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Animal Disease and Human Health Risk
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On Wednesday, March 20, 1996, "Mad Cow Disease" grabbed headlines worldwide. The shock
waves were generated by a group of prestigious British scientists who revealed that the
fatal cattle disease was likely being transmitted to humans.1 The news brought the
British meat industry to a virtual standstill. English folk avoided the meat markets.
The European Union and a cascade of other countries banned British beef. When the dust
had settled, beef imports had been banned by 23 nations.
Since 1986, autopsies of British cattle dying with mad cow disease revealed a nervous
system infection that ate tiny holes in the brain. When viewed under a microscope, the
brain actually looked like a sponge. This sponge-like appearance gave rise to the
disease's scientific name: Bovine Spongiform Encephalopathy or "BSE." This cumbersome
name could literally be translated: cows' (bovine) sponge-like (spongiform) brain
disease (encephalopathy).
The lay term, "mad cow disease," in addition to being much easier to pronounce and
remember, also conveys the fact that infected cows often develop mental deterioration
and behavioral abnormalities. "Formerly" docile animals become irritable, nervous, or
aggressive. They often lose weight, and develop severe coordination problems before
dying within two weeks to six months.2 The number of cattle affected is staggering,
as stated in Figure 1: Cases of Mad Cow Disease.3
Beside being a terrible tragedy for the cattle population, BSE has powerful emotional
appeal for other reasons. It is one of a group of fatal brain diseases that can be
transmitted from one living creature to another. These diseases are technically called
"transmissible spongiform encephalopathies." Many British consumers had apparently
comforted themselves for years with the thought that it was unlikely for BSE to spread
from cows to humans. However, even before March, 1996, there were serious concerns
about human risk, because transmissible encephalopathies were known to affect many
other animals besides cattle. Mice, sheep, goats, monkeys, pigs, mink, and other
cattle have all come down with a spongiform encephalopathy when given meat from cattle
that were known to have the disease. Roughly 20 animal species have been documented
to come down with diseases resembling BSE. They are listed in Figure 2: Animals
Afflicted with Diseases Resembling BSE.4
Furthermore, cattle themselves likely contracted the disease from a different species.
The epidemic in British cows has been traced to a similar sheep spongiform
encephalopathy called scrapie.5 This sheep disease gets its name from the fact
that afflicted sheep can become mentally deranged and are known to literally
scrape the wool off their own hide.
Before concerns about mad cow disease surfaced, it was common for British cattle to
receive protein supplements in the form of meat and bone meal from other animals
such as sheep.6 Evidence suggests that the practice of feeding these reprocessed
sheep carcasses (which included their brains) to cattle allowed the cow population
to acquire BSE. Before the full extent of the problem was recognized, disease
transmission was further amplified when the carcasses of BSE-infected cows were
also used in the process of making animal feed.7, 8 Thus, healthy cows were not
only fed infected tissues of sheep but also of other cows.
References
1 The British The Spongiform Encephalopathy Advisory Committee. Report to Parliament on
March 22, 1996 (printed report downloaded from Microsoft Network's BSE forum).
2 Pratt K. Bovine Spongiform Encephalopathy. Update. Animal and Plant Health Inspection
Services (APHIS). U.S. Department of Agriculture, 1996 p. 1.
3 Ministry of Agriculture, Fisheries, and Food (MAFF), United Kingdom (UK): BSE: 12-month
summary of developments. Http://www.maff.gov.uk.animalh/bse/bseanni.htm. Updated to
Feb. 28, 1997.
4 Patterson WJ, Dealler S. Bovine spongiform encephalopathy and the public health.
J Public Health Med 1995 Sep;17(3):261-268.
5 World Health Organization Press Release (WHO/28). International Experts Propose
Measures To Limit Spread Of BSE And Reduce Possible Human Risks From Disease; 3
April 1996. (printed report downloaded from Microsoft Network's BSE forum).
6 Pratt K. Bovine Spongiform Encephalopathy. Update. Animal and Plant Health Inspection
Services (APHIS). U.S. Department of Agriculture, 1996 p. 1.
7 Wilesmith JW. An epidemiologist's view of bovine spongiform encephalopathy. Philos Trans
R Soc Lond B Biol Sci 1994 Mar 29;343(1306):357-361.
8 World Health Organization Press Release (WHO/28). International Experts Propose Measures
To Limit Spread Of BSE And Reduce Possible Human Risks From Disease; 3 April 1996. (printed
report downloaded from Microsoft Network's BSE forum).
Notice of Credit
The article above is compliments of the Uchee Pines Institute, Seale, Alabama, a teaching and
treatment facility devoted to natural remedies. For mor information, call 334-855-4781,e-mail:
ucheepine@csi.com, or visit their Website:
http://www.ucheepines.org.
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