國人食用BSE發生國丹麥之進口牛肉健康風險評估

A Health Risk Assessment of vCJD Risk on Taiwanese Consumers for Consuming Imported Beef Product from Denmark, a BSE-occurred Country

牛海綿狀腦病（Bovine Spongiform Encephalopathy, BSE）又稱狂牛症是一種對牛隻具神經毒性且致命的腦部疾病，研究指出BSE的致病普恩蛋白（protease-resistant PrP）有人畜共通的傳染機制，因此BSE與食用牛肉的風險管理需進一步探討。雖然台灣未發現BSE案例，但由於國內食用牛肉長期仰賴進口牛肉，因此食用BSE發生國進口之牛肉成為食品安全中重要的項目，也需要有量化的健康風險資料來做為評估的依據。本研究以丹麥進口牛肉食品為例，評估國人食用進口牛肉而感染新變異型庫賈氏病（new variant CJD, vCJD）之健康風險，參考生物性健康風險評估架構（包含評估目的與範圍、有害物質鑑定、暴露評估、有害物質特性化、風險特性化）以機率分析方法納入評估參數之不確定性，評估模式考慮大腦中異常PrP^（Res）累積的生物學機制參數，暴露機率和預期的攝取感染性濃度，最後估算出食用丹麥帶骨牛肉的終生風險中位數為1.09×10^（-8），95％信賴區間上限為1.31×10^（-8），若以過去已開放進口之BSE發生國家之評估結果比較，其終生風險中位數位於荷蘭（8.82×10^（-9））與日本（1.13×10^（-8））之間。 Bovine Spongiform Encephalopathy (BSE), also known as mad cow disease, is a neurotoxic and fatal brain disease in cattle. Protease-resistant Prion is the infectious agent with infection mechanism common to both humans and animals; therefore, the risk analysis of BSE and edible beef needs to be further estimated. Although there was no BSE case in Taiwan, since domestic beef has long relied on imported beef, the beef imported from the BSE-occurred country has become an important issue. Thus, quantitative health risk data in food safety is an important reference for risk management. Danish imported-beef was used as an example to assess the health risks of new variant CJD (vCJD) in the consumption of imported beef by Taiwanese consumers. This research used the quantitative microbial risk assessment framework, which included the purpose and range of assessment, hazard identification, exposure assessment, hazard characterization and risk characterization. The risk assessment used the certainty and probability method that included the biological mechanism parameters of abnormal prion accumulation in brain, exposure probability and expected infectious concentration of ingestion. We implemented the sensitivity analysis to identify the sensitive risk factor. After arranging the data, we collected and ran the Monte Carlo simulation to estimate the lifelong risk for intaking Danish beef. The median of the risk is 1.09×10^(-8) and the 95th percentile of confidence interval upper limit is 1.31×10^(-8). When compared with countries that allowed beef products imported from BSE-occurred country, Taiwan's median of lifelong risk is in between Netherland (8.82×10^(-9)) and Japan (1.13×10^(-8)).