
Subsections
BSE
Bovine Spongiform Encephalopathy (B S E) was first described in
1986 related to cattle feed containing meet and bones from carcasses of sheep being feed to bovines.
On the 70th the preparation of animal feed was simplified, and the
temperature reduced. The agent of BSE could now survive and
Great Britain became the hotbed of the mad cow disease. The zoologist Sir Richard
Southwood [208] blames us all because we all want to eat cheap food.
Science, agriculture and politics have failed to get the disease under control.
In the meanwhile 27 persons died on CJD "new variant Creutzfeldt-Jacob-Disease".
It seems to be the start of a horrible epidemic.
Human diseases caused by priones have different forms:
Kuru: The tribe of fore in Papua-Newguinea were cannibals, eating brains of
diseased.After ceasing the cannibalic practice new infections were no more recorded.
The disease was called Kuru and was characterized by loss of coordination of movements developing until madness.
Creutzfeldt-Jakob disease: Is spread through out the world,
being described in 1920 by Creutzfeldt and Jacob.
The disease begins at the age of 60 with disturbed sleep, hallucination, dementia, unable to speak and to read,
and alterations of movements. It leads to death within several month up to two years
10 to 15% of all cases of CJD are of hereditary origin.A small number is transmitted by surgical
interventions, such as transplants.
Gerstmann-Sträussler-Scheinker
Syndrome and Lethal Familiar Insomnia [28]
The signs of the disease are similar to those of the CJ disease.All these diseases are caused
by proteins priones (PrP) (Proteinaceus infectious Particles)[4].
These proteins remain infectious even after being treated by methods of
lesion of nucleic acid, however lose their virulence when treated with hydrolysing or denaturing substances .
Genetic cause
Priones or PrP - Proteins exist in two forms:
One form causes the CJD (Creutzfeldt-Jakob Disease) disease being infectious.
The other form of PrP- Proteins is not pathogenic and is synthesized by the organism himself.
It is not contagious.
The theory that priones also can cause CJD through a genetic mechanism was explained
by Prusiner.
In 1988 it was discovered that patients with Gerstmann-Sträussler-Scheinker syndrome had a
change in their genetic code, compared with healthy persons.
The contagious PrP-protein may be inherited. The difference between the genetic code from
these patients compared with healthy persons lies in a change at the Gen-PrP from the DNA,
one of the 750 radicals from the part of the DNA
responsible for the synthesis of PrP protein. These radicals are the alphabet from which
the genetic code is composed.
Her sequence in the molecule of DNA decides the composition of the proteins. The code for the synthesis of each
aminoacid is represented by three basic radicals. This part is called CONDOM. In the
case of the syndrome of GSS the condom 102 suffers a mutation. The PrP protein
has a proline aminoacid in the
place where normally the basic radical leucine
is located.
This small change in the structure of the PrP is responsible for the start of the disease of GSS.
Today 18 types of genetic modifications which are responsible for the synthesis of
PrP-scrapie are known.
The normal form of PrP protein found in healthy people is called PrP-cellular.
PrP-scrapie has turned out to be the global denomination for all diseases
close related to the human and animal scrapie. The specific activity of PrP
scrapie consists in its stereoisomeric configuration. The PrP scrapie does
not necessarily present a genetic mutation related to a change of leucine
by proline. What matters is that molecules of PrP having the same distribution
of aminoacids differ in their stereoisomeric configuration. The priones are
able to transfer her stereoisomeric configuration to other normal molecules
of PrP-cellular which now turn out to be infectious.
The structure with this
property is called twisted beta structure. The aminoacids have a
beta-helicoidal twisted screw form and represent the scrapie PrP.
The cellular PrP form has a twisted alfa-helicoidal chain. In some places of
the alfa-helicoidal chain there may be a change of aminoacids which cause
an unstable condition in the molecule being therefore vulnerable to an inversion of
her twist, acquiring the same configuration of the scrapie PrP molecule thus
becoming infectious.
The pathological activity of scrapie PrP is still partially unknown. It seems
that PrP
destroys the nervous cells producing amylaceous substances which
accumulate as
amylaceous plaques which can be seen under microscope.
These plaques are also found in the
Alsheimer Disease, Parkinson and
amiotrofic lateral sclerosis, demonstrating certain link
between these groups of anomalies.
Priones are particles of infectious proteins causing degenerative diseases of the central
nervous system in human and in animals. Unlike other substances which are situated between
priones and other superior elements the prions do not have the form of nucleic acid
which could be made responsible for reproduction as below:
- Phytopathogenic viroids are composed of nucleic acid having some times no superficial
protective layer.
- Virus with RNA and DNA, genetic material necessary to imprint the informations in the invaded cell forcing the cell to produce new proteins
Priones distinguishes itself from virus or viroids by the following qualities:
- They cause infectious diseases.
- They cause diseases of hereditary origin.
- Prions may influence other proteins to become dangerous.
Prions always cause mortal diseases.They are localized in brain and stay without symptoms for decades.
They have their influence spread over the muscular system.
Usual spongiform encephalopathies:
Scrapie in lamb and goats: The animals can no more coordinate the movements and cannot
maintain itself on foot,
being frightened and scrape itself until there is no skin left. This gave origin to the name
of the disease = to SCRAPE .
Other encephalopathies:
Encephalopathies of Canadian marten, chronic degenerative disease of elk, feline spongiform encephalopathy of
cat and the bovine spongiform encephalopathy (B S E).
- 1963- The agent of the disease proved to get from one species to another
as BSE contaminated material was fed to minks in a farm of Idaho. All animals
died of spongiform encephalopathy.
The possibility of scrapie agent to overcome the species-barrier was again
proved in 1986 by veterinarians in Weybridge finding an antelope with
scrapie encephalopathy.
- 70th decade: The preparation of fodder containing carcasses of
diseased animals was simplified.The temperature
reduced to lower costs. The agent of BSE
could survive.As this fodder was also exported, BSE reached Switzerland,
France and other countries. It was used to feed not only bovines but also
pigs, chicken and fish.
pork, chicken and fish do not live long enough to show the signs of the
disease even being infectious, representing therefore a deadly menace.
- December 1984: The veterinarian Dr. David Bee treating cases of BSE sent samples to
a national central veterinary laboratory in Weybridge.
The results of these analysis never reached Dr. Bee. [208]
- Up to 1985 before the disease was known, 54.000 BSE infected cattle entered the human food chain. It is supposed that later on the number of infected cows which were already consumed as human food mount up to 750.000.
- April 1986: Dr Collin told that probably there was a new disease
coming up. Nobody took care of that.
- 1986- The first case of BSE was described related to meal
from carcasses of diseased animals.
- June 1987 Dr.Howard Rees, then chief veterinarian of the Ministry of
Agriculture, Fisheries and Food (MAFF) forwarding informations regarding to BSE to the MAFF Secretary
Sir Michael Franklin
added his concern about possible public misrepresentation which could cause
serious financial damage.[208]
Meanwhile in Sweden the ban of animal feed with animal meal was imposed.Only two years later Germany reacted stopping the import of animal meal from Great Britain.
- July 1987: Dr Whitaker, preparing a report on cases of BSE he
had worked on, was advised by the Ministry of Agriculture of Great Britain
not to use the word "scrapie-like".
- April 1988 The Government of UK organized a body of experts under
the zoologist Richard Southwood. This committee
wrote to be absurd human being in danger because of BSE.[208]
- 1989 - British government installed a follower group "Spongiform
Encephalopathy Advisory Committee" (SEAC)under medical advice of David Tyrrell
The Group confirmed the statement of Minister Gummer UK beef being safe.Later on
Tyrell gave an explanation about the meaning of the word "safe".He said:
"It does not mean there is no risk, it only means that the risk is very
small."
The SEAC - Group failed to set strong measures against the spreading
disease, still allowing the sell of fodder made of BSE corpses.
- 1990 The Agricultural minister John Gummer and his chief
veterinary Meldrum
stated "British beef is safe ".
- May 1990 - The first British cat died of BSE. Meldrum said: "There is no reason
to be worried. It was just a cat out of seven millions.[208]
- September 1990 - The "Veterinary Record" reported a pig being infected by BSE.
- 1998 - Prohibition to use ruminant-derived protein in form of meat and
bone meal (mbm) in ruminant feed, which was the main cause of BSE cases in Switzerland and France. The incubation of 5 years caused this prohibition
not to show immediate effect. The number of cases of BSE doubled from one year
to another until having his peak in 1992.
- 1999.- Germany has closed his frontiers for living cattle but allowed the import of meat of cattle from Great Britain.
- 1994.-German veterinary officials stated human safety regarding BSE, existing no possibility of human
contamination by consuming BSE-positive beef. This cannot be sustained today
and shows how careless BSE meat was officially handled !
- 1994.- One case of BSE on a cow in Diepholz (Germany, near Osnabrück). This cow had been imported from Great Britain.
- German Health Minister Horst Seehofer will determine all 5 000 cattle
imported from England to be slaughtered. The agriculture lobby did succeed to stop the killing.
- 1995- Further measures against BSE and prevention to transmission to humans:
1- Slaughter of suspect cases
2- Destruction of carcasses
3- Ban of specified offal
4- Ban on using bovine vertebral column to produce mechanically recovered meat
5- Ban on using beef from cattle over 8 month old.
6- Ban of use of intestines and thymus from calves under 6 month old.
7- Ban of using the entire head.
Despite the growing menace of spreading BSE in cattle mainly in France,
Portugal and Switzerland the EU Commission is not willing to forbid animal
meal made of bones,carcasses, brains, spinal cord, blood, gelatine, lard and
marrow as animal feed for pigs, poultry and fish. Ruminants are not allowed
any more to be fed with animal meal.
Animal feed free of animal meal is now being produced in Germany with main ingredients:
Soy bean from USA, Argentina and Brazil.
Rapeseed cake from Pakistan, India and Germany.
Peas, broad been (Vicia faba), sunflower seed cake, maize germ cake and maize gluten feed.
400.000 tons of animal meal can thus be replaced by vegetable ingredients supplying the aminoacids which are necessary for a healthy growth.
Genetic modified Soybean, rapeseed and maize gluten feed must be replaced by NON-GMO to avoid another loss of confidence of the consumer.
Milk substitute in organic farming
Milk substitute being fed to young animals should contain only milk
fat. other animal fat is to be banned. Milk substitute should therefor
be made out of half unskimmed milk and half vegetable fat. The cheap
variant using animal fat from condemned animals was certainly a
vector of BSE disease which had been fed until December 2000.
It had been discovered that the BSE pathogens are very resistant in
fat and can be destroyed only with temperatures of mor than
150
C. Fat used in powdered milk substitutes had only been
heated up to 100
C. All German farmers with BSE in their herd had
fed powdered milk substitutes of low temperature origin.
All efforts should be undertaken to reduce spreading of BSE regardless to costs and industrial interests.
To inactivate the BSE agents Germany uses 133
C heat and 3 bar pressure during 20 minutes to decontaminate the meal. This method is not being used in other countries. France is willing to forbid therefore completely the use of animal meal.
The problem arises how to get rid of 300.000 tons of meal/year which have to be burned, causing dioxins. The proteins demand of 55 to 66% in animal meal must be covered with soybean meal ( 44 to 46 % protein). Stock market reacted immediately with rising prices for soybean meal.
BSE was present in cattle in the Northern Ireland, in Great Britain, Switzerland and in France in the Departments 22 (Côte du Nord), 29 (Finistere), 35 (Ile de Vilalne), 50 (Manche). In February 1997 was discovered a case of BSE in Germany. This cow had been imported from England. Her identification mark had been falsified as being original German. In Switzerland there has been reported recently a case of BSE The contamination in this case was told to be interplacental or over the milk. Since January 1977 until march there were 15 cases of BSE in Switzerland. (Welt am Sonntag 3.3.97).
- February 1996- The SEAC-Committee admits the situation to be "dramatical".
There were already 10 patients having Creutzfeldt-Jakob-disease.
- 1998.- At the beginning of 1998 there were two more cases of BSE on Belgian cattle (in Ruddervoorde) reported.
- 1998, 11. February. The daily newspaper Jeversches Wochenblatt reports.
human disease caused by infectious BSE meat in Great Britain in France and in
two cases in Portugal.
- 1998, march.Within two month the beef ban for Northern Ireland will be lowered to permit the export of beef from
certified herds being free of BSE for a period of eight years.
The province of Northern Ireland had "only" 1.766 cases of BSE and 28 cases last year,compared with 170.000 cases
in the rest of the United Kingdom.
The UK Ministry of Agriculture announces further pressure to liberate export of cattle born after August 1,1996 when all
stocks of potentially contaminated feed at farms and mills were destroyed.
- From January to October 1998 there were 66 new cases of BSE in Portuguese cattle, summing up to 380 cases. The European Commission decided to forbid the exportation of meat of Portuguese cattle.[444]
BSE seems to continue to spread on the continent of Europe.
- 1999, April[506] A new case of BSE was diagnosed on French
cattle. Since 1990 there were 103 cases in France reported. 1998 brought 18
cases. The Minister of Agriculture of France Jean Glavany says that these
cases have resulted from contaminated feed made from carcasses of cattle
defined of BSE. Starting at the end of 1996 stronger regulations
concerning animal meal were introduced. Glavany says that infected meal which
in France is allowed for chicken, pig and fish were fed to ruminants by
mistake. Glavany expects BSE cases to reduce in 20002. What about the
menace of contaminated fodder which is still fed to pigs, chicken and fish ?
Safety of meat is of no concern 11 cases of BSE reported in Belgium.
- Netherlands 6 reported cases.
- Germany: 6 reported cases
- Italy: 2 cases of BSE
- Ireland: 471 cases of BSE.
- In the European Union there were 183.639 cases of BSE. 95%
of these cases were reported in the United Kingdom[943]
- 1999.- The European Commission lifts the export prohibition of meat from great Britain. The agricultural Minister of Germany Karl-Heinz Funke states: Nowhere can the consumer be so safe as by us''
- September 2000.- The EU Commission discovers on control of animal feed in Bavaria 75% of samples to contain animal meal. There is no reaction of the authorities of Bavaria
- November 22.- The German Heath Minister Funke take position against the prohibition of animal meal as fodder.
- Two German cows were tested positive for BSE on 24 of November 2000. One had been slaughtered and the meat had been distributed for sell. All parts could be recalled. The other cow had been sold two years to Portugal were the test was made. Germany turned out to be considered as not BSE free country.
- December, 6. 2000The Institute for Meat research of Germany sends a warning to the Government of Germany telling that there is a great danger emanating from meat from separator meat used in sausages.
- December, 19.- EU Commissioner David Byrne urges the German
Government to stop the sell of sausages with bovine meat as
ingredient and to start a recall of these products.
- 30.November 2001: There are 124 BSE cases in Germany of which 39
had no sings of the disease. The selling of this meat was avoided by
the test of BSE. Half of these animals were born in Bavaria[942]
The birthday of 90% of these positive animals dates on 1995 and 1996.
- BSE is reported from Austria and Japan. In Japan contaminated
British animal meal had been fed.
BSE is therefore not under control.
The European Commission has therefore established a decision in order to
strengthen the rules related to BSE: Starting with 1.10.00 the parts like
head, brains, eyes, tonsils, spinal cord and a part of the intestine of
cattle with more than 12 month of age must be separated and incinerated. In
case of sheep and goats additionally the melt must be removed and
incinerated.
This rule is valid in all countries of the EU, This rule is also valid
for the production of animal flour for feedstuff.
Germany in level two of BSE-risk
The European Commission in its report from June 2000 has classified Germany as
level two of the risk of BSE. Germany is surpassed only by Great Britain and
Portugal in BSE risk.
During the time of uncontrolled spread of infected corpses Germany had
imported infected meat and animal feed from great Britain. The EU Commission
expects therefore many cases of BSE and CJD in Germany.
In February 2001 the total number of 41 BSE positive cases had been reported
in Germany.
Concerns over gelatin (used in Food and medicaments capsules
dragees etc) following the BSE crisis in Europe and thus being spread over the
whole world have led researchers to look after alternatives.
Alternatives to gelatin
- E 406 Agar-Agar
- E 412 Guar gum
- E 410 Carob seed
- Inulin:Inulin is made from chicory.It has good
technological properties and a stimulating effect on Bifidus bacteria which are part of the normal intestinal flora
building therefore a protective wall against the Helicobacter pylori which is known as agent of intestinal ulcers which
escalate to cancer.
- Amylopectic potato starch, produced
from genetically modified Potatoes with 25% more amylopectin with no amylose
is told to be another substitute to gelatin.
Amylopectic potato starch after processing has no genetically modified
material left. According to the European
Novel Food Directive there is no need to declare the GM origin on food
label.
Amylopectic potato starch is gluten-free and has a
function as food fiber.
- Sugar beet fiber is used to improve the
consistency and taste of meet products such as meet balls, hamburgers and meat
loaf improving its juiciness.
Another ingredient to improve exact portioning and specific shapes, sizes and
weights is a frozen coagulated protein in combination with
thrombin, an enzyme that will catalyze cross-linking between fibrinogen and
meat collagen.
All these new ingredients may become important alternatives to gelatin in
case of BSE spreading.
- Agar Agar E 406 is a gelling agent extracted from the cell walls of red algae.
- Guar meal E 412 is a gelling
agent from the seeds of the guar plant which grows in India.
- Locust bean gum E 410indexLocust bean gum, alternative to gelatine
is a gelling agent of the seeds of the locust tree.
Lecithin from brains and nervous system material:
Lecithin extracted from brains and nervous systems from BSE cattle was used in
the production of chocolate.
As BSE still keeps going and meal from diseased animals is still being fed
there is no safety for European beef,
All BSE-tests like Prionics are only safe when the animal already has clinical
signs of the disease. In Germany 60% of cattle is slaughtered being under two
years of age when tests fail.
To be sure not to get the deadly CJ disease try to get beef from
Argentina,Australia, Chile, New Zealand and Paraguay. There is canned meat
imported from these countries. Corned beef is safe, but it is very salty.
Very dangerous is meat from Great Britain, Portugal, France,Switzerland,Spain,
Germany and everything which comes from eastern countries like Poland,
because contaminated, unsafe meat is sold there to be imported in the European
Community.
In USA there are cases of BSE in wild animals. All care should be made to
avoid the spread of BSE in USA cattle. Wild animals should therefore not be
used in the production of meal for animal feed because transmission of priones
is still unknown. Unsafe are stock cubes and dry soups and sauces as they
contain meat extracts .
As The menace of BSE disease and CJD increases the search for a safe test on
blood which can demonstrate the presence of the disease in animal and in human
beings turned out to be a run against the time.
There are other diseases
which are probably caused by priones like parkinson and Alzheimer, rheumatic
forms and some sort of tumors which may interfere in the immunological
reactions used for the diagnosis. Boehringer Ingelheim ( Germany ) tries to
find such a test. Prionics is now in use to test animals on BSE but it is
not safe as there are many false negative results.
[860]
The situation of Transmissible Spongiform Encephalopathy (TSE) of small
ruminants like goats and sheep in Europe is analysed by the EU Food Safety in
its release "new information about TSE in goats". []
Evaluation of the validated TSE tests found that they do not perform equally
toward atypical cases and that difference in performance result in under- or
non recognition of various types of scrapie. Moreover, a new type of TSE
(atypical scrapie cases/NOR98) not previously recognized in the EU, was
detected in small ruminants. Currently atypical/Nor98 has been detected in a
large number of European countries and approximately constitutes 80% of test
positive cases identified in EU.
New tests have to successfully pass all stages of a new evaluation process.
New tests should detect classical scrapie, atypical scrapie and BSE in sheep
and detection of preclinical cases and comply with criteria on limitations
posed by analytical sensitivity in comparison with bioassay. The criteria set
higher standards than have previously been approved for validation of small
ruminant post mortem TSE tests for classical scrapie and BSE as well as for
atypical scrapie.
Considering data available about abnormal PrP distribution in the three
recognized small ruminants TSE forms (BSE, classical scrapie and atypical
scrapie) the use of brainstem appears to be the best compromise for detection
of all TSE agents in small ruminants. In consequence, officially confirmed (by
CRL and NRL) positive/negative brainstem will be used for the evaluation of
tests.
The BIOHAZ panel recommends that tests already approved for the detection of
TSE in small ruminants should be required to participate in the new evaluation
in order to confirm their robustness and their ability to fulfil the additional
performance requirements (e.g. atypical cases and analytical sensitivity).
[861]
Christina J Sigurdson and colleagues 2007 developed a method based on a
fluorescent molecule, a conjugated polymer for detecting and characterizing
prions. The new method can distinguish between different strains of prions,
whereas the classic methods like antibodies detection and the Congo red
staining do not make the distinction.
As the disease was narrowed down public concern about BSE ebbed away. New
methods of diagnosis are, however, being developed, because scientists are
aware of a possible species barrier braking of the disease, what could make
them rapidly contagious within the species.
The method was tested on BSE, scrapie and mad elk disease (CWD) infected
mice. New strains of prions emerged throughout several generations which could
be identified with the new method.
According to the authors the luminescent conjugated polymers (LCPs) method,
emit conformation-dependent fluorescence spectra, for characterizing prion
strains, helping to detect structural differences among discrete protein
aggregates and to link protein conformational features with disease phenotypes.
The method is now being adapted to blood controls as several cases are known
of human BSE infected donors have transmitted the vCJD disease to other
patients during the blood transfusion. [862]
Milk and related products an the risk of transmission of BSE
[863] According to
Martin Krönke, professor of microbiology at the University of Cologne milk
and related products from diseased cows may contain pathogenic agents of BSE.
The transmission of the disease to mankind through milk products is
theoretically possible. Krönke is Leibniz-Prize winner 2001 regarding his
researches on immunology and cell biology.
Clinical signs of BSE in cows:
[858]
Cows with BSE disease loss weight, reduce milk. The disease is marked by:
- Disorder of behavior:Restlessness, nervousness, fearfulness or
start to bite.
- Disorder of sensitivity: Lash out when the hind foots are
touched with a broom. Striking with the head and horn and grinding of teeth
when touched with a pencil on head and neck. Wince with sudden noise such as
clapping.
- Disorder of motility: Ataxia, plunge down and impossibility to
stand up.
- Buckle up or wavering during free walking and loose of balance
with break down.
- Animals start suddenly to lash out during milking.
- Excessive licking of the nose.
- Goggle-eye.
- Refusal to cross a small ditch followed by sudden jump over.
- Refusal to cross the door of the stable followed by sudden jump through.
All clinical signs may be intensified by stress such as transport or
diminished under calm conditions.
There are no signs that certain breeds or a sex are more susceptible to BSE
disease.Incubation period is two to eight years.
Infected animals disease between 2 to 12 years, most frequently 4 to 6 years
of age.
On living cattle with signs of BSE normal liquor stands for BSE disease
meanwhile central nervous system diseases change liquor with signs of
infection. A final diagnosis is the histological alterations of the brain.
In advanced stage of the disease these sings may be absent.
The clinical signs can be used to monitor a herd without complicated tests.
These signs should be carefully observed all over the world to avoid an
outbreak in other continents. The WHO warns for possible outbreaks of BSE
worldwide. According to WHO it may be that the disease is already present in
Argentina and Brazil only not being noted because no tests are being made.
Brazil is already told to be careless in relation to BSE making no effort to
test their cattle. The clinical signs may become useful as they are not
expensive and very useful to detect outbreaks of BSE in developing countries.
Cows with the clinical signs of BSE should be burned and not be used as human
food or animal feed.
In western Canada 14.000 domestic elks were slaughtered to control the Elk
Disease which is a BSE-like neuropathological disease. 14 elks were found to
have clinical signs such as:
Swallow complaints
Loss of orientation
Rapid loss of weight
Death by starving
Canada has about 54.000 domestic elks for meat production which is an important
industry in the province of Saskatchewan.
Globalization and the destruction of geographical, economic and ecological
isolated units are the main cause of the spread of diseases such as BSE, Elk
Disease, Foot and Mouth Disease and other epidemiological relevant epidemics.
BSE-Risk material according to resolutions of the European Commission
2000/418/EG (29.6.2000) and 2001/2/EG (27.9.2001):
Skull, including brain, eyes, tonsils, spinal cord and intestines from cattle,
sheep and goats over twelve month of age.
Spleen of sheep and goats of all age
There is a strong possibility that prions reach the blood stream, lung and
heart during slaughter by bolt with the slaughter gun as material of the brain
squirts all around.
BSE infection danger from contaminated pastures
The Ministry of Environment of Germany was concerned with the possibility of
cattle infection with BSE prions due to pastures contaminated with manure from
diseased animals (early 2000).
According to professor Georg Pauli from the Robert-Koch Institute in Berlin,
there is not such a danger. Sheep which lamb outdoor can deposit infectios
placenta on the ground. This material is being ingested by other sheep
spreading in this way scrapie. Manure contaminated pastures do not present
such danger because the prions are unable to multiplicate or stay infectious
over more than several weeks on ground but are not assimilated by plants.
Not free of any doubt is the possibility of a direct intake of prions of fresh
manure contamination of pastures without the way over a plant host.
BSE infection danger for humans are often underestimated. Infectious prions may
come from primary infective material from diseased animals.
Secondary infective material is all material coming from slaughterhouse which
processes cattle. utensils are contaminated by risk material such as spinal
cord cutting the animal corps on halves or the spreading of brain material by
the slaughter gun. Cleaning and disinfection in normal industrial processing
are not sufficient to avoid BSE risk.
Temperature inactivation of prions takes place only at 330
C and a
pressure of 3 bar during 30 minutes. Normal cooking, heating and freezing do
not inactivate the prions. It is believed small wounds make a direct
infection due to contact with BSE material possible. Butchers are therefore
advised to take safety precautions.
[938]
According to the EFSA the ruminant epidemic of bovine spongiform
encephalopathy was spread in cattle due to feed containing BSE contaminated
animal proteins. The practice of feeding animal proteins to cattle and other
farmed animals destined for the human food chain had been banned since 2001.
The EFSA assessed now the risks certain uses of animal proteins in animal feed.
In their report the EFSA says that no Transmissible Spongiform
Encephalopathies (TSEs) have been identified as occurring in pigs or poultry
under natural conditions. The EFSA concluded that the risk of transmitting
BSE to pigs utilizing poultry Processed Animal Proteins PAPs and vice versa,
that means, feeding pigs with poultry proteins and visa versa is negligible.
In this case human risk of BSE would be negligible, as long no future TSE
infection is found in pigs and poultry.
The risk of transmitting BSE through small quantities of animal proteins in
feed to ruminants can not be excluded and would increase the human exposure
the risk of BSE.
The risk of transmitting BSE to non-ruminants is considered to be lower than
to ruminants, as long as intra-species recycling is avoided, and the increase
in the exposure risk of BSE to humans is negligible.
The Commission may now lift the ban of PAPs in feed between pigs and birds and
vice versa.
Health and nutrition authorities
from European countries and EU- Commission
Health and nutrition authorities have failed to protect
the population from the hazards of BSE and have made it possible the disease to
keep on spreading all over the word.
In France the families of four people which died of the new variant of
Creutzfeldt-Jakob disease blame the government of having failed to react
properly in the years of 1988 to 1996 causing their death.
According to documents concerning this matter which have been presented by the
plaintiffer the French government had knowledge since 1990 of the risk of
human BSE-contamination. The government banned the import of beef from Great
Britain with delay of 6 years.
There is also a charge against the European Union which did not stopped the
trade of animal feed from UK with the Continent in order not to delay the
opening of the European Market in 1992. France supported this decision in
order to protect her meat industry[939].
On December 6, 2001 the scientific committee which advises the EU-Commission
has confirmed that prions of unknown origin are responsible for the
transmission of the BSE disease by means of feed and other contaminations and
in a small number from the animal mother to its child.[940] tests Such
meager statement is a sign of disorientation on regard to BSE.
Since 1995 there were 101 n CJD cases reported.
| Year |
Reported cases |
| |
of nCJD |
| 1995 |
3 |
| 1996 |
10 |
| 1997 |
10 |
| 1998 |
18 |
| 1999 |
15 |
| 2000 |
28 |
Reported total cases of vCJD in humans until 2007 in UK are 158.[1361]
Reported total cases of vCJD in France until 2007 are 21 [1362]
Chronic Wasting Disease CWD
Chronic Wasting Disease in whitetail deer and elk is found in Colorado,Wyoming,
Nebraska, Wisconsin and Illinois, Kansas, South Dakota,Montana, Oklahoma,New
Mexico, Alberta and Saskatchewan.
It causes spongy holes in the brains of the animals. They slobber, stagger,
lose weight and die. There is no cure.
The disease belongs to the family of disorders that includes scrapie in sheep,
mad cow disease in cattle and Creutzfeldt-Jakob disease in humans.
Research is being done in order to see whether Chronic Wasting Disease can jump
from deer to other species such as cattle and even humans through exposure to
infectious agents such as venison and velvet antler used in food
supplements.[1364]
The prions that cause CWD may persist in the environment for years. It is
therefore suggested to avoid plowing under the carcasses of animals that have
died of scrapie, mad cow disease or other prion disease or use these carcasses
in fertilizer because animals may consume contaminated soil while grazing.
There is although the possibility that prions in the soil could be absorbed by
plants and worms which are consumed by the animals.
[1363]
Brent L. Race and colleagues 2007 studied the potential for cross-species
transmission of chronic wasting disease (CWD) of deer and elk. According to he
researchers CWD prevalence in wild elk is much lower than its prevalence in
wild deer. The researchers found that the quantification of prion protein
from tonsil and retropharyngeal lymph nodes showed much higher levels of PrPres
in deer than in elk, suggesting that CWD-infected deer may be more likely than
elk to transmit the disease to other cervids and have a greater potential to
transmit CWD to noncervids.
The high presence of PrPres in deer lymphoid tissues suggest that infectivity
might also be present in other peripheral tissues such as intestine, kidney, or
salivary glands, which could possibly lead to excretion or secretion of
infectivity in faeces, urine, or saliva. in confined settings, where
animal-to-animal contact increases.
Earlier studies have not shown any evidence for transmission of CWD to humans.
CWD has been transmitted to cattle by intracerebral but not by oral
inoculation, and no reports have found that co-pasturing of CWD-infected deer
or elk with cattle has resulted in transmission. Raymond and colleagues 2000
[1364] found in vitro assays designed to test the susceptibility of
humans or cattle to CWD suggested a very low probability of transmission to
humans. Raymond suggests that there might be a barrier at the molecular level
that should limit the susceptibility of non-cervid species to CWD.
Race and colleagues suggest that among livestock, sheep might be a possible
target for CWD infection in appropriate situations such as co-pasturing. Also,
a CWD agent from putatively infected sheep could have a host range not usually
associated with CWD and might cross species barriers more readily than CWD from
cervids. Thus, if CWD continues to expand in deer and elk populations, the
possibility of transmission to noncervid species will require continued
surveillance
Soil as reservoir of prions [1366]
Farm soil is a potential long-term reservoir for BSE infective agents according
to findings that point out that prions bind tightly to clay.
Ban of import of all cervids in Oregon
To avoid further spreading of the CWD Oregon has imposed a permanent ban on
the import of all live grazing deerlike animals called cervids. allowed are
only boned wrapped and cut meat. Not allowed are brainparts, whole heads or
spines
Allowed are hides and portions of clean skull plates with antler
attached.[1367]
History of CWD
mid-1990s: For years the disease remained confined to Colorado and Wyoming.
1996: The disease was found on an elk farm in Saskatchewan
1997 Signs of the disease in an elk farm of South Dakota.
1998: Elk farms of Nebraska were found to be infected, followed by Oklahoma an
in subsequent years Montana, Kansas and Alberta followed.
2002: New Mexico, Minnesota Wisconsin and Illinois reported cases of CWD.
The National Institutes of Health researchers warn that prion diseases may be
more common than originally thought, raising public health concerns about the
practice of giving other farm animals feed made from the byproducts of other
animals.
Goats can suffer from scrapie, which is a type of TSE (Transmissible Spongiform
Encephalopathy), a group of diseases that also includes BSE in cattle. Scrapie
has been known for centuries. A goat slaughtered in France in 2002 has a type
of TSE which might be BSE. the mouse bioassay (which takes two years to
complete) was confirmed on the 28.01.2005.
This TSE was detected in a healthy goat as part of the normal surveillance
measures which have been in place in the EU for many years.BSE has never been
found under natural circumstances in ruminants other than cattle. Its presence
in goats or other ruminants has been viewed as theoretically possible but has
never been detected.
Arising from this EU testing programme, a healthy goat slaughtered in 2002 in
France was tested at random for TSEs. Now preliminary results indicate that a
goat slaughtered in France in 2002 has a type of TSE which might be BSE. It is
believed that the goat was infected by feed with BSE prion contaminated meat.
As this feed was banned for use in all ruminants, there is no risk of a
widespread problem.
Based on these facts, the European Food Safety Authority (EFSA) has advised
that goat milk and derived products are unlikely to present any risk of TSE
contamination if the milk comes from healthy animals.
Currently, as a precautionary measure and following scientific advice, milk and
meat from goats which are affected by TSE cannot be used. These rules were in
place before the case of BSE in a goat was discovered. As for cattle and sheep,
specified risk materials (the tissues most likely to carry infectivity if the
disease is present) are also removed from all goats even if there is no
infection detected. While it is not possible to say that there is absolutely no
risk, any potential risk will be mitigated by the safety measures put in
place.
In light of the above, the European Commission advises no change in current
consumption of goat milk, cheese and meat.
BSE/TSE Statement 2004 of the EFSA on health risks of the
consumption of milk from goats
[1371]
Since the early 1990s, the BSE/TSE risk for milk and milk products has been
discussed by scientific organisations, risk assessment bodies and public health
organisations. Research has focused predominantly on the bovine species, while
data on small ruminants, particularly goats, are limited. Indeed,
epidemiological and experimental data on ruminants so far available have not
provided evidence that milk or milk products harbour prion infectivity.
Some research data support the finding that milk, colostrum and tissues of the
mammary gland from bovine can be classified in the category of no detectable
infectivity. However, based on a number of observations from research data,
mainly research concerning sheep, there are indications that infectivity in the
milk from small ruminants cannot be totally excluded. In case of mastitis, one
could expect an infiltration of potentially infected blood into the milk as the
blood-milk barrier may not or only partly exist. But even in the case of
absence of mastitis the barrier may not be 100% effective.
From the limited data available today it is concluded that in the light of
current scientific knowledge and irrespective of their geographical origin,
milk and milk derivatives (e.g. lactoferrin, lactose) from small ruminants are
unlikely to present any risk of TSE contamination provided that milk is sourced
from clinically healthy animals. Exclusion of animals with mastitis is
considered to reduce the potential risk. Further assurance of healthy milk
could include milk tests for total somatic cell counts indicative of
inflammation.
The EFSA in its statement of 2005 enumerates some of the difficulties
concerning somatic cell count accuracy of goat milk: [1372]
- The somatic cell count accuracy is affected by the apocrine nature of milk secretion in goats. Cytoplasmic particles, which derive from the apical part of secretory cells, are normal constituents in goat milk. Certain methods used to count somatic cells cannot distinguish these cytoplasmic particles, similar in size to somatic cells, from real somatic cells, which may lead to false readings. Moreover, the reference microscopy method, which is based on staining procedures, does not give satisfactory results in the majority of laboratories, when used on goat milk.
- Somatic cells that are identified in milk from healthy cows or ewes are mainly macrophages. Less than 30 % are other leukocytes. Higher levels of the latter are considered to be indicative of inflammation. On the other hand, leukocytes can reach up to 60 % of total cells in normal goat milk. The somatic cell count is therefore difficult to interpret in terms of udder inflammation.
- Non infectious factors greatly influence the somatic cell count in goats. Physiological normality is dependent on the stage of lactation, age, time of sampling, the oestrus period, feed, stress, breed and the region. Most experts in this field therefore consider that a specific somatic cell count-value derived from one population of goats may describe a normal animal health status in a second population and indicate mastitis in a third population.
The panel concluded in 2005 [1372] that due to the high variability
of SCC in goat milk, even in healthy animals, SCC cannot be relied on neither
as a specific indicator for TSE risk nor as an indicator of udder health. It is
recommended to continue the increased surveillance in goats and to initiate
additional research that would allow for a Quantitative Risk Assessment in
goats. The above recommendations should be extended to include sheep.
BSE in Sweden
One cow was tested positive for BSE in Sweden in 2006.The Swedish Board of
Agriculture (BOA) believes that the cow had been fed meat and bone meal by
mistake. Not all safety routines were in place during the first years of the
infected cow's life.
The animal was probably infected about ten years ago. An investigation has
started in order to find what feedingstuffs the animal may have eaten during
its lifetime. This investigation will also find so-called risk animals on the
farm, for instance animals in the same age bracket that have eaten the same
feedingstuffs. [1373]
In the EU, BSE incidents have been falling dramatically since 1992. Extensive
testing and controls programmes are responsible for the decline of incidences
of the disease from 37,280 cases in 1992 to recent figures reported by the
OIE. The favorable development led the EC to adopt a roadmap in July of 2005,
with the aim of softening restrictions and reducing testing costs.
The World Organisation for Animal Health published the details of BSE in
countries that reported cases in 2004. According to this report Ireland found
126 cases of BSE in its cattle in 2004, compared with 137 found in Spain. The
UK had the highest incidence of BSE cases in the world in 2004 with 343 cases
confirmed, followed by Spain, Ireland. Portugal was fourth in the BSE league,
reporting 92 cases in 2004, followed by Germany with 59 cases. France reported
54 cases of BSE in the same year. [1374]
[189]
According to the Corrigendum to Regulation (EC) No 853/2004 of the European
Parliament and of the Council of 29April 2004 laying down specific hygiene
rules for food of animal origin, the production process for gelatine must
ensure that:
1. For the production of gelatine intended for use in food, the following raw
materials may be used:
(a) bones;
(b) hides and skins of farmed ruminant animals;
(c) pig skins;
(d) poultry skin;
(e) tendons and sinews;
(f) wild game hides and skins;
and
(g) fish skin and bones.
2. The use of hides and skins is prohibited if they have undergone any tanning
process, regardless of whether this process was completed.
3. Raw materials listed in point1(a) to(e) must derive from animals which have
been slaughtered in a slaughterhouse and whose carcases have been found fit for
human consumption following ante-mortem and post-mortem inspection or, in the
case of hides and skins from wild game, found fit for human consumption.
4. Raw materials must come from establishments registered or approved pursuant
to Regulation (EC) No 852/2004 or in accordance with this Regulation.
5. Collection centres and tanneries may also supply raw material for the
production of gelatine intended for human consumption if the competent
authority specifically authorises them for this purpose and they fulfil the
following requirements.
(a) They must have storage rooms with hard floors and smooth walls that are
easy to clean and disinfect and, where appropriate, provided with refrigeration
facilities.
(b) The storage rooms must be kept in a satisfactory state of cleanliness and
repair, so that they do not constitute a source of contamination for the raw
materials.
(c) If raw material not in conformity with this chapter is stored and/or
processed in these premises, it must be segregated from raw material in
conformity with this chapter throughout the period of receipt, storage,
processing and dispatch.
Chapter II: Transport and Storage of Raw Materials
1. In place of the identification mark provided for in Annex II, Section I, a
document indicating the establishment of origin and containing the information
set out in the Appendix to this Annex must accompany raw materials during
transport, when delivered to a collection centre or tannery and when delivered
to the gelatine-processing establishment.
2. Raw materials must be transported and stored chilled or frozen unless they
are processed within 24 hours after their departure. However, degreased and
dried bones or ossein, salted, dried and limed hides, and hides and skins
treated with alkali or acid may be transported and stored at ambient
temperature.
Chapter III: Requirements for the Manufacture of Gelatine
1. The production process for gelatine must ensure that:
(a) all ruminant bone material derived from animals born, reared or slaughtered
in countries or regions classified as having a low incidence of BSE in
accordance with Community legislation is subjected to a process which ensures
that all bone material is finely crushed and degreased with hot water and
treated with dilute hydrochloric acid (at minimum concentration of 4% and pH
12.5) for a period of at least 20 days with a sterilisation step of 138 to 140C
during four seconds or by any approved equivalent process;
and
(b) other raw material is subjected to a treatment with acid or alkali,
followed by one or more rinses. The pH must be adjusted subsequently. Gelatine
must be extracted by heating one or several times in succession, followed by
purification by means of filtration and sterilisation.
2. If a food business operator manufacturing gelatine complies with the
requirements applying to gelatine intended for human consumption in respect of
all the gelatine that it produces, it may produce and store gelatine not
intended for human consumption in the same establishment.
Chapter IV: Requirements for Finished Products
Food business operators must ensure that gelatine complies with the residue
limits set out in the following table:
| Residue |
Limit |
| As |
1 ppm |
| Pb |
5 ppm |
| Cd |
0,5 ppm |
| Hg |
0,15 ppm |
| Cr |
10 ppm |
| Cu |
30 ppm |
| Zn |
50 ppm |
[]
The fifth annual CJD Foundation Family Conference, July 6-8 in Washington, D.C.
and also join our advocacy visits to the Hill on July 9. Check
http://www.cjdfoundation.org/headlines.php?ptime=1166193255
website for the program, and other information about this event.
Some of the problems the foundation looks after are:
[191]
Over the last few years, a type of Acquired CJD called variant
(vCJD) has been identified in young people. vCJD has been linked to ingestion
of beef tainted with BSE (bovine spongiform encephalopathy), most cases have
occurred in the United Kingdom. Testing cows being slaughtered helped to reduce
the risk of vCJD.
However, according to Florence's Newsletter, the USDA tests so few cows it
would be impossible for anyone to know how prevalent U.S. BSE really is. Cattle
testing was increased from 40,000 per year to 375,000 for an 18 month period
following the discovery - there are 35 million cattle slaughtered for the U.S.
food supply each year. The Secretary of Agriculture Mike Johanns was asked
last July by a commission leaded by CDJ Disease Foundation that the increased
number of BSE testing should not be cut back but instead that it be increased.
One week after this petition USDA cut back to the previous 40,000.
In a letter to Florence at the Creutzfeld-Jacobs Disease Foundation dated October 3, 2006 Mr.
Johanns stated.... "With regard to USDA's activities, it is important to
understand ...USDA's BSE surveillance is being conducted not as a food safety
measure but rather as a monitoring effort designed to evaluate the
effectiveness of the United States' BSE safeguarding measures with respect to
animal health".
According to Florence it is difficult to understand how human
risk from infected meat takes a back seat to what appears to be a policy
benefiting specific special interest groups.
A statement released end May2007 reported that Japan and South Korea will soon
be opening their borders to US
cattle again based on the U.S. upgraded rating from the OIE (World Organization
for Animal Health) from "possible risk" to "controlled risk".
The USDA's Chief Veterinary Office Dr. Ron DeHaven serves as the U.S. official delegate to the
OIE. Through the OIE decision the USDA is now able to avoid accountability at
all costs, even those directly related to human lives.
[192]
Mathilde Paul and colleagues 2007 studied the role of meat and bone meal
(MBM), animal fat and dicalcium phosphate (DCP) after the feed ban on the risk
for BSE epidemics.
In France, meat-and-bone meal (MBM) has been banned from cattle feed since July
30, 1990. However, through January 1, 2007, 957 cases of bovine spongiform
encephalopathy (BSE) have been detected in cattle born after the ban.
According to the authors the source of infection in cattle born after the MBM
ban still involves MBM. The BSE agent may have entered cattle feed by
cross-contamination with feed for monogastric species (pigs and poultry) in
which MBM was still authorized until November 2000. Cross-contamination could
have occurred within factories, during feed delivery to the farm, or on mixed
farms that have cattle and pigs or poultry.
The authors raise the question of effectiveness of the ban that was initially
restricted to bovines and belatedly extended to other species to reduce
cross-contamination.
The role of MBM as a source of BSE after the ban of MBM for cattle is well
documented through cross-contamination in feed factories. The authors found
that the total ban of MBM for farm animals in November 2000 was essential for
controlling the spread of BSE.
According to Paul and colleagues, together with other studies say that the
implication of animal DCP as a source of BSE, if it existed, should have been
marginal.
In contrast, a risk analysis by the European Food Safety Agency [2] considers
the potential role of animal DCP in cattle infection as to be of the same order
of magnitude as the residual risk from cross-contamination with MBM.
This study cannot exclude a minor effect of animal fat in milk replacers
because of the solubility of prions and the possible contamination with protein
impurities by contact with other infectious materials at the slaughterhouse.
Animal fat is incorporated in cattle feed in milk replacer and in proprietary
concentrates.
The authors point to the fact that in current context of the decreasing
epidemic, economic pressure is increasing to release the ban of MBM in feed for
monogastric species.

OurFood (c) 1998 - 2008 by Karl Heinz Wilm - Imprint (Impressum)