First successful CWD vaccine tested in deer
First successful CWD vaccine tested in deer
Posted Jan. 28, 2015
The first successful vaccination of deer against chronic wasting disease is
reported in the journal Vaccine, (Vaccine 2015;38:726–33), posted online in
advance of print Dec. 21, 2014.
Researchers say the breakthrough may not only protect U.S. livestock
against CWD but may also shed new light on human diseases suspected of being
caused by prion infections, such as Creutzfeldt-Jakob disease, kuru, familial
insomnia, and variably protease-sensitive prionopathy. Some studies also have
associated prionlike infections with Alzheimer’s disease.
“Now that we have found that preventing prion infection is possible in
animals, it’s likely feasible in humans as well,” said senior study investigator
and neurologist Thomas Wisniewski, MD, a professor at New York University’s
Langone Medical Center.
Should further vaccine experiments prove successful, Dr. Wisniewski
believes as little as 10 percent of a cervid herd would need to be inoculated to
induce herd immunity.
Chronic wasting disease is found in wild and captive cervids of North
America. Scientists fear CWD could possibly spread to livestock in the same
regions, especially cattle.
For the study, five deer were given the vaccine; another six were given a
placebo. All the deer were exposed to prion-infected brain tissue. They also
were housed together, engaging in group activities similar to those in the wild.
Scientists say this kept them in constant exposure to the infectious
prions.
Deer receiving the vaccine were given eight boosters over 11 months until
key immune antibodies were detectable in blood, saliva, and feces. The deer also
were monitored daily for signs of illness, and investigators performed biopsies
of the animals’ tonsils and gut tissue every three months to search for signs of
CWD infection.
Within two years, all the deer given the placebo had developed CWD. Four
deer given the vaccine took substantially longer to develop infection, while the
fifth animal was infection-free at the time of the report’s publication.
Dr. Wisniewski and his team made the vaccine using Salmonella bacteria to
mirror the most common mode of natural infection—ingestion of prion-contaminated
food or feces. The team inserted a prionlike protein into the genome of an
attenuated Salmonella bacterium, which produced anti-prion antibodies.
“Although our anti-prion vaccine experiments have so far been successful on
mice and deer, we predict that the method and concept could become a widespread
technique for not only preventing, but potentially treating, many prion
diseases,” said lead study investigator Fernando Goni, PhD, an associate
professor at NYU Langone.
Mucosal immunization with an attenuated Salmonella vaccine partially
protects white-tailed deer from chronic wasting disease
Fernando Goñia, Candace K. Mathiasone, Lucia Yimf, Kinlung Wonga, Jeanette
Hayes-Kluge, Amy Nallse, Daniel Peysera, Veronica Estevezf, Nathaniel Denkerse,
Jinfeng Xuc, David A. Osbornh, Karl V. Millerh, Robert J. Warrenh, David R.
Browng, Jose A. Chabalgoityf, Edward A. Hoovere, Thomas Wisniewskia, b, d, , a
Department of Neurology, New York University School of Medicine, 550 First
Avenue, New York, NY 10016, United States b Department of Pathology, New York
University School of Medicine, 550 First Avenue, New York, NY 10016, United
States c Department of Population Health, New York University School of
Medicine, 550 First Avenue, New York, NY 10016, United States d Department of
Psychiatry, New York University School of Medicine, 550 First Avenue, New York,
NY 10016, United States e College of Veterinary Medicine and Biomedical
Sciences, Colorado State University, Fort Collins, CO, United States f
Laboratory for Vaccine Research, Department of Biotechnology, Instituto de
Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
g Department of Biology and Biochemistry, University of Bath, UK h Warnell
School of Forestry and Natural Resources, University of Georgia, United States
Received 20 August 2014, Revised 13 November 2014, Accepted 19 November 2014,
Available online 21 December 2014
doi:10.1016/j.vaccine.2014.11.035 Get rights and content
--------------------------------------------------------------------------------
Highlights
• We have developed a Salmonella vaccine strain that expresses cervid
PrP.
• The Salmonella vaccine has been tested in white tailed deer.
• The vaccine induced a mucosal and systemic response to cervid PrP and
PrPCWD.
• Vaccinated deer had partial protection for chronic wasting disease.
• This is the first partially effective vaccine for a prion disease.
--------------------------------------------------------------------------------
Abstract
Prion disease is a unique category of illness, affecting both animals and
humans, in which the underlying pathogenesis is related to a conformational
change of a normal, self-protein called PrPC (C for cellular) to a pathological
and infectious conformer known as PrPSc (Sc for scrapie). Bovine spongiform
encephalopathy (BSE), a prion disease believed to have arisen from feeding
cattle with prion contaminated meat and bone meal products, crossed the species
barrier to infect humans. Chronic wasting disease (CWD) infects large numbers of
deer and elk, with the potential to infect humans. Currently no prionosis has an
effective treatment. Previously, we have demonstrated we could prevent
transmission of prions in a proportion of susceptible mice with a mucosal
vaccine. In the current study, white-tailed deer were orally inoculated with
attenuated Salmonella expressing PrP, while control deer were orally inoculated
with vehicle attenuated Salmonella. Once a mucosal response was established, the
vaccinated animals were boosted orally and locally by application of polymerized
recombinant PrP onto the tonsils and rectal mucosa. The vaccinated and control
animals were then challenged orally with CWD-infected brain homogenate. Three
years post CWD oral challenge all control deer developed clinical CWD (median
survival 602 days), while among the vaccinated there was a significant
prolongation of the incubation period (median survival 909 days; p = 0.012 by
Weibull regression analysis) and one deer has remained CWD free both clinically
and by RAMALT and tonsil biopsies. This negative vaccinate has the highest
titers of IgA in saliva and systemic IgG against PrP. Western blots showed that
immunoglobulins from this vaccinate react to PrPCWD. We document the first
partially successful vaccination for a prion disease in a species naturally at
risk.
--------------------------------------------------------------------------------
Graphical abstract Illustrates the study design of the CWD vaccination
experiment. There were five vaccinated white-tailed deer and 6 vehicle controls.
Deer were matched for Prnp genotype (95Q/96G/116A/138S/226Q), except two deer in
both the control and vaccinated group had the most common polymorphism (∼26% of
deer) that confers partial resistance to CWD infection, codon 96 G/S instead of
96 G/G.
Full-size image
Keywords Prion protein; Immunization; Salmonella vaccine strain; Bovine
spongiform encephalopathy; Chronic wasting disease; White-tailed deer; Mucosal
vaccination
Corresponding author at: New York University School of Medicine, ERSP, Rm
802, 450 East 29th Street, New York, NY 10016, United States. Tel.: +1 212 263
7993; fax: +1 212 263 7528. Copyright © 2014 Elsevier Ltd. All rights reserved.
Sunday, December 21, 2014
Mucosal immunization with an attenuated Salmonella vaccine partially
protects white-tailed deer from chronic wasting disease
Friday, December 19, 2014
Pan-Provincial Vaccine Enterprise Inc. (PREVENT) Conducting a Chronic
Wasting Disease (CWD) Vaccine Efficacy Trial in Elk
for some reason I am not sure this is long enough for true test results, and party for a vaccine that will stop cwd. don’t get me wrong, it’s good news for a change. ...kind regards, terry
98 | Veterinary Record | January 24, 2015
EDITORIAL
Scrapie: a particularly persistent pathogen
Cristina Acín
Resistant prions in the environment have been the sword of Damocles for
scrapie control and eradication. Attempts to establish which physical and
chemical agents could be applied to inactivate or moderate scrapie infectivity
were initiated in the 1960s and 1970s,with the first study of this type focusing
on the effect of heat treatment in reducing prion infectivity (Hunter and
Millson 1964). Nowadays, most of the chemical procedures that aim to inactivate
the prion protein are based on the method developed by Kimberlin and
collaborators (1983). This procedure consists of treatment with 20,000 parts per
million free chlorine solution, for a minimum of one hour, of all surfaces that
need to be sterilised (in laboratories, lambing pens, slaughterhouses, and so
on). Despite this, veterinarians and farmers may still ask a range of questions,
such as ‘Is there an official procedure published somewhere?’ and ‘Is there an
international organisation which recommends and defines the exact method of
scrapie decontamination that must be applied?’
From a European perspective, it is difficult to find a treatment that could
be applied, especially in relation to the disinfection of surfaces in lambing
pens of affected flocks. A 999/2001 EU regulation on controlling spongiform
encephalopathies (European Parliament and Council 2001) did not specify a
particular decontamination measure to be used when an outbreak of scrapie is
diagnosed. There is only a brief recommendation in Annex VII concerning the
control and eradication of transmissible spongiform encephalopathies (TSE
s).
Chapter B of the regulation explains the measures that must be applied if
new caprine animals are to be introduced to a holding where a scrapie outbreak
has previously been diagnosed. In that case, the statement indicates that
caprine animals can be introduced ‘provided that a cleaning and disinfection of
all animal housing on the premises has been carried out following
destocking’.
Issues around cleaning and disinfection are common in prion prevention
recommendations, but relevant authorities, veterinarians and farmers may have
difficulties in finding the specific protocol which applies. The European Food
and Safety Authority (EFSA ) published a detailed report about the efficacy of
certain biocides, such as sodium hydroxide, sodium hypochlorite, guanidine and
even a formulation of copper or iron metal ions in combination with hydrogen
peroxide, against prions (EFSA 2009). The report was based on scientific
evidence (Fichet and others 2004, Lemmer and others 2004, Gao and others 2006,
Solassol and others 2006) but unfortunately the decontamination measures were
not assessed under outbreak conditions.
The EFSA Panel on Biological Hazards recently published its conclusions on
the scrapie situation in the EU after 10 years of monitoring and control of the
disease in sheep and goats (EFSA 2014), and one of the most interesting findings
was the Icelandic experience regarding the effect of disinfection in scrapie
control. The Icelandic plan consisted of: culling scrapie-affected sheep or the
whole flock in newly diagnosed outbreaks; deep cleaning and disinfection of
stables, sheds, barns and equipment with high pressure washing followed by
cleaning with 500 parts per million of hypochlorite; drying and treatment with
300 ppm of iodophor; and restocking was not permitted for at least two years.
Even when all of these measures were implemented, scrapie recurred on several
farms, indicating that the infectious agent survived for years in the
environment, even as many as 16 years after restocking (Georgsson and others
2006).
In the rest of the countries considered in the EFSA (2014) report,
recommendations for disinfection measures were not specifically defined at the
government level. In the report, the only recommendation that is made for sheep
is repopulation with sheep with scrapie-resistant genotypes. This reduces the
risk of scrapie recurrence but it is difficult to know its effect on the
infection.
Until the EFSA was established (in May 2003), scientific opinions about TSE
s were provided by the Scientific Steering Committee (SSC) of the EC, whose
advice regarding inactivation procedures focused on treating animal waste at
high temperatures (150°C for three hours) and high pressure alkaline hydrolysis
(SSC 2003). At the same time, the TSE Risk Management Subgroup of the Advisory
Committee on Dangerous Pathogens (ACDP) in the UK published guidance on safe
working and the prevention of TSE infection. Annex C of the ACDP report
established that sodium hypochlorite was considered to be effective, but only if
20,000 ppm of available chlorine was present for at least one hour, which has
practical limitations such as the release of chlorine gas, corrosion,
incompatibility with formaldehyde, alcohols and acids, rapid inactivation of its
active chemicals and the stability of dilutions (ACDP 2009).
In an international context, the World Organisation for Animal Health (OIE)
does not recommend a specific disinfection protocol for prion agents in its
Terrestrial Code or Manual. Chapter 4.13 of the Terrestrial Code, General
recommendations on disinfection and disinsection (OIE 2014), focuses on
foot-and-mouth disease virus, mycobacteria and Bacillus anthracis, but not on
prion disinfection. Nevertheless, the last update published by the OIE on bovine
spongiform encephalopathy (OIE 2012) indicates that few effective
decontamination techniques are available to inactivate the agent on surfaces,
and recommends the removal of all organic material and the use of sodium
hydroxide, or a sodium hypochlorite solution containing 2 per cent available
chlorine, for more than one hour at 20ºC.
The World Health Organization outlines guidelines for the control of TSE s,
and also emphasises the importance of mechanically cleaning surfaces before
disinfection with sodium hydroxide or sodium hypochlorite for one hour (WHO
1999).
Finally, the relevant agencies in both Canada and the USA suggest that the
best treatments for surfaces potentially contaminated with prions are sodium
hydroxide or sodium hypochlorite at 20,000 ppm. This is a 2 per cent solution,
while most commercial household bleaches contain 5.25 per cent sodium
hypochlorite. It is therefore recommended to dilute one part 5.25 per cent
bleach with 1.5 parts water (CDC 2009, Canadian Food Inspection Agency
2013).
So what should we do about disinfection against prions? First, it is
suggested that a single protocol be created by international authorities to
homogenise inactivation procedures and enable their application in all
scrapie-affected countries. Sodium hypochlorite with 20,000 ppm of available
chlorine seems to be the procedure used in most countries, as noted in a paper
summarised on p 99 of this issue of Veterinary Record (Hawkins and others 2015).
But are we totally sure of its effectiveness as a preventive measure in a
scrapie outbreak? Would an in-depth study of the recurrence of scrapie disease
be needed?
What we can conclude is that, if we want to fight prion diseases, and
specifically classical scrapie, we must focus on the accuracy of diagnosis,
monitoring and surveillance; appropriate animal identification and control of
movements; and, in the end, have homogeneous and suitable protocols to
decontaminate and disinfect lambing barns, sheds and equipment available to
veterinarians and farmers. Finally, further investigations into the resistance
of prion proteins in the diversity of environmental surfaces are required.
References
snip...
98 | Veterinary Record | January 24, 2015
Persistence of ovine scrapie infectivity in a farm environment following
cleaning and decontamination
Steve A. C. Hawkins, MIBiol, Pathology Department1, Hugh A. Simmons, BVSc
MRCVS, MBA, MA Animal Services Unit1, Kevin C. Gough, BSc, PhD2 and Ben C.
Maddison, BSc, PhD3 + Author Affiliations
1Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey
KT15 3NB, UK 2School of Veterinary Medicine and Science, The University of
Nottingham, Sutton Bonington, Loughborough, Leicestershire LE12 5RD, UK 3ADAS
UK, School of Veterinary Medicine and Science, The University of Nottingham,
Sutton Bonington, Loughborough, Leicestershire LE12 5RD, UK E-mail for
correspondence: ben.maddison@adas.co.uk Abstract Scrapie of sheep/goats and
chronic wasting disease of deer/elk are contagious prion diseases where
environmental reservoirs are directly implicated in the transmission of disease.
In this study, the effectiveness of recommended scrapie farm decontamination
regimens was evaluated by a sheep bioassay using buildings naturally
contaminated with scrapie. Pens within a farm building were treated with either
20,000 parts per million free chorine solution for one hour or were treated with
the same but were followed by painting and full re-galvanisation or replacement
of metalwork within the pen. Scrapie susceptible lambs of the PRNP genotype
VRQ/VRQ were reared within these pens and their scrapie status was monitored by
recto-anal mucosa-associated lymphoid tissue. All animals became infected over
an 18-month period, even in the pen that had been subject to the most stringent
decontamination process. These data suggest that recommended current guidelines
for the decontamination of farm buildings following outbreaks of scrapie do
little to reduce the titre of infectious scrapie material and that environmental
recontamination could also be an issue associated with these premises.
SNIP...
Discussion
Thorough pressure washing of a pen had no effect on the amount of
bioavailable scrapie infectivity (pen B). The routine removal of prions from
surfaces within a laboratory setting is treatment for a minimum of one hour with
20,000 ppm free chlorine, a method originally based on the use of brain
macerates from infected rodents to evaluate the effectiveness of decontamination
(Kimberlin and others 1983). Further studies have also investigated the
effectiveness of hypochlorite disinfection of metal surfaces to simulate the
decontamination of surgical devices within a hospital setting. Such treatments
with hypochlorite solution were able to reduce infectivity by 5.5 logs to lower
than the sensitivity of the bioassay used (Lemmer and others 2004). Analogous
treatment of the pen surfaces did not effectively remove the levels of scrapie
infectivity over that of the control pens, indicating that this method of
decontamination is not effective within a farm setting. This may be due to the
high level of biological matrix that is present upon surfaces within the farm
environment, which may reduce the amount of free chlorine available to
inactivate any infectious prion. Remarkably 1/5 sheep introduced into pen D had
also became scrapie positive within nine months, with all animals in this pen
being RAMALT positive by 18 months of age. Pen D was no further away from the
control pen (pen A) than any of the other pens within this barn. Localised hot
spots of infectivity may be present within scrapie-contaminated environments,
but it is unlikely that pen D area had an amount of scrapie contamination that
was significantly different than the other areas within this building.
Similarly, there were no differences in how the biosecurity of pen D was
maintained, or how this pen was ventilated compared with the other pens. This
observation, perhaps, indicates the slower kinetics of disease uptake within
this pen and is consistent with a more thorough prion removal and
recontamination. These observations may also account for the presence of
inadvertent scrapie cases within other studies, where despite stringent
biosecurity, control animals have become scrapie positive during challenge
studies using barns that also housed scrapie-affected animals (Ryder and others
2009). The bioassay data indicate that the exposure of the sheep to a farm
environment after decontamination efforts thought to be effective in removing
scrapie is sufficient for the animals to become infected with scrapie. The main
exposure routes within this scenario are likely to be via the oral route, during
feeding and drinking, and respiratory and conjunctival routes. It has been
demonstrated that scrapie infectivity can be efficiently transmitted via the
nasal route in sheep (Hamir and others 2008), as is the case for CWD in both
murine models and in white-tailed deer (Denkers and others 2010, 2013).
Recently, it has also been demonstrated that CWD prions presented as dust when
bound to the soil mineral montmorillonite can be infectious via the nasal route
(Nichols and others 2013). When considering pens C and D, the actual source of
the infectious agent in the pens is not known, it is possible that biologically
relevant levels of prion survive on surfaces during the decontamination regimen
(pen C). With the use of galvanising and painting (pen D) covering and sealing
the surface of the pen, it is possible that scrapie material recontaminated the
pens by the movement of infectious prions contained within dusts originating
from other parts of the barn that were not decontaminated or from other areas of
the farm.
Given that scrapie prions are widespread on the surfaces of affected farms
(Maddison and others 2010a), irrespective of the source of the infectious prions
in the pens, this study clearly highlights the difficulties that are faced with
the effective removal of environmentally associated scrapie infectivity. This is
likely to be paralleled in CWD which shows strong similarities to scrapie in
terms of both the dissemination of prions into the environment and the facile
mode of disease transmission. These data further contribute to the understanding
that prion diseases can be highly transmissible between susceptible individuals
not just by direct contact but through highly stable environmental reservoirs
that are refractory to decontamination.
The presence of these environmentally associated prions in farm buildings
make the control of these diseases a considerable challenge, especially in
animal species such as goats where there is lack of genetic resistance to
scrapie and, therefore, no scope to re-stock farms with animals that are
resistant to scrapie.
Scrapie Sheep Goats Transmissible spongiform encephalopathies (TSE)
Accepted October 12, 2014. Published Online First 31 October 2014
Monday, November 3, 2014
Persistence of ovine scrapie infectivity in a farm environment following
cleaning and decontamination
PPo3-22:
Detection of Environmentally Associated PrPSc on a Farm with Endemic
Scrapie
Ben C. Maddison,1 Claire A. Baker,1 Helen C. Rees,1 Linda A. Terry,2 Leigh
Thorne,2 Susan J. Belworthy2 and Kevin C. Gough3 1ADAS-UK LTD; Department of
Biology; University of Leicester; Leicester, UK; 2Veterinary Laboratories
Agency; Surry, KT UK; 3Department of Veterinary Medicine and Science; University
of Nottingham; Sutton Bonington, Loughborough UK
Key words: scrapie, evironmental persistence, sPMCA
Ovine scrapie shows considerable horizontal transmission, yet the routes of
transmission and specifically the role of fomites in transmission remain poorly
defined. Here we present biochemical data demonstrating that on a
scrapie-affected sheep farm, scrapie prion contamination is widespread. It was
anticipated at the outset that if prions contaminate the environment that they
would be there at extremely low levels, as such the most sensitive method
available for the detection of PrPSc, serial Protein Misfolding Cyclic
Amplification (sPMCA), was used in this study. We investigated the distribution
of environmental scrapie prions by applying ovine sPMCA to samples taken from a
range of surfaces that were accessible to animals and could be collected by use
of a wetted foam swab. Prion was amplified by sPMCA from a number of these
environmental swab samples including those taken from metal, plastic and wooden
surfaces, both in the indoor and outdoor environment. At the time of sampling
there had been no sheep contact with these areas for at least 20 days prior to
sampling indicating that prions persist for at least this duration in the
environment. These data implicate inanimate objects as environmental reservoirs
of prion infectivity which are likely to contribute to disease transmission.
2012
PO-039: A comparison of scrapie and chronic wasting disease in white-tailed
deer
Justin Greenlee, Jodi Smith, Eric Nicholson US Dept. Agriculture;
Agricultural Research Service, National Animal Disease Center; Ames, IA USA
snip...
The results of this study suggest that there are many similarities in the
manifestation of CWD and scrapie in WTD after IC inoculation including early and
widespread presence of PrPSc in lymphoid tissues, clinical signs of depression
and weight loss progressing to wasting, and an incubation time of 21-23 months.
Moreover, western blots (WB) done on brain material from the obex region have a
molecular profile similar to CWD and distinct from tissues of the cerebrum or
the scrapie inoculum. However, results of microscopic and IHC examination
indicate that there are differences between the lesions expected in CWD and
those that occur in deer with scrapie: amyloid plaques were not noted in any
sections of brain examined from these deer and the pattern of immunoreactivity
by IHC was diffuse rather than plaque-like.
*** After a natural route of exposure, 100% of WTD were susceptible to
scrapie.
Deer developed clinical signs of wasting and mental depression and were
necropsied from 28 to 33 months PI. Tissues from these deer were positive for
PrPSc by IHC and WB. Similar to IC inoculated deer, samples from these deer
exhibited two different molecular profiles: samples from obex resembled CWD
whereas those from cerebrum were similar to the original scrapie inoculum. On
further examination by WB using a panel of antibodies, the tissues from deer
with scrapie exhibit properties differing from tissues either from sheep with
scrapie or WTD with CWD. Samples from WTD with CWD or sheep with scrapie are
strongly immunoreactive when probed with mAb P4, however, samples from WTD with
scrapie are only weakly immunoreactive. In contrast, when probed with mAb’s 6H4
or SAF 84, samples from sheep with scrapie and WTD with CWD are weakly
immunoreactive and samples from WTD with scrapie are strongly positive. This
work demonstrates that WTD are highly susceptible to sheep scrapie, but on first
passage, scrapie in WTD is differentiable from CWD.
2011
*** After a natural route of exposure, 100% of white-tailed deer were
susceptible to scrapie.
*** We conclude that TSE infectivity is likely to survive burial for long
time periods with minimal loss of infectivity and limited movement from the
original burial site. However PMCA results have shown that there is the
potential for rainwater to elute TSE related material from soil which could lead
to the contamination of a wider area. These experiments reinforce the importance
of risk assessment when disposing of TSE risk materials.
*** The results show that even highly diluted PrPSc can bind efficiently to
polypropylene, stainless steel, glass, wood and stone and propagate the
conversion of normal prion protein. For in vivo experiments, hamsters were ic
injected with implants incubated in 1% 263K-infected brain homogenate. Hamsters,
inoculated with 263K-contaminated implants of all groups, developed typical
signs of prion disease, whereas control animals inoculated with non-contaminated
materials did not.
PRION 2014 CONFERENCE
CHRONIC WASTING DISEASE CWD
A FEW FINDINGS ;
Conclusions. To our knowledge, this is the first established experimental
model of CWD in TgSB3985. We found evidence for co-existence or divergence of
two CWD strains adapted to Tga20 mice and their replication in TgSB3985 mice.
Finally, we observed phenotypic differences between cervid-derived CWD and
CWD/Tg20 strains upon propagation in TgSB3985 mice. Further studies are underway
to characterize these strains.
We conclude that TSE infectivity is likely to survive burial for long time
periods with minimal loss of infectivity and limited movement from the original
burial site. However PMCA results have shown that there is the potential for
rainwater to elute TSE related material from soil which could lead to the
contamination of a wider area. These experiments reinforce the importance of
risk assessment when disposing of TSE risk materials.
The results show that even highly diluted PrPSc can bind efficiently to
polypropylene, stainless steel, glass, wood and stone and propagate the
conversion of normal prion protein. For in vivo experiments, hamsters were ic
injected with implants incubated in 1% 263K-infected brain homogenate. Hamsters,
inoculated with 263K-contaminated implants of all groups, developed typical
signs of prion disease, whereas control animals inoculated with non-contaminated
materials did not.
Our data establish that meadow voles are permissive to CWD via peripheral
exposure route, suggesting they could serve as an environmental reservoir for
CWD. Additionally, our data are consistent with the hypothesis that at least two
strains of CWD circulate in naturally-infected cervid populations and provide
evidence that meadow voles are a useful tool for CWD strain typing.
Conclusion. CWD prions are shed in saliva and urine of infected deer as
early as 3 months post infection and throughout the subsequent >1.5 year
course of infection. In current work we are examining the relationship of
prionemia to excretion and the impact of excreted prion binding to surfaces and
particulates in the environment.
Conclusion. CWD prions (as inferred by prion seeding activity by RT-QuIC)
are shed in urine of infected deer as early as 6 months post inoculation and
throughout the subsequent disease course. Further studies are in progress
refining the real-time urinary prion assay sensitivity and we are examining more
closely the excretion time frame, magnitude, and sample variables in
relationship to inoculation route and prionemia in naturally and experimentally
CWD-infected cervids.
Conclusions. Our results suggested that the odds of infection for CWD is
likely controlled by areas that congregate deer thus increasing direct
transmission (deer-to-deer interactions) or indirect transmission
(deer-to-environment) by sharing or depositing infectious prion proteins in
these preferred habitats. Epidemiology of CWD in the eastern U.S. is likely
controlled by separate factors than found in the Midwestern and endemic areas
for CWD and can assist in performing more efficient surveillance efforts for the
region.
Conclusions. During the pre-symptomatic stage of CWD infection and
throughout the course of disease deer may be shedding multiple LD50 doses per
day in their saliva. CWD prion shedding through saliva and excreta may account
for the unprecedented spread of this prion disease in nature.
see full text and more ;
Monday, June 23, 2014
*** PRION 2014 CONFERENCE CHRONIC WASTING DISEASE CWD
*** Infectious agent of sheep scrapie may persist in the environment for at
least 16 years***
Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3
New studies on the heat resistance of hamster-adapted scrapie agent:
Threshold survival after ashing at 600°C suggests an inorganic template of
replication
Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel
Production
Detection of protease-resistant cervid prion protein in water from a
CWD-endemic area
A Quantitative Assessment of the Amount of Prion Diverted to Category 1
Materials and Wastewater During Processing
Rapid assessment of bovine spongiform encephalopathy prion inactivation by
heat treatment in yellow grease produced in the industrial manufacturing process
of meat and bone meals
Sunday, December 21, 2014
Mucosal immunization with an attenuated Salmonella vaccine partially
protects white-tailed deer from chronic wasting disease
Friday, December 19, 2014
Pan-Provincial Vaccine Enterprise Inc. (PREVENT) Conducting a Chronic
Wasting Disease (CWD) Vaccine Efficacy Trial in Elk
Friday, January 16, 2015
Indiana SENATE BILL No. 442 Miller Pete Hunting wildlife Removes exotic
mammals from the animals that may be propagated or offered for hunting at a
shooting preserve Makes it a Class C misdemeanor
CHRONIC WASTING DISEASE CWD TSE PRION, how much does it pay to find CWD
$$$
CWD, spreading it around...
Tuesday, January 06, 2015
APHIS Provides Additional Information on Chronic Wasting Disease (CWD)
Indemnity Requests January 5, 2015 05:26 PM EST
when an industry is catering to the public, with products which can risk
human and animal health, in my opinion, you should have NO property rights. you
should not be able to hide behind property rights when you are clearly risking
human and animal health from your product, or the way you handle that product.
if you are going to raise, grow, produce a product for the consumer, you have an
obligation NOT to risk the public domain, public property, and or the wild
animal populations. just my opinion. ...
Wednesday, January 28, 2015
Another new prion disease: relationship with central and peripheral
amyloidoses
here we go again...
spontaneous atypical BSE ???
if that's the case, then France is having one hell of an epidemic of
atypical BSE, probably why they stopped testing for BSE, problem solved
$$$
As of December 2011, around 60 atypical BSE cases have currently been
reported in 13 countries, *** with over one third in France.
so 20 cases of atypical BSE in France, compared to the remaining 40 cases
in the remaining 12 Countries, divided by the remaining 12 Countries, about 3+
cases per country, besides Frances 20 cases. you cannot explain this away with
any spontaneous BSe. ...TSS
Sunday, October 5, 2014
France stops BSE testing for Mad Cow Disease
Thursday, July 24, 2014
*** Protocol for further laboratory investigations into the distribution of
infectivity of Atypical BSE SCIENTIFIC REPORT OF EFSA New protocol for Atypical
BSE investigations
Monday, December 1, 2014
Germany Bovine Spongiform Encephalopathy BSE CJD TSE Prion disease A Review
December 1, 2014
Wednesday, January 28, 2015
BOVINE HEPARIN POSITION STATEMENT ON THE REINTRODUCTION and POTENTIAL BSE
TSE PRION RISK FACTORS THEREFROM
Thursday, January 29, 2015
Identification of H-type BSE in Portugal
Thursday, January 29, 2015
OIE REPORT Bovine spongiform encephalopathy Prion (atypical BSE type H),
Norway Information received on 29/01/2015
Tuesday, December 16, 2014
Evidence for zoonotic potential of ovine scrapie prions
Hervé Cassard,1, n1 Juan-Maria Torres,2, n1 Caroline Lacroux,1, Jean-Yves
Douet,1, Sylvie L. Benestad,3, Frédéric Lantier,4, Séverine Lugan,1, Isabelle
Lantier,4, Pierrette Costes,1, Naima Aron,1, Fabienne Reine,5, Laetitia
Herzog,5, Juan-Carlos Espinosa,2, Vincent Beringue5, & Olivier Andréoletti1,
Affiliations Contributions Corresponding author Journal name: Nature
Communications Volume: 5, Article number: 5821 DOI: doi:10.1038/ncomms6821
Received 07 August 2014 Accepted 10 November 2014 Published 16 December 2014
Article tools Citation Reprints Rights & permissions Article metrics
Abstract
Although Bovine Spongiform Encephalopathy (BSE) is the cause of variant
Creutzfeldt Jakob disease (vCJD) in humans, the zoonotic potential of scrapie
prions remains unknown. Mice genetically engineered to overexpress the human
prion protein (tgHu) have emerged as highly relevant models for gauging the
capacity of prions to transmit to humans. These models can propagate human
prions without any apparent transmission barrier and have been used used to
confirm the zoonotic ability of BSE. Here we show that a panel of sheep scrapie
prions transmit to several tgHu mice models with an efficiency comparable to
that of cattle BSE. The serial transmission of different scrapie isolates in
these mice led to the propagation of prions that are phenotypically identical to
those causing sporadic CJD (sCJD) in humans. These results demonstrate that
scrapie prions have a zoonotic potential and raise new questions about the
possible link between animal and human prions.
Subject terms: Biological sciences• Medical research At a glance
why do we not want to do TSE transmission studies on chimpanzees $
5. A positive result from a chimpanzee challenged severly would likely
create alarm in some circles even if the result could not be interpreted for
man. I have a view that all these agents could be transmitted provided a large
enough dose by appropriate routes was given and the animals kept long enough.
Until the mechanisms of the species barrier are more clearly understood it might
be best to retain that hypothesis.
snip...
R. BRADLEY
1: J Infect Dis 1980 Aug;142(2):205-8
Oral transmission of kuru, Creutzfeldt-Jakob disease, and scrapie to
nonhuman primates.
Gibbs CJ Jr, Amyx HL, Bacote A, Masters CL, Gajdusek DC.
Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of sheep
and goats were transmitted to squirrel monkeys (Saimiri sciureus) that were
exposed to the infectious agents only by their nonforced consumption of known
infectious tissues. The asymptomatic incubation period in the one monkey exposed
to the virus of kuru was 36 months; that in the two monkeys exposed to the virus
of Creutzfeldt-Jakob disease was 23 and 27 months, respectively; and that in the
two monkeys exposed to the virus of scrapie was 25 and 32 months, respectively.
Careful physical examination of the buccal cavities of all of the monkeys failed
to reveal signs or oral lesions. One additional monkey similarly exposed to kuru
has remained asymptomatic during the 39 months that it has been under
observation.
snip...
The successful transmission of kuru, Creutzfeldt-Jakob disease, and scrapie
by natural feeding to squirrel monkeys that we have reported provides further
grounds for concern that scrapie-infected meat may occasionally give rise in
humans to Creutzfeldt-Jakob disease.
PMID: 6997404
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6997404&dopt=Abstract
Recently the question has again been brought up as to whether scrapie is
transmissible to man. This has followed reports that the disease has been
transmitted to primates. One particularly lurid speculation (Gajdusek 1977)
conjectures that the agents of scrapie, kuru, Creutzfeldt-Jakob disease and
transmissible encephalopathy of mink are varieties of a single "virus". The U.S.
Department of Agriculture concluded that it could "no longer justify or permit
scrapie-blood line and scrapie-exposed sheep and goats to be processed for human
or animal food at slaughter or rendering plants" (ARC 84/77)" The problem is
emphasised by the finding that some strains of scrapie produce lesions identical
to the once which characterise the human dementias"
Whether true or not. the hypothesis that these agents might be
transmissible to man raises two considerations. First, the safety of laboratory
personnel requires prompt attention. Second, action such as the "scorched meat"
policy of USDA makes the solution of the acrapie problem urgent if the sheep
industry is not to suffer grievously.
snip...
76/10.12/4.6
Nature. 1972 Mar 10;236(5341):73-4.
Transmission of scrapie to the cynomolgus monkey (Macaca fascicularis).
Gibbs CJ Jr, Gajdusek DC.
Nature 236, 73 - 74 (10 March 1972); doi:10.1038/236073a0
Transmission of Scrapie to the Cynomolgus Monkey (Macaca fascicularis)
C. J. GIBBS jun. & D. C. GAJDUSEK
National Institute of Neurological Diseases and Stroke, National Institutes
of Health, Bethesda, Maryland
SCRAPIE has been transmitted to the cynomolgus, or crab-eating, monkey
(Macaca fascicularis) with an incubation period of more than 5 yr from the time
of intracerebral inoculation of scrapie-infected mouse brain. The animal
developed a chronic central nervous system degeneration, with ataxia, tremor and
myoclonus with associated severe scrapie-like pathology of intensive astroglial
hypertrophy and proliferation, neuronal vacuolation and status spongiosus of
grey matter. The strain of scrapie virus used was the eighth passage in Swiss
mice (NIH) of a Compton strain of scrapie obtained as ninth intracerebral
passage of the agent in goat brain, from Dr R. L. Chandler (ARC, Compton,
Berkshire).
2001
Suspect symptoms
What if you can catch old-fashioned CJD by eating meat from a sheep
infected with scrapie?
28 Mar 01
Like lambs to the slaughter
31 March 2001
by Debora MacKenzie Magazine issue 2284.
FOUR years ago, Terry Singeltary watched his mother die horribly from a
degenerative brain disease. Doctors told him it was Alzheimer's, but Singeltary
was suspicious. The diagnosis didn't fit her violent symptoms, and he demanded
an autopsy. It showed she had died of sporadic Creutzfeldt-Jakob disease.
Most doctors believe that sCJD is caused by a prion protein deforming by
chance into a killer. But Singeltary thinks otherwise. He is one of a number of
campaigners who say that some sCJD, like the variant CJD related to BSE, is
caused by eating meat from infected animals. Their suspicions have focused on
sheep carrying scrapie, a BSE-like disease that is widespread in flocks across
Europe and North America.
Now scientists in France have stumbled across new evidence that adds weight
to the campaigners' fears. To their complete surprise, the researchers found
that one strain of scrapie causes the same brain damage in mice as sCJD.
"This means we cannot rule out that at least some sCJD may be caused by
some strains of scrapie," says team member Jean-Philippe Deslys of the French
Atomic Energy Commission's medical research laboratory in Fontenay-aux-Roses,
south-west of Paris. Hans Kretschmar of the University of Göttingen, who
coordinates CJD surveillance in Germany, is so concerned by the findings that he
now wants to trawl back through past sCJD cases to see if any might have been
caused by eating infected mutton or lamb.
Scrapie has been around for centuries and until now there has been no
evidence that it poses a risk to human health. But if the French finding means
that scrapie can cause sCJD in people, countries around the world may have
overlooked a CJD crisis to rival that caused by BSE.
Deslys and colleagues were originally studying vCJD, not sCJD. They
injected the brains of macaque monkeys with brain from BSE cattle, and from
French and British vCJD patients. The brain damage and clinical symptoms in the
monkeys were the same for all three. Mice injected with the original sets of
brain tissue or with infected monkey brain also developed the same
symptoms.
As a control experiment, the team also injected mice with brain tissue from
people and animals with other prion diseases: a French case of sCJD; a French
patient who caught sCJD from human-derived growth hormone; sheep with a French
strain of scrapie; and mice carrying a prion derived from an American scrapie
strain. As expected, they all affected the brain in a different way from BSE and
vCJD. But while the American strain of scrapie caused different damage from
sCJD, the French strain produced exactly the same pathology.
"The main evidence that scrapie does not affect humans has been
epidemiology," says Moira Bruce of the neuropathogenesis unit of the Institute
for Animal Health in Edinburgh, who was a member of the same team as Deslys.
"You see about the same incidence of the disease everywhere, whether or not
there are many sheep, and in countries such as New Zealand with no scrapie." In
the only previous comparisons of sCJD and scrapie in mice, Bruce found they were
dissimilar.
But there are more than 20 strains of scrapie, and six of sCJD. "You would
not necessarily see a relationship between the two with epidemiology if only
some strains affect only some people," says Deslys. Bruce is cautious about the
mouse results, but agrees they require further investigation. Other trials of
scrapie and sCJD in mice, she says, are in progress.
People can have three different genetic variations of the human prion
protein, and each type of protein can fold up two different ways. Kretschmar has
found that these six combinations correspond to six clinical types of sCJD: each
type of normal prion produces a particular pathology when it spontaneously
deforms to produce sCJD.
But if these proteins deform because of infection with a disease-causing
prion, the relationship between pathology and prion type should be different, as
it is in vCJD. "If we look at brain samples from sporadic CJD cases and find
some that do not fit the pattern," says Kretschmar, "that could mean they were
caused by infection."
There are 250 deaths per year from sCJD in the US, and a similar incidence
elsewhere. Singeltary and other US activists think that some of these people
died after eating contaminated meat or "nutritional" pills containing dried
animal brain. Governments will have a hard time facing activists like Singeltary
if it turns out that some sCJD isn't as spontaneous as doctors have
insisted.
Deslys's work on macaques also provides further proof that the human
disease vCJD is caused by BSE. And the experiments showed that vCJD is much more
virulent to primates than BSE, even when injected into the bloodstream rather
than the brain. This, says Deslys, means that there is an even bigger risk than
we thought that vCJD can be passed from one patient to another through
contaminated blood transfusions and surgical instruments.
Tuesday, December 23, 2014
*** FDA PART 589 -- SUBSTANCES PROHIBITED FROM USE IN ANIMAL FOOD OR FEED
VIOLATIONS OFFICIAL ACTION INDICATED OAI UPDATE DECEMBER 2014 BSE TSE PRION
CWD TO HUMANS, AND RISK FACTORS THERE FROM (see latest science)
Tuesday, November 04, 2014
*** Six-year follow-up of a point-source exposure to CWD contaminated
venison in an Upstate New York community: risk behaviours and health outcomes
2005–2011
Friday, December 5, 2014
*** SPECIAL ALERT The OIE recommends strengthening animal disease
surveillance worldwide OIE
BSE TSE PRION AKA MAD COW DISEASE ? ‘’the silence was deafening’’ ...tss
Comment from Terry Singeltary Sr. This is a Comment on the Animal and
Plant Health Inspection Service (APHIS) Notice: Agency Information Collection
Activities; Proposals, Submissions, and Approvals: Bovine Spongiform
Encephalopathy; Importation of Animals and Animal Products
For related information, Open Docket Folder Docket folder icon
--------------------------------------------------------------------------------
Show agency attachment(s) AttachmentsView All (0) Empty
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Comment View document:Docket No. APHIS-2014-0107 Bovine Spongiform
Encephalopathy; Importation of Animals and Animal Products Singeltary Submission
;
I believe that there is more risk to the world from Transmissible
Spongiform Encephalopathy TSE prion aka mad cow type disease now, coming from
the United States and all of North America, than there is risk coming to the USA
and North America, from other Countries. I am NOT saying I dont think there is
any risk for the BSE type TSE prion coming from other Countries, I am just
saying that in 2015, why is the APHIS/USDA/FSIS/FDA still ignoring these present
mad cow risk factors in North America like they are not here?
North America has more strains of TSE prion disease, in more species
(excluding zoo animals in the early BSE days, and excluding the Feline TSE and
or Canine TSE, because they dont look, and yes, there has been documented
evidence and scientific studies, and DEFRA Hound study, that shows the canine
spongiform encephalopathy is very possible, if it has not already happened, just
not documented), then any other Country in the world. Mink TME, Deer Elk cervid
CWD (multiple strains), cBSE cattle, atypical L-type BSE cattle, atypical H-type
BSE cattle, atyical HG type BSE cow (the only cow documented in the world to
date with this strain), typical sheep goat Scrapie (multiple strains), and the
atypical Nor-98 Scrapie, which has been linked to sporadic CJD, Nor-98 atypical
Scrapie has spread from coast to coast. sporadic CJD on the rise, with different
strains mounting, victims becoming younger, with the latest nvCJD human mad cow
case being documented in Texas again, this case, NOT LINKED TO EUROPEAN TRAVEL
CDC.
typical BSE can propagate as nvCJD and or sporadic CJD (Collinge et al),
and sporadic CJD has now been linked to atypical BSE, Scrapie and atypical
Scrapie, and scientist are very concerned with CWD TSE prion in the Cervid
populations. in my opinion, the BSE MRR policy, which overtook the BSE GBR risk
assessments for each country, and then made BSE confirmed countries legal to
trade mad cow disease, which was all brought forth AFTER that fateful day
December 23, 2003, when the USA lost its gold card i.e. BSE FREE status, thats
the day it all started. once the BSE MRR policy was shoved down every countries
throat by USDA inc and the OIE, then the legal trading of Scrapie was validated
to be a legal trading commodity, also shoved through by the USDA inc and the
OIE, the world then lost 30 years of attempted eradication of the BSE TSE prion
disease typical and atypical strains, and the BSE TSE Prion aka mad cow type
disease was thus made a legal trading commodity, like it or not. its all about
money now folks, trade, to hell with human health with a slow incubating
disease, that is 100% fatal once clinical, and forget the fact of exposure,
sub-clinical infection, and friendly fire there from i.e. iatrogenic TSE prion
disease, the pass it forward mode of the TSE PRION aka mad cow type disease. its
all going to be sporadic CJD or sporadic ffi, or sporadic gss, or now the
infamous VPSPr. ...problem solved $$$
the USDA/APHIS/FSIS/FDA triple mad cow BSE firewall, well, that was nothing
but ink on paper.
for this very reason I believe the BSE MRR policy is a total failure, and
that this policy should be immediately withdrawn, and set back in place the BSE
GBR Risk Assessments, with the BSE GBR risk assessments set up to monitor all
TSE PRION disease in all species of animals, and that the BSE GBR risk
assessments be made stronger than before.
lets start with the recent notice that beef from Ireland will be coming to
America.
Ireland confirmed around 1655 cases of mad cow disease. with the highest
year confirming about 333 cases in 2002, with numbers of BSE confirmed cases
dropping from that point on, to a documentation of 1 confirmed case in 2013, to
date. a drastic decrease in the feeding of cows to cows i.e. the ruminant mad
cow feed ban, and the enforcement of that ban, has drastically reduced the
number of BSE cases in Europe, minus a few BABs or BARBs. a far cry from the
USDA FDA triple BSE firewall, which was nothing more than ink on paper, where in
2007, in one week recall alone, some 10 MILLION POUNDS OF BANNED POTENTIAL MAD
COW FEED WENT OUT INTO COMMERCE IN THE USA. this is 10 years post feed ban. in
my honest opinion, due to the blatant cover up of BSE TSE prion aka mad cow
disease in the USA, we still have no clue as to the true number of cases of BSE
mad cow disease in the USA or North America as a whole. ...just saying.
Number of reported cases of bovine spongiform encephalopathy (BSE) in
farmed cattle worldwide* (excluding the United Kingdom)
Country/Year
snip...please see attached pdf file, with references of breaches in the USA
triple BSE mad cow firewalls, and recent science on the TSE prion disease.
...TSS No documents available. AttachmentsView All (1) Empty Docket No.
APHIS-2014-0107 Bovine Spongiform Encephalopathy; Importation of Animals and
Animal Products Singeltary Submission View Attachment:
Sunday, January 11, 2015
Docket No. APHIS-2014-0107 Bovine Spongiform Encephalopathy; Importation of
Animals and Animal Products Singeltary Submission
*** HUMAN MAD COW DISEASE nvCJD TEXAS CASE NOT LINKED TO EUROPEAN TRAVEL
CDC ***
Sunday, November 23, 2014
*** Confirmed Variant Creutzfeldt-Jakob Disease (variant CJD) Case in Texas
in June 2014 confirmed as USA case NOT European
the patient had resided in Kuwait, Russia and Lebanon. The completed
investigation did not support the patient's having had extended travel to
European countries, including the United Kingdom, or travel to Saudi Arabia. The
specific overseas country where this patient’s infection occurred is less clear
largely because the investigation did not definitely link him to a country where
other known vCJD cases likely had been infected.
Sunday, December 14, 2014
*** ALERT new variant Creutzfeldt Jakob Disease nvCJD or vCJD, sporadic CJD
strains, TSE prion aka Mad Cow Disease United States of America Update December
14, 2014 Report
Wednesday, January 28, 2015
Another new prion disease: relationship with central and peripheral
amyloidoses here we go again...
Thursday, January 15, 2015
41-year-old Navy Commander with sporadic Creutzfeldt–Jakob disease CJD TSE
Prion: Case Report
Subject: *** Becky Lockhart 46, Utah’s first female House speaker, dies
diagnosed with the extremely rare Creutzfeldt-Jakob disease aka mad cow type
disease
what is CJD ? just ask USDA inc., and the OIE, they are still feeding the
public and the media industry fed junk science that is 30 years old.
why doesn’t some of you try reading the facts, instead of rubber stamping
everything the USDA inc says.
sporadic CJD has now been linked to BSE aka mad cow disease, Scrapie, and
there is much concern now for CWD and risk factor for humans.
My sincere condolences to the family and friends of the House Speaker Becky
Lockhart. I am deeply saddened hear this.
with that said, with great respect, I must ask each and every one of you
Politicians that are so deeply saddened to hear of this needless death of the
Honorable House Speaker Becky Lockhart, really, cry me a friggen river. I am
seriously going to ask you all this...I have been diplomatic for about 17 years
and it has got no where. people are still dying. so, are you all stupid or
what??? how many more need to die ??? how much is global trade of beef and other
meat products that are not tested for the TSE prion disease, how much and how
many bodies is this market worth?
Saturday, January 17, 2015
*** Becky Lockhart 46, Utah’s first female House speaker, dies diagnosed
with the extremely rare Creutzfeldt-Jakob disease
Thursday, January 22, 2015
Transmission properties of atypical Creutzfeldt-Jakob disease: a clue to
disease etiology?
Tuesday, December 30, 2014
TSEAC USA Reason For Recalls Blood products, collected from a donors
considered to be at increased risk for Creutzfeldt-Jakob Disease (CJD), were
distributed END OF YEAR REPORT 2014
who’s kidding whom $$$ i.e. USDA INC AND THE OIE
2014
***Moreover, L-BSE has been transmitted more easily to transgenic mice
overexpressing a human PrP [13,14] or to primates [15,16] than C-BSE.
***It has been suggested that some sporadic CJD subtypes in humans may
result from an exposure to the L-BSE agent.
*** Lending support to this hypothesis, pathological and biochemical
similarities have been observed between L-BSE and an sCJD subtype (MV genotype
at codon 129 of PRNP) [17], and between L-BSE infected non-human primate and
another sCJD subtype (MM genotype) [15].
snip...
Monday, October 10, 2011
EFSA Journal 2011 The European Response to BSE: A Success Story
snip...
EFSA and the European Centre for Disease Prevention and Control (ECDC)
recently delivered a scientific opinion on any possible epidemiological or
molecular association between TSEs in animals and humans (EFSA Panel on
Biological Hazards (BIOHAZ) and ECDC, 2011). This opinion confirmed Classical
BSE prions as the only TSE agents demonstrated to be zoonotic so far
*** but the possibility that a small proportion of human cases so far
classified as "sporadic" CJD are of zoonotic origin could not be excluded.
*** Moreover, transmission experiments to non-human primates suggest that
some TSE agents in addition to Classical BSE prions in cattle (namely L-type
Atypical BSE, Classical BSE in sheep, transmissible mink encephalopathy (TME)
and chronic wasting disease (CWD) agents) might have zoonotic potential.
snip...
Thursday, August 12, 2010
Seven main threats for the future linked to prions
First threat
The TSE road map defining the evolution of European policy for protection
against prion diseases is based on a certain numbers of hypotheses some of which
may turn out to be erroneous. In particular, a form of BSE (called atypical
Bovine Spongiform Encephalopathy), recently identified by systematic testing in
aged cattle without clinical signs, may be the origin of classical BSE and thus
potentially constitute a reservoir, which may be impossible to eradicate if a
sporadic origin is confirmed.
*** Also, a link is suspected between atypical BSE and some apparently
sporadic cases of Creutzfeldt-Jakob disease in humans.
*** These atypical BSE cases constitute an unforeseen first threat that
could sharply modify the European approach to prion diseases.
Second threat
snip...
Friday, January 30, 2015
Scrapie: a particularly persistent pathogen
Terry S. Singeltary Sr.
posted by Terry S. Singeltary Sr. at
5:12 PM
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