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HOLLY NOTE: This is one of our last newsletters ever published. At the time, BSE, CJD and vCDJ were real and terrifying concerns. That worry was well- founded as this disease killed many people and animals quickly. Literally millions of animals were slaughtered to prevent its spread. It appears once more this lethal disease is making headlines.
THE COW CONNECTION
By Holly Deyo
As of January 1, 2001, every bovine reaching 30 months of age
and intended for human consumption must be tested for BSE in the
European Union. This does not guarantee food is 100% safe, but
it is a vast improvement. Professor Peter Smith, acting chairman
of the Spongiform Encephalopathy Advisory Committee stated, "Thousands
of infected animals were going into the food chain in the late
1980s and early 1990s and it is estimated that there is now only
about one animal going into the food chain a year."1 (That's still one too many!)
TESTING 1 - 2 - 3, TESTING
Canada's BSE Surveillance and Monitoring program has been active since 1992. In the first 6 months of 1998, a total of 674 bovine brains were tested (down 11% from the 1997 total). Canada's bovine population was 12,654,500 strong in 2000. About 3.5 million were slaughtered for use. Assuming there were comparable numbers for 1998, 674 tests performed out of 3.5 million cows is a pittance. All specimens came back negative.
Only one cow in Canada, which had been imported from the UK in
1987, has ever been found to have BSE. That cow and all its herdmates
are now enjoying life in "cow heaven".
As of the first week of January 2001, Canada has instituted a
tagging program. The number identifies the exact location of the
farm where a beef or dairy cow was born. It is designed to trace
an animal within hours.
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BSE SURVEILLANCE IN CANADA
(Number of BSE samples vs cow population)
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If you look back to last week's newsletter at the incidence of
CJD in Canada, it primarily shows up in the three provinces where
it's mostly densely populated. There is also a higher percentage
of BSE testing in those provinces: Ontario, British Columbia and
Quebec.
BSE SURVEILLANCE IN AMERICA
America, too, has done extensive testing for BSE with the biggest
jump in both brains submitted to be tested as well as actual testing
performed during this past year.
This program in effect since 1990 began BSE educational outreach,
educating the entire veterinary field and producers about the
clinical signs and pathology of this disease.
That same year, they also began a program to trace back cattle
imported from the UK. Of 496 cattle imported into the U.S. from
the U.K. between 1981 and 1989, only 32 are "missing."
In 1993, the surveillance program was expanded to include "downer"
cows - those cattle who, for a variety of reasons, are unable
to stand.
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BSE Surveillance NVSL Bovine Brain Submissions
by Fiscal Year as of October 31, 2000
Source: USDA
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By 1994, testing included looking for abnormal prion proteins.
If you look where these CJD cases have occurred in America (see Moo Madness - Part 1), they loosely parallel areas in which the greatest number of BSE testing has
been performed. In any given year, approximately 30,000,000 head
of beef are slaughtered in the US. Considering only 11,700 brains
have been tested for BSE over ten years out of ~100,000,000 animals
maintained in herds each year, these numbers are pitifully small
compared to the number of cows tested in the UK and France.
BSE SURVEILLANCE IN AUSTRALIA
Australia began testing cattle for BSE in 1998 through the NTSESP
(National Transmissible Spongiform Encephalopathy Surveillance
Program). The program is jointly funded by industry and the government
under Animal Health Australia.
As of March 31, 1999, Australia's cattle numbered 25,833,000.
Annually, about 2 million head are slaughtered for human consumption.
Out of nearly 26 million head of beef, normally only 500 cows
are tested for BSE each year. Australia estimates that by raising
"the sampling levels to 500 cattle and sheep (will) provide a
95% probability of finding a 0.5% level of infection."2
SIGNS OF TROUBLE
Testing is requested when a farmer or producer spots a bovine
acting "funny", exhibiting signs of a neurological disorder. A
cow might seem anxious, fearful and apprehensive. They react more
to sound and touch. Sometimes they'll lick their nose or hind
quarters excessively. When walking they sway which is sometimes
seen with high stepping back feet. The bovine may separate from
the herd, seem nervous, have trouble standing and lose weight.
These signs are similar to sheep with Scrapie.
The farmer then notifies a government authorized veterinarian
in his area. The animal is slaughtered and the brain is sent in
for testing.
Since cattle are imported to Australia as they are in the US and
Canada, bovines are quarantined for a time before being released
into the community. This may be an exercise in futility as cows
may take up to 30 months to show signs of BSE.
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NOTE: Numbers in green area are samples testing negative only.
Source: Animal Health Australia
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In Australia, the attitude is pretty relaxed, but concerned. One
scientist worried that Australia might become too complacent since
this country has neither scrapie or BSE.
I spoke with Simon Winters of Animal Health Australia Monday and he shared that they are working on a new test method which would allow abattoirs (slaughter houses) to examine bovines on the spot. This procedure has yet to be determined if it's suitable.
NO PERFECT TEST
A leading Italian scientist and professor of pathology at the
University of Zurich's Institute of Neuropathology, Adriano Aguzzi
warned that BSE tests aren't infallible and can't guarantee of
the health of animals.
"Anything you test in terms of infectious disease has a window
of false negatives. Even if many tests are negative, we cannot
be sure that BSE has been defeated,"3 stated Aguzzi. BSE can't be detected unless it's in the late
incubation stage. Dr. Aguzzi who is considered one of the leading
scientists in his field, gave a further sobering commentary on
the human form of the disease. "If you look at the numbers, it
is impossible to avoid the conclusion that the number of vCJD
(variant Creutzfeldt-Jakob Disease) cases is increasing exponentially.
I am not optimistic."4
Complicating matters is having no test for BSE while cattle are "on the hoof", that is, still alive. However, one such test may be on the way.
Researchers at Colorado State University are scrambling to find a live test for chronic wasting disease in deer and elk, but significant obstacles still stand in the way.
As of August 2002,a tonsil test developed by the Colorado Division of Wildlife remains the only way to test a living animal for the fatal brain disease, found in wild deer and elk herds.
Doctors at Colorado State University are trying to perfect a simpler and more efficient method that would test the animal's urine or blood.4.5 Should this pan out, it might be applicable to cattle.
Both animals and people can harbor prions, the infectious protein which causes the disease in everything, and not show any symptoms. This makes testing the beef imperative before it is sent off for consumption if we are to stay head, and in some countries, get ahead of this lethal disease.
France, with 5.7 million cattle, is now testing 20,000 animals
each week and found 153 infected animals last year. Shouldn't the rest
of us be performing a few more tests, make that a lot more tests? Maybe they are. . .
Continue
© Text and Graphics, 2001 Stan and Holly Deyo, except where otherwise
credited
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