6.1 OIE conditions for a Scrapie free country

Conditions to be satisfied in order to be classed as a scrapie-free country as defined in the OIE International Animal Health Code Draft Chapter 3.3.8 on scrapie as existing at 1 June 1999, specifically as defined in Articles 3.3.8.1 1) – 5) inclusive and 3.3.8.2, 1), 3) and 4), are as follows:

The scrapie status of a flock, a zone or a country can only be determined by continuous surveillance and monitoring. [No serological tests are available.] Post mortem examination of brains of suspect animals is required to confirm the presence of disease [using histopathology and immunohistochemistry or western blot or scrapie associated fibrils (SAF) detection by electron microscopy].

The minimum requirements for effective surveillance are:

4) laboratory examination of brain material from clinically suspect animals which are slaughtered or which die, in accordance with the diagnostic techniques set out in the Manual;

5) maintenance of records including the number and results of all investigations for at least 7 years.

Article 3.3.8.2.

Scrapie free country or zone

and

4) introductions of sheep and goats, semen and embryos/ova from countries or zones not free from scrapie are carried out in accordance with Article 3.3.8.4., Article 3.3.8.5., Article 3.3.8.6. or Article 3.3.8.7., as relevant.

6.2 ARTICLE 3.3.8.1 Statements supporting the case for Argentina

To support the contention that Argentina is a scrapie-free country, the following statements can be made and in regard to ARTICLE 3.3.8.1 of the Code:

6.2.1 Keeping up to date with current knowledge and diagnostic methods

Argentina fully understands the complexities of scrapie in sheep and goats (CHAPTER 2). Argentina continuously updates its knowledge of the disease, results of recent research and diagnostic methodology. Apart from using their own staff for this purpose, veterinarians, medical doctors, and TSE scientists of international reputation are consulted to ensure that Argentina is fully equipped for the purpose.

6.2.2 High standards of Official Veterinary surveillance, reporting and control

Argentina has a highly efficient State Animal Health Veterinary Service (SENASA) comprised of field and laboratory veterinarians and support staff who have considerable experience of animal disease control and surveillance. Working together as a team they have successfully eradicated foot and mouth disease (FMD) from the country by consistently ensuring high quality surveillance and control methods and strict border control over the importation of animals and animal products, thus maintaining the country free of the disease. The recommendations in the OIE International Animal Health Code chapter on FMD are followed. Annual or bi-annual inspection of animals by SENASA staff for the identification of sheep scab and for FMD surveillance (and blood testing) provides the basis of good clinical surveillance of all farm animals in Argentina. It is during these examinations that clinical inspection of all sheep and goats (as well as cattle) in Argentina is conducted for evidence of TSE (CHAPTER 3). The extensive awareness programme (CHAPTER 4) ensures that all livestock farmers, veterinarians and SENASA staff employed on these inspections are fully aware of the clinical signs of scrapie and BSE. Such examinations are supplemented with clinical examinations of animals at markets, abattoirs and other gatherings (CHAPTER 4) and of sheep and goats over 18 months of age reported to SENASA with progressive neurologic signs. SENASA has a sound knowledge of all the industries relevant to the control of TSE. SENASA also has administrative control of all livestock farms and premises, and, in so far as hygiene, safety and animal disease control are concerned, of the associated industries, including artificial insemination centres, embryo transfer facilities, medicinal products used in animals, abattoirs, rendering plants and feed premises. Laboratories that conduct official investigations and tests for animal TSE including scrapie are approved by SENASA and are under the direct control of SENASA.

6.2.3 Clinical inspection, laboratory diagnosis and record keeping

Clinical inspection, compulsory slaughter of animals suspected to have scrapie, BSE or any TSE, or which die or may have died from these diseases, and laboratory examination of brain material is carried out in every case using the diagnostic techniques set out in the current issue OIE Manual of Standards for diagnostic tests and vaccines (in preparation). All tests are conducted in laboratories approved by SENASA. Records of the number and results of these investigations are kept for a minimum period of seven years.

6.3 ARTICLE 3.3.8.2, 1), 3) and 4), statements supporting the case for Argentina

6.3.1 Notification

All exotic diseases, including scrapie, BSE and all animal TSE, and certain endogenous diseases have been notifiable in Argentina since 1900 under Law #3959 (Animal Health Law Enforcement Authority). Specific resolutions now specifically deal with scrapie (Resolution #695/96) and BSE (Resolution #172/97). Thus there has been a policy for the compulsory notification to the Competent Authority of scrapie, BSE and indeed all animal TSE continuously since 1900.

Failure to report the clinical suspicion of disease is a punishable offence under the Animal Health Act from 1900 (APPENDIX B). If a financial loss is incurred by a farmer as a result of Government intervention, e.g. compulsory slaughter of a sheep, there is provision for compensation. No charge is made to the owner for any laboratory examination. A balance is kept between punishment for non-compliance and compensation for loss, and is under continuous review. There is thus a strong motivation for sheep and goat farmers and zoo owners to ensure notification of suspect cases of scrapie, partly due to their historical and ethical approach to FMD notification upon which their livelihood depends.

6.3.2 Absence of clinical cases

There has been no recorded or reported clinical (or pathological) case of scrapie in sheep, goats or moufflon in Argentina since the XVI^th century or before.

During this period, as more and more knowledge was gained about the disease the quality of surveillance has improved. This has been mainly at the clinical level (the essential aspect of surveillance for disease) and is due to the requirements for frequent inspections of all ruminant and porcine species by personnel trained to recognise FMD, scrapie and BSE. The additional visits made as part of the sheep scab control programme assist in this process. Since the advent of BSE, surveillance has included more examination of sheep and goats brains than hitherto and the number will be increased in the future (see below).

6.3.3 Continuous surveillance and monitoring

An effective and continuous surveillance and monitoring system is practised in Argentina (see also 6.2.2 above).

All farmed ruminant species (including CERVIDAE (deer) and CAMELIDAE (llamas, alpacas, vicunas and guanacos) are regularly and frequently inspected (once or twice a year) for evidence of FMD by trained personnel who are familiar with the clinical signs of scrapie. It is therefore unlikely that scrapie, would be missed if it occurred. Even a sporadic event (e.g. sporadic or familial scrapie, if these hypothetical forms exist as they do in man as naturally-occurring forms of CJD) would also be unlikely to be missed especially if there was transmission of that disease to other animals. Continuous clinical monitoring is the vital method to detect scrapie if it occurs. Furthermore any sheep or goats older than 18 months of age displaying signs of progressive neurologic disease are compulsorily destroyed and their brains are examined for the presence of TSE in SENASA-approved laboratories and using methods specified in the Manual. This is supplemented in Argentina by an increasing surveillance for scrapie by pathological methods mainly in sheep, but also in goats. Targeted populations provide brains (in the period April 1997-April 1999) and other tissues (under development) upon which diagnostic tests can be applied, e.g. histopathology of the brain, immunoblotting and immunocytochemistry of brain tissue. No test has yet given a positive result for TSE (TABLES 1 and 2).

Argentina recognises that surveillance for scrapie by these methods needs to be further developed and is doing so. This effort will ensure more brains from target populations are examined in future and the methods used will be the most sensitive available. The result will be to increase still further the confidence that Argentina is a scrapie-free country. The target number of brains to be examined in the year April 1997-April 1998 and April 1998-April 1999, will be based on TABLE I of the OIE Guidelines for continuous surveillance and monitoring of BSE (Appendix VIIIb of Document 65 SE/12/CS1, OIE 1997c). In subsequent years at least this number of brains will be examined and, in addition, other methods may be used depending on the stage of their scientific development and validation. A sufficient number of pathological examinations are carried out on brain material to provide a 95% level of confidence of detecting scrapie if it is present at a prevalence rate exceeding 0.1% out of the total number of chronic wasting conditions in the population of sheep and goats older than 18 months of age.

6.3.4 Ruminant MBM Feed Ban

The feeding of meat-and-bone meal (MBM) derived from ruminants from infected countries to sheep and goats has been banned in Argentina since July 1995 (RESOLUTIONS 429/90, 382/95, 203/96, 252/95 and 611/96, APPENDIX B) and effectively enforced.

Effective enforcement is the responsibility of port officers of SENASA and the Customs and Excise staff employed to detect illegal imports. In addition the feeding of ruminant protein to ruminant animals, even from indigenous safe sources of MBM is prohibited and gives a substantial increased confidence that any risk is at a very low level indeed. Enforcement of the law is verified by random sampling of ruminant feed in feed mills and on farm and by subjecting samples to either the microscopic test or ELISA for ruminant protein. No breaches of the regulations have been found following checks of over 102 samples in the period April 1997-June 1999.

6.3.5 Importation of sheep, goats, semen and embryos/ova

Importation of sheep, goats, semen and embryos/ova is effectively enforced and is the responsibility of port officers of SENASA and the Customs and Excise staff employed to detect illegal imports. Legal imports from all countries including those from countries or zones not free from scrapie are carried out in accordance with Articles 3.3.8.4, Article 3.3.8.5, Article 3.3.8.6 and Article 3.3.8.7 as relevant.

6.3.6 ABSENCE OF BSE IN CATTLE IN ARGENTINA AND ABSENCE OF ANY ANIMAL TSE IN ARGENTINA

EVIDENCE FOR THE ABSENCE OF BSE IN CATTLE IN ARGENTINA IS PROVIDED IN THE SISTER DOCUMENT "BSE RISK FACTORS IN ARGENTINA" AND IN A DOSSIER PRESENTED TO THE EUROPEAN COMMISSION. THE RESULTS OF THE CONTINUOUS SURVEILLANCE FOR BSE AND OTHER ANIMAL TSE IN ARGENTINA SHOW THAT NO CASES OF ANIMAL TSE OF ANY KIND HAVE BEEN DETECTED IN THE PERIOD FOLLOWIG PUBLICATION OF THESE DOCUMENTS.

6.4 CONCLUSION I

The criteria established in draft by the OIE for declaring a country as scrapie–free have been satisfied for Argentina. THERE IS ALSO NO EVIDENCE FOR THE OCCURRENCE OF BSE IN ANY SPECIES OR ANY OTHER ANIMAL TSE IN ARGENTINA.

6.5 ADDITIONAL ASSURANCES I

Additional assurances that scrapie does not exist in Argentina can be given namely:

• The origin of sheep and the period (XIXth century) during which major imports (mainly from Europe especially Great Britain) were being made to establish the Argentine national flock is similar to that of imports into Australia, New Zealand and South Africa. All these countries remained scrapie-free in the same period.

• The predominant breeds in Argentina are white-faced and fine-wool breeds. The main end-product of the Argentine sheep industry is high quality wool for export. Meat production is subsidiary and there is little incentive for genetic advancement for meat as the Argentine trade is for small carcasses of 12 kg rather than the heavier weights (20 kg) provided by high quality meat-producing breeds some of which are also more frequently reported as affected by scrapie. These breeds have either not been imported or if they have, have not established themselves in any significant numbers. In particular Suffolk sheep, which are strongly associated with the introduction of scrapie to scrapie-free countries (including Australia and New Zealand which have eradicated the disease and the USA which has not) number less than 10 individuals and these are under SENASA surveillance.

• Introduction of scrapie into Argentina is highly improbable because breeds likely to carry the disease are avoided, no imports from scrapie-infected countries are permitted since 1990 (RESOLUTION 420/90, APPENDIX B). Also all imported sheep and goats are recorded in Registers of the Rural Society and the flocks to which they go are recorded in the Flock Book of the Rural Society that is supervised by SENASA. Thus the flocks containing imported sheep are known and subjected to more stringent surveillance. At present individual imported animals are subject to special scrutiny (RESOLUTION 471/95, APPENDIX B).

• Semen and embryos are subject to the same controls and certifications as live animals. Imports are only allowed from scrapie-free countries since 1990 and are, in practice, seldom important in terms of numbers. Recipient animals and offspring from embryos are identified and monitored by SENASA. In any case they have to satisfy the conditions of Articles 3.3.8.6 and 3.3.8.7.

• The predominant breeds of sheep in Argentina are Australian Merinos, Romney Marsh and Corriedale. None is a breed commonly affected by scrapie. Indeed it has been claimed that no case has been identified in any of these pure breeds. Whatever is the truth scrapie is rare in these breeds.

• Sheep rearing is extensive - in some areas e.g. Patagonia, very extensive with < 1 sheep/2Ha. Risks from scrapie transmission between sheep are therefore very low and much lower than in countries with intensive systems using high densities of grazing. In the Buenos Aires region stocking rates are higher but still extensive as the better grassland is used for cattle.

• The possibility of sheep from other countries with land borders with Argentina entering the country is small due to the geographical features (Andes) and rivers. Also not all boundary land is suitable for sheep. Furthermore, breeds of sheep in neighbouring countries are mainly different from those in Argentina and so such animals would be easily recognised by farmers and animal health personnel. Risks from this source would in any case be very small because the scrapie status of neighbouring countries is not significantly different from that in Argentina.

6.6 CONCLUSION II

The national sheep flock in Argentina has a low risk of harbouring scrapie.

6.7 ADDITIONAL ASSURANCES II

• The commercial profitability of sheep is such that feeding concentrates is unjustifiable and indeed would have no benefit even if it was done. Concentrate feeding would only apply to specialised meat and milk-producing animals which do not exist in significant numbers. Thus the accidental inclusion of MBM into a ration or cross-contamination of such a ration is impossible as only grass or roughage (hay/silage) is fed. Of course sheep graze other indigenous plants but this is totally devoid of a scrapie risk.

• No brain-derived vaccines are used in any animal species in Argentina, so iatrogenic sources of disease are unlikely.

• Most waste products from sheep (uneaten CNS or LRS tissue from animals passed fit for human consumption) are disposed of on farm and therefore are not recycled to any species. Some abattoirs controlled by SENASA do slaughter sheep and waste products including CNS and LRS tissues which, if not consumed, are disposed of by rendering. The end use of the MBM so produced is for feeding poultry, pigs and pets.

• The average age of sheep is increasing in Argentina making available a larger number of older animals for scrapie surveillance purposes.

6.8 CONCLUSION III

Additional guarantees beyond those required by the OIE can be given to support the view that Argentina is a scrapie-free country.

7. FINAL CONCLUSIONS

ARGENTINA IS A SCRAPIE-FREE COUNTRY AS DEFINED BY THE OIE.

ARGENTINA INTENDS TO STAY SCRAPIE-FREE BY ADOPTING SCIENTIFIC PRINCIPLES TO REDUCE THE RISK OF SCRAPIE OCCURRENCE AND BY CONTINUOUSLY CONDUCTING SURVEILLANCE AND MONITORING FOR THE PRESENCE OF THE DISEASE.

ARGENTINA HAS A POLICY OF CONTINUOUSLY DEVELOPING ITS MONITORING AND SURVEILLANCE FOR SCRAPIE TO PROVIDE THE BEST GUARANTEES FOR ITS CUSTOMERS AT HOME AND ABROAD.

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