Que tal treinarmos um pouco o nosso inglês?
Autor: 1º ano C | Publicado: 2012-04-25T17:03:00-03:00

Bovine Spongiform Encephalopathy&nbsp;(BSE), commonly known as&nbsp;mad-cow disease, is a fatal&nbsp;neurodegenerative disease&nbsp;in&nbsp;cattle&nbsp;that causes a spongy degeneration in the&nbsp;brain&nbsp;and&nbsp;spinal cord. BSE has a long&nbsp;incubation period, about 30&nbsp;months to 8&nbsp;years, usually affecting adult cattle at a peak age onset of four to five years, all&nbsp;breeds&nbsp;being equally susceptible.&nbsp;In the&nbsp;United Kingdom, the country worst affected, more than 180,000&nbsp;cattle have been infected and 4.4&nbsp;million&nbsp;slaughtered during the eradication program.

The disease may be most easily transmitted to human beings by eating food contaminated with the brain, spinal cord or digestive tract of infected carcasses.&nbsp;However, it should also be noted that the infectious agent, although most highly concentrated in nervous tissue, can be found in virtually all tissues throughout the body, including blood.&nbsp;In humans, it is known as&nbsp;new variant&nbsp;Creutzfeldt–Jakob disease&nbsp;(vCJD or nvCJD), and by October&nbsp;2009, it had killed 166&nbsp;people in the United Kingdom, and 44 elsewhere&nbsp;Between 460,000 and 482,000&nbsp;BSE-infected animals had entered the human&nbsp;food chain&nbsp;before controls on high-risk&nbsp;offal&nbsp;were introduced in 1989.


A British inquiry into BSE concluded that the&nbsp;epizootic&nbsp;was caused by cattle, who are normally&nbsp;herbivores, being fed the remains of other cattle in the form of&nbsp;meat and bone meal&nbsp;(MBM), which caused the infectious agent to spread.&nbsp;The cause of BSE may be from the contamination of MBM from sheep with&nbsp;scrapie&nbsp;that were processed in the same slaughterhouse. The epidemic was probably accelerated by the recycling of infected bovine tissues prior to the recognition of BSE.&nbsp;The origin of the disease itself remains unknown. The infectious agent is distinctive for the high temperatures at which it remains viable; this contributed to the spread of the disease in the United Kingdom, which had reduced the temperatures used during its&nbsp;rendering&nbsp;process.&nbsp;Another contributory factor was the feeding of infected protein supplements to very young calves.

The first reported case in&nbsp;North America&nbsp;was in December&nbsp;1993 from&nbsp;Alberta,&nbsp;Canada.

Another case reported later in May&nbsp;2003. The first known U.S. occurrence came in December of the same year though it was later confirmed that it was a cow of Canadian origin and imported to the U.S.&nbsp;Canada announced two additional cases of BSE from Alberta in early 2005.&nbsp;In June&nbsp;2005&nbsp;Dr.&nbsp;John Clifford, chief veterinary officer for the&nbsp;United States Department of Agriculture&nbsp;animal health inspection service, confirmed a fully domestic case of BSE in&nbsp;Texas. Dr.&nbsp;Clifford would not identify the ranch, calling that "privileged information".&nbsp;A new case of Mad Cow disease was recently found in a dairy cow on April 23, 2012 in&nbsp;California&nbsp;during a planned Agriculture Department surveillance program. United States health authorities were quick to point out that the animal was never a threat to the nation's food supply and claim that this is an atypical case of BSE caused by "just a random mutation that can happen every once in a great while in an animal."