Economic consequences of a scrapie outbreak in Australia

Overview \r\n The ABARES report presents estimates of the economic impact of a hypothetical outbreak of scrapie in Australia's sheep and goat population under three disease spread scenarios: • eradicable epidemic - an outbreak occurs and is successfully eradicated \r\n• managed spread - eradication is unsuccessful and spread is slowed by control measures \r\n• uncontrolled spread - without control measures in place, the disease spreads uncontrolled. \r\n\r\n ABARES also estimated the trade impacts that may result following an outbreak of scrapie. Due to uncertainty around the extent of export market disruptions, three export ban scenarios by China, Japan and the Republic of Korea were modelled - as these countries have been sensitive to outbreaks of notifiable livestock diseases in the past. \r\n\r\n The ABARES report indicates that Australia benefits significantly from remaining free of scrapie, and that in the event of an outbreak, it would also likely benefit from measures to eradicate the disease or control its spread. \r\n\r\nKey Issues \r\n Scrapie is a progressive neurodegenerative disease affecting sheep and goats. It belongs to the group of livestock diseases which includes mad cow disease (bovine spongiform encephalopathy or BSE) in cattle. Scrapie (unlike BSE) is not associated with any known human health risks. Australia is one of the few major sheep producing countries that is free of scrapie and only allows imports of live sheep or genetic material under strict conditions from selected countries. \r\n\r\n\tAustralia would benefit significantly from preventing the entry of scrapie, and from detecting it relatively early if it enters. If detected within 10 years of entry, efforts to eradicate the disease are likely to be both successful and cost effective. Eradication would likely be achieved an average of eight years after detection of the disease, but outbreaks could last up to 50 years. \r\n\r\n If detected early enough to be eradicable, modelled costs of controlling and eradicating scrapie-ncluding income losses from movement restrictions, were modest-estimated at an average of $4.7 million (in 2016 dollars). Most of the economic impact from an eradicable outbreak came from trade losses. \r\n• For example, if the outbreak led to a three-month ban on sheep meat by China and Japan, and a three-month ban on beef by Korea, the estimated trade losses would be $70 million over 10 years, of which $36 million would be lost by the beef industry. \r\n• A three-month ban on beef to Korea is based on existing agreed certification with Korea requiring Australian exporters to include an attestation that Australia is free of scrapie on export certificates for a range of beef and sheep meat products.. \r\n\r\n An eradication campaign is estimated to yield a benefit-cost ratio between 5:1 and 10:1, based on an assumed cost of $3 million to run epidemic control centres. \r\n\r\n If the disease was not detected in time to be eradicable, it would still be cost-effective for Australia to implement measures to slow the spread. ABARES estimated the cost of uncontrolled spread to be in excess of $406 million (in 2016 dollars), compared to the estimated $119 million to $150 million cost of slowing the spread.

概述
澳大利亚农业与资源经济科学局（Australian Bureau of Agricultural and Resource Economics and Sciences, ABARES）的报告估算了澳大利亚绵羊与山羊种群假想暴发羊痒病（Scrapie）后的经济影响，设定了三种疾病传播场景：
• 可根除疫情：疫情暴发后被成功根除；
• 可控传播：根除失败，但通过防控措施减缓疾病扩散；
• 无控传播：未采取任何防控措施，疾病不受限制地蔓延。

此外，ABARES还估算了羊痒病暴发后可能产生的贸易影响。鉴于出口市场受冲击程度存在不确定性，报告针对中国、日本及大韩民国设定了三种出口禁令场景——这三个国家过往对须通报畜禽疫病暴发均较为敏感。

该报告指出，澳大利亚维持无羊痒病状态将获得显著收益；若暴发疫情，采取根除或控制疾病扩散的措施也将为澳大利亚带来可观收益。

核心议题
羊痒病（Scrapie）是一种渐进性神经退行性疾病，可感染绵羊与山羊。它与牛海绵状脑病（BSE，即疯牛病）同属一类畜禽疫病。与疯牛病不同，目前尚未发现羊痒病会对人类健康构成已知风险。澳大利亚是少数维持无羊痒病状态的主要绵羊生产国之一，仅允许从特定国家在严格条件下进口活绵羊或畜禽遗传材料。

若能阻止羊痒病传入澳大利亚，或在其传入后尽早检出，澳大利亚均可获得显著收益。若在疫情传入10年内完成检出，根除该疾病的工作大概率既能成功也具备成本效益。平均而言，疾病检出后8年即可完成根除，但疫情可能持续长达50年。

若能尽早检出疫情并实现根除，防控与根除羊痒病的模拟成本（含因畜禽移动限制产生的收入损失）相对较低，平均估算为470万美元（以2016年美元计价）。可根除疫情带来的大部分经济影响源于贸易损失。
• 例如，若疫情导致中国与日本对羊肉实施为期3个月的禁令，韩国对牛肉实施为期3个月的禁令，那么10年内预计的贸易损失将达7000万美元，其中牛肉行业将损失3600万美元。
• 韩国对牛肉实施的3个月禁令，基于现有与韩国达成的认证协议：韩国要求澳大利亚出口商在多款牛肉及羊肉制品的出口证书中，附加澳大利亚无羊痒病的声明。

据估算，若设立疫情防控中心的成本为300万美元，那么根除行动的收益成本比将介于5:1至10:1之间。

若未能及时检出疫情以实现根除，澳大利亚采取措施减缓疾病扩散仍具备成本效益。ABARES估算，无控传播的总成本将超过4.06亿美元（以2016年美元计价），而减缓传播的成本预计为1.19亿至1.50亿美元。