Iowa Two Wild Deer Test Positive for Chronic Wasting Disease in Allamakee County
Two Wild Deer Test Positive for Chronic Wasting Disease in Allamakee
County
Posted: 01/20/2015 Two wild deer harvested during the recent hunting season
have been confirmed positive for chronic wasting disease in Allamakee
County.
The first case of chronic wasting disease (CWD) in a wild Iowa deer was
confirmed in Allamakee County in 2014.
“This is precisely why we stepped up our efforts to increase the number of
samples in a five-mile surveillance area around where we found the positive
sample in 2014. The more information we have, the better position we are going
to be in to implement a strategy to slow the spread,” said Iowa Department of
Natural Resources Wildlife Bureau Chief Dale Garner.
“We can’t thank hunters enough for helping us collect the samples we
needed,” said Garner.
The Iowa Department of Natural Resources is currently working to obtain as
much information as possible about the infected deer to implement its CWD
response plan.
Currently, approximately half of the 300 samples collected in the
surveillance area have been processed. Once all of the samples have been
analyzed, Garner said public meetings will be scheduled in Allamakee County to
discuss the results with the local public. DNR plans to collect additional
samples.
CWD is a neurological disease affecting primarily deer and elk. It is
caused by an abnormal protein, called a prion, that attacks the brains of
infected animals, causing them to lose weight, display abnormal behavior and
lose bodily functions. Signs include excessive salivation, thirst and urination,
loss of appetite, progressive weight loss, listlessness and drooping ears and
head. The only reliable test for CWD requires testing of lymph nodes or brain
material after the animal is dead.
There is currently no evidence that humans contract CWD by eating venison.
However, the World Health Organization and the Center for Disease Control and
Prevention recommend that hunters do not eat the brain, eyeballs or spinal cord
of deer and that hunters wear protective gloves while field dressing game and
boning out meat for consumption.
Prior to the positive detection in Iowa, CWD had been previously detected
in every bordering state. Since 2002, the DNR has collected more than 900
samples of deer from within a five-mile radius of where the deer are believed to
have been harvested. Statewide, approximately 57,000 wild deer have been tested
since 2002.
Media contact: Kevin Baskins, Iowa Department of Natural Resources, at
515-725-8288.
Wednesday, April 09, 2014
Iowa : Chronic Wasting Disease Detected for First Time in Wild Iowa Deer
Chronic Wasting Disease Found in Iowa
Posted: 07/23/2012
DES MOINES – A white-tail deer at a hunting preserve in Davis County has
become the first positive detection of chronic wasting disease (CWD) in Iowa.
The positive sample was verified this week, and DNR is working closely with the
State Veterinarian on this isolated incident.
There is no evidence that CWD can spread to humans, pets or domestic
livestock such as pork, beef, dairy, poultry, sheep or goats.
The Davis County facility where the animal was held has been inspected by
the Iowa Department of Natural Resources (DNR) and Iowa Department of
Agriculture and Land Stewardship (IDALS) to ensure that any remaining deer
remain contained. The facility is surrounded by an eight-foot fence. A
quarantine has also been issued for the facility.
“Given all of Iowa’s surrounding states have confirmed cases of CWD, Iowa
DNR was prepared to address this isolated incident,” said DNR Deputy Director
Bruce Trautman.
The DNR and IDALS have a CWD response plan in place to address the disease.
“We have a CWD surveillance program in place to test deer, elk and moose at
the facilities that raise farm deer and we have worked closely with DNR to plan
for a possible finding of the disease,” said Iowa State Veterinarian Dr. David
Schmitt.
Iowa has tested 42,557 wild deer and over 4,000 captive deer and elk as
part of the surveillance program since 2002 when CWD was found in Wisconsin.
The DNR will increase testing of wild deer in the area by working with
hunters and landowners to collect samples from hunter harvested deer beginning
this fall.
CWD is a neurological disease that only affects deer, elk and moose. It is
caused by an abnormal protein, called a prion, which affects the brains of
infected animals, causing them to lose weight, display abnormal behavior and
lose bodily functions. Signs include excessive salivation, thirst and urination,
loss of appetite, progressive weight loss, listlessness and drooping ears and
head.
The prions can attach to soil and spread the disease among deer. Chronic
wasting disease was first identified in captive mule deer at a research facility
in Colorado in 1967. Prior to the positive detection in Iowa, CWD had been
detected in every bordering state.
For Immediate Release
Thursday, October 2, 2014
Dustin Vande Hoef 515/281-3375 or 515/326-1616 (cell) or
Dustin.VandeHoef@IowaAgriculture.gov Share on facebook Share on twitter Share on
email Share on print More Sharing Services 1
TEST RESULTS FROM CAPTIVE DEER HERD WITH CHRONIC WASTING DISEASE RELEASED
79.8 percent of the deer tested positive for the disease
DES MOINES – The Iowa Department of Agriculture and Land Stewardship today
announced that the test results from the depopulation of a quarantined captive
deer herd in north-central Iowa showed that 284 of the 356 deer, or 79.8% of the
herd, tested positive for Chronic Wasting Disease (CWD). The owners of the
quarantined herd have entered into a fence maintenance agreement with the Iowa
Department of Agriculture and Land Stewardship, which requires the owners to
maintain the 8’ foot perimeter fence around the herd premises for five years
after the depopulation was complete and the premises had been cleaned and
disinfected
CWD is a progressive, fatal, degenerative neurological disease of farmed
and free-ranging deer, elk, and moose. There is no known treatment or vaccine
for CWD. CWD is not a disease that affects humans.
On July 18, 2012, USDA Animal and Plant Health Inspection Service’s (APHIS)
National Veterinary Services Lab in Ames, IA confirmed that a male white tail
deer harvested from a hunting preserve in southeast IA was positive for CWD. An
investigation revealed that this animal had just been introduced into the
hunting preserve from the above-referenced captive deer herd in north-central
Iowa.
The captive deer herd was immediately quarantined to prevent the spread of
CWD. The herd has remained in quarantine until its depopulation on August 25 to
27, 2014.
The Iowa Department of Agriculture and Land Stewardship participated in a
joint operation to depopulate the infected herd with USDA Veterinary Services,
which was the lead agency, and USDA Wildlife Services.
Federal indemnity funding became available in 2014. USDA APHIS appraised
the captive deer herd of 376 animals at that time, which was before depopulation
and testing, at $1,354,250. At that time a herd plan was developed with the
owners and officials from USDA and the Iowa Department of Agriculture and Land
Stewardship.
Once the depopulation was complete and the premises had been cleaned and
disinfected, indemnity of $917,100.00 from the USDA has been or will be paid to
the owners as compensation for the 356 captive deer depopulated.
The Iowa Department of Agriculture and Land Stewardship operates a
voluntary CWD program for farms that sell live animals. Currently 145 Iowa farms
participate in the voluntary program. The above-referenced captive deer facility
left the voluntary CWD program prior to the discovery of the disease as they had
stopped selling live animals. All deer harvested in a hunting preserve must be
tested for CWD.
IOWA DEPARTMENT OF NATURAL RESOURCES EMERGENCY CONSENT ORDER
18. On June 5, 2013, DNR conducted a fence inspection, after gaining
approval from surrounding landowners, and confirmed that the fenced had been cut
or removed in at least four separate locations; that the fence had degraded and
was failing to maintain the enclosure around the Quarantined Premises in at
least one area; that at least three gates had been opened; and that deer tracks
were visible in and around one of the open areas in the sand on both sides of
the fence, evidencing movement of deer into the Quarantined Premises.
spreading cwd around...
Between 1996 and 2002, chronic wasting disease was diagnosed in 39 herds of
farmed elk in Saskatchewan in a single epidemic. All of these herds were
depopulated as part of the Canadian Food Inspection Agency’s (CFIA) disease
eradication program. Animals, primarily over 12 mo of age, were tested for the
presence CWD prions following euthanasia. Twenty-one of the herds were linked
through movements of live animals with latent CWD from a single infected source
herd in Saskatchewan, 17 through movements of animals from 7 of the secondarily
infected herds.
***The source herd is believed to have become infected via importation of
animals from a game farm in South Dakota where CWD was subsequently diagnosed
(7,4). A wide range in herd prevalence of CWD at the time of herd depopulation
of these herds was observed. Within-herd transmission was observed on some
farms, while the disease remained confined to the introduced animals on other
farms.
spreading cwd around...
Friday, May 13, 2011
Chronic Wasting Disease (CWD) outbreaks and surveillance program in the
Republic of Korea
Chronic Wasting Disease (CWD) outbreaks and surveillance program in the
Republic of Korea
Hyun-Joo Sohn, Yoon-Hee Lee, Min-jeong Kim, Eun-Im Yun, Hyo-Jin Kim,
Won-Yong Lee, Dong-Seob Tark, In- Soo Cho, Foreign Animal Disease Research
Division, National Veterinary Research and Quarantine Service, Republic of Korea
Chronic wasting disease (CWD) has been recognized as an important prion
disease in native North America deer and Rocky mountain elks. The disease is a
unique member of the transmissible spongiform encephalopathies (TSEs), which
naturally affects only a few species. CWD had been limited to USA and Canada
until 2000.
On 28 December 2000, information from the Canadian government showed that a
total of 95 elk had been exported from farms with CWD to Korea. These consisted
of 23 elk in 1994 originating from the so-called “source farm” in Canada, and 72
elk in 1997, which had been held in pre export quarantine at the “source
farm”.Based on export information of CWD suspected elk from Canada to Korea, CWD
surveillance program was initiated by the Ministry of Agriculture and Forestry
(MAF) in 2001.
All elks imported in 1997 were traced back, however elks imported in 1994
were impossible to identify. CWD control measures included stamping out of all
animals in the affected farm, and thorough cleaning and disinfection of the
premises. In addition, nationwide clinical surveillance of Korean native
cervids, and improved measures to ensure reporting of CWD suspect cases were
implemented.
Total of 9 elks were found to be affected. CWD was designated as a
notifiable disease under the Act for Prevention of Livestock Epidemics in 2002.
Additional CWD cases - 12 elks and 2 elks - were diagnosed in 2004 and
2005.
Since February of 2005, when slaughtered elks were found to be positive,
all slaughtered cervid for human consumption at abattoirs were designated as
target of the CWD surveillance program. Currently, CWD laboratory testing is
only conducted by National Reference Laboratory on CWD, which is the Foreign
Animal Disease Division (FADD) of National Veterinary Research and Quarantine
Service (NVRQS).
In July 2010, one out of 3 elks from Farm 1 which were slaughtered for the
human consumption was confirmed as positive. Consequently, all cervid – 54 elks,
41 Sika deer and 5 Albino deer – were culled and one elk was found to be
positive. Epidemiological investigations were conducted by Veterinary
Epidemiology Division (VED) of NVRQS in collaboration with provincial veterinary
services.
Epidemiologically related farms were found as 3 farms and all cervid at
these farms were culled and subjected to CWD diagnosis. Three elks and 5
crossbreeds (Red deer and Sika deer) were confirmed as positive at farm 2.
All cervids at Farm 3 and Farm 4 – 15 elks and 47 elks – were culled and
confirmed as negative.
Further epidemiological investigations showed that these CWD outbreaks were
linked to the importation of elks from Canada in 1994 based on circumstantial
evidences.
In December 2010, one elk was confirmed as positive at Farm 5.
Consequently, all cervid – 3 elks, 11 Manchurian Sika deer and 20 Sika deer –
were culled and one Manchurian Sika deer and seven Sika deer were found to be
positive. This is the first report of CWD in these sub-species of deer.
Epidemiological investigations found that the owner of the Farm 2 in CWD
outbreaks in July 2010 had co-owned the Farm 5.
In addition, it was newly revealed that one positive elk was introduced
from Farm 6 of Jinju-si Gyeongsang Namdo. All cervid – 19 elks, 15 crossbreed
(species unknown) and 64 Sika deer – of Farm 6 were culled, but all confirmed as
negative.
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
PPo4-4:
Survival and Limited Spread of TSE Infectivity after Burial
PPo4-4:
Survival and Limited Spread of TSE Infectivity after Burial
Karen Fernie, Allister Smith and Robert A. Somerville The Roslin Institute
and R(D)SVS; University of Edinburgh; Roslin, Scotland UK
Scrapie and chronic wasting disease probably spread via environmental
routes, and there are also concerns about BSE infection remaining in the
environment after carcass burial or waste 3disposal. In two demonstration
experiments we are determining survival and migration of TSE infectivity when
buried for up to five years, as an uncontained point source or within bovine
heads. Firstly boluses of TSE infected mouse brain were buried in lysimeters
containing either sandy or clay soil. Migration from the boluses is being
assessed from soil cores taken over time. With the exception of a very small
amount of infectivity found 25 cm from the bolus in sandy soil after 12 months,
no other infectivity has been detected up to three years. Secondly, ten bovine
heads were spiked with TSE infected mouse brain and buried in the two soil
types. Pairs of heads have been exhumed annually and assessed for infectivity
within and around them. After one year and after two years, infectivity was
detected in most intracranial samples and in some of the soil samples taken from
immediately surrounding the heads. The infectivity assays for the samples in and
around the heads exhumed at years three and four are underway. These data show
that TSE infectivity can survive burial for long periods but migrates slowly.
Risk assessments should take into account the likely long survival rate when
infected material has been buried.
The authors gratefully acknowledge funding from DEFRA.
Friday, December 14, 2012
DEFRA U.K. What is the risk of Chronic Wasting Disease CWD being introduced
into Great Britain? A Qualitative Risk Assessment October 2012
snip...
In the USA, under the Food and Drug Administration’s BSE Feed Regulation
(21 CFR 589.2000) most material (exceptions include milk, tallow, and gelatin)
from deer and elk is prohibited for use in feed for ruminant animals. With
regards to feed for non-ruminant animals, under FDA law, CWD positive deer may
not be used for any animal feed or feed ingredients. For elk and deer considered
at high risk for CWD, the FDA recommends that these animals do not enter the
animal feed system. However, this recommendation is guidance and not a
requirement by law.
Animals considered at high risk for CWD include:
1) animals from areas declared to be endemic for CWD and/or to be CWD
eradication zones and
2) deer and elk that at some time during the 60-month period prior to
slaughter were in a captive herd that contained a CWD-positive animal.
Therefore, in the USA, materials from cervids other than CWD positive
animals may be used in animal feed and feed ingredients for non-ruminants.
The amount of animal PAP that is of deer and/or elk origin imported from
the USA to GB can not be determined, however, as it is not specified in TRACES.
It may constitute a small percentage of the 8412 kilos of non-fish origin
processed animal proteins that were imported from US into GB in 2011.
Overall, therefore, it is considered there is a __greater than negligible
risk___ that (nonruminant) animal feed and pet food containing deer and/or elk
protein is imported into GB.
There is uncertainty associated with this estimate given the lack of data
on the amount of deer and/or elk protein possibly being imported in these
products.
snip...
36% in 2007 (Almberg et al., 2011). In such areas, population declines of
deer of up to 30 to 50% have been observed (Almberg et al., 2011). In areas of
Colorado, the prevalence can be as high as 30% (EFSA, 2011). The clinical signs
of CWD in affected adults are weight loss and behavioural changes that can span
weeks or months (Williams, 2005). In addition, signs might include excessive
salivation, behavioural alterations including a fixed stare and changes in
interaction with other animals in the herd, and an altered stance (Williams,
2005). These signs are indistinguishable from cervids experimentally infected
with bovine spongiform encephalopathy (BSE). Given this, if CWD was to be
introduced into countries with BSE such as GB, for example, infected deer
populations would need to be tested to differentiate if they were infected with
CWD or BSE to minimise the risk of BSE entering the human food-chain via
affected venison.
snip...
The rate of transmission of CWD has been reported to be as high as 30% and
can approach 100% among captive animals in endemic areas (Safar et al., 2008).
snip...
In summary, in endemic areas, there is a medium probability that the soil
and surrounding environment is contaminated with CWD prions and in a
bioavailable form. In rural areas where CWD has not been reported and deer are
present, there is a greater than negligible risk the soil is contaminated with
CWD prion.
snip...
In summary, given the volume of tourists, hunters and servicemen moving
between GB and North America, the probability of at least one person travelling
to/from a CWD affected area and, in doing so, contaminating their clothing,
footwear and/or equipment prior to arriving in GB is greater than negligible.
For deer hunters, specifically, the risk is likely to be greater given the
increased contact with deer and their environment. However, there is significant
uncertainty associated with these estimates.
snip...
Therefore, it is considered that farmed and park deer may have a higher
probability of exposure to CWD transferred to the environment than wild deer
given the restricted habitat range and higher frequency of contact with tourists
and returning GB residents.
snip...
*** The potential impact of prion diseases on human health was greatly
magnified by the recognition that interspecies transfer of BSE to humans by beef
ingestion resulted in vCJD. While changes in animal feed constituents and
slaughter practices appear to have curtailed vCJD, there is concern that CWD of
free-ranging deer and elk in the U.S. might also cross the species barrier.
Thus, consuming venison could be a source of human prion disease. Whether BSE
and CWD represent interspecies scrapie transfer or are newly arisen prion
diseases is unknown. Therefore, the possibility of transmission of prion disease
through other food animals cannot be ruled out. There is evidence that vCJD can
be transmitted through blood transfusion. There is likely a pool of unknown size
of asymptomatic individuals infected with vCJD, and there may be asymptomatic
individuals infected with the CWD equivalent. These circumstances represent a
potential threat to blood, blood products, and plasma supplies.
Sunday, December 28, 2014
CHRONIC WASTING DISEASE CWD TSE PRION DISEASE AKA MAD DEER DISIEASE USDA
USAHA INC DECEMBER 28, 2014
Tuesday, January 06, 2015
APHIS Provides Additional Information on Chronic Wasting Disease (CWD)
Indemnity Requests January 5, 2015 05:26 PM EST
Thursday, January 15, 2015
INDIANA HB1453 - high fence hunting preserve bill has been introduced by
Rep. Sean Eberhart and he received monetary contribution from Indiana Deer and
Elk Farmers Advocates INC.
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
TSS
posted by Terry S. Singeltary Sr. at
8:18 PM
0 Comments:
Post a Comment
Subscribe to Post Comments [Atom]
<< Home