Where's the Beef?|​狂牛病知多少

by Matthew Brown

Cases of mad cow disease have subsided in recent years, but what have we learned?

狂牛病的案例近年来已有减少的迹象，但我们从中学到什么教训？

In 1984, a cow in Britain fell ill. The disease was found to be a new one, and people's worst fears quickly came true. The disease rapidly spread among cattle in Britain and even infected humans that had eaten the tainted beef. From the time the UK Ministry of Agriculture accepted that there was a new disease in 1986 until October 2009, 165 people had died of bovine spongiform encephalopathy, more commonly known as mad cow disease (MCD).

The story of MCD is not pretty. Along with the 165 human fatalities, more than 179,000 cattle had been infected in the UK alone. Raising cattle and producing beef is a major industry, and the need to stop the disease from spreading was an urgent one. Therefore, some 4.4 million cows were slaughtered in an effort to eradicate the disease.

MCD attacks the brains and spinal cords of cattle. The deterioration of their brains affects their behavior, which is the reason for the name of the disease. The disease seems to be caused and spread only by cattle eating other cattle. Cows are herbivores, so how do they eat other cows? The answer again is not very pleasant. To save money on cattle feed, farmers oftentimes grind up the remains of dead cows and combine it with their normal food. Since the feed is ground and mixed together, it's hard to tell which food has been contaminated or which cows may have consumed it.

Thanks to the enormous slaughter of the cattle that might have been infected, the disease now seems to be under control. Only five or so cases per year have been found in recent years. However, the disease is not fully understood, and as demonstrated by the recent protests in Taiwan, people are still worried. Some people believe that MCD shows us that farming methods and slaughtering practices are not totally safe, healthy, or reliable.

1.  How was MCD controlled?

(A) Everyone in the world stopped eating beef.

(B) Cattle were fed only grain.

(C) A large number of cattle were put to death.

(D) New drugs were quickly injected into infected cattle.

2.  How did MCD get its name?

(A) Infected cows started behaving strangely.

(B) Cows started to go insane when they were about to be slaughtered.

(C) The name refers to the panic people feel about the disease.

(D) Farmers were very upset about the slaughtering of their precious meat.

3.  MCD spreads when _____.

(A) cows are slaughtered in large numbers

(B) cows attack and eat each other

(C) cows eat food that contains parts of other cows

(D) cows mix with other animals

4.  According to the article, has MCD been stopped?

(A) Yes, it has been stopped completely.

(B) It seems to have been mostly stopped.

(C) No, it is still spreading quickly.

(D) It was stopped in 1984, the year it started.

　　1984 年英国的一只牛生病了。该疾病被证实是一种新疾病，人们心底的恐惧很快就成真了。这种疾病在英国的牛只间迅速传开来，甚至连食用到受感染牛肉的人，也遭到感染。从英国农业部长在 1986 年确认这是一种新的疾病，到 2009 年 10月为止，已有 165 人死于『牛海绵状脑病』，也就是一般俗称的『狂牛病』。

　　狂牛病的内情并不光采。除了这 165 名死于该疾病的患者外，光是英国就还有 17 万 9 千头牛感染此疾病。饲养牛只与生产牛肉是个庞大的产业，首要之务便是阻止该疾病扩散。因此，约有 4 百 40 万头牛只遭到扑杀，好杜绝该疾病。

　　狂牛病会攻击牛的脑部和脊髓神经。脑部受损会影响牛只的行为，这也是狂牛病这个名称的由来。该疾病似乎是因为牛只吃到其他牛所造成并传染开来。牛是草食动物，那么牠们怎么会吃其他牛只呢？原因一样不很光采。为了省饲料钱，饲主往往把死牛的尸体磨碎，再和普通饲料混在一起。因为饲料已经被磨碎搅拌在一起，所以很难分辨哪里的饲料受到污染，或是哪些牛可能已经把饲料吃下肚。

　　由于大规模扑杀可能受到感染的牛只，狂牛病现在似乎得到控制。近年来每年大约只有 5 起病例发生。然而，该疾病尚未被全盘了解，而最近在台湾所发生的抗议显示出民众仍然非常担心。有些人认为狂牛病显示，饲养方式和屠宰的程序并非百分之百安全、健康和可信赖。

标准答案: 1. (C)　2. (A)　3. (C)　4. (B)

For Your Information

狂牛病据信是由于『朊毒体』（prion）引起的。所谓的『朊毒体』是一类不含核酸而仅由蛋白质构成、可自我复制并具感染性的因子。朊毒体具体的活动和复制机制目前还不是很清楚，但是它们通常被认为是引起传染性海绵状脑病的原因（例如狂牛病和羊骚症）。

当英国和美国相继爆发狂牛病后，澳大利亚及纽西兰则因从未发生狂牛症病例而受惠，受到牛肉消费国的欢迎；这两个国家顺利吃下原先美国牛肉的市场，即使美国牛在部分国家重新开放后，仍无法撼动其市占率，成为狂牛病风暴中少数受惠的牛肉生产国。（数据源：维基百科）