On Monday, February 9, 2004, Dr. Ron DeHaven, Deputy Administrator
of Veterinary Services for USDA's Animal and Plant Health Inspection Service,
announced that the field investigation of the case of BSE in a cow in the State
of Washington is complete. This will be the last written daily update. However,
information will be provided in the future on an as needed basis.
A summary of the investigation follows.
Investigation
The epidemiological tracing and DNA evidence proves that the BSE
positive cow slaughtered in the State of Washington on December 9, 2003, was
born on a dairy farm in Calmar, Alberta, Canada, on April 9, 1997. She was moved
to the United States in September 2001 along with 80 other cattle from that
dairy. A brain sample collected from the cow at slaughter tested positive for
BSE on December 23rd.
The epidemiological investigation to find additional animals from
the source herd led to a total of 189 investigations (these were investigations,
not premises, and one investigation may or may not equal one premises; in some
cases there are no premises [a dealer that just trucks animals from one place to
another] but, more likely, one investigation can equal more than one premises),
leading to complete herd inventories on 51 premises in three States: Washington,
Oregon and Idaho. The inventories involved the examination of the identification
on more than 75,000 animals. All herd inventories have now been completed and
appropriate analysis of those inventories performed. There are no premises
remaining under hold order.
A total of 255 "Animals of Interest" were identified on 10 premises
in Washington, Oregon, and Idaho. "Animals of Interest" are defined as animals
that were - or could have been -from the source herd in Alberta, Canada. All 255
animals were depopulated and BSE testing was negative on all of them. The
carcasses from all of the euthanized animals were disposed of in landfills in
accordance with all federal, state, and local regulations.
Included in the 255 animals of interest were 28 positively
identified back to the group of 80 cattle that entered the U.S. with the index
cow, as well as 7 heifers out of a group of 17 heifers which were also known to
be from the source herd. It is not believed that all of these 17 entered the
United States, but all of them would be considered minimal risk and not
significant to the investigation.
Guidelines on bovine spongiform encephalopathy (BSE) issued by the
World Organization for Animal Health (OIE), the international animal heath
standard setting organization, state that animals born on a premises within one
year (before or after) of a BSE-affected animal should be considered of greater
risk to the country reporting the BSE detection. As such, USDA has focused on 25
of the 81 animals also born into the birth herd of the index animal. Based on
normal culling practices of local dairies, APHIS estimated that the Agency would
be able to locate approximately 11 of these animals. APHIS definitively located
13 of these animals, plus the index cow, for a total of 14.
We feel confident that the remaining animals represent very little
risk. Even in countries like the United Kingdom where the prevalence of BSE has
been very high, it is very uncommon to find more than one or maybe two positive
animals within a herd. Any of these animals showing nervous system disorder - or
any that are nonambulatory at the time of slaughter - will be condemned and not
allowed into the human food chain. Any animals slaughtered after January 12th
would have the SRMs removed and not allowed into the human food chain. SRMs, or
Specified Risk Materials, are those tissues or portions of the carcass likely to
contain the infectious agent in an infected animal. And finally, we have had an
effective feed ban in place for over 6 years, thus preventing the transmission
of the disease to other animals.
Over 2,000 tons of meat and bone meal being held due to potential
contamination with protein from the positive cow is on hold and will soon be
disposed of in a landfill in accordance with all Federal, State, and local
regulations.
Breakdown Summaries
Summary of the 255 depopulated:
28 were part of the 81
220 could have been part of the 81
7 heifers that were part of group of 17 heifers, some, but not all of
which, entered the US
Of the 81 that came in from Canada (29 definitively accounted for):
1 is the BSE-positive cow and was located in the Index herd in Mabton, WA.
9 were located in the Index herd in Mabton, WA.
3 were located at a facility in Tenino, WA.
6 were located at a facility in Connell, WA.
1 was located at a facility in Quincy, WA.
3 were located at a facility in Mattawa, WA.
1 was located at a facility in Moxee, WA.
3 were located at a facility in Burley, ID.
1 was located at a facility in Othello, WA.
1 was located a facility in Mabton, WA.
Of the 17 other cattle from the Canadian birth herd (these heifers are
not part of the original 81 animals and it is not known how many of the 17
actually entered the United States). To date, seven animals have been identified
in the United States:
3 were at a facility in Quincy, WA.
1 was at a facility in Boardman, OR.
1 was at a facility in Othello, WA.
1 was at a facility in Burley, ID
1 was at the second facility in Mabton, WA
Depopulation Activities
USDA has conducted selective depopulation activities at these facilities:
Sunnyside, WA (bull calf premises) - a total of 449 animals depopulated
Mabton, WA (index premises) - a total of 131 animals depopulated
Mattawa, WA - a total of 39 animals depopulated
Connell, WA - a total of 15 animals depopulated
Boardman, OR - a total of 20 animals depopulated
Quincy, WA - a total of 18 animals depopulated
Tenino, WA - a total of 4 animals depopulated
Moxee, WA - a total of 15 animals depopulated
Othello, WA - a total of 3 animals depopulated
Burley, ID - a total of 7 animals depopulated
Mabton, WA (second premises) - a total of 3 animals depopulated
Testing Activities
All adult animals depopulated were sampled and tested for BSE. The
bull calves depopulated at Sunnyside, WA, were not sampled because they were too
young for the BSE agent to be detected. There have been a total of 255 samples
taken from the animals depopulated in the Mabton index herd, the herds in
Mattawa, Connell, Quincy, Tenino, Moxee, Othello, and the second Mabton
facility, as well as facilities in Boardman, OR, and Burley, ID. All samples
have tested negative for BSE.
International Review Subcommittee Report
The report from the International Review Subcommittee was delivered
to the Secretary's Advisory Committee for Foreign Animal and Poultry Diseases
last Wednesday morning, Feb 4th. That same afternoon, the Co-chairs of the
Advisory Committee and members of the Subcommittee provided the Secretary of
copy of the report and briefed her on its content.
The International Team commended the Secretary on the open and
transparent manner in which this investigation was conducted and the manner in
which their findings were reported to the public and media.
The report identified several positive findings and actions taken
by the US since finding this BSE positive cow:
They commended the Department on the comprehensive and thorough
epidemiological investigation, and suggested all relevant information had been
obtained at this point. Their recommendation to conclude the investigation is
consistent with the actions we have taken to do just that.
They stated that the tracing and recall of the rendered meat and bone meal
(MBM) that may have been contaminated with specified risk materials from the
index case was effective and appropriate.
They indicated that the U.S. ban on SRMs from cattle over 30 months of age
removes the highest risk tissues from the human food supply and is in
accordance with international standards
The Subcommittee confirmed the action taken by the Secretary in her
December 30th announcement to prohibit air injection stunning for slaughter
animals.
In addition, the Subcommittee confirmed the validity of the
Secretary's announcement to prohibit Advanced Meat Recovery (or AMR) and
mechanically separated meat from cattle over 30 months.
The Subcommittee recognized the food safety merit of prohibiting
nonambulatory cattle from entering the human food supply, while cautioning the
challenges this action presents to our surveillance efforts.
They confirmed that the testing of all normal cattle slaughtered for human
consumption to be scientifically unjustified, both in terms of protecting
human and animal health.
They recommended the adoption of rapid screening tests, which is
consistent with the Department's announcement to accept applications for
licensure of such tests.
The Subcommittee acknowledged the importance of effective animal
identification and traceability systems, again consistent with the Secretary's
announcement to accelerate the implementation of such a plan within the US.
The subcommittee acknowledged the efforts of the US government to follow a
science-based approach to policy formulation.
They also recognized the US efforts to act responsibly with regard to
containment and proper destruction of risk materials in order to protect human
health, animal health, and the environment
The Subcommittee also made several recommendations, all of which
are being fully analyzed by USDA and our Food and Drug Administration
colleagues. These include:
A recommendation for a very aggressive surveillance program that tests all
high-risk animals (that is, nonambulatory animals and animals with central
nervous system disorders) greater than 30 months of age. This testing would be
for a one year period. The results from that intensive surveillance could then
be considered in an evaluation of the overall BSE program. The Subcommittee
also suggested that consideration be given to random sampling of animals
greater than 30 months of age at slaughter, to encourage disease reporting at
the farm level.
The Subcommittee recommended that a number of laboratories throughout the
United States should be approved by USDA's National Veterinary Services
Laboratories or "NVSL" to conduct screening tests as part of the national
surveillance program. The national reference laboratory should remain within
NVSL, and NVSL should be responsible for confirmatory and proficiency testing.
The subcommittee urged the United States to collaborate with the global
community in the evaluation and validation of new BSE diagnostic tests.
As for feed issues, the Subcommittee recommends banning SRMs from all
animal feed as well as excluding all mammalian and poultry protein from
ruminant feed. This recommendation is based on the possibility of
cross-contamination in a ruminant-to-ruminant feed ban
The Subcommittee emphasized the need for an effective educational and
outreach program on BSE.
The Subcommittee recognized that the North American
BSE situation vividly demonstrates the unwarranted and very significant social
and financial impact when importing countries fail to comply with science-based
international rules regarding trade. The subcommittee hopes that the United
States will continue to demonstrate leadership in trade matters by adopting
import/export policy in accordance with the science and international standards.
By continuing to do so, we can help to discourage irrational trade barriers when
countries identify their first case of BSE.
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