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As a result of the Argentine experience with foot-and-mouth disease (FMD) in 2001, a need was postulated for the establishment of efficient supranational schemes for continuous surveillance of the interrelations between tropical extractives livestock systems and the prairies that are optimal for the feeding of livestock in the southern region of South America. FMD in Argentina and in other countries, new or re-emerging risks from avian influenza with potential risks for public health, the spongiform encephalopathies, porcine reproductive and respiratory syndrome, and classical swine fever, among other animal diseases, have generated a strong reaction and evolution within the veterinary services of the country. These present lessons will influence decision-making within countries and should be accepted by the technical and scientific community. From the perspective of the official animal health sector and with the FMD eradication plan as a basis within the national territory, we have worked not only to achieve international recognition and credibility within animal health systems, but also to realize the formation of a regional block of countries that can be recognized internationally as an area with equivalent animal health status. We emphasize not only that this lesson is useful in FMD, but also that it is possible to apply the valuable conclusions reached for other emerging or re-emerging diseases.

Within the framework of the International Animal Health Code of the Office International des Epizooties (OIE), important contributions have been made by the Animal and Plant Health Inspection Service/United States Department of Agriculture (APHIS/USDA), the Ministry of Agriculture of Canada, the Ministry of Agriculture and Fisheries of New Zealand and other organisations, by the development of risk assessment methods and regionalization criteria for risk assessment. The authors attempt to contribute to these efforts by proposing a regional risk evaluation of foot and mouth disease (FMD) in South America. Two examples of risk assessments for international trade, i.e., in bovine embryos and in meat, are used to demonstrate the importance of an effective disease surveillance system as the basis for risk regionalization for international trade in animals and animal products. As a result of progress in the control and eradication of FMD in South America, it is expected that major livestock production regions will soon be in low- to very low-risk categories.

The authors describe the method used in Argentina for quantification of risk in controls of the potency and innocuity of foot and mouth disease vaccine. Quantitative risk analysis is a relatively new tool in the animal health field, and is in line with the principles of transparency and equivalency of the Sanitary and Phytosanitary Agreement of the Uruguay Round of the General Agreement on Tariffs and Trade (GATT: now World Trade Organisation [WTO]). The risk assessment is presented through a description of the steps involved in manufacturing the vaccine, and the controls performed by the manufacturer and by the National Health Animal Service (Servicio Nacional de Sanidad Animal: SENASA). The adverse situation is considered as the lack of potency or innocuity of the vaccine, and the risk is estimated using a combination of the Monte Carlo simulation and the application of a Bayesian model.

A scheme for registering pharmaceutical and biological products for veterinary use was introduced in Argentina in 1994, as part of a joint scheme for countries of the Common Market of the South (Mercado Común del Sur: "Mercosur'). The authors describe the main features of these regulations, and the process which led to their development.

Bovine spongiform encephalopathy (BSE) is a new disease of cattle first described in the United Kingdom in November 1986. BSE belongs to the scrapie-related group of diseases. The epidemiological studies performed in the United Kingdom demonstrate that the BSE epidemic was caused by feeding cattle with ruminant-derived protein contaminated by a scrapie-like agent. Until June 1994, the disease had been detected in indigenous cattle in Ireland, Switzerland and France. Three cases reported in Germany, two in the Sultanate of Oman, and single cases in the Falkland Islands (Islas Malvinas), Denmark, Portugal and Canada occurred in animals imported from the United Kingdom. Several countries have implemented surveillance programmes analysing the risk factors involved in the epidemic. An analysis of risk factors conducted in Argentina shows that it is highly unlikely that BSE or scrapie exist in the country, or will arise via feed in the future. As a continuation of the analysis of risk factors, a surveillance programme was implemented in the field and in abattoirs. Specialised personnel were trained in the clinical, histopathological and biochemical detection of the disease through a network of laboratories which covered 85% of the total cattle population and 100% of the high-risk group (dairy cows over five years of age). By using a statistical procedure with reference to the bovine population in nine provinces, 1,019 brains from animals belonging to the high-risk group were selected and studied by histopathological and biochemical analyses for BSE detection. The results were negative in all cases. It can be concluded from this analysis (with a sensitivity of detection of 2.95 per 1,000, and 95% statistical confidence) that Argentina may be regarded as BSE-free, and that the importation of infected animals or by-products may represent the sole potential source of introduction of BSE infection into the country in the future.

Epidemiological studies conducted in the United Kingdom have revealed the risk factors involved in the epidemic of bovine spongiform encephalopathy (BSE). This has facilitated a detailed study of risk factors associated with the possible introduction of BSE into Argentina. An analysis has been made of the numbers and geographical distribution of cattle in the country, the structure of the Veterinary Services responsible for controlling animal diseases, the way in which cattle and sheep are slaughtered, and the use of slaughter waste in the feed industry. The results of this analysis form the basis of a discussion of whether scrapie or BSE could become endemic in Argentina through contaminated feed or another route. The authors conclude that Argentina may be regarded as free from BSE, and that the importation of infected bovines is the sole potential risk for introduction of BSE in the future.