The US Agriculture Department (USDA) issued the following statement about the discovery of a suspected case of "mad cow disease" in Washington state:
Agriculture Secretary Ann M Veneman today [Tuesday] announced that
the US Department of Agriculture has diagnosed a presumptive
positive case of bovine spongiform encephalopathy (BSE) in an
adult Holstein cow in the state of Washington.
Despite this finding, we remain confident in the safety of
our beef supply," Veneman said. "The risk to human health from
BSE is extremely low."
Because the animal was non-ambulatory (downer) at
slaughter, samples were taken Dec 9 as part of USDA's targeted
BSE surveillance system. The samples were sent to USDA's
National Veterinary Services Laboratory in Ames, Iowa.
Positive results were obtained by both histology (a visual
examination of brain tissue via microscope) and immunohistochemistry (the gold standard for BSE testing that detects prions through a staining technique). Test results were returned on Dec 22 and retested on Dec 23.
USDA has initiated a comprehensive epidemiological
investigation working with state, public health, and industry
counterparts to determine the source of the disease. USDA will
also work with the Food and Drug Administration as they conduct
animal feed investigations, the primary pathway for the spread
This investigation has begun while the sample is being sent
to the world reference laboratory in England for final
confirmation. USDA will take the actions in accordance with its
BSE response plan, which was developed with considerable input
from federal, state and industry stakeholders.
BSE is a progressive neurological disease among cattle that
is always fatal. It belongs to a family of diseases known as
transmissible spongiform encephalopathies. Also included in
that family of illnesses is the human disease, variant
Creutzfeldt-Jakob Disease (vCJD), which is believed to be
caused by eating neural tissue, such as brain and spinal cord,
from BSE- affected cattle.
USDA has determined that the cow comes from a farm in
Washington State and as part of the USDA response plan, the
farm has been quarantined.
After the animal was slaughtered, the meat was sent for
processing and USDA's Food Safety and Inspection Service is
working to determine the final disposition of products from the