What is "Mad Cow Disease"
(Bovine Spongiform Encephalopathy)?
Mad Cow Disease is the layperson's name
for Bovine Spongiform Encephalopathy (BSE), a transmissible, slowly
progressive, degenerative, fatal disease affecting the central nervous
system of adult cattle.
Does Mad Cow Disease affect humans?
Bovine spongiform encephalopathy is
a disease that affects cattle. However, there is a disease similar
to BSE called variant Creutzfeldt-Jakob Disease, which is found in
humans. There have been a small number of cases of variant
Creutzfeldt-Jakob Disease reported, primarily in the United Kingdom,
occurring in people who consumed beef that may have been contaminated.
There is strong scientific evidence that the agent that causes BSE in
cattle is the agent that causes variant Creutzfeldt-Jakob Disease in
people. The one reported case of variant Creutzfeldt-Jakob Disease in
the United States was from a young women that contracted the disease
while residing in the UK. The symptoms appeared years later after the
young woman moved to the U.S.
The disease,variant Creutzfeldt-Jakob
Disease, which primarily affects younger persons, is very hard to
diagnose until the disease has nearly run its course. In its early
stages, the disease may manifest itself through neurologic
symptoms, but it is not until the latter stages of the disease that
brain abnormalities detectable by x-ray or MRI can be seen.
The incubation period of variant CJD
appears to be several years or longer. Initial symptoms may be
psychiatric, similar to depression or (less often) psychosis. Patients
may complain of unusual sensory symptoms, such as "stickiness"
of the skin. Later symptoms include unsteady gait, involuntary
movements, dementia, and mutism, progressing inevitably to death within
1-2 years. There is no treatment.
Variant CJD can only be acquired by
eating beef or beef products; i.e if you do not consume beef or beef
products while visiting a country which has reported "mad cow
disease", you cannot become infected. There is no evidence of any
risk from pork, lamb, milk or milk products. The Centers for Disease
Control suggests that people can reduce their risk by either abstaining
from beef completely or eating only solid pieces of muscle meat, such as
steak, rather than products like sausage or chopped meat that might be
contaminated during processing. Cooking, drying, or freezing does not
inactivate the agent that causes new variant CJD or prevent its
When and how did BSE in cattle occur?
BSE has been of great concern since 1986,
when it was first reported among cattle in the United Kingdom. At
its peak, in January 1993, almost 1,000 new cases per week were
identified. The outbreak in the United Kingdom may have started from the
feeding of contaminated sheep meat-and-bone meal to cattle. The nature
of the transmissible agent in BSE is not known.Why or how this substance
changes to become disease-producing is still unknown.
Milk and milk products from cows are not
believed to pose any risk for transmitting the BSE agent because
experiments have shown that milk from BSE-infected cows has not caused
BSE in cows or other test animals
Is Mad Cow Disease
occurring in the United States?
On December 23, 2003, the U.S. Department of Agriculture announced a
diagnosis of Mad Cow Disease in an adult Holstein cow from Washington
State. Samples were taken from the cow on December 9 as part of USDA's
Mad Cow Disease surveillance program.
posted 12-30-03 on kidsgrowth.com