s cattle Johne’s disease tools

Biosecurity plans

List of CVO MAP-approved veterinarians

Biosecurity Sciences Laboratory

These Frequently Asked Questions have been compiled by Dr Lawrence Gavey, Principal Veterinary Officer (Animal Disease Containment) – Animal Biosecurity and Welfare, Department of Agriculture and Fisheries, Queensland.

The information provided here is current as at 1 July. It is subject to change. Please check with your state or territory legislation and Animal Health Australia for the most up to date information.