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Re: Mad Cow disease, BSE; Justice is served.



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The WellnessWise Electronic Journal
Volume 2, Number 7; April 14, 1996

CONTENTS:  Special "Mad Cow" Issue

Section I..........From the Editor's Keyboard

Section II
 Mad Cow Disease:  A Sobering "Wake Up Call"? 

Section III....Parting Words

Permission to Reproduce
Subscription Information
Back Issues

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SECTION I

FROM THE EDITOR'S KEYBOARD

>From the Editor's keyboard.

Lately, in the midst of making preparations for a major
physical transition, I've also done some professional gear
shifting. Over the last month or two I've had the privilege of
spending quite a bit of my time helping to edit Dr. Neil
Nedley's new preventive medicine book.

In early and mid March we had been working on a chapter that
deals with how some human illnesses are related to diseases in
animals. Of particular interest to Dr. Nedley and the rest of
us was Bovine Spongiform Encephalopathy (BSE) more commonly
known as "mad cow disease." Consequently when Britain's
Spongiform Encephalopathy committee made its stunning
announcement last month that BSE may be related to human
illness, we were primed to more intelligently access the
information.

Although we still feel there are many unanswered questions,
the current interest in BSE seemed to necessitate a special
issue of WEJ. I have received requests for this material from
a number of individuals both in the US and abroad. It was only
logical to share it with WEJ readers as well. Dr. Nedley's new
book, due out within the next year, will deal in greater depth
with "mad cow disease." In fact, an entire chapter examines
animal diseases that pose a threat to human health.

As always, I look forward to your comments to help me keep on
target. If you've read something on "mad cow disease" that
I've neglected, let me know. If you feel I'm not even handed
in my treatment, communicate that as well please.

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With our next issue we plan to return to our regular format
which features scripts from the WellnessWise radio program
along with Phylis Austin's Science/Health Abstracts feature.
+-------------------------------------------------------------

MAD COW DISEASE: A SOBERING "WAKE UP CALL"?

Copyright 1996 by David J. DeRose, MD, MPH

"Mad Cow Disease" grabbed headlines in late March 1996 when a
group of prestigious British Scientists were constrained to
admit that the fatal disease could possibly be transmitted to
humans. The news brought the British meat industry to a
virtual standstill. English folk avoided the meat markets. The
European Union and a cascade of other countries banned British
beef.

Referred to as Bovine Spongiform Encephalopathy (BSE) by the
medical community, the illness is aptly named. The designation
makes it clear that we are talking about a brain disease
(encephalopathy) that affects cows (bovine). Furthermore, the
disease riddles the afflicted cow's brain with tiny
holes -- causing it to look like a sponge under a microscope
(thus rendering the brain "spongiform"). The lay term, "mad
cow disease," in addition to being much easier to pronounce,
also conveys the fact that infected cows may develop mental
deterioration and behavioral abnormalities.

First diagnosed in Britain in 1986, BSE has powerful emotional
appeal. It is one of a group of fatal brain diseases that can
be transmitted from one living creature to another. These
diseases are technically called "transmissible
encephalopathies." Many British consumers had apparently
comforted themselves for years with the thought that it was
unlikely for such a disease to spread from cows to humans.
However, even before March 1996, I would guess that scientists
who were aware of this fatal cattle disease would -- if honest
 -- have to admit to some level of discomfort. After all,
transmissible encephalopathies affect many other creatures
besides cattle. Some 16 or 18 animal species have been
documented to come down with diseases that resemble BSE. Many
or all of those species can apparently get a BSE-like disease
>from  eating infected cattle meat. Furthermore, cattle
themselves likely contracted the disease from a different
species. Most researchers believe that BSE was introduced into
British cattle herds by feeding them dead sheep carcasses
which were infected with a similar illness called "scrapie."
(The sheep disease gets its name from the fact that afflicted
sheep can become mentally unstable and literally "scrape" the
wool off their hide.)

HUMANS CAN GET TRANSMISSIBLE ENCEPHALOPATHIES

However, it is not only animals that can contract
transmissible encephalopathies. Humans can also get them. A
disease called Creutzfeldt-Jakob disease (CJD) can be thought
of as a type of fast acting Alzheimer's disease. This is an
extremely rare illness that has typically occurred in older
individuals. I have personally only seen one patient with this
rare and fatal disease.

We know from cannibalistic tribes in New Guinea, that a
disease like CJD is transmissible to humans. There, at one
time, the dead were honored through ritual cannibalistic
rites. Children typically ate the brains of their deceased
parents during these rituals. Many of them did get a disease
called "kuru" which is a transmissible spongiform
encephalopathy similar (if not the same as) CJD. The disease
sometimes took up to 30 years to develop. Young children who
engaged in these cannibalistic practices tended to develop the
illness sooner than their older siblings or peers who also
consumed infected brains.

Many scientists had speculated that if sheep could transmit
the disease to beef, beef could transmit the disease to
humans. In fact even in the United States, a country which
claims to have no evidence of BSE, there have been reports
that are less than comforting. For example, an outbreak of a
related illness, Transmissible Mink Encephalopathy occurred on
a Wisconsin mink farm. It was discovered that the mink illness
was likely related to that farmer's practice of feeding them
local "downer" dairy cows. This is a designation for cows that
either are so ill that they fall down and can not get up, or
actually are found dead on the farm. Deemed unfit for human
consumption, such cows have been used for animal feed among
other things. In this case, the carcasses found their way into
the minks' diets.

The mink outbreak provided another example of probable BSE
infecting other species. (The link could not be made
definitely since the "downer cow or cows" that were fed to the
mink were not autopsied.) It also raised another concern:
countries like the US who think they have nothing to worry
about, may in fact have diseased animals in their herds.

Despite assurances from the USDA that BSE has not crossed the
Atlantic, the mink story leaves us with an uncomfortable
feeling. However, there is even more disturbing news.
Laboratory research has demonstrated that different strains of
prions do exist. For example, a British researcher found that
when he injected the prions from an infected group of goats
into mice, those mice developed an encephalopathy (brain
disease) characterized by drowsiness. The prions from a
different group of infected goats also caused brain disease
when injected into mice; however, instead of becoming
lethargic, the diseased mice turned hyperactive! The message
was clear: there were apparently at least two different
strains of scrapie-like illness in goats. When transmitted to
another species (in this case the mice) the infected rodents
came down with one or the other of these two very different
looking diseases.

Such research has raised an important question. If scrapie in
goats could give rise to different appearing diseases in mice,
could sheep scrapie result in more than one type of cow
disease? There is some suggestion that this could be the case.
There may well be more than one strain or type of BSE. The
different types may cause different looking diseases. Some who
have been studying links between cattle and mink disease in
the US, have raised the concern that BSE is present in
America, but "looks different" than the British variant due to
a different BSE strain. Specifically, the BSE in the US may be
one cause of "downer cow" disease rather than its "mad cow"
cousin in England.

FINALLY TAKING NOTICE

It was Creutzfeldt-Jakob statistics that really got the
medical community's attention in March 1996. By that time some
eight young Britons had succumbed to this devastating illness.
The unusual occurrence of the disease in young people combined
with a different pattern to the sponge-like brain destruction,
prompted leading British scientists to raise the concern that
BSE may be the source of a new variant of CJD. Further
thickening the plot was the occurrence of a worrisome cluster
of CJD in British dairy farmers.

The biggest concern, of course, is that we are just glimpsing
the tip of that proverbial iceberg. One prominent researcher
is putting estimates of BSE-related CJD well into the
thousands. And the problem does not appear to be confined to
Britain. There are worrisome reports now from France and
Italy. Still others are raising concerns that some cases of
"Alzheimer's" may actually be spongiform encephalopathy.
Granted, all of these conjectures may not prove true; but what
if just some of them are? Even if only in part?

PRIONS: FRIGHTENING CARRIERS OF DISEASE

Adding to the fear of this relatively newly appreciated
disease is the nature of the BSE infectious agent. Many animal
borne diseases are caused by bacteria or viruses. Risk from
these illnesses can often be decreased or eliminated by a
combination of careful washing, refrigeration and thorough
cooking. Bovine spongiform encephalopathy, however, appears to
be caused by an unusual infectious agent known as a "prion"
(pronounced "pree-on"). Prions are truly very unusual
infectious agents. They have no genetic material and consist
entirely of protein. Research suggests that these prion
proteins are similar in structure to proteins that occur
naturally in the brains of humans and other animals. The
prions differ from those similar normal proteins, however, in
their three dimensional shape. Prions seem to cause disease by
coming into contact with those normal proteins and then
stimulating them to change their shape to mimic the prion
protein. This change in shape appears to set up a chain
reaction. Normal proteins change their shape to look like the
prion proteins and then later influence neighboring proteins
to do the same. The end result is a progressively devastating
and ultimately fatal disease. No treatment has yet been
discovered.

Making the picture even bleaker is the resiliency of prions.
They are not destroyed by the usual means used to kill
infectious agents. They are resistant even to boiling at
temperatures as high as 250 degrees Celsius (well over 400
degrees Fahrenheit). They are also resistant to ionizing
radiation.

Prion related diseases are also extremely difficult to
diagnose. There is no way to do a blood test for BSE and an
infected animal does not mount any immune response to the
infection. Tell-tale signs of diseases like BSE are usually
only possible to diagnose at autopsy. However, not all
infected animals necessarily have the characteristic
sponge-like brain changes. Of particular concern, animals who
carry the disease and have not yet developed signs of BSE, may
not show the characteristic brain involvement.

WHAT ANIMAL PRODUCTS ARE FREE OF PRIONS?

Of even more concern is the fact that we do not know which
tissues could carry the infection. Most of the focus of late
has been on beef. This is warranted. Although organ tissue
carries the greatest risk, animal studies do suggest that meat
itself can transmit prion-related diseases. However, we cannot
exclude the possibility that milk could also carry
disease-inducing prions. Many may recall how some years ago
assurances were given that a mother could not pass HIV to her
child by nursing. Of course, we now know that HIV can be
transmitted in breast milk. Granted, prion diseases are vastly
different than HIV. The risk from milk (if it does exist) does
appear to be much smaller than from eating beef or cattle
organ tissues. Nonetheless, a British BSE expert has pointed
out that there has been at least one human case that suggests
passage of prions in milk. This was the case of a woman dying
with CJD who demonstrated the infectious agent in her
colostrum (the type of breast milk made in the initial days
following delivery).

Eating the flesh of other animals (besides cows) or drinking
their milk may not be safe either. These other animals may
also be affected with a prion-related diseases. As we have
already mentioned, sheep as well as goats can become infected
with such illnesses. Even if some of these illnesses do not
seem to be easily transmitted to humans (because of what is
often called, "the species barrier"), the possibility exists
that different strains of prions could present more danger.

OTHER CONSIDERATIONS

There is one other very important aspect that needs to be
reemphasized. These transmissible spongiform encephalopathies
have extremely long incubation periods. (This is the technical
term for how long it takes for a person with the infection to
actually show signs of the disease) As already mentioned, in
humans, there is evidence that kuru can take up to 30 years to
manifest itself. This is likely to be the same with CJD. With
BSE, it may take up to 6-8 years or more before infected cows
show signs of the disease. The important implication is that
thousands of animals and humans may now be infected yet not
develop symptoms for many years.

The current British proposal to slaughter all older cows may
not go far enough. If younger cows are infected they may not
yet show any signs of the disease. However, an infected cow
can theoretically transmit the illness whether or not it has
yet developed symptomatic disease. The widely publicized 1988
ban on feeding dead sheep parts to British cattle did not stop
the epidemic. When the statistics were reviewed in a 1995
report, over half of all the British cattle that had developed
BSE were born after the ban was implemented. The important
message is that young cows may be infected, and may be able to
transmit disease to humans.

CONCLUSIONS

The Consumers' Association , an independent British "watchdog
group", has been quoted as saying that the only way to avoid
BSE risk would be to stop eating beef all together. Others are
saying even more. Some are suggesting that the time has come
to recognize that disease in animals has become so rampant
that we all need to seriously consider becoming vegetarians.
They point out that BSE is just one of many fatal diseases
linked to animals. Literally hundreds of deaths have been
documented in the US alone from a host of animal related
infections. Some of the most significant causative agents may
not yet be household words, however most will recognize at
least one of them: salmonella, listeria, campylobacter, and
yersinia. Of course, we can't forget that the risk of dying
prematurely from the Western World's two leading killers,
cancer and heart disease, generally rises with increasing
consumption of animal products.

If there is even a small chance of getting a severe fatal
disease, some are suggesting it would be prudent to avoid all
animal products. But maybe a few other questions are more
important. What is the next transmissible disease in animals
that will be recognized? Do I want to wait for tragedy to
strike me or someone close to me -- or have I already had
warning enough?

APPENDIX: IS IT ALREADY TOO LATE?

If you have been eating beef and using other animal products
for years is it already too late? The answer is clearly, "no."
In the case of human prion related diseases, there is evidence
that the total amount of prion exposure affects the incubation
period of the disease. In other words, someone who eats a
large amount of prion containing foods may develop the disease
in 10 years or less, while someone with moderate, yet
significantly less, exposure may develop the condition in
15-20 years. Another with still smaller exposure may not come
down with the illness for 30 or more years.

Thus, even if someone was doomed to come down with a condition
like CJD (because of previous exposure to prions), it may be
possible to delay the onset of the disease significantly. And
don't forget: a diet that moves away from animal products can
also dramatically help you decrease your risk of other
diseases like heart disease and cancer.

FURTHER INFORMATION

Those interested in additional information on BSE and/or other
animal related diseases are encouraged to ask to be placed on
the mailing list for prepublication information on Dr. Neil
Nedley's book when it becomes available. In addition to the
written text, an accompanying CD-ROM with color visuals
suitable for public presentations will be available. Send
e-mail to "docderose@aol.com" with the request "Nedley list"
(leave off the quotes, of course.) You will receive further
information when it becomes available.

SELECTED REFERENCES:

Almond JW, Brown P, Gore SM, Hofman A, Wientjens DPWM, Ridley
RM, et al. Will bovine spongiform encephalopathy transmit to
humans? . British Medical Journal 1995;311:1415-21 (25
November)

Brown, P. Bovine spongiform encephalopathy and
Creutzfeldt-Jakob disease: The link is unproved, but no better
explanation is presently forthcoming. British Medical Journal,
30 March 1996

Dealler SF, Lacey RW Transmissible spongiform
encephalopathies: the threat of BSE to man. Food Microbiology
1990;7: 253-79.

Dealler, S & Kent, J. BSE: an update on the statistical
evidence; British Food Journal 1995, volume 97, p3-18;

Gore SM. More than happenstance: Creutzfeldt-Jakob disease in
farmers and young adults. British Medical Journal
1995;311:1416-8.

Gore, SM Bovine Creutzfeldt-Jakob disease? Failures of
epidemiology must be remedied. British Medical Journal, 30
March 1996

Gruzen, T; U.S. Never Banned Suspect Feed Fda, Keeping Watch
On British Beef Crisis, Says Safeguards Exist; Chicago
Tribune, Thursday, March 28, 1996

Hoinville LJ, Wilesmith JW, Richards MS. An investigation of
risk factors for cases of bovine spongiform encephalopathy
born after the introduction of the "feed ban." Vet Rec
1995;136:312-8.

Lacey RW, Bovine spongiform encephalopathy is being maintained
by vertical and horizontal transmission, British Medical
Journal 20 January 1996;312:180-1.

Lacey RW. Creutzfeldt-Jakob disease and bovine spongiform
encephalopathy. British Medical Journal 1996;312:180-1. (20
January)

Patterson, WJ & Dealler, S. Bovine spongiform encephalopathy
and public health. J. Public Health Medicine. Volume 17 number
3, 1995, pages 261-268.

Prusiner SB, Molecular Biology Of Prion Diseases. Science
(Magazine) Vol. 252, pages 1515-1522; June 14, 1991.

Prusiner SB, The Prion Diseases. Scientific American. January
1995 Volume 272 Number 1 Pages 48-57.

Wells GAH, Wilesmith JW. The neuropathology and epidemiology
of bovine spongiform encephalopathy. Brain Pathol
1995;5:91-103.

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SECTION III
   
PARTING WORDS
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Send all correspondence to:
   
David J. DeRose, MD, MPH
Email: docderose@aol.com (preferred) 74532.622@compuserve.com 

Please join me in expressing gratitude to Dr. DeRose for
making this information available to the world community.

 Jai Maharaj <jai@mantra.com>
%:%:%:%:%:%:%:%:%:%:%:%:%:%:%:%:%:%:%:%:%:%:%:% Om Shanti %:%:%


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