英语与精读100篇UNIT17.doc

TEXT ONE Britons’ most searing memories of their encounter with foot-and-mouth disease in 2001 are of the piles of animals slaughtered to try to stop its spread. Such a draconian policy might have been accepted had the disease been controlled quickly. But its ineffectiveness—more than 6m cows, sheep and pigs were culled before the disease was eradicated—led to widespread revulsion and a government rethink. Just as in 2001, if an animal is thought to be infected, its herd will be culled and a quarantine zone set up. But this time, unless the disease is stamped out quickly, animals nearby will also be vaccinated to create a “fire-break” across which it is unlikely to travel. Already 300,000 doses of vaccine have been ordered, so that if government vets decide that slaughter alone is unlikely to be effective, they can start vaccinating straight away. Humans almost never catch foot-and-mouth and it rarely kills the cloven-hooved beasts it affects. But animals produce less milk and meat, so its economic effects are severe. It is also highly contagious: infected livestock produce the virus that causes it in large quantities, and transmit it through saliva, mucus, milk, faeces and even droplets in their breath. Even so, only countries where foot-and-mouth is endemic, as in parts of Latin America, vaccinate all animals. One reason is cost: the disease is caused by a virus with seven main types and tens of sub-types, with a targeted vaccine needed for each strain and shots repeated, perhaps as often as twice a year. It is also because vaccinating damages exports. Places that are free from foot-and-mouth are unwilling to import vaccinated beasts, or fresh meat from them, because they may still carry the disease. The fear of being shut out of foreign markets led to the British governments disastrous foot-dragging over vaccination in 2001. But that same year an outbreak in the Netherlands involving 26 farms was brought under control in just one month by vaccinating 200,000 an