National Perspectives on IBR Control and Eradication in Belgium and The Netherlands
Report of the infectious bovine rhinotracheitis (IBR) Technical Working Group (TWG) of Animal Health Ireland on a study visit to Belgium and the Netherlands 2015.
Supported by the Golden Jubilee Trust
Report of the infectious bovine rhinotracheitis (IBR) Technical Working Group (TWG) of Animal Health Ireland on a study visit to Belgium and the Netherlands to examine national
perspectives on IBR control and eradication. Supported by the Golden Jubilee Trust
Dr Elizabeth Lane Donal Lynch Colin Mason Mary Newman Dr Ronan O’Neill Dr Michael Gunn
Dr David Graham Dr Stephen Conroy John Fagan William Fitzgerald Tim Geraghty Dr Maria Guelbenzu
Animal Health Ireland, 4-5 The Archways, Carrick-on-Shannon, Co. Leitrim, N41 WN27 071 9671928, admin@animalhealthireland.ie www.animalhealthireland.ie
Contents
Page
1. Executive summary
02
2. Ireland: Conclusions and recommendations
05 07 10 10 11 11 13 14 16 17 18 20 20 21 22 23 25 25 25 26 27 28 31 31 34 37 21 26 29
3. Introduction and Context
4. Belgium
�. Livestock sector
B. History of and drivers for IBR control
C. Programme description
�. Organisations and individuals involved; roles and responsibilities
�. Costs and Funding
�. Laboratory testing and data management
�. Vaccination
�. Progress to date
�. Future development and goals
�. Lessons learned
5. The Netherlands
�. Livestock sector
�. History of and drivers for IBR control
�. Programme description
�. Organisations and individuals involved; roles and responsibilities
�. Costs and funding
F. Laboratory testing and data management
�. Vaccination
�. Progress to date
�. Future development and goals
�. Lessons learned
6. Ireland: Conclusions and recommendations
Appendicies
Appendix 1: Itinerary of IBR study visit
Appendix 2: Details of Belgian, Dutch and Irish delegates
References
CONTROL AND ERADICATION IN BELGIUM AND THE NETHERLANDS 1
1 EXECUTIVE SUMMARY
• INFECTIOUS BOVINE RHINOTRACHEITIS (IBR) is primarily a viral respiratory disease of cattle spread by nose to nose contact or through the air. It can also be shed in semen and transmitted venereally. Following recovery, cattle are considered to be lifelong carriers of the virus which can be shed intermittently from the airways and reproductive tract thereafter. • Infection with IBR virus is widespread in Irish dairy and beef herds, with evidence of exposure in over 70% of herds. • Current EU legislation prohibits bulls with evidence of exposure from entering semen collection centres for the purposes of intra- community trade. • A number of EU Member States (MS) have completed IBR eradication programmes, or have such programmes underway. MS may submit their programmes for eradication or demonstration of freedom to the Commission for approval. Where approval is given, MS are granted additional guarantees in relation to intra-community trade.
• Losses due to IBR may accrue due to disease (both clinical and sub-clinical), the impact on semen collection centres (both exclusion of high genetic merit sires and the catastrophic losses where biosecurity is breached and infection in introduced) and the loss of live exportmarkets due to an inability to satisfy the additional guarantees required to trade with the relevant MS. • Foodwise 2025 states that, subject to a favourable cost benefit (currently underway), a national eradication programme will be initiated in 2019. • IBR is prioritized for action by Animal Health Ireland (AHI). A Technical Working Group (TWG) of AHI is currently considering options for such an eradication programme. To inform its discussions, the TWG undertook a study visit to Belgium and the Netherlands in September 2015. • In the programme in both countries, twice yearly vaccination plays a central role, supported by a companion test which allows vaccinated and infected animals to be differentiated.
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NATIONAL PERSPECTIVES ON IBR
EXECUTIVE SUMMARY
• In both countries the programmes are owned and led by the farming industry, in partnership with the government and the veterinary profession, with this being identified as critical to success. Key drivers for control have been the maintenance of live export markets, avoidance of losses due to disease and improved animal health, maintaining trade in semen and embryos and reducing antimicrobial use. • Belgium began a compulsory national eradication programme in 2012, preceded by a voluntary period lasting 5 years. The programme was approved by the Commission in 2014 when Article 9 status was awarded. Live exports from Ireland to Belgium have essentially ceased as a consequence. o IBR-free herds with no evidence of exposure are assigned an I-4 status; those which are free but in which vaccine has been, or currently is, used are assigned an I-3 status. Herds that are still infected and vaccinating (twice yearly) are assigned an I-2 status. o The programme has made more rapid progress in Wallonia (southern Belgium) than in Flanders (northern Belgium). In part this is considered due to a greater use of vaccine in Flanders, with herds acquiring (and remaining at) I-2 status. In Wallonia, more use was made of a “snap shot” herd screen to get an initial serological picture, allowing many herds of previously unknown status to progress to I-3 or I-4 status. o The programme is managed in Flanders by Dierengezondheidszorg Vlaanderen (DGZ) and in Wallonia by the Regional Association of Animal Health and Identification (ARSIA). o Testing to award and maintain statuses is carried out in accordance with 2004/558/ EC, with the exception that a partial herd test, based on epidemiological principles, is carried out to maintain I-3 and I-4 status, rather than a whole herd test. o Each herdowner appoints an “Epidemiological Surveillance” (ES) vet,
from whom they obtain vaccine and who is responsible for initial investigation and sampling of suspect outbreaks. The ES vet also administers the vaccine, although this may be devolved to the herd owner. ARSIA maintains records of vaccination at animal level, while DGZ maintains records at herd level. The compulsory programme has made good progress with herd- and animal- level prevalence decreasing from 52% and 22% respectively in 2011 to 18% and 4% in 2015. A roadmap to eradication has been developed which will implement a series of additional control measures, with the goal of freedom (and Article 10 status). • The Netherlands began a compulsory eradication programme in 1998, following several years of voluntary control. The programme design was based on the outcomes of economic and scenario modelling. o During the first phase of the programme (reduction phase) all herds had to be vaccinated by a vet unless they were able to obtain a dispensation from vaccination. These dispensations were available, subject to conditions, for all animals in herds that could demonstrate evidence of being IBR- free, and for non-breeding beef herds/veal units; in vaccinating herds groups of young stock which could be shown to be IBR- free could also obtain a dispensation from vaccination. o All serological testing was conducted using the gE ELISA. Extensive and frequent use was made of bulk tank milk testing for monitoring of free herds. Acknowledged limits in sensitivity were considered to be satisfactorily overcome by frequent testing, with epidemiological studies indicating that introduction of infection to a naïve herd would be quickly detected and onward spread limited. o Testing of three animals per-sub-population was used to confirm freedom from infection in suckler herds and in young stock seeking dispensation from vaccination.
CONTROL AND ERADICATION IN BELGIUM AND THE NETHERLANDS 3
EXECUTIVE SUMMARY
o By 1999 the programme was making good progress with 25% of dairy herds and 18% of other herds having achieved an IBR-free status. A further 26% of dairy herds and 67% of other herds had a within herd prevalence of <10%. o The compulsory programme was stopped suddenly in 1999 following the death of cows on a limited number of farms due to contamination of live IBR vaccine with BVDV type II. o Many herds continued voluntarily with the programme and in 2006 a voluntary IBR-free programme and a voluntary IBR monitoring programme were introduced. These are primarily aimed at dairy herds and again make extensive use of BTM testing. 28% of dairy herds are certified as IBR-free with a further 15% in the monitoring programme. o Preparatory work has been undertaken to prepare for a possible new national eradication programme. Initial modelling work supports the use of BTM sampling in dairy herds and abattoir surveillance in suckler herds, while acknowledging that such an approach is not aligned with current EU requirements.
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NATIONAL PERSPECTIVES ON IBR
IRELAND Conclusions and recommendations of the IBR TWG
2
1. A STUDY on losses to Irish farmers due to IBR is currently underway and the outputs of this work will inform the benefits element of a cost:benefit analysis (CBA) for a national IBR eradication programme. The IBR TWG is currently developing options for an eradication programme. Costs of each of these options will be determined, informing the cost element of the CBA. In addition to the testing regimes for acquisition and maintenance of a free herd laid down by 2004/558/EC, further options should consider the use of a snap shot to determine herd status with a view to avoiding herds unnecessarily embarking on vaccination programmes, the sampling of limited numbers of animals for maintenance of free herd status (both used in Belgium) and the use of bulk tank milk and abattoir surveillance as used in the Dutch programme. 2. If a voluntary phase is to be included in a national programme, it should be of limited duration (no more than one year).
3. Both Belgian and Dutch farmers have taken ownership of addressing IBR. Their role in driving and supporting the IBR eradication and control programmes is one of the key factors in the success of the programmes in these countries. 4. Scenario and economic modelling should be used as part of the CBA of each eradication option. These should at minimum include the testing regime as defined by 2004/558/EC along with the approaches taken in Belgium and the Netherlands. 5. The impact of the new Animal Health Law on future IBR programmes, including the mechanism by which a country could apply for formal recognition of an eradication programme (or freedom), permitted testing and surveillance options and the continued availability of additional guarantees in relation to intra- community trade, should be clarified as quickly as possible, with consideration given to the use of output-based measures.
CONTROL AND ERADICATION IN BELGIUM AND THE NETHERLANDS 5
IRELAND: CONCLUSIONS AND RECOMMENDATIONS
6. While both Belgium and the Netherlands recognise the need to control IBR as a disease, freedom to trade through obtaining Article 9 status is a major driver for both countries. Paradoxically they also recognise that Article 9 (or 10) statuses impose limitations in relation to importing stock. This is considered to be less of an issue for Ireland, given the limited number of imported animals, but also needs to be recognised, particularly in relation to trade with Northern Ireland. 7. While a formal decision on the implementation of a national programme in Ireland remains to be taken, planning and implementation of a number of measures should be considered at this stage. a. Implementation of a national programme in Ireland will have as an initial objective the obtaining of Article 9 status. An application will have to provide information to address a series of points laid down in 64/432/EEC, including a system for notification of IBR outbreaks and providing data on the distribution of the disease. Consideration should be given to progressing both of these requirements, including undertaking additional surveys, if required, to determine prevalence. The winter screening programme conducted annually in Belgium provides a template for ongoing surveillance, but consideration should be given to using other matrices and sample types such as bulk tank milk. b. The Central Veterinary Research Laboratory should be formally recognised as the National Reference Laboratory for IBR and resources and functions assigned, including approval of test methods, determination of the sensitivity and specificity of diagnostic tests for blood and milk (including bulk tank samples) and development and implementation of protocols to manage aspecific results. c. Consideration should be given to development of a national database capable of recording herd vaccination details and managing herd statuses.
d. Given that the majority of live imports come from Northern Ireland, Animal Health and Welfare NI (AHWNI) should be encouraged to consider an IBR eradication programme in NI and the Department of Agriculture and Rural Development encouraged to prohibit the use of non-marker vaccines. Steps should also be taken to raise awareness of the legislative prohibition on the use of non- marker vaccines in Ireland. e. In advance of any national programme, establish a pilot programme, based on the requirements of 2004/558/EC to allow herds that wish to do so to acquire a formal IBR- free status.
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NATIONAL PERSPECTIVES ON IBR
3 INTRODUCTION AND CONTEXT
INFECTIOUS BOVINE RHINOTRACHEITIS (IBR) is a viral disease of cattle. The primary route of transmission of the virus is animal to animal spread by the respiratory tract. Disease is characterised primarily by respiratory disease, milk drop and abortion. Following infection and recovery, cattle are lifelong carriers, with the potential to shed the virus intermittently, particularly at times of increased stress. The virus may also be shed in semen and transmitted venereally and for this reason bulls with evidence of exposure to IBR virus (including vaccine virus) are prohibited from entry to semen collection centres for the purposes of intra-community trade 1 . Entry of the virus to the semen collection centre of the National Cattle Breeding Centre (NCBC) at Enfield, Co. Meath in 2011, resulted in the culling of all bulls present. A number of European countries have embarked upon, or completed, eradication programmes for IBR. Member states of the European Community which have a compulsory national IBR control programme in place may submit details of the programme to the Commission for approval according to the requirements setdown inArticle9ofCouncil Directive
64/432/EEC 2 . Similarly, Article 10 of this Directive allows countries which consider themselves free of IBR to submit evidence seeking official recognition of freedom. In both cases, the Directive provides for countries with approved eradication programmes, or freedom, to seek additional guarantees, relating to intra-Community trade, to assist with efforts at eradication or maintenance of freedom. These guarantees must not exceed those which the Member State implements nationally. Full details of the additional guarantees relating to IBR are defined in Commission Decision 2004/558/EC 3 . Essentially cattle moving into Member States with an approved (Article 9) programme or IBR-free status (Article 10) must come from an IBR-free territory (Article 10 status) or satisfy the following conditions: (a) theymustcomefromaholdingonwhich, according to official information, no clinical or pathological evidence of infectious bovine rhinotracheitis has been recorded for the past 12 months; (b) theymust have been isolated in a facility approved by the competent authority for 30 days immediately prior to movement and all bovine animals in the same isolation facility must have remained free of
CONTROL AND ERADICATION IN BELGIUM AND THE NETHERLANDS 7
INTRODUCTION AND CONTEXT
clinical signs of infectious bovine rhinotracheitis during that period; (c) they and all other bovine animals in the same isolation facility must have been subjected with negative results to a serological test carried out on blood samples for IBR. Four derogations are provided under which cattle may move to countries with approved (Article 9) programmes from other countries with Article 9 programmes or with no approved programme. 2004/558/EC also lays down detailed guidance on the sample types (individual bloods, pools of individual milks and bulk tank milk), animals and testing frequency required for a holding to acquire and maintain an IBR-free status. Annexes 1 and 2 of 2004/558/EC list countries and regions with Article 9 and Article 10 programmes. This list is regularly updated, most recently as COMMISSION IMPLEMENTING DECISION (EU) 2015/250 4 . At the time of publication of this Decision (13th February 2015), the following countries had approved programmes/freedom: Article 9: Belgium, Czech Republic, all regions of Germany except the Federal States of Bavaria, Thuringia, Saxony, Saxony-Anhalt, Brandenburg, Berlin and Mecklenburg-Western Pomerania, and in Italy the regions of Friuli-Venezia Giulia and Valle d’Aosta and the Autonomous Province of Trento. Article 10: Denmark, in Germany the Federal States of Bavaria, Thuringia, Saxony, Saxony-Anhalt, Brandenburg, Berlin and Mecklenburg-Western Pomerania, in Italy the Autonomous Province of Bolzano, Austria, Finland and Sweden. The potential for restriction of live exports from Ireland should trading partners acquire Article 9 or 10 status is illustrated by the change in numbers following Belgium’s acquisition of Article 9 status in October 2014. In 2014 a total of 21.360 animals were exported to Belgium up to 10 th October. During the same period in 2015, exports were reduced by 97.8% to 473 5 .
The Council of the EU has recently published a proposal for a Regulation on transmissible animal diseases (the Animal Health Law) 6 . In time it is expected that this single piece of legislation will consolidate and replace much of the current legislation. While many of the details, including the diseases that are listed and the means of surveillance remain to be provided, it is expected that recognition will continue to be provided for countries that are free, or engaged in the eradication of IBR. IBR is prevalent in Ireland, with evidence indicating that approximately 75-80% of beef 7 and dairy 7,8 herds contain cattle that have been exposed at some point and are carriers of the virus. There is currently no specific legislation in Ireland addressing IBR eradication. However, since 2002 only marker vaccines may be marketed 9 . When used with a companion (gE) test, it is possible to distinguish animals that are vaccinated but not infected from animals that have been infected. A study of experts and farmers about non-regulatory animal health issues facing Irish livestock industries identified IBR as one of a number of priority issues to be addressed 10 . AHI has established a technical working group (TWG) on IBR which has to date focussed on the development of a number of resources providing evidence-based best practice for dealing with IBR at farm level 11 . The next step is to consider the merits or otherwise of addressing IBR at a national level. Reflecting this, the AHI Strategic Plan 2015-2017 12 contains the following on IBR: Programme objective To eradicate infectious bovine rhinotracheitis (IBR/ BoHV-1) from the national herd, subject to a positive cost-benefit analysis and a mandate from AHI stakeholders.
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NATIONAL PERSPECTIVES ON IBR
INTRODUCTION AND CONTEXT
Strategic objectives
the benefits mentioned above, will provide the basis of a benefit/cost evaluation for each. Considerable experience in IBR control already exists in Europe. To assist the TWG in the development of options for a national control programme, a study visit to Belgium and the Netherlands was undertaken from 7th to 10th September 2015. This provided an opportunity to meet with representatives from government, laboratories, industry, farmers and veterinary practitioners to gain insights into their current programmes, the drivers for their initiation, associated challenges and goals and lessons learned. This report, supported by published material and responses to supplementary questions, provides a summary of the findings of the visit. Details of the visit programme, and of those attending the various meetings, are provided in Appendices 1 and 2 respectively.
Key outcomes to be achieved in the lifetime of the current strategic plan: • Develop a framework for a national control programme, consistent with the requirements for such programmes, as established in EU legislation. • Complete a cost-benefit analysis (CBA) for a national IBR eradication programme. • Taking into account the outcome of the CBA, seek a mandate from AHI stakeholders on whether or not to progress to a national eradication programme. • Subject to a mandate from stakeholders, commence the implementation of a national communications strategy and other initial elements of the eradication programme. In addition, the Animal Health section of the Foodwise 2025 13 document which presents a 10 year vision for the Irish agri-food sector published in 2015 by the Department of Agriculture. Food and the Marine (DAFM), contains the following undertaking: “DAFM to support the carrying out an economic appraisal by Teagasc of the benefit/costs of implementing a compulsory national IBR eradication programme for consideration by AHI and its stakeholders with the expectation that if the outcome shows a favourable return on resource deployed that a national eradication programme will be initiated by 2019.” Work on the economic appraisal, focussing on losses incurred by the industry due to IBR, began in 2015 with initial results due in early 2016, with the resulting estimate providing the benefits to be achieved by eradication. The IBR TWG has also begun considering options for the structure of a national control programme, with the goal of developing one or more options to be evaluated, taking into account factors including legislative requirements, cost, complexity and time to eradication. The costs of these options, along with
CONTROL AND ERADICATION IN BELGIUM AND THE NETHERLANDS 9
4 BELGIUM
reflecting larger average herd size in Wallonia, which also has a higher overall cattle density. 4,501 herds in Flanders have ten animals or less. While the size of the cattle population has remained relatively stable over the past years, the numbers of herds has been decreasing gradually (~41,100 in 2006). The average number of cows in suckler and dairy herds is 53 and 66 respectively. Approximately 950,000 calves are born each year. The average population density is 80 cattle/km 2 14 . Identification and registration of cattle is performed through a central database (SANITEL) managed by the Federal Agency for the Safety of the Food Chain (FASFC). Around 316,000 fattening calves (average age 20±17 days) and around 329,000 older animals (average age 2.69 years±2.59) are traded annually 15 .
A. Livestock sector BELGIUM is a federal country comprising the two provinces of Flanders in the north and Wallonia in the south, plus the Brussels Capital Region. Among beef breeds, the Belgian Blue is pre- dominant. However, French beef breeds are also increasing in importance, especially the Limousin, Blonde d’Aquitaine and Charolais. Dairy cows are more common in Flanders while suckler cows are more common in Wallonia (Table 1). The dairy cow population is dominated by Holstein-Friesians (about two-thirds of the dairy cow population). While Flanders has a larger number of herds than Wallonia (15,350 and 10,201 respectively), the numbers of cattle are similar (1,358,629 and 1,237,060; 2,595,689 combined),
Dairy
Beef
Mixed
Total
Calves/yr
Herds 15,350 10,201 25,551 116,323
Flanders Wallonia
656,096 352,126
600,066 788,527
102,467 96,407 198,874
1,358,629 1,237,060 2,595,689 6,135,172
- -
Belgium 1,008,222
1,388,593
950,000
Ireland
2,131,048
Table 1. Comparison of cattle sectors in Belgium and Ireland
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NATIONAL PERSPECTIVES ON IBR
BELGIUM
B. History and drivers for IBR control History 1990s –Vaccines allowing the differentiation of infected and vaccinated (DIVA) animals (marker vaccines) were developed in the Netherlands. Epidemiological studies suggested that eradication programmes incorporating the use of marker vaccines were possible. 1997 – A voluntary programme was started simultaneously with the Netherlands (enabled by national legislation; Royal Decree [RD ] 08/08/1997). A serological survey indicated seroprevalences at farm and animal level of 67% and 35.9% respectively 16 . The marketing of non-marker vaccines was forbidden and restrictions on animal movement were introduced depending on herd status. The programme had limited uptake from farmers and practitioners, particularly from the beef sector. 2004 –Germany achievedArticle 9 status, stimulating renewed interest in Belgium. 2005-06 – a series of IBR round table meetings were held between stakeholders to agree a new approach to control. 2007-2012 – A revised voluntary programme was introduced, supportedby legislation (RD22/11/2006) with a clear indication that the programme would become compulsory from 2012 onwards. 2012 – Launch of the compulsory programme, with all herds, excluding veal calf units, required to have a status of I-2 (see Programme description below for details) or above based on serological results or regular vaccination. 2014 – Belgium awarded Article 9 status on 8 th October 17 . Drivers for IBR control • Maintenance of live trade: Belgium is the second largest exporter of live beef cattle in Europe (~150 000 exported per year), of which 60-70% go to the Netherlands and the remainder to Germany, France and Italy.
• Maintenance of trade in semen and embryos • Avoiding an increased IBR seroprevalence in imported animals from other countries running eradication programmes. (A view was also expressed that the restriction on imports was also a negative outcome, restricting supply of animals for veal and fattening units). C. Programme description The ultimate aim of the programme is to achieve IBR eradication and Article 10 status. IBR is a compulsorily notifiable disease. Herd qualification (categorization) is dealt with by the two regional animal health laboratories (ARSIA/ DGZ) for the Flanders and the Wallonia regions. Herd testing and classification Herds are typically assigned to one of four main statuses based on test results or vaccination. I-1 – Unknown status herds (not participating in testing or vaccination). These herds can only move animals directly to slaughter, must house cattle all year round and must avoid direct contact with animals from herds of higher status. This status will be withdrawn in 2016, with these herds required to progress to I-2 status. Veal units are currently exempt from the programme. I-2 – Herds that have implemented a vaccination programme and are either known to be infected based on the results of blood testing or which have elected to vaccinate without initial blood testing. All animals must have completed a primary course of vaccination by 10 months of age (or within 35 days of entry) followed by hyperimmunisation (booster vaccination) at regular intervals (one to eight months) thereafter. Vaccinations must be logged onto the database run by the appropriate regional animal health association, which then manages the herd status. There is currently no requirement for regular monitoring (sampling and testing) of these herds.
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CONTROL AND ERADICATION IN BELGIUM AND THE NETHERLANDS
BELGIUM
I-2D- this is a transitional status that may be awarded for a maximum of 12 months to herds where an initial round of testing indicates that less than 10% of the herd is infected. In this case, only infected animals may be vaccinated with the goal of removing themwithin 12 months and progressing directly to I-4 status. I-3 – IBR-free, based on two rounds of negative blood test results (using gE test) on samples of all animals aged 12 months and above at an interval of 4-7 months, with an annual test thereafter. While 2004/558/EC requires that all eligible animals are tested to maintain a free status, the programme requires sampling of a maximum of 26 animals per herd, with this number chosen to detect, with 95% confidence, at least one positive animal when the herd prevalence is 15% or greater. The sensitivity (Se) of the test is assumed to be 70% (i.e. 70% of infected animals will give a positive result) and the specificity (Sp) 100% (i.e. there will be no false positives). Herds with this status may continue to vaccinate if they wish. I-4 – Officially IBR-free. To qualify, all animals over 12 months are individually blood sampled with negative antibody results (gB test) when tested twice 4-7 months apart to qualify, with an annual maintenance test thereafter sampling a maximum of 21 animals per herd, with this number chosen to detect, with 95% confidence, at least one positive animal when the herd prevalence is 15% or greater. The assumed Se and Sp of the test are 95% and 100% respectively. These herds are not permitted to vaccinate, and cannot contain animals that have been previously vaccinated (gB positive, gE negative). Herds may progress directly to an I-4 status or evolve from an I-3 status, following a cessation of vaccination and removal of all vaccinated animals over time. Herd snap shot Herds of unknown status that were not vaccinating were encouraged to perform a herd “snap shot” before deciding whether to vaccinate (obtaining I-2 status) or seek official freedom (I-4 status). This required the sampling of a maximum of 26 animals and testing by gB ELISA. This testing was
subsidized by the Animal Health Fund (see below) which contributed 50% of the cost. Where all results were negative (70% of cases) the herd was highly likely to be free, and could progress directly to I-4 status subject to completion of the additional herd screenings with negative results. Approximately 15% of herds had a small number of positives (1-4), with these typically being older animals. Removal of these (or adoption of an I-2D status) could again allow these herds to achieve I-4 status within a relatively short period. The remaining 15% of herds, with a higher seroprevalence, were recommended to vaccinate, acquiring an I-2 status. Bio-exclusion controls There is an obligation on I-1 herds to avoid contact with higher status herds. Prescribed bio-exclusion measures for these herds include keeping cattle housed at all times and only moving cattle directly to slaughter. Herds with I-3 and I-4 statuses must purchase only gE- (from I-2 or I-3 herds) or gB- (from I-4) negative animals to maintain their status. Purchased animals must be tested within 5 days of arrival and again 28-40 days after arrival, with derogation from the second test where the herd of origin also has I-3 or I-4 status. On a practical level this has led to reluctance to move to I-4 level, as the number of gB- negative bulls on the market is low. For this reason known-negative herds tend to stay at I-3 so that they have a wide selection of bulls to select from. Suspect Outbreaks If there is suspicion of infection based on clinical signs, the farmer must contact his Epidemiological Surveillance (ES) vet (see below under D for details). If a diagnosis of IBR cannot be ruled out following a clinical examination they will collect samples and send these to DGZ/ARSIA (or CODA-CERVA) (see below under D for details) for virological analysis and notify the Federal Agency for the Safety of the Food Chain (FASFC).
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NATIONAL PERSPECTIVES ON IBR
BELGIUM
Thereafter • No movement is allowed, except to the slaughterhouse under permit from FASFC. • All bovines must be kept inside or in a place without contact with any other holding/animals. • Pending the test results, the herd status is suspended on SANITEL, with their herd assigned a status of I-0. • Biosecurity measures on the farm are strengthened; personnel access to the farm is limited and a register must be kept of all visitors; protective clothing must be used by visitors and must not be taken off the farm; hands, footwear and vehicles must be disinfected. • Where an outbreak is confirmed, notification is issued to all contact holdings and their veterinarians • Measures are lifted at the earliest 30 days after notification by the vet of complete disappearance of clinical signs. • After 30 days, an I-2 status is assigned to the herd if vaccination is performed. Alternatively the herd may test and cull to re-gain a higher status. Failure to act results in the herd becoming I-1. • An epidemiological investigation is made by an FASFC investigator to determine the most probable origin of each outbreak. (Most are attributed to either the purchase of a positive animal [where quarantine was not applied] or reactivation of infection in an older carrier animal). • The number of confirmed outbreaks has fallen from 11 in 2011 to one in 2014. D. Organisations and individuals involved; roles and responsibilities • The Minister of Agriculture has ultimate responsibility for the following organisations, bodies and activities involved in the IBR eradication programme.
• The Federal Public Service Health, Food Chain Safety and Environment (SPF SPSCAE [SPF]) has regulatory jurisdiction, having responsibility for the legislation in support of the programme. The SPF also manages the Animal Health Fund (see below under funding) and is responsible for the National Reference Laboratory for animal diseases (CODA-CERVA; see below). • The Federal Agency for the Safety of the Food Chain (FAFSC; Food Agency) was established in 2000. It is responsible for ensuring the safety of the food chain and the quality of food in order to protect the health of humans, animals and plants. It has powers to monitor compliance with the standards set by the SPF on animal health and disease, including IBR. It is also responsible for the implementation of official controls and outbreak investigations and for reporting to the European Commission and other European institutions. Official veterinarians of FAFSC are located in a number of centres in each province as Provincial Control Units (UPC; http://www. favv-afsca.fgov.be/upc/), being responsible for overall programme supervision and investigation of outbreaks. • The Centre for Study and Veterinary and Agrochemical Research (VAR; http://www.coda- cerva.be/index.php?lang=en ) was established in 1997. It is the federal scientific establishment and serves as theNational ReferenceLaboratory (NRL) for IBR. The NRL conducts mainly confirmatory testing and is responsible for quality control of diagnostic reagents used in regional laboratories as part of the official IBR eradication programme. The Coordination of Diagnostic Veterinary Epidemiological Research and Risk Analysis (CODA-CERVA) is a unit of the VAR. It provides expert advice to the IBR programme through membership of the IBR Technical Working Group (see below under funding) and carries out scientific research to maintain and expand this technical expertise. It also has a fundamental role in the management of the quality of testing carried out by recognised laboratories, including: a. Authorisation of the commercial ELISA kits that can be used within the programme
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CONTROL AND ERADICATION IN BELGIUM AND THE NETHERLANDS
BELGIUM
b. Performance of quality control for each batch of those kits c. Delivery of mandatory proficiency tests to the recognised laboratories d. Confirmatory testing by virus neutralisation test and ELISA of doubtful antibody test results and virus isolation and PCR testing of samples from suspect clinical outbreaks . • Approved regional Animal Health associations. The Regional Association of Animal Health and Identification (ARSIA) and Dierengezondheidszorg Vlaanderen (DGZ) can be considered as official regional laboratories mandated by the FASFC to perform first line routine testing of samples linked with IBR certification in Wallonia and Flanders respectively. Each has its own laboratory and is also responsible for a range of administrative tasks, including recording of vaccination and assigning herd statuses. Further details on ARSIA were obtained during the visit as follows. It is a farmer-owned and run organisation representing some 24,000 farmers including 11,000 cattle owners. 240 delegates are members of a representative general assembly overseenbya24-personexecutiveboardoverseen in turn by a 6-person steering committee. Its two main areas of activity are managing animal identification and registration and animal health. The organisation has a budget of ~12M euro, of which 70% is derived from farmers, 18% from the government and 12% from the Animal Health Fund. • Herd owners and veterinary practitioners. The herd owner and their veterinary practitioner are recognised as critical elements of the programme. By law, each farm must have a nominated Epidemiological Surveillance (ES) vet to oversee regulated diseases including IBR. Vaccines must be obtained from, and blood samples taken by, the ES vet. The herd owner is required to notify the ES vet if they suspect an outbreak of IBR, with the ES vet then carrying out clinical examination and sampling. The ES vet also plays an important role in ensuring and enforcing optimal farm biosecurity. They must visit each herd at least
three times a year, rising to six times per year for herds with I-2 status. A substitute ES vet is also named in the event that the primary veterinary practice is unavailable. The strength and value of this contract is considered to lie in the mutual trust between the partnership of vet and farmer. E. Costs and Funding The costs of the programme are typically borne directlyorindirectlybyfarmersandthewiderindustry. Costs of vaccination, fees for private veterinary practitioners and laboratory charges are paid by the farmer. Some of these costs have been subsidized at points in the programme via the Animal Health Funds (see below), which have also contributed to the costs of programme administration. Government funds the cost of an annual sero-prevalence survey (winter screening; see H below for details) for a range of diseases, including IBR. The results of this screening provide an objective measure of national prevalence at both animal and herd levels. Vaccine costs are approximately €5/dose with a veterinary administration charge (where this option is taken) of ~€2.50/animal. Sampling costs are ~€2.50/animal and test costs are approximately €7.00/blood sample (before any subsidy from the Animal Health Funds). In ARSIA, farmers may pay a voluntary annual fee, the amount of which is based on herd size, to a “solidarity fund”. Contributors to this fund obtain a discount of approximately 50% on test costs. Animal Health Funds (AHF) exist for the bovine, porcine, dairy, poultry, and small ruminant sectors, with the bovine sectoral fund in place since 1998. Each of the five funds was established to address animal health crises (including Brucellosis and Foot and Mouth Disease) and were designed to build up financial reserves to support future emergencies. The Animal Health Funds are based on the principles of co-financing, co-responsibility and co- management by producers and government, with mandatory contributions from all breeders. Cattle owners pay a contribution which varies according to the health-related risks associated with the particular enterprise type or farming activity.
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NATIONAL PERSPECTIVES ON IBR
BELGIUM
Farmers are invoiced once per year for the bovine fund based on herd data in SANITEL according to the schedule in Table 2. Approximately 95% of farmers pay the requested amount. Measures are currently being discussed to address non-payment by the remaining 5%. Where the charges are applied at 100%, they generate approximately €7M annually. However, when the reserve funds are adequate, the level at which charges are applied are reduced from 100% of that permissible. For example, in 2014/15 the charges were applied at a rate of 43%, generating €3M. In addition, a Dairy Fund has been in place since 1995. This collects €720,000 annually, derived from €0.13/1000L from producers and €0.11/1000L from buyers (annual milk production is approximately 3000M litres). The Animal Health Funds are part of the state budget and subject to EU legislation relating to State Aid. Each fund has its own budget, resources, expenditure and financial reserves. Ultimately, decisions on expenditure from the funds are taken by the Minister of Agriculture, based on input from the Council of the AHF for the bovine sector and dairy sectors, which in turn has a Working Group on IBR. The Working Group is supported by a technical working group (TWG). THE IBR TWG is made up of various groups and organisations that have different roles within the eradication programme, including €2.56 Fee per animal purchased (under 1 year old) €0.27 Fee per animal purchased (over 1 year old) €3.90 Table 2. Schedule of charges applied to cattle owners by the Animal Health Fund to the bovine sector Fixed fee per herd (non-veal) Fixed fee per veal calf herd €26.00 €134.34 Fee per animal born €0.27 Fee per animal over 1 year old
• Farmers’ associations • ARSIA and DGZ • CODA-CERVA
The total spending on the IBR programme to date by the AHF has been €8,500,000, with the expenditure per year increasing with time as shown:
• 2007-2010- €200,000 • 2011- €500,000
• 2012-2015- €1,800,000. This comprises €300,000 to both ARSIA and DGZ for database management and a further €600,000 to each organisation. This covers the cost of one programme veterinarian per organisation, incentives to motivate farmers to progress to acquire and maintain an I-3 or I-4 status, the costs of additional analysis in case of aspecific reactions and communication and technical support. The allocation of these funds by ARSIA and DGZ has varied over time. During the voluntary phase of the programme, the AHF was used to incentivize farmers to screen their herds. In 2012 this remained at 50% of the test cost, but currently in Wallonia is €1.90/ animal where testing is carried out to acquire IBR- free status. Where testing is carried out to maintain a free status, a subsidy of €3.70/animal applies. In addition to funding from AHF, other regional and provincial funds have also been provided to the programme. Based on data presented, earlier uptake of serological screening rather than blanket vaccination in Wallonia saved farmers an average of €1,481 per herd between 2010 and 2013. This had a major impact in the costs of participation to the farmer in each region. In Flanders (15,350 herds, 1.2 million cattle) in the years 2010-2013 farmers spent €4.67M on serological testing (average €304 per herd) but €60.2M on vaccination (average €3921 per herd). In contrast, in Wallonia (10,201 herds, 1.2M cattle) more was spent on serology initially, totalling €7.4M in the same years (average €725 per herd). There was a saving on vaccination however, with only €20.6M spent in total (average €2019 per herd).
• Veterinary authorities • Veterinary practitioners
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CONTROL AND ERADICATION IN BELGIUM AND THE NETHERLANDS
BELGIUM
F. Laboratory testing and data management National Reference Laboratory (NRL) The NRL (CODA-CERVA) provides expert advice to the IBR programme through membership of the IBR Technical Working Group and carries out scientific research to maintain and expand this technical expertise. It also has a fundamental role in the management of the quality of the tests carried out by the recognised laboratories. This includes the following: 1. Authorisation of the commercial ELISA kits that can be used within the programme 2. Performance of quality control for each batch of approved kits, 3. Performance of mandatory proficiency tests for the recognised laboratories 4. Confirmatory testing of serological results by virus neutralisation test and the performance of virus isolation and PCR on samples collected following clinical suspicion of IBR. The NRL does not perform the routine testing of samples for the IBR eradication programme, with this work carried out in recognised laboratories. Recognised laboratories Recognised laboratories must: 1. Use only authorized kits and approved batches and be accredited to ISO 17025 for each kit they use. 2. Use the serum controls provided by the NRL. 3. Participate in proficiency testing organised by the NRL. 4. Store non-negative samples for 30 days. Currently only two laboratories are recognised: DGZ for Flanders and ARSIA for Wallonia. Two main test methods are carried out: the IBR gB ELISA and the IBR gE ELISA. The gB test will detect antibodies generated following either vaccination or infection and therefore is used only in herds with I-4 status
and those seeking to acquire this status. Marker vaccines do not create gE antibodies while infection does. Therefore this test can be used to differentiate infected from vaccinated animals (DIVA). Therefore a gE-negative test result is consistent with an uninfected animal, irrespective of its vaccinal status. The IBR gE ELISA is used in and I-2 and I-3 herds. Programme databases ARSIA and DGZ maintain separate programme databases, each of which delivers similar functionality in terms of management of herd status, taking into account test results and vaccination, detection of non-compliances with the programme and communication with farmers and vets. Differences exist in the degree of automation of the assigning and maintaining of herd statuses and in the recording of vaccinations. For I-3/I-4 status, a manual check of serological screening results is performed at ARSIA before the status is attributed and recorded manually in a specific software programme, whereas at DGZ 90% of herd statuses are attributed by an automated programme. In addition, ARSIA record vaccination details at individual animal level, whereas DGZ record this at herd level (see below under Vaccination for details). Test results are reported to both farmers and vets. The programme databases also interact with the national SANITEL database, sharing identification and registration information and also herd statuses. Farmers, vets and traders have access to herd-level information on the databases of ARSIA and DGZ. Initially, farmers were asked to grant permission to share this data but the sharing of this information is now established in legislation. The databases also generate lists of animals to test to maintain I-3 and I-4 status. Currently, only serum samples are tested within the programme. Work is ongoing to evaluate whether milk will be used in the future. CODA-CERVA have evaluated tests for bulk tank milk samples as part of a broader study (IBRDIA). The underlying concern related to the fact that some test methods would give a negative result even when there were a variable
16
NATIONAL PERSPECTIVES ON IBR
BELGIUM
low percentage of positive animals contributing to the sample. The IBR gB and gE ELISAs, were found to give a negative result when the prevalence fell to 10% and 10-15% respectively. Another ELISA test format (Indirect ELISA; detecting antibodies to a range of viral proteins) was least affected, giving a positive result with a 2% prevalence of positive animals. One option that is available to address this is the use of concentration techniques, which have been shown to reduce these thresholds to 0.2% and 0.33% respectively. However, these concentration protocols are relatively costly to perform. Issues with testing A key issue identified was the generation of “aspecific” positive test results, particularly in test- negative herds with I-3 and I-4 status, with the potential to cause herds to lose their status. Potential explanations include kit issues, cross-reactions with other herpesviruses (e.g. BoHV-2, BoHV-5, Caprine HV-1, Cervid HV-1) and previously unrecognised vaccination. The lack of confirmatory testing for the IBR gE ELISA makes it difficult to investigate the origin of these. The NRL conducts further investigation of samples generating aspecific results and have developed complex algorithms for further testing and interpretation of these results. Between 01/12/2006 and 01/11/2012, 1.4 % of all sera tested by gB ELISA triggered a confirmation procedure due to the result being considered aspecific. These samples came from 23.6% of all herd screenings. The parallel figures for the gE ELISA were 0.3% of samples and 7.1% of herd screenings. There are no specific protocols for the management of seronegative latent carrier (SNLC) animals. G. Vaccination Previously, vaccination against IBR was used to prevent clinical signs rather than for eradication. Vaccination was generally performed once a year, most commonly at housing. In the context of eradication, vaccination is limited to marker
(gE deleted vaccines) given twice per year. The rationale for vaccination twice per year (hyper- immmunization) rather than just once is that the former reduces the level of shedding of virus in addition to protecting against clinical disease but also to prevent shedding from latent carriers. In the context of eradication, biosecurity is important to ensure that infected animals are not introduced to the herd. Both live and dead IBR vaccines are available from several pharmaceutical companies. All of these vaccines, regardless of licensed indications, are used on a 6 monthly basis (referred to as hyperimmunisation) following initial vaccination (primovaccination) which may be a single or double dose depending on the brand and type of vaccine. The choice of vaccine brand and type is determined by the ES vet in conjunction with the herd owner. There were no concerns raised with regard to herds changing between vaccine brands. For herds to acquire and maintain an I-2 status, all animals over 3 months of age and present in the herd for 35 days or more must receive a primo- vaccination consisting of either a single dose or two doses at a 21-35 day interval. Thereafter all animals must receive a booster dose within 8 months of the preceding one. Therefore I-2 status is acquired or maintained if all animals older than 10 months of age are primo- vaccinated or hyper-immunised and all animal older than 17 months have been hyper-immunised. Decision to vaccinate At the start of the programme, the decision for non-vaccinating herds of unknown status to either vaccinate or seek an I-4 status fell to the farmer and his veterinary practitioner. The use of the snap shot screen described earlier was encouraged, but many herds, particularly in Flanders, did not use this strategy, instead adopting a vaccination policy. In this way many herds that were free or had low prevalence of infection acquired an I-2 status, even though a proportion could have proceeded rapidly to an I-4 status.
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CONTROL AND ERADICATION IN BELGIUM AND THE NETHERLANDS
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