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From: TSS ()
Date: April 18, 2005 at 1:06 pm PST

-------- Original Message --------
Date: Mon, 18 Apr 2005 14:37:31 -0500
From: "Terry S. Singeltary Sr."
Reply-To: Bovine Spongiform Encephalopathy

##################### Bovine Spongiform Encephalopathy #####################

A ProMED-mail post

ProMED-mail, a program of the
International Society for Infectious Diseases

Date: Fri 15 Apr 2005
From: ProMED-mail
Source: Reuters

Bush administration may ease "downer cattle" ban
The Bush administration said on Friday it may allow some injured cattle to
be slaughtered for human food, easing a regulation that the Agriculture
Department (USDA) adopted 15 months ago after the nation's 1st case of mad
cow disease.

Consumer groups said they oppose any changes in regulations aimed at
keeping the deadly disease out of the food supply. The USDA prohibited all
so-called downer cattle -- those too sick or injured to walk -- from being
slaughtered for human food, soon after a Washington State dairy cow was
diagnosed with bovine spongiform encephalopathy (BSE) in December 2003. The
ban was part of a package of tighter USDA regulations to prevent mad cow
disease, whose symptoms can include an inability to walk.

Agriculture Secretary Mike Johanns suggested that the ban on downer cattle
may be eased after the USDA completes an enhanced surveillance program of
US cattle later this year [2005]. "There is a compelling argument: If
you've got an animal that's clearly under 30 months that broke a leg in
transit, there is no threat of BSE whatsoever," Johanns told reporters
after addressing the National Cattlemen's Beef Association. "Why are we
doing this? I'm going to thoughtfully consider those arguments," he added.

Scientists believe that mad cow disease is spread through contaminated
livestock feed. Young animals are considered to pose the least risk of
disease because BSE takes several years to incubate. The ban on downer
cattle being slaughtered for human food represents a sizable financial loss
to cattle ranchers. For example, a 1110 pound steer is worth around USD
1000 if slaughtered for steaks and ground beef, but brings less than USD
200 if condemned as a downer and used for pet food.

About 195 000 cattle are downers out of more than 30 million slaughtered
annually, according to industry estimates. USDA officials previously said
the department would review all of its anti-mad cow regulations after it
completes an expanded testing program sometime in 2005. Johanns' comments
on Friday were the most explicit to date of potential changes the
government is examining.

"When we get to a point where we're ready to wrap up the increased
surveillance and decide what next to do, I want to look at a range of
issues," said Johanns, a former governor of Nebraska, a major
cattle-producing state. Senator Ben Nelson, a Nebraska Democrat, will take
part in the review, he said.

No other cases of BSE have been found in the US cattle herd, despite
expanded testing since June 2004. As of 10 Apr 2005, the USDA tested 314
394 animals in its expanded surveillance program. That will be completed in
the next few months, opening the door for USDA to propose changes based on
its findings.

Consumer advocates said cattle unable to walk should not be used for human
consumption. "I'm not surprised to hear that the Bush administration might
backtrack on important BSE protections if the surveillance program doesn't
turn up additional positives," said Caroline Smith DeWaal, food safety
director for the Center for Science in the Public Interest. "Downer cattle
represent less-healthy animals and should be kept out of the food supply,"
she added. Other farm groups have expressed concern that the ban on downer
cattle could eventually lead to a similar restriction on pigs sent to

The package of mad cow prevention measures adopted by the USDA 15 months
ago included a ban on using brains and small intestines from older cattle
for human food and a ban on stunning cattle with a powerful air injection
to the skull. The Food and Drug Administration (FDA) is still considering
whether to ban the use of cattle blood as a protein supplement for calves
and the use of chicken litter as cattle feed.

[byline: Randy Fabi]

-- ProMED-mail [First of all, this relaxation in
the current policy has not been adopted; it is only a proposal being
examined in the light of science and economics. Unless you have ridden
in the back of a cattle truck and understand the pressure of jostling
around at highway speeds with lots of animals trying to remain standing,
then you do not understand the difficulty these animals face. There are
reasons that animals can fall, and can be injured. It does not mean they
have a neurological disease. Other reasons for "downer cattle" include
having a large calf, which can injure the obturator nerve as the calf
squeezes through the birth canal. Though neurological disease is not a
factor in the ratio of the size of the calf vs that of the birthing
canal, a downer cow is the result. This is not brain-related
neurological disease any more than if a severed spinal cord on an
athlete resulted from a throw from his polo pony. Although there are
clearly some reasons unrelated to BSE that may result in an animal being
termed a downer, there is also the risk that any relaxation in policy
could be extended too far. Surely safeguards and strict guidelines would
have to accompany the possible new rules. With the current policy, the
downers are probably being disposed of through their own "underground"
or "black market", because they are not turning up at inspected
slaughter facilities. The reasons these animals became downers still
exist, but the use of these animals has changed. Furthermore, one only
has to check with pet food companies to realize their policy is "no
downers." There are TSEs in cats, and we may some day discover a TSE in
dogs. The pet food makers want no part of downers, so there is no reason
to believe that downers are becoming pet food. In addition, when the
increased BSE surveillance was announced by USDA, many rendering
companies did not want to take part for risk of a recall. The ability to
hold a carcass until testing is complete has allowed the renderers to
remain an active part of agriculture without the risk of a
neurologically tainted product. Relaxing the policy will require
enormous hurdles to be overcome. Justification will have to be balanced
with science. It may even mean that the large feedlots could become
responsible for testing all of the slaughtered animals, which could open
certain markets to Japan. It may also mean testing of animals under 30
months. As to the concerns in the article that a ban on downer animals
could be extended to swine, perhaps it should. In a recent study of
swine, spongiform encephalopathy changes were noted in the brains of
market swine, despite the absence of any outward signs of clinical
neurological disease. There are safety and economic issues to be
considered. The public will have to understand that if we are to
maintain a cheap food source, then reasonable concessions may have to be
made. The public must come to grips with the realization that no
activity -- including consumption of food -- has zero risk. The key is
to realize that risk is relative. No one is discounting the horrible
nature of vCJD, but we must remember that about 150 people dying from
the disease in about 10 years represents a low risk. More Americans are
killed by fatal car crashes in a month than have succumbed to vCJD in 10
years worldwide, yet I do not see Americans seeking to ban cars. Perhaps
it is possible to accept downer cattle into the food supply after they
have been tested with a more specific test, such as western blot.
Perhaps relaxing the current standards will result in testing any animal
destined for human consumption. There are many acceptable ways to relax
the standards from an economic standpoint and still maintain stringent
food security. - Mod.TG To play the role of devil's advocate here, the
conclusion that all of the animals that break their legs while in
transport are healthy reminds this moderator of polio cases "found" in
Brazil back in '85 that treating physicians had classified as paralysis
secondary to trauma. Of course the children had fallen (the cause of the
trauma) as a result of the onset of paralysis that was related to
poliovirus infection. At that time, because of NIDs (National
Immunization Days) that had been held twice a year for the preceding 5
years, physicians (both clinical and within public health) were convince
that there couldn't be polio cases any more given the high levels of
vaccination coverage, and therefore flaccid paralysis had to be due to
another etiology and not poliovirus infection. The statement in the
newswire that young animals are felt to be safe because it takes years
to incubate the disease is a bit misleading, as infection of the animals
has usually occurred at a young age -- it is the expression of the
clinical disease that takes years to manifest. The younger animals were
felt to be "safer" because they were born after feed regulations were
imposed to eliminate/reduce infection of these animals through
contaminated food products fed to the cattle. A question that remains is
whether an infected, as yet asymptomatic animal is not a risk for
disease transmission across species (to humans eating products from that
infected yet asymptomatic animal). Withholding testing for BSE by
pre-supposing absolutely no risk of BSE under age 30 months is
guaranteeing that one will not identify BSE in the under 30 months age
group. The converse of "seek and ye shall find" -- "don't look and it
ain't there". - Mod.MPP] [see also: 2004 --- BSE, bovine - USA: susp
(03) 20041118.3096 BSE surveillance - USA (06) 20040805.2138 BSE, bovine
- USA: susp. (02) 20040627.1720 BSE, bovine - USA: susp. 20040626.1713
BSE surveillance - USA (05) 20040603.1511 BSE surveillance - USA (04)
20040527.1431 BSE surveillance - USA (03) 20040525.1400 BSE surveillance
- USA (02) 20040511.1275 BSE surveillance - USA (TX) 20040507.1246 BSE,
bovine - USA (WA) (19): tests, corr. 20040416.1047 BSE, bovine - USA
(WA) (19): tests 20040414.1011 BSE, bovine - USA (WA)(18) 20040323.0810
BSE, bovine - USA (WA) (17) 20040319.0767 BSE, bovine - USA (WA) (16):
new regulations 20040318.0747 BSE, bovine - USA (WA)(15) 20040210.0455
BSE, bovine - USA: APHIS report 20040205.0426 BSE, bovine - USA (WA)
(14) 20040123.0275 BSE, bovine - USA (WA) (13) 20040119.0219 BSE, bovine
- USA (WA) (12) 20040118.0195 BSE, bovine - USA (WA) (11) 20040116.0175
BSE, bovine - USA (WA) (10) 20040116.0173 BSE, bovine - USA (WA)(09)
20040110.0113 BSE, bovine - USA (WA)(08) 20040109.0100 BSE, bovine - USA
(WA) (07) 20040109.0095 BSE, bovine - USA (WA) (06) 20040106.0068 BSE,
bovine - USA (WA)(05) 20040106.0058 BSE, bovine - USA (WA)(04): testing
20040105.0052 BSE, bovine - USA (WA)(03) 20040105.0047 BSE, bovine - USA
(WA) (02) 20040103.0021 BSE, bovine - USA (WA) 20040101.0004 2003 ---
BSE, bovine - USA (WA) (09): new regulations 20031230.3172 BSE, bovine -
USA (WA)(08): recall 20031230.3166 BSE, bovine - USA (WA) (07)
20031228.3157 BSE, bovine - USA (WA) (06) 20031227.3142 BSE, bovine -
USA (WA) (05) 20031226.3136 BSE, bovine - USA (WA) (04) 20031225.3131
BSE, bovine - USA (WA) (03) 20031224.3127 BSE, bovine - USA (WA) (02):
OIE 20031224.3126 BSE, bovine - USA (WA) 20031223.3119]
************************************************************ --------
Original Message --------
Subject: Re: PRO/AH> BSE policy - USA: change considered
Date: Mon, 18 Apr 2005 12:09:21 -0500
From: "Terry S. Singeltary Sr."
References: <>


AN excellent commentary by Tam et al. I would kindly
like to add, 'sub clinical TSE', and a downer that may have fallen
and broke a leg, hip etc, due to the first symptoms of a TSE, however
far fetched this may be, it is very possible, and any cow going into
the food chain, whether animal or human, is one too many. SO,
any relaxing of this downer ban, is just not acceptable, unless
as Tam points out, 100% testing with the most sensitive testing
to date, ie Western Blot with the addition of phospohtungstic acid
precipitation step (Bio-Rad Deslys et al) and or the CDI Prusiner
et al are boasting about. However, even 100% BSE/TSE testing
will only be as good as the tests being used, and the ones doing
the testing. you have to want to find it...

Issued: Monday, 28 August 2000

A team of researchers led by Professor John Collinge at the Medical
Research Council Prion Unit1 report today in the Proceedings of the
National Academy of Sciences, on new evidence for the existence of a
'sub-clinical' form of BSE in mice which was unknown until now.

The scientists took a closer look at what is known as the 'species
barrier' - the main protective factor which limits the ability of
prions2 to jump from one species to infect another. They found the mice
had a 'sub-clinical' form of disease where they carried high levels of
infectivity but did not develop the clinical disease during their normal
lifespan. The idea that individuals can carry a disease and show no
clinical symptoms is not new. It is commonly seen in conventional
infectious diseases.

Researchers tried to infect laboratory mice with hamster prions3 called
Sc237 and found that the mice showed no apparent signs of disease.
However, on closer inspection they found that the mice had high levels
of mouse prions in their brains. This was surprising because it has
always been assumed that hamster prions could not cause the disease in
mice, even when injected directly into the brain.

In addition the researchers showed that this new sub-clinical infection
could be easily passed on when injected into healthy mice and hamsters.

The height of the species barrier varies widely between different
combinations of animals and also varies with the type or strain of
prions. While some barriers are quite small (for instance BSE easily
infects mice), other combinations of strain and species show a seemingly
impenetrable barrier. Traditionally, the particular barrier studied here
was assumed to be robust.

Professor John Collinge said: "These results have a number of important
implications. They suggest that we should re-think how we measure
species barriers in the laboratory, and that we should not assume that
just because one species appears resistant to a strain of prions they
have been exposed to, that they do not silently carry the infection.
This research raises the possibility, which has been mentioned before,
that apparently healthy cattle could harbour, but never show signs of, BSE.

"This is a timely and unexpected result, increasing what we know about
prion disease. These new findings have important implications for those
researching prion disease, those responsible for preventing infected
material getting into the food chain and for those considering how best
to safeguard health and reduce the risk that theoretically, prion
disease could be contracted through medical and surgical procedures."


(OFFICE HOURS) OR 07818 428297 OR 0385 774357 (OUT-OF-OFFICE-HOURS) OR
ON 00 61 3 8344 3995 (DURING OFFICE HOURS) OR 00 61 3 9443 0009


Professor Collinge is a consultant neurologist and Director of the newly
formed MRC Prion Unit based at The Imperial College School of Medicine
at St Mary's Hospital. He is also a member of the UK Government's
Spongiform Encephalopathy Advisory Committee (SEAC). The MRC prion unit
is was set up in 1999, and its work includes molecular genetic studies
of human prion disease and transgenic modelling of human prion diseases.

Prions are unique infectious agents that cause fatal brain diseases such
as Creutzfeldt-Jakob disease (CJD) in humans and scrapie and BSE (mad
cow disease) in animals. In some circumstances prions from one species
of animals can infect another and it is clear that BSE has done this to
cause the disease variant CJD in the UK and France. It remains unclear
how large an epidemic of variant CJD will occur over the years ahead.

The strain of prion used here to infect the mice is the Sc237 strain
(also known as 263K) which infects hamsters, and until now was assumed
not to infect mice.

This research was funded by the Medical Research Council and Wellcome

The Medical Research Council (MRC) is a national organisation funded by
the UK tax-payer. Its business is medical research aimed at improving
human health; everyone stands to benefit from the outputs. The research
it supports and the scientists it trains meet the needs of the health
services, the pharmaceutical and other health-related industries and the
academic world. MRC has funded work which has led to some of the most
significant discoveries and achievements in medicine in the UK. About
half of the MRC's expenditure of £345 million is invested in over 50 of
its Institutes and Units, where it employs its own research staff. The
remaining half goes in the form of grant support and training awards to
individuals and teams in universities and medical schools.

The Wellcome Trust is the world's largest medical research charity with
a spend of some £600 million in the current financial year 1999/2000.
The Wellcome Trust supports more than 5,000 researchers, at 400
locations, in 42 different countries to promote and foster research with
the aim of improving human and animal health. As well as funding major
initiatives in the public understanding of science, the Wellcome Trust
is the country's leading supporter of research into the history of

©2002 Medical Research Council
Data Protection policy | Contact the MRC

Following recently published research into Transmittable Spongiform
(TSE) in mice, at their 29 September meeting, SEAC discussed the
possibility that prion
disease might exist in sub-clinical form.
The research demonstrates that asymptomatic mice that are not thought to be
susceptible to TSE infection are still able to replicate prion protein
to high levels and
could transmit disease to other mice.
Members noted that existing UK control measures on food safety of beef
already took into account the possibility that animals with no clinical
signs may be
incubating disease. SEAC was concerned, however, that in other countries
where BSE
was present and less stringently monitored, sub-clinical infection could
The committee also recommended further research into pigs and poultry to
earlier findings that these species appear not to harbour TSE infection
after oral exposure.
Sub-clinical prion disease?

Rev Sci Tech. 1992 Jun;11(2):605-34.

Sub-acute, transmissible spongiform encephalopathies: current concepts
and future needs.

Bradley R, Matthews D.

Ministry of Agriculture, Fisheries and Food, Central Veterinary
Laboratory, Addlestone, Surrey, United Kingdom.

The first diagnosis of bovine spongiform encephalopathy (BSE) in the
United Kingdom in 1986 was to stimulate the most intensive
epidemiological study of any animal disease of all time in that country.
It led also to the initiation of a broad-based research programme with
an international flavour. This principally involved scientists and
veterinarians in Europe (especially the United Kingdom) and the United
States of America, especially those with experience of slow infections
in general and experimental scrapie in particular. This final chapter
highlights some of the significant discoveries made in the study of BSE
and related diseases of this group but also emphasises the deficits in
knowledge which need to be corrected before such diseases as scrapie in
sheep and goats can be brought under control. The benefits resultant
upon effective disease control will be manifest as improvement in animal
production, welfare and, importantly, the removal of trading barriers
currently in place to protect countries in which diseases such as BSE
and scrapie do not exist. Of key importance is the development of a
simple, cheap and effective diagnostic test for use in the live animal
before the onset of clinical signs. This will be difficult since the
nature of the causal agents is uncertain and none provokes either a
detectable immune response or inflammatory reaction in the host. The
earlier chapters, written by acknowledged specialists from around the
world, deal with the specific diseases in detail and all present some of
the most recent knowledge available. Here the authors emphasise the
important role that major national and international agencies have in
effecting the highest level of control possible in the absence of key
information. International collaboration with countries in which these
diseases exist, and as well as those where they are absent, is of
paramount importance. It is essential that the BSE epidemic which has
severely affected the cattle industry of the United Kingdom is not
allowed to happen in developing countries. Whereas the former has
implemented stringent control measures based on scientific knowledge and
is well on the way to eradicating the disease, the latter could have
much greater difficulty in establishing control. The answer is clear.
BSE must be prevented from occurring elsewhere. To do that, knowledge of
BSE and other members of the group should be widely dispersed and it is
the purpose of this issue to do just that.

NEW findings of BASE in cattle in Italy of Identification of a second
bovine amyloidotic spongiform encephalopathy: Molecular similarities
with sporadic Creutzfeldt-Jakob disease

Adaptation of the bovine spongiform encephalopathy agent to primates and
comparison with Creutzfeldt- Jakob disease: Implications for human
health THE findings from Corinne Ida Lasmzas*, [dagger] , Jean-Guy
Fournier*, Virginie Nouvel*, Hermann Boe*, Domnque Marc*, Franois
Lamoury*, Nicolas Kopp [Dagger ] , Jean-Jacques Hauw, James Ironside,
Moira Bruce [||] , Dominique Dormont*, and Jean-Philippe Deslys* et al,
that The agent responsible for French iatrogenic growth hormone-linked
CJD taken as a control is very different from vCJD but is similar to
that found in one case of sporadic CJD and one sheep scrapie isolate;

Characterization of two distinct prion strains derived from bovine
spongiform encephalopathy transmissions to inbred mice

Terry S. Singeltary Sr.
P.O. Box 42
Bacliff, Texas USA 77518

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