Temporal patterns of chronic wasting disease prion excretion in three cervid species
Authors: Ian H. Plummer1, Scott D. Wright2,†, Chad J. Johnson3, Joel A. Pedersen3, Michael D. Samuel4
VIEW AFFILIATIONS
*Correspondence: Michael D. Samuel, mdsamuel@wisc.edu
First Published Online: 15 July 2017, Journal of General Virology doi: 10.1099/jgv.0.000845 Subject: Research Article - TSE Agents Received: 07/12/2016 Accepted: 22/05/2017 Cover date: 15/07/2017
Chronic wasting disease (CWD) is the only naturally occurring transmissible spongiform encephalopathy affecting free-ranging wildlife populations. Transmission of CWD occurs by direct contact or through contaminated environments; however, little is known about the temporal patterns of CWD prion excretion and shedding in wild cervids. We tested the urine and faeces of three species of captive cervids (elk, mule and white-tailed deer) at 6, 12, 18 and 24 months after oral inoculation to evaluate the temporal, species- and genotype-specific factors affecting the excretion of CWD prions. Although none of the animals exhibited clinical signs of CWD during the study, we determined that all three cervid species were excreting CWD prions by 6 months post-inoculation. Faecal samples were consistently positive for CWD prions for all three cervid species (88 %), and were more likely to be positive than urine samples (28 %). Cervids with genotypes encoding for the prion protein (PRNP) that were considered to be more susceptible to CWD were more likely to excrete CWD prions (94 %) than cervids with genotypes considered to be less susceptible (64 %). All cervids with CWD prions in their urine also had positive faeces (n=5), but the converse was not true. Our study is the first to demonstrate CWD prion excretion in urine by asymptomatic elk and mule deer. Our results indicate that the excretion of CWD prions in faeces and, to a lesser extent, urine may provide an important avenue for depositing prions in the environment.
Keyword(s): cervids, prions, PMCA, excretion, shedding, chronic wasting disease
P144 Environmental Contamination Assessment of CWD Shed in Excreta by RT-QuIC
Dr. Davin Henderson1, Ms. Joanne Tennant1, Dr. Nicholas Haley2, Dr. Nathaniel Denkers1, Dr. Candace Mathiason1, Dr. Edward Hoover1 1Prion Research Center. Department of Microbiology, Immunology and Pathology. Colorado State University, Fort Collins, United States, 2Midwestern State University, Glendale , United States
Chronic wasting disease affects free-ranging or captive populations of deer, elk and moose in the United States, Canada, Korea, and most recently Norwegian caribou and moose. CWD is unique in its ability to spread in wild populations, which likely occurs through environmental dissemination or direct contact with prions shed into bodily fluids or excreta. We have made progress to rapidly and cost-effectively detect CWD in urine and feces, which contribute substantially to environmental contamination.
Aims: 1) Using real-time quaking induced conversion (RT-QuIC) we will estimate environmental contamination via urine and feces by CWD positive animals throughout the disease course. 2) We will apply RT-QuIC to estimate CWD incidence in populations without animal capture and assess the persistence of prion seeding activity in feces under environmental conditions in the native range of cervid species.
Methods: CWD prions in fecal and urine samples will be concentrated via iron oxide mediated extraction (IOME) and assayed by RT-QuIC using temperature adjustment modifications to select increase to preserve sensitivity while minimizing specificity. Results: We assayed longitudinal cohorts of whitetailed deer for prion shedding in feces and urine during the CWD disease course and determined shedding kinetics and consistency. We applied a quantitative approach to these data using a reference brain sample to determine the levels of CWD prions shed in feces and urine during the disease course.
Conclusions: In deer experimentally inoculated with CWD approximately 100 (Tg5037) cervid PrP mouse LD50 doses are shed in urine and ~90 (TG5037) mouse LD50 doses are shed in feces per day. The relationship between cerPrP transgenic mouse and cerivd LD50 doses remains to be determined. In the future, we will apply RT-QuIC detection of CWD in feces to estimate CWD incidence in populations without animal capture and to determine how long prion seeding activity remains active in fecal samples under potentially harsh environment conditions that exist in the native range of cervid species.
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P155 Sensitive detection of PrPCWD in soil from CWD infected farm by PMCAb
Hyun Joo Sohn1, Kyung Je Park1, In Soon Roh1, Hyo Jin Kim1, Hoo Chang Park1, Director of division Hae Eun Kang1 1Foreign animal disease division, Animal And Plant Quarantine Agency(QIA), Gimcheon, South Korea
Aims: Chronic wasting disease (CWD) is the prion disease that is known spread horizontally. CWD has confirmed last in Republic of Korea in 2016 since first outbreak of CWD in 2001. The environmental reservoirs mediate the transmission of this disease. The significant levels of infectivity have been detected in the saliva, urine, and feces of TSE-infected animals. Using serial protein misfolding cyclic amplification with beads (sPMCAb), we developed a detection method for CWD PrPCWD in soil from CWD affected farm in 2010. We found to detect PrPCWD in soil from CWD infected farm, but not detect PrPCWD in soil of normal cervid farm in Korea. Our method appears to be a very useful technique for monitoring PrPCWD levels in environmental conditions.
Methods: There are total of three steps with two washing steps for PrPCWD extraction and one amplification step for PrPCWD detection from soils of natural CWD farms which have confirmed horizontal spread of CWD in 2010 and 2016. The first washing step consists of slow rotating to remove large impurities. The second washing step was detached PrPCWD from abnormal prion contaminated soil by strong vortex. The last step was PrPCWD amplification step using sPMCAb. Sonication was performed with a Misonix 4000 sonicator with amplitude set to level 70, generating an average output of 160W during each cycle. One round consisted of 56 cycles of 30 sec of sonication followed 10min of 37℃ incubation. The samples(20uL) after each round of amplification were mixed with proteinase K (200ug/ml) and incubated 37℃ for 1hr. Samples were separated by SDS-PAGE and transferred onto PVDF membrane. After blocking, the membrane was incubated for 1h with 1st antibody S1 anti rabbit serum (QIA, 1:3000) and developed with enhanced chemiluminescent detection system
Results: We had collected 35 soil samples from the four farms which were confirmed CWD and five trace farm in 2016. After three rounds of sPMCAb, we detected PrPCWD in 10 samples from areas which were positive animals habitat but not detect PrPCWD in soil of wild cervids habitat and normal cervid farm in Korea. These results suggest that our method can be a very useful tool for monitoring PrPCWD contamination in environments
Conclusions: This sPMCAb method using soil washing solution by slow rotating and vortex is effective extraction method of PrPCWD from CWD contaminated soils. The method developed in this study will be useful for assessment of PrPCWD levels in the contaminated soils.
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P52 NaPTA/RT-QUIC detection of PrPCWD in saliva and urine of CWD-infected cervids and TgElk mice
Hyun Joo Sohn1, Kyung Je Park1, Gordon Mitchell2, In Soon Roh1, Hyo Jin Kim1, Hae Eun Kang1 1Foreign Animal Disease Division Animal And Plant Quarantine Agency(QIA), Gimcheon, South Korea, 2Canadian Food Inspection Agency, Ottawa, Canada
Aims: Chronic wasting disease(CWD) is the only prion disease affecting free-ranging animals, reported in North America, South Korea and Norway. CWD agents are shed in saliva, urine and feces which most likely contribute to the horizontal transmission between cervid species.The development of amplification-based seeding assays have been instrumental in the detection of low levels of prions in clinical samples. Using NaPTA precipitation and real-time quaking-induced conversion(NaPTA/RT-QUIC), we established a ultrasensitive detection method for PrPCWD in the saliva and urine of CWD affected cervids. Also we performed the longitudinal study to detect PrPCWD from ,in the CWD-infected, sequentially sampled transgenic mice overexpressing elk prion protein(TgElk mice).
Methods: Five saliva and two urine samples from CWD-infected cervids at the terminal stage of disease, and 28 urine samples from sequentially sampled CWD-infected TgElk mice (TgElk CWD) were stored at -80℃. 100uL of each sample was mixed with 10uL 2.8% sodium phosphotungustic acid (NaPTA) and incubated for 1hr at 37℃ with shaking at 1,350 rpm. Samples were centrifuged for 30min at 16,100 g. The pellet was resuspended in 10uL of 0.1% SDS/PBS for 30min at 55℃. RT-QUIC reactions were set up in 96-well clear bottom optic plates and consisted of 98uL RT-QUIC buffer [final concentrations of 1XPBS, 1mM EDTA, 10uM Thioflavin, 300mM NaCl buffer and 0.1mg/ml recombinant hamster recombinant protein(23-231) and 2uL of sample. The RT-QUIC assay was performed on a FLUOstar Omega fluorescence plate reader that was preheated to 55℃ for 60hr with 1min shaking at 700rpm followed by 1min incubation.
Results: NaPTA/RT-QUIC was applied to measure PrPCWD in urine samples collected on every 15days from 30dpi to 120dpi when CWD infected TgElk mice reached terminal stage. . and dpi typicallyCWD in PrPCWD in the urine in TgElk CWD was detectable in early stages(30 and 45dpi), disappeared during the intermediate stages of infection(60 and 75dpi) and reached the highest levels at 90dpi. PrPCWD was also detectable in late and terminal stages(120dpi). In addition, PrPCWD was detected in terminal urine samples from two sika deer(experimental cases) and terminal saliva samples from five cervids were also observed to consistently yield positive results by the NaPTA/RT-QUIC assay.
Conclusions: We demonstrate that CWD prions can be detected by NaPTA/RT-QUIC in the saliva and urine of TgElk mice, red deer and sika deer at the early and terminal stages of disease. Our method appears to be a very useful technique for both diagnosis and surveillance of CWD
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PRION 2017 DECIPHERING NEURODEGENERATIVE DISORDERS
Subject: PRION 2017 CONFERENCE DECIPHERING NEURODEGENERATIVE DISORDERS VIDEO
PRION 2017 CONFERENCE DECIPHERING NEURODEGENERATIVE DISORDERS
PRION 2017 CONFERENCE VIDEO
P.141: Abundant prion shedding in CWD-infected deer revealed by Realtime conversion
Edward A Hoover,1 Davin M Henderson,1 Nathaniel D Denkers,1 Candace K Mathiason,1 Matteo Manca,2,3 and Byron Caughey2 1Prion Research Center, Colorado State University; Fort Collins, CO USA; 2Laboratory of Persistent Viral Diseases, NI AID; Hamilton, MT USA; 3Department of Biomedical Sciences, University of Cagliari; Monserrato, Italy
Background/Introduction. Chronic wasting disease (CWD) is unique among prion diseases in its efficient lateral transmission in nature. While the presence of infectious prions in body fluids and excreta of infected cervids has been demonstrated by bioassay, the dynamics, magnitude, and consequences of prion shedding remain unknown. The present studies were undertaken to determine the kinetics, duration, and magnitude of prion shedding in infected white-tailed deer.
Materials and Methods. Longitudinal samples were collected from white-tailed deer over a 2-year span after either oral (n=11)] aerosol (n = 6) CWD exposure. The assay protocol employed phosphotungstic acid precipitation of either whole saliva or the pelleted fraction of urine to seed recombinant Syrian hamster prion PrP substrate in RT-QuIC reactions. Prion seeding activity was assayed in 8 replicates of each sample employing thioflavin T detection in a 96-well plate-based fluorometer. Prion seeding reaction rate was determined by taking the inverse of the time at which samples exceeded a threshold of 5 standard deviations above the mean fluorescence of negative controls (1/time to threshold). Seeding activity was quantitated by comparing the realtime conversion reaction rate to a standard curve derived from a reference bioassayed brain pool homogenate from deer with terminal CWD.
Results. We analyzed >200 longitudinally collected, blinded, then randomized saliva and urine samples from 17 CWDinfected and 3 uninfected white-tailed deer. We detected prion shedding as early as 3 months post exposure and sustained thereafter throughout the disease course in both aerosol and orally exposed deer. The incidence of non-specific false positive results from > 500 saliva and urine samples from negative control deer was 0.8%. By comparing real-time reaction rates for these body fluids to a bioassayed serially diluted brain control, we estimated that ≤1 ml of saliva or urine from pre-symptomatic infected deer constitutes a lethal infectious prion dose.
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.
Acknowledgments. Support: NIH-RO1-NS-061902; Morris Animal Foundation D12ZO-045
P.154: Urinary shedding of prions in Chronic Wasting Disease infected white-tailed deer
Nathaniel D Denkers,1 Davin M Henderson, 1 Candace K Mathiason,1 and Edward A Hoover1 1Prion Research Center, Department of Microbiology, Immunology, and Pathology, Colorado State University; Fort Collins, CO USA
Background/Introduction. Chronic wasting disease (CWD) is unique among prion diseases in its efficient lateral transmission in nature, yet the dynamics and magnitude of shedding and its immediate and long term consequences remain unknown. The present study was designed to determine the frequency and time span in which CWD prions are shed in urine from infected white-tailed deer using adapted real-time quaking-induced conversion (RT-QuIC) methodology.
Materials and Methods. Longitudinal urine samples were collected by free catch or catheterization over a 2-year period from oral-route infected [CWD+ (n = 11)] and aerosol-route-infected [CWD+ (n = 6); CWD- (n = 3)] white-tailed deer. High speed centrifugation pelleted material from 500 µl of urine was treated with sodium phosphotungstic acid (Na-PTA), resuspended in 0.05% SDS buffer, and used as seed in RT-QuIC assays employing recombinant Syrian hamster prion PrP substrate. Eight (8) replicates of each sample were run and prion seeding activity was recorded as thioflavin T binding fluorescence (480 nm emission) using a fluorimeter-shaker. Samples were considered positive if they crossed an established threshold (5 standard deviations above the negative mean fluorescence).
Results. In our oral-route inoculation studies, prion seeding activity has been demonstrated in urine collected at 6 months post-inoculation in 6 of 10 deer (11 of 80 replicates; 14%), and intermittently at later time points in all 11 CWD+ exposed deer. Our aerosol-route inoculation studies also showed prion seeding activity in urine collected at 6 months post-inoculation in 1 of 2 deer (3 of 16 replicates; 19%), and intermittently at later time points in 4 of 6 CWD+ exposed deer. Urine from sham-inoculated control deer and all baseline samples yielded 3 false-positive prion seeding activities (3 of 352 replicates; 0.8%).
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.
Acknowledgments. Support: NIH: RO1-NS-061902 and Morris Animal Foundation: D12ZO-045 P.178: Longitudinal quantitative analysis of CWD prions shed in saliva of deer
Davin M Henderson, Nina Garbino, Nathaniel D Denkers, Amy V Nalls, Candace K Mathiason, and Edward A Hoover Prion Research Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University; Fort Collins, CO USA
Background/Introduction. Chronic Wasting Disease (CWD) is an emergent rapidly spreading fatal prion disease of cervids (deer, elk and moose). CWD has now been identified in 22 States (including two new states within the last year), 2 Canadian provinces, and South Korea. Shedding of infectious prions in excreta (saliva, urine, feces) may be an important factor in CWD transmission. Here we apply an adapted version of a rapid in vitro assay [real-time quaking-induced conversion (RT-QuIC)] to determine the time of onset, length, pattern, and magnitude of prion shedding in saliva of infected deer.
Materials and Methods. The RT-QuIC assay was performed as previously described in Henderson et al. PLoS-One (2013). Saliva samples were quantitated by comparison to a RT-QuIC reaction rate standard curve of a bioassayed obex sample from a terminally ill cervid.
Results. To better understand the onset and length of CWD prion shedding we analyzed >150 longitudinally collected, blinded, then randomized saliva samples from 17 CWD-infected and 3 uninfected white-tailed deer. We observed prion shedding, as detected by the RT-QuIC assay, as early as 3 months from inoculation and sustained shedding throughout the disease course in both aerosol and orally exposed deer. We estimated the infectious lethal dose of prions shed in saliva from infected deer by comparing real-time reaction rates of saliva samples to a bioassayed serially diluted brain control. Our results indicate that as little as 1 ml of saliva from pre-symptomatic infected deer constitutes a lethal CWD prion dose.
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.
Acknowledgments. Supported by NIH grant RO1-NS-061902 and grant D12ZO-045 from the Morris Animal Foundation.
Sunday, September 13, 2015
urine, feces, and chronic wasting disease cwd tse prion risk factors, loading up the environment
Subject: MAD DEER/ELK DISEASE AND POTENTIAL SOURCES
Date: Sat, 20 Jul 2002 09:43:10 -0700
From: "Terry S. Singeltary Sr."
Subject: MAD DEER/ELK DISEASE AND POTENTIAL SOURCES
Date: Sat, 25 May 2002 18:41:46 -0700
From: "Terry S. Singeltary Sr."
Reply-To: Bovine Spongiform Encephalopathy To: BSE-L@uni-karlsruhe.de
######## Bovine Spongiform Encephalopathy #########
MAD DEER/ELK DISEASE AND POTENTIAL SOURCES
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now, what about those 'deer scents' of 100% urine', and the prion that is found in urine, why not just pass the prion with the urine to other deer...
Mrs. Doe Pee Doe in Estrus Model FDE1 Mrs. Doe Pee's Doe in Estrus is made from Estrus urine collected at the peak of the rut, blended with Fresh Doe Urine for an extremely effective buck enticer. Use pre-rut before the does come into heat. Use during full rut when bucks are most active. Use during post-rut when bucks are still actively looking for does. 1 oz.
ELK SCENT/SPRAY BOTTLE *
Works anytime of the year *
100 % Cow Elk-in-Heat urine (2oz.) *
Economical - mix with water in spray mist bottle *
Use wind to your advantage
Product Code WP-ESB $9.95
prions in urine?
[PDF] A URINE TEST FOR THE IN-VIVO DIAGNOSIS OF PRION DISEASES
Terry S. Singeltary Sr.
Thank You For Your Comments Thank you for submitting your comments on the Draft Deer Management Plan.
DRAFT Virginia Deer Management Plan 2015-2024 (bans urine scents do to CWD 2015)
Saturday, January 31, 2015
European red deer (Cervus elaphus elaphus) are susceptible to Bovine Spongiform Encephalopathy BSE by Oral Alimentary route
From: Terry S. Singeltary Sr.
Sent: Saturday, November 07, 2015 11:54 AM
To: David.Putnam@pa.gov ; D.Putnam@pa.gov ; Putnam@pa.gov Cc: pgc-swregion@pa.gov ; pgc-ncregion@pa.gov ; pgccomments@pa.gov
Subject: re-Pennsylvania 2015 September Minutes CWD Urine Scents
MONDAY, JUNE 17, 2013
Early detection of chronic wasting disease prions in urine of pre-symptomatic deer by real-time quaking-induced conversion assay
First evidence of intracranial and peroral transmission of Chronic Wasting Disease (CWD) into Cynomolgus macaques: a work in progress
Stefanie Czub1, Walter Schulz-Schaeffer2, Christiane Stahl-Hennig3, Michael Beekes4, Hermann Schaetzl5 and Dirk Motzkus6 1
University of Calgary Faculty of Veterinary Medicine/Canadian Food Inspection Agency; 2Universitatsklinikum des Saarlandes und Medizinische Fakultat der Universitat des Saarlandes; 3 Deutsches Primaten Zentrum/Goettingen; 4 Robert-Koch-Institut Berlin; 5 University of Calgary Faculty of Veterinary Medicine; 6 presently: Boehringer Ingelheim Veterinary Research Center; previously: Deutsches Primaten Zentrum/Goettingen
This is a progress report of a project which started in 2009. 21 cynomolgus macaques were challenged with characterized CWD material from white-tailed deer (WTD) or elk by intracerebral (ic), oral, and skin exposure routes. Additional blood transfusion experiments are supposed to assess the CWD contamination risk of human blood product. Challenge materials originated from symptomatic cervids for ic, skin scarification and partially per oral routes (WTD brain). Challenge material for feeding of muscle derived from preclinical WTD and from preclinical macaques for blood transfusion experiments. We have confirmed that the CWD challenge material contained at least two different CWD agents (brain material) as well as CWD prions in muscle-associated nerves.
Here we present first data on a group of animals either challenged ic with steel wires or per orally and sacrificed with incubation times ranging from 4.5 to 6.9 years at postmortem. Three animals displayed signs of mild clinical disease, including anxiety, apathy, ataxia and/or tremor. In four animals wasting was observed, two of those had confirmed diabetes. All animals have variable signs of prion neuropathology in spinal cords and brains and by supersensitive IHC, reaction was detected in spinal cord segments of all animals. Protein misfolding cyclic amplification (PMCA), real-time quaking-induced conversion (RT-QuiC) and PET-blot assays to further substantiate these findings are on the way, as well as bioassays in bank voles and transgenic mice.
At present, a total of 10 animals are sacrificed and read-outs are ongoing. Preclinical incubation of the remaining macaques covers a range from 6.4 to 7.10 years. Based on the species barrier and an incubation time of > 5 years for BSE in macaques and about 10 years for scrapie in macaques, we expected an onset of clinical disease beyond 6 years post inoculation.
PRION 2017 DECIPHERING NEURODEGENERATIVE DISORDERS
Subject: PRION 2017 CONFERENCE DECIPHERING NEURODEGENERATIVE DISORDERS VIDEO
PRION 2017 CONFERENCE DECIPHERING NEURODEGENERATIVE DISORDERS
PRION 2017 CONFERENCE VIDEO
Chronic Wasting Disease CWD TSE Prion to Humans, who makes that final call, when, or, has it already happened?
TUESDAY, JUNE 13, 2017
PRION 2017 CONFERENCE ABSTRACT First evidence of intracranial and peroral transmission of Chronic Wasting Disease (CWD) into Cynomolgus macaques: a work in progress
TUESDAY, JUNE 13, 2017
PRION 2017 CONFERENCE ABSTRACT Chronic Wasting Disease in European moose is associated with PrPSc features different from North American CWD
TUESDAY, JULY 04, 2017
*** PRION 2017 CONFERENCE ABSTRACTS ON CHRONIC WASTING DISEASE CWD TSE PRION ***
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
Location: Virus and Prion Research
Title: Disease-associated prion protein detected in lymphoid tissues from pigs challenged with the agent of chronic wasting disease
Author item Moore, Sarah item Kunkle, Robert item Kondru, Naveen item Manne, Sireesha item Smith, Jodi item Kanthasamy, Anumantha item West Greenlee, M item Greenlee, Justin
Submitted to: Prion Publication Type: Abstract Only Publication Acceptance Date: 3/15/2017 Publication Date: N/A Citation: N/A Interpretive Summary:
Technical Abstract: Aims: Chronic wasting disease (CWD) is a naturally-occurring, fatal neurodegenerative disease of cervids. We previously demonstrated that disease-associated prion protein (PrPSc) can be detected in the brain and retina from pigs challenged intracranially or orally with the CWD agent. In that study, neurological signs consistent with prion disease were observed only in one pig: an intracranially challenged pig that was euthanized at 64 months post-challenge. The purpose of this study was to use an antigen-capture immunoassay (EIA) and real-time quaking-induced conversion (QuIC) to determine whether PrPSc is present in lymphoid tissues from pigs challenged with the CWD agent.
Methods: At two months of age, crossbred pigs were challenged by the intracranial route (n=20), oral route (n=19), or were left unchallenged (n=9). At approximately 6 months of age, the time at which commercial pigs reach market weight, half of the pigs in each group were culled (<6 challenge="" groups="" month="" pigs="" remaining="" the="">6 month challenge groups) were allowed to incubate for up to 73 months post challenge (mpc). The retropharyngeal lymph node (RPLN) was screened for the presence of PrPSc by EIA and immunohistochemistry (IHC). The RPLN, palatine tonsil, and mesenteric lymph node (MLN) from 6-7 pigs per challenge group were also tested using EIA and QuIC.
Results: PrPSc was not detected by EIA and IHC in any RPLNs. All tonsils and MLNs were negative by IHC, though the MLN from one pig in the oral <6 5="" 6="" at="" by="" detected="" eia.="" examined="" group="" in="" intracranial="" least="" lymphoid="" month="" months="" of="" one="" pigs="" positive="" prpsc="" quic="" the="" tissues="" was="">6 months group, 5/6 pigs in the oral <6 4="" and="" group="" months="" oral="">6 months group. Overall, the MLN was positive in 14/19 (74%) of samples examined, the RPLN in 8/18 (44%), and the tonsil in 10/25 (40%). Conclusions:
This study demonstrates that PrPSc accumulates in lymphoid tissues from pigs challenged intracranially or orally with the CWD agent, and can be detected as early as 4 months after challenge.
CWD-infected pigs rarely develop clinical disease and if they do, they do so after a long incubation period. This raises the possibility that CWD-infected pigs could shed prions into their environment long before they develop clinical disease.
Furthermore, lymphoid tissues from CWD-infected pigs could present a potential source of CWD infectivity in the animal and human food chains.
CONFIDENTIAL
EXPERIMENTAL PORCINE SPONGIFORM ENCEPHALOPATHY
While this clearly is a cause for concern we should not jump to the conclusion that this means that pigs will necessarily be infected by bone and meat meal fed by the oral route as is the case with cattle. ...
we cannot rule out the possibility that unrecognised subclinical spongiform encephalopathy could be present in British pigs though there is no evidence for this: only with parenteral/implantable pharmaceuticals/devices is the theoretical risk to humans of sufficient concern to consider any action.
Our records show that while some use is made of porcine materials in medicinal products, the only products which would appear to be in a hypothetically ''higher risk'' area are the adrenocorticotrophic hormone for which the source material comes from outside the United Kingdom, namely America China Sweden France and Germany. The products are manufactured by Ferring and Armour. A further product, ''Zenoderm Corium implant'' manufactured by Ethicon, makes use of porcine skin - which is not considered to be a ''high risk'' tissue, but one of its uses is described in the data sheet as ''in dural replacement''. This product is sourced from the United Kingdom.....
snip...see much more here ;
WEDNESDAY, APRIL 05, 2017
Disease-associated prion protein detected in lymphoid tissues from pigs challenged with the agent of chronic wasting disease
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
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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.
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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.
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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).
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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.
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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.
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What is the risk of chronic wasting disease being introduced into Great Britain? A Qualitative Risk Assessment October 2012
I strenuously once again urge the FDA and its industry constituents, to make it MANDATORY that all ruminant feed be banned to all ruminants, and this should include all cervids, as well as non-ruminants such as cats and dogs as well, as soon as possible for the following reasons...
TUESDAY, APRIL 18, 2017
*** EXTREME USA FDA PART 589 TSE PRION FEED LOOP HOLE STILL EXIST, AND PRICE OF POKER GOES UP ***
THURSDAY, JULY 13, 2017
EFSA BSE Sixty cases of mad cow disease since 2001 breached feed ban likely the cause
Scientists investigate origin of isolated BSE cases
TUESDAY, MARCH 28, 2017
*** Passage of scrapie to deer results in a new phenotype upon return passage to sheep ***
National Prion Center could lose all funding just as concern about CWD jumping to humans rises
SATURDAY, JULY 15, 2017
National Prion Center could lose all funding just as concern about CWD jumping to humans rises
*** I URGE YOU ALL TO WATCH THESE VIDEOS ***
Terry S. Singeltary Sr.
SUNDAY, JULY 16, 2017
Temporal patterns of chronic wasting disease prion excretion in three cervid species
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