Genetic Approaches and Tools to Prevent, Control, and Eradicate Transmissible Spongiform Encephalopathies 2024 Annual Report ARS Research
Research Project: Genetic Approaches and Tools to Prevent, Control, and Eradicate Transmissible Spongiform Encephalopathies
Location: Animal Disease Research Unit
2024 Annual Report
Objectives Objective
1: Identify genes outside of PRNP that are associated with prion disease. Objective 1A: Identify and characterize genes outside of PRNP that are associated with Scrapie in North American small ruminants. Objective 1B: Identify and characterize genes outside of PRNP that are associated with CWD in North American cervids.
Objective 2: Determine the influence of prion genotypes and tissue constituents on the detection of TSE prions.
Objective 2A: Develop improved methods for antemortem detection of Scrapie in small ruminants. Objective 2B: Determine the influence of genetic variations in the prion protein on the detection and susceptibility of prion infection in small ruminants
Approach The goal of Objective 1 is to identify genetic markers outside the prion protein gene (PRNP) associated with prion disease. Variation in PRNP can substantially impact the development of TSEs. Still, only a few PRNP genotypes in small ruminants, and none in cervids, are known to confer strong resistance to prion infection. Studies in several species, including sheep and deer, indicate that genetic factors other than PRNP also impact prion diseases. Therefore, genome-wide association and prediction studies will be performed to identify regions outside of PRNP associated with Scrapie in sheep (Objective 1A) and Chronic Wasting Disease in elk (Objective 1B).
The goal of Objective 2 is to determine the influence of PRNP genotypes and tissue constituents on the detection of prions. The sensitivity of current diagnostic methods is poor compared to bioassay. In contrast, modern protein-misfolding assays known as RT-QuIC and sPMCA can be equivalently sensitive as bioassay but are variably inhibited by tissue factors, including omnipresent blood.
To improve the applied assay performance, Objective 2A will test the hypothesis that heme, a significant blood component, is present in various types of diagnostic samples at concentrations that reduce the sensitivity of protein misfolding assays. The inhibitory mechanisms of heme will be investigated using the RT-QuIC assay since its reagents are fully defined. A novel strategy to mitigate assay inhibition through heme-sequestration will be examined in RT-QuIC and sPMCA assays. In addition, the utility of these misfolding assays to detect prions in different species relies on the genotype of the prion protein used as substrate. The RT-QuIC assay uses bacterial recombinant prion protein as substrate. In contrast, sPMCA assay performance depends on prion protein produced in a eukaryotic system, usually as brain homogenate of transgenic mice.
Objective 2B aims to overcome the limited genetic representation and animal use of current substrate sources by producing recombinant protein substrate using a scalable baculovirus-insect cell system (BICS). An array of PRNP genotypes will be screened for sensitivity as a substrate for the sPMCA assay in detecting multiple forms of prions from sheep, goats, and cervid species. The BICS recombinant substrates will be used to test the hypotheses (1) that the seeded-conversion profiles of sPMCA using different substrate genotypes can differentiate interspecies transmission of CWD to sheep from naturally occurring forms of scrapie in sheep, and (2) that the PRNP S146 and K222 genotypes found in goats both confer strong resistance to oral infection by classical scrapie prions.
Progress Report This report documents FY2024 progress for project 2022-13610-013-000D, which started in October 2021. In support of Objective 1, additional samples from sheep and elk naturally exposed to classical scrapie and chronic wasting disease (CWD), respectively, were acquired and processed. Enzymatic digestion, quality checks, and loading into shipping plates were completed for all sheep samples. The shipping plates were sent out for genotyping on the Illumina OvineHD BeadChip, which contains approximately 600,000 single-nucleotide polymorphisms across the sheep genome. Genome-wide association (GWAS) analyses will commence once the results are returned. For elk, GWAS analyses were conducted using genotype-by-sequencing data from 1,240 samples. Covariate data was added, and principal components analysis was completed. Genotype-by-sequencing will commence on elk samples newly received and processed this fiscal year once quality check results are returned. Additional metadata was received and added to an elk genomics study with a National Parks Service collaborator. For Sub-objective 2A, research to understand and mitigate the inhibitory effects of heme on ultrasensitive prion detection assays continued. Blood is naturally present in tissues and variably contaminates samples, especially during live-animal sample collection. Contaminating blood also undergoes variable degrees of hemolysis, releasing hemoglobin from red blood cells. Prolonged pre-exposure of prions to hemoglobin did not produce a measurable effect on prion seeding activity. Heme and hemoglobin were determined to interact with the assay’s substrate prion protein (PrP) in a rapid, non-cascading manner, effectively reducing the amount of substrate protein available to participate in seeded aggregation reactions. Rescue from this mechanism of inhibition was not possible with the heme-binding protein HasA since this bacterial protein also potently interacted with the PrP substrate with similar consequences. These effects of heme and hemoglobin were similar for several PrP sequences commonly used as assay substrates. Under Sub-objective 2B, progress has been made to produce a non-animal source of PrP substrate for the seeded aggregation assay known as the protein misfolding cyclic amplification (sPMCA) assay. Efforts were made to employ technological advances in baculovirus-insect cell systems (BICS) after failing to reliably express high-titer, stable lines of a recombinant baculovirus (bac-2-bac). A newer BICS, known as the bac-2-the-future (B2F) system, was obtained from the National Institutes of Health. The B2F system utilizes several bioengineered advances that result in higher efficiency production of baculoviruses at lower cost. Several PrP-recombinant B2F baculoviruses have now been produced at high titers in Sf9 insect cells. A second modification to the workflow was to use an insect cell line known as High Five during recombinant PrP production. Switching to using the B2F baculovirus and High Five insect cells has dramatically improved the efficiency and quantity of BICS recombinant PrP production. This new B2F/High Five production system is now being scaled up so that its recombinant product can resume testing as a non-animal source of PrP substrate in sPMCA. Nevertheless, work has continued to adapt protein aggregation assays to differentiate strains of prions in small ruminants. Earlier work demonstrated the ability to differentiate classical scrapie from CWD infections in sheep by tissue bioassay using two lines of transgenic mice. This differentiation has now been achieved in far less time, days versus years, by two modified benchtop methods—an sPMCA protocol using substrates produced from two transgenic mouse lines and a real-time quaking-induced conversion (RT-QuIC) assay using two bacterial recombinant PrPs as substrate. These modified sPMCA and RT-QuIC assays were able to differentiate CWD and classical scrapie independent of native host species (elk or deer versus sheep or goats) and irrespective of two CWD-susceptible genotypes in white-tailed deer and two scrapie-susceptible genotypes in sheep. These assays are now being applied to test the differentiation of first- and second-passaged CWD in sheep and a goat from classical scrapie. With the continued expansion of CWD in cervid populations across North America, these rapid benchtop assays make possible higher throughput and cost-effective testing to classify any re-emergent prion disease in sheep or goats as either classical scrapie or as a spillover event of CWD from infected cervids or contaminated environments. Research on the resistance of specific goat genotypes to classical scrapie infection continued. From the original study, all goats bearing the fully susceptible PrP genotype (NN146/QQ222) succumbed quickly to classical prion disease after oral inoculation. In contrast, no conventional evidence of scrapie infection could be detected in NS146 goats nor in QK222 goats inoculated with the same inoculum. Since then, groups of transgenic mice have been monitored for prion infection after being inoculated with hindbrain homogenate from either an affected NN146/QQ222 goat, the two longest-surviving NS146 goats, or the two longest-surviving QK222goats. All NN146/QQ222 goat-inoculated mice were terminated with the development of clinical disease consistent with prion infection, whereas all the QK222 goat-inoculated mice reached the endpoint of the experiment or were terminated due to intercurrent illnesses. The endpoint for NS146 goat-inoculated mice has reached to the next fiscal year but none have developed clinical signs of prion infection. The tissues of NN146/QQ222 goat-inoculated mice and QK222 goat-inoculated mice have been tested by conventional assays and by RT-QuIC; the latter included the use of different substrate protein sequences to enhance the detection of prion strain drift. Evidence of classical scrapie infection was readily detected by both methods in NN146/QQ222 goat-inoculated mice. No evidence of prion infection was detected in QK222 goat-inoculated mice nor in the hindbrain or medial retropharyngeal lymph nodes (MRPLN) of any of the original inoculated QK222 goats. No evidence of prion infection was observed using conventional or RT-QuIC methods in tissues from a single inoculated KK222 goat that survived four years until termination for an intercurrent illness. Significant progress continued in developing protocols and reagents to enhance prion surveillance efforts, especially those directed at antemortem testing and detection of early-stage infections. Samples of the rectal mucosa from white-tailed deer naturally exposed to CWD that previously produced RT-QuIC assay results incongruent with conventional diagnostics have now all been inoculated into transgenic mice. In a similar study, progress was made comparing the results of immunohistochemistry and the RT-QuIC assay using MRPLN from naturally exposed white-tailed deer. Diagnostic performance criteria of the reaction data were measured, and the effects of infection stage and deer PrP genotype were determined. All samples producing RT-QuIC reaction data incongruent with paired immunohistochemistry results have been retested by RT-QuIC, and samples with sufficient samples remaining have been inoculated into transgenic mice. The availability from these animals of additional tissue in paraffin-embedded blocks at the National Veterinary Services Laboratories has been confirmed. Blocks have been selected and are expected to be received this fiscal year. This will allow precise estimation of prion accumulation using machine learning-assisted, high-resolution digital whole slide image analysis of chromogen. These tissue blocks will also be used to correlate the presence of lymphoid tissue markers by antibody detection using paired fixed and frozen lymphoid tissues. Antibodies have been selected that robustly identify follicular marker proteins in rectal mucosa and medial retropharyngeal lymph node (MRPLN) tissues of sheep and goats. The whole slide images of prion-processed tissue sections will also be used to support a new collaboration with researchers at Washington State University endeavoring to use artificial intelligence to enhance the prion surveillance workflow of pathologists. Progress was made in research that aims to quantify the binding attributes and spectrum of selectivity of previously described ‘prion selective’ DNA aptamers using a modern technological advance known as biolayer interferometry (BLI). Samples for use in these experiments continue to be identified from geographically dispersed cases of classical and atypical scrapie in sheep and goats, as well as CWD in elk and deer. Several representative crude homogenates were made to support initial testing. Benchtop generation of prions was begun to support the adaptation of BLI methods to prion-related work. Methods of prion purification were compared using different strains of prion. The purified proteins were assessed by gel electrophoresis and western blotting and are starting to be used in experiments to detect and measure binding attributes of anti-prion antibodies and DNA aptamers with BLI. To date, methods to reduce the non-specific binding of non-disease forms of PrP and of other tissue constituents have been examined for several types of biosensor probes. The commonly used diagnostic reagent, anti-prion mouse monoclonal antibody F99, was successfully loaded onto a mouse anti-Fc coated biosensor as monitored by BLI. Similarly, recombinant PrP was successfully loaded onto a nickel-nitrilotriacetic acid (Ni-NTA)-coated biosensor but resulted in loss of epitope binding by F99. Serum-free antibody F99 was purified and biotinylated; biotinylated F99 was successfully loaded onto two forms of streptavidin-coated biosensors that then could be used to detect recombinant PrP in solution.
Accomplishments 1. Validation of a standardized protocol that detects chronic wasting disease in preclinical deer using biopsy samples of rectal mucosa. Effective management of chronic wasting disease in cervids may require new methods to enhance surveillance efforts. ARS researchers in Pullman, Washington, and at the National Animal Disease Center, Ames, Iowa, in collaboration with researchers from the Animal and Plant Health Inspection Agency, the U.S. Geological Survey, and Texas A&M University, standardized a real-time quaking-induced (RT-QuIC) assay protocol that detects chronic wasting disease in preclinical white-tailed deer using samples of rectal mucosa. In less than 30 hours and in a 96-well format, the diagnostic sensitivity of the protocol was similar and with some deer genotypes possibly better than the current method of microscopic evaluation of immunohistochemically stained thin tissue sections by a pathologist. This standardized RT-QuIC protocol could enhance disease management as a more cost-effective, higher throughput alternative method for sensitive detection of preclinical infection in living white-tailed deer.
2. New method provides practical, sensitive detection of prion and prion-like aggregates on surfaces. Disease-specific protein aggregates accumulate in the brain of prion and prion-like neurodegenerative diseases. Exposure of susceptible individuals to surfaces contaminated by these pathologic aggregates can result in transmission of disease. An ARS researcher in Pullman, Washington, in collaboration with researchers from the National Institutes of Health, Case Western University, Indiana University, the National Veterinary School of Toulouse in France, the National Agriculture and Food Research Organization in Japan, and the University of Verona in Italy, have now described a practical method for the sensitive detection of these pathologic aggregates on stainless steel and acrylic surfaces. Called the surface real-time quaking-induced conversion (sfRT-QuIC) assay, the method was successfully adapted to surface detection of pathologic aggregates from a variety of diseases, including the animal prion diseases scrapie and chronic wasting disease, and prion (Creutzfeldt-Jacob) and prion-like (Parkinson’s and Alzheimer’s) diseases of humans. The direct sampling technique could be applied to small and large surfaces, and the recovered sample could be stored before testing. Sensitive detection of pathologic protein aggregates on solid surfaces such as machinery, tools, and surgical instruments might help prevent disease dissemination.
3. Greater frequency of chronic wasting disease in free-ranging elk genetically tolerant to disease progression raises concerns related to prion transmission and strain evolution. Genetic variations in the prion protein gene of Rocky Mountain elk do not confer complete resistance to fatal infection by chronic wasting disease. However, elk carrying one or two copies of the leucine variant at position 132 of the prion protein (132L*, where * is either M or L) survive much longer than 132MM elk. An ARS researcher in Pullman, Washington, in collaboration with researchers at the University of Wyoming, the University of California at Davis, the National Park Service, and the Animal and Plant Health Inspection Service, found a higher frequency of 132L* elk in areas of Wyoming with high infection rates, consistent with the expected positive effect of prolonged survival on reproduction. However, the frequency of chronic wasting disease infection in 132L* elk was also higher than previous estimates. To improve the long-term management of native elk populations, these findings underscore the importance of determining the effects of prolonged infection on disease transmission from 132L* elk and the potential for driving prion strain diversification.
Review Publications Hoar, B.R., Ernest, H.B., Johnson, L.N., LaCava, M.E., Sandidge, D.J., Gerow, K., Mousel, M.R., Galloway, N.L., Swain, W., Malmberg, J.L. 2024. Ecology and chronic wasting disease epidemiology shape prion protein gene variation in Rocky Mountain elk (Cervus elaphus nelsoni). Journal of Wildlife Diseases. 60(2):496-501. https://doi.org/10.7589/JWD-D-23-00062. Piel III, R.B., Veneziano, S.E., Nicholson, E.M., Walsh, D.P., Lomax, A.D., Nichols, T.A., Seabury, C.M., Schneider, D.A. 2024. Validation of a real-time quaking-induced conversion (RT-QuIC) assay protocol to detect chronic wasting disease using rectal mucosa of naturally infected, pre-clinical white-tailed deer (Odocoileus virginianus). PLOS ONE. 19(6). Article e0303037. https://doi.org/10.1371/journal.pone.0303037. Orrú, C.D., Groveman, A.R., Hughson, A.G., Barrio, T., Isiofia, K., Race, B., Ferreira, N.C., Gambetti, P., Schneider, D.A., Masujin, K., Miyazawa, K., Ghetti, B., Zanusso, G., Caughey, B. 2024. Sensitive detection of pathological seeds of a-synuclein, tau and prion protein on solid surfaces. PLoS Pathogens. 20(4). Article e1012175. https://doi.org/10.1371/journal.ppat.1012175. Fry, L.M., DenHerder, J., Clyde, G.L., Williams, L.A., Schneider, D.A. 2023. Biphasic pleural mesothelioma in a goat. Canadian Veterinary Journal. 64(9):828-832. Furtado, A.P., Fry, L.M., Piel, L.M., Bastos, R.G., Schneider, D.A., Varvil, M.S. 2023. B-cell leukemia in an adult sheep. Veterinary Clinical Pathology. 52(4):716-721. https://doi.org/10.1111/vcp.13303.
https://www.ars.usda.gov/research/project/?accnNo=441236&fy=2024
Research Project: Rapid Antemortem Tests for the Early Detection of Transmissible Spongiform Encephalopathies and Other Animal Diseases 2024 Annual Report
https://www.ars.usda.gov/research/project?accnNo=441758&fy=2024
Volume 30, Number 10—October 2024
Research
Temporal Characterization of Prion Shedding in Secreta of White-Tailed Deer in Longitudinal Study of Chronic Wasting Disease, United States
Our findings suggest that deer expressing alternative PRNP polymorphisms might live longer and, although they shed fewer prions throughout CWD course, might over their extended lifespan increase CWD prions in the environment
https://wwwnc.cdc.gov/eid/article/30/10/24-0159_article
“Our findings suggest that deer expressing alternative PRNP polymorphisms might live longer and, although they shed fewer prions throughout CWD course, might over their extended lifespan increase CWD prions in the environment”
Prion protein gene sequence and chronic wasting disease susceptibility in white-tailed deer (Odocoileus virginianus)
Adam L Brandt, Amy C Kelly, Michelle L Green, Paul Shelton, Jan Novakofski & Nohra E Mateus-Pinilla
Pages 449-462 | Received 21 Sep 2015, Accepted 23 Oct 2015, Published online: 21 Dec 2015 https://doi.org/10.1080/19336896.2015.1115179
The presence of aa96S has been associated with slowed disease progression, longer life span among captive deer,Citation26,27 and does not appear to affect the rate at which prions are shed from infected individuals.Citation38 Additionally, CWD infected mule deer have been found to excrete pathogenic prions while asymptomatic.Citation39 This contributes to concerns that wild deer with aa96S may be shedding infectious prions into the environment for longer periods of time than deer lacking the mutation, but are not symptomatic or detectable by immunohistochemical procedures.
https://www.tandfonline.com/doi/full/10.1080/19336896.2015.1115179#d1e354
https://pmc.ncbi.nlm.nih.gov/articles/PMC4964855/pdf/kprn-09-06-1115179.pdf
''There are no known familial or genetic TSEs of animals, although polymorphisms in the PRNP gene of some species (sheep for example) may influence the length of the incubation period and occurrence of disease.''
c) The commonest form of CJD occurs as a sporadic disease, the cause of which is unknown, although genetic factors (particularly the codon 129 polymorphism in the prion protein gene (PRNP)) influence disease susceptibility. The familial forms of human TSEs (see Box 1) appear to have a solely genetic origin and are closely associated with mutations or insertions in the PRNP gene. Most, but not all, of the familial forms of human TSEs have been transmitted experimentally to animals. There are no known familial or genetic TSEs of animals, although polymorphisms in the PRNP gene of some species (sheep for example) may influence the length of the incubation period and occurrence of disease.
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/209755/Part_1_-_Introduction.pdf
P-145 Estimating chronic wasting disease resistance in cervids using real time quaking- induced conversion
Nicholas J Haley1, Rachel Rielinqer2, Kristen A Davenport3, W. David Walter4, Katherine I O'Rourke5, Gordon Mitchell6, Juergen A Richt2 1
Our studies demonstrate that in vitro amplification metrics predict in vivo susceptibility, and that alleles with multiple codons, each influencing resistance independently, do not necessarily contribute additively to resistance. Importantly, we found that the white-tailed deer 226K substrate exhibited the slowest amplification rate among those evaluated, suggesting that further investigation of this allele and its resistance in vivo are warranted to determine if absolute resistance to CWD is possible. ***at present, no cervid PrP allele conferring absolute resistance to prion infection has been identified.
PRION 2016 CONFERENCE TOKYO
http://prion2016.org/dl/newsletter_03.pdf
http://web.archive.org/web/20170126101814/http://prion2016.org/dl/newsletter_03.pdf
http://chronic-wasting-disease.blogspot.com/2017/04/
***> at present, no PrPC allele conferring absolute resistance in cervids has been identified.
J Gen Virol. 2017 Nov; 98(11): 2882–2892.
Published online 2017 Oct 23. doi: 10.1099/jgv.0.000952
Estimating chronic wasting disease susceptibility in cervids using real-time quaking-induced conversion
Chronic wasting disease (CWD) resistance in cervids is often characterized as decreased prevalence and/or protracted disease progression in individuals with specific alleles; at present, no PrPC allele conferring absolute resistance in cervids has been identified.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5845664/pdf/jgv-98-2882.pdf
SUNDAY, MAY 04, 2025
Texas Senate Bill 2651 establishment of a pilot program to breed deer resistant to CWD TSE Prion, what could go wrong?
https://chronic-wasting-disease.blogspot.com/2025/05/texas-senate-bill-2651-establishment-of_4.html
Texas S.B. 2843 Directs TPWD to conduct a comprehensive study of current measures to control chronic wasting disease (CWD) in deer
Trying to legislate CWD is what got Texas in this CWD mess to begin with, how did that work out$$$ Legislators and Politicians need to stay away and let TPWD and TAHC et try and contain this mess that Legislators and Politicians got us in, called CWD TSE Prion…terry
https://chronic-wasting-disease.blogspot.com/2025/04/texas-sb-2843-directs-tpwd-to-conduct.html
Friday, February 21, 2025
LEGISLATING CWD TSE Prion, Bills to release Genetically Modified Cervid into the wild, what could go wrong?
https://chronic-wasting-disease.blogspot.com/2025/02/legislating-cwd-tse-prion-bills-to.html
Texas CWD Update May 2025
WEDNESDAY, MAY 14, 2025
Texas CWD TSE Prion Cases Rises to 1099 Confirmed Cases To Date
Entries CWD Positives
Positive Number CWD Positive Confirmation Date Free Range Captive County Source Species Sex Age
1099 5/5/25 Breeder Deer Gillespie Facility #14 White-tailed Deer M 4.9 1098 4/24/25 Breeder Deer Zavala Facility #23 White-tailed Deer F 7.8 1097 4/24/25 Breeder Deer Zavala Facility #23 White-tailed Deer F 7.8 1096 4/17/25 Breeder Release Site Zavala N/A White-tailed Deer M 10.5 1095 4/3/25 Breeder Deer Kimble Facility #26 White-tailed Deer F 2.5 1094 4/3/25 Breeder Deer Kimble Facility #26 White-tailed Deer F 6.5 1093 4/3/25 Breeder Deer Kimble Facility #26 White-tailed Deer F 3.5 1092 4/3/25 Breeder Deer Frio Facility #24 White-tailed Deer F 1.7 1091 4/3/25 Breeder Deer Frio Facility #24 White-tailed Deer F 1.7 1090 4/3/25 Breeder Deer Frio Facility #24 White-tailed Deer F 3.7 1089 4/3/25 Breeder Deer Frio Facility #24 White-tailed Deer F 5.7 1088 4/3/25 Breeder Deer Frio Facility #24 White-tailed Deer F 5.7 1087 4/3/25 Breeder Deer Frio Facility #24 White-tailed Deer F 7.7 1086 4/3/25 Breeder Deer Frio Facility #24 White-tailed Deer F 3.7 1085 4/3/25 Breeder Deer Frio Facility #24 White-tailed Deer F 3.7 1084 3/19/25 Free Range El Paso N/A Mule Deer M 6.5 1083 3/14/25 Breeder Deer Frio Facility #24 White-tailed Deer M 1.7 1082 2/27/25 Breeder Deer Kaufman Facility #36 White-tailed Deer F 0.5 1081 2/27/25 Breeder Deer Kaufman Facility #36 White-tailed Deer M 1.5 1080 2/21/25 Breeder Deer Gillespie Facility #15 White-tailed Deer M 2.5 1079 2/19/25 Breeder Deer Frio Facility #24 White-tailed Deer M 1.4 1078 2/13/25 Breeder Release Site Medina Facility #3 Elk F 4 1077 1/14/25 Breeder Deer Frio Facility #24 White-tailed Deer F 2.5 1076 1/14/25 Breeder Deer Frio Facility #24 White-tailed Deer M 1.5 1075 1/14/25 Breeder Deer Frio Facility #24 White-tailed Deer M 1.5 1074 1/24/25 Breeder Deer Zavala Facility #23 White-tailed Deer F 1.5 1073 1/24/25 Breeder Deer Zavala Facility #23 White-tailed Deer F 4.5 1072 1/24/25 Breeder Deer Zavala Facility #23 White-tailed Deer M 2.5 1071 1/24/25 Breeder Deer Zavala Facility #23 White-tailed Deer M 2.5 1070 1/24/25 Breeder Deer Zavala Facility #23 White-tailed Deer M 3.5 1069 2/4/25 Breeder Release Site Brown N/A White-tailed Deer F 2.6 1068 1/23/25 Breeder Release Site Sutton N/A White-tailed Deer M 6.5 1067 1/23/25 Breeder Release Site Medina Facility #3 White-tailed Deer M 5.5 1066 1/24/25 Breeder Release Site Hunt N/A White-tailed Deer M 2.5 1065 1/14/25 Breeder Release Site Zavala N/A White-tailed Deer M 5.5 1064 1/14/25 Breeder Release Site Zavala N/A White-tailed Deer M 5.5 1063 1/16/25 Free Range Hudspeth N/A Mule Deer M 8.5 1062 1/7/25 Breeder Deer Real Facility #29 White-tailed Deer F 3.4 1061 12/26/24 Breeder Release Site Brown N/A White-tailed Deer F 3.5
Snip…see full list of CWD Positives;
https://tpwd.texas.gov/huntwild/wild/diseases/cwd/positive-cases/listing-cwd-cases-texas.phtml
https://chronic-wasting-disease.blogspot.com/2025/05/texas-cwd-tse-prion-cases-rises-to-1099.html
December 2024
***> TEXAS CWD TSE PRION POSITIVE SAMPLES BY CALENDAR YEAR JANUARY 1 TO DECEMBER 31 2024 TOTAL TO DATE 1061 CASES CONFIRMED
Texas CWD total by calendar years
https://chronic-wasting-disease.blogspot.com/2024/12/texas-cwd-tse-prion-positive-samples-by.html
May 2024
Texas TAHC TPWD Confirm 132 More Cases of CWD TSE PrP
Jumps from 663 in March, to 795 Positive In May 2024, wow!
https://tpwd.texas.gov/huntwild/wild/diseases/cwd/positive-cases/listing-cwd-cases-texas.phtml#texasCWD
https://chronic-wasting-disease.blogspot.com/2024/05/texas-tahc-tpwd-confirm-132-more-cases.html
TPWD CWD Tracking
https://tpwd.texas.gov/huntwild/wild/diseases/cwd/positive-cases/listing-cwd-cases-texas.phtml#texasCWD
Counties where CWD Exposed Deer were Released
https://tpwd.texas.gov/documents/257/CWD-Trace-OutReleaseSites.pdf
Number of CWD Exposed Deer Released by County
https://tpwd.texas.gov/documents/258/CWD-Trace-OutReleaseSites-NbrDeer.pdf
TRUCKING CWD
“CWD spreads among wild populations at a relatively slow rate, limited by the natural home range and dispersed nature of wild animals.”
NOW HOLD YOUR HORSES, Chronic Wasting Disease CWD of Cervid can spread rather swiftly, traveling around 50 MPH, from the back of truck and trailer, and Here in Texas, we call it ‘Trucking CWD’…
Preventive Veterinary Medicine Volume 234, January 2025, 106385
Use of biosecurity practices to prevent chronic wasting disease in Minnesota cervid herds
Vehicles or trailers that entered the farm were used to transport other live cervids, cervid carcasses, or cervid body parts in past 3 years in 64.3 % (95 % CI 46.3–82.3) of larger elk/reindeer herds compared to 13.6 % (95 % CI 4.7–22.4) of smaller deer herds.
Snip…
Identifying the exact pathway of initial CWD transmission to cervid herds is often not possible, in part due to many potential pathways of transmission for the infection, including both direct and indirect contact with infected farmed or wild cervids (Kincheloe et al., 2021). That study identified that transmissions from infected farmed cervids may occur from direct contact with the movement of cervids from one herd to another and from indirect contact with the sharing of equipment, vehicles, clothing, reproductive equipment, and potentially through semen or embryos.
https://www.sciencedirect.com/science/article/abs/pii/S016758772400271X
***> Department records indicate that within the last five years (since January 1, 2020), 30 deer breeding facilities where CWD has been confirmed transferred a total of 8,799 deer to 249 additional deer breeding facilities and 487 release sites located in a total of 144 counties in Texas. <***
https://www.sos.state.tx.us/texreg/pdf/backview/0411/0411adop.pdf
Texas Kimble County Farm Chronic Wasting Disease CWD TSE Prion Approximate Herd Prevalence 12%
SUMMARY MINUTES OF THE 407th COMMISSION MEETING Texas Animal Health Commission
September 22, 2020
Chronic Wasting Disease (CWD):
A new CWD positive breeding herd was disclosed in February 2020 in Kimble County. This herd depopulation was completed in July 2020. Including the two index positive deer, an additional eight more positive deer were disclosed (approximate herd prevalence 12%). Since July 2015 and prior to this discovery, five positive captive breeder herds have been disclosed and four of those are in Medina County. One herd in Lavaca and three herds in Medina County were depopulated leaving one large herd in Medina County that is managed on a herd plan. A new zone was established in Val Verde County in December 2019 as a result of a positive free-ranging White-tailed Deer (WTD). A second positive WTD was also disclosed in February 2020 in the same area.
SUMMARY MINUTES OF THE 407th COMMISSION MEETING – 9/22/2020
Scrapie: The flock identified in April 2016 remains under quarantine in Hartley County.
https://www.tahc.texas.gov/agency/meetings/minutes/SummaryMinutes_CommMtg_2020-09-22
http://web.archive.org/web/20201017124040/https://www.tahc.texas.gov/agency/meetings/minutes/SummaryMinutes_CommMtg_2020-09-22.pdf
Chronic Wasting Disease in Texas A Real Disease with Proven Impacts
Produced by a coalition of concerned hunters, landowners, & conservationists (last update 1/2025)
https://storymaps.arcgis.com/stories/b93f528938ac48e9b56dcc79953cbec0
Aug 18, 2021
Oh, Deer
Heading Off a Wildlife Epidemic
CWD poses a significant threat to the future of hunting in Texas. Deer population declines of 45 and 50 percent have been documented in Colorado and Wyoming. A broad infection of Texas deer populations resulting in similar population impacts would inflict severe economic damage to rural communities and could negatively impact land markets. Specifically, those landowners seeking to establish a thriving herd of deer could avoid buying in areas with confirmed CWD infections. As they do with anthrax-susceptible properties, land brokers may find it advisable to inquire about the status of CWD infections on properties that they present for sale. Prospective buyers should also investigate the status of the wildlife on prospective properties. In addition, existing landowners should monitor developments as TPWD crafts management strategies to identify and contain this deadly disease.
Dr. Gilliland (c-gilliland@tamu.edu) is a research economist with the Texas Real Estate Research Center at Texas A&M University.
https://www.recenter.tamu.edu/articles/tierra-grande/oh-d
TEXAS BREEDER DEER ESCAPEE WITH CWD IN THE WILD, or so the genetics would show?
OH NO, please tell me i heard this wrong, a potential Texas captive escapee with cwd in the wild, in an area with positive captive cwd herd?
apparently, no ID though. tell me it ain't so please...
23:00 minute mark
''Free Ranging Deer, Dr. Deyoung looked at Genetics of this free ranging deer and what he found was, that the genetics on this deer were more similar to captive deer, than the free ranging population, but he did not see a significant connection to any one captive facility that he analyzed, so we believe, Ahhhhhh, this animal had some captive ahhh, whatnot.''
https://youtu.be/aoPDeGL6mpQ?t=1384
Commission Agenda Item No. 5 Exhibit B
DISEASE DETECTION AND RESPONSE RULES
PROPOSAL PREAMBLE
1. Introduction.
snip...
A third issue is the accuracy of mortality reporting. Department records indicate that for each of the last five years an average of 26 deer breeders have reported a shared total of 159 escapes. Department records for the same time period indicate an average of 31 breeding facilities reported a shared total of 825 missing deer (deer that department records indicate should be present in the facility, but cannot be located or verified).
https://tpwd.texas.gov/business/feedback/meetings/2022/1104/agenda/item.phtml?item=5
On January 21, 2017 a tornado took down thousands of feet of fence for a 420-acre illegal deer enclosure in Lamar County that had been subject to federal and state investigation for illegally importing white-tailed deer into Mississippi from Texas (a CWD positive state). Native deer were free to move on and off the property before all of the deer were able to be tested for CWD. Testing will be made available for a period of three years for CWD on the property and will be available for deer killed within a 5-mile radius of the property on a voluntary basis.
https://www.mdwfp.com/media/254796/2016-17-deer-report.pdf
“It is interesting to note that, in 2001, the State of Texas shifted its deer management strategies toward the same leanings that Kroll has suggested for Wisconsin. In Texas, the change was brought about via heavy lobbying from the high-fence deer ranching industry. This pressure helped convince the Texas Parks and Wildlife to change their regulations and allow private landowners to select the own deer biologists.”
http://www.texasmonthly.com/story/which-side-fence-are-you
Chronic Wasting Disease in Texas
A Real Disease with Proven Impacts
Produced by a coalition of concerned hunters, landowners, & conservationists (last update 08/2023)
Snip…
Since 2012, CWD has been detected in wild deer in just 7 counties in Texas and is only established in the western panhandle and far west Texas.
In that same period of time, captive deer breeders have exposed almost half of Texas counties to CWD.
Deer held in captive breeding facilities are confined to much tighter spaces, and have intimate contact with many more animals on a daily basis. By far the greatest factor in amplifying the spread of CWD is the artificial movement of these animals, shipped in livestock trailers hundreds of miles, far outside of their natural home range, and ultimately released to co-mingle with wild deer.
Each year, Texas captive deer breeders liberate 20,000-30,000 deer from their pens to the wild.
For every deer breeding facility where a CWD positive deer is discovered, an epidemiological investigation is conducted by the Texas Parks & Wildlife Department and the Texas Animal Health Commission to determine how many other deer may have been exposed to the disease and where they have been shipped. Because of the prolific artificial movement of captive deer, one deer with CWD can impact hundreds of other facilities and ranches across the state.
Unfortunately, released deer in Texas are not required to retain any kind of visible identification (an ear tag), and for this reason, the vast majority of released deer cannot be relocated for testing.
As of August 2023, 116 Texas counties have received possibly infected breeder deer that cannot be located, putting more than 140,000 landowners at risk of the disease.
Snip
The state of Texas has been testing for CWD since 2002. Since that time, more than 302,360 captive and free range deer have been tested.
From 2015-2022, more than 127,000 samples were collected from hunter-harvested and roadkill deer. This sampling rate and risk-based distribution provides scientists confidence that they would have detected the disease if it existed at a very low prevalence (<1%) in any given region at the time sampling began.
Snip…
We have learned from other states where CWD has been present the longest, that a constant increase in the prevalence of the disease may lead to a significant decline in the deer population. When disease prevalence exceeds 20%, deer populations have declined by up to 50%. In some areas of Colorado, where CWD has been present since 1985, mule deer abundance has declined by 45% since that time, despite adequate habitat and no hunting ( Miller et al. 2008 ). Similarly, the South Converse Game Unit in Wyoming has documented CWD prevalence exceeding 50% and has seen an approximate 50% decline in mule deer populations.
Snip…
Rural Economies
Deer hunting is the lifeblood of rural Texas. White-tailed deer hunting is by far the most impactful segment of the hunting economy, representing $4.3 billion, according to a recent Texas A&M Study. And while deer breeders represent a very small segment of that economy (less than 5%), they represent one of the greatest risks. ( Full Texas A&M Report )
Real Estate
Rural land prices are largely driven by recreational buyers with hunting as a top land amenity. Without deer hunting, many of these properties will be worth much less.
Conservation Funding
Deer hunters are the largest funders of wildlife conservation in Texas through excise taxes on firearms, ammunition, and gear along with active membership supporting and funding conservation organizations. If deer hunting suffers due to CWD, all wildlife in Texas lose.
Culture & Health
Texas’ native deer herd has iconic value for all Texans. Deer hunting brings families together, creates camaraderie in communities, and serves to connect Texans to nature. There is no better protein than wild, locally harvested, non-GMO and totally organic venison. A healthy deer herd leads to healthy Texans and a healthy and prosperous Texas.
Snip…
This isn't a disease for our lifetime. It's a disease for our grandchildren's lifetime.
- Dr. Bob Dittmar, Former Texas State Wildlife Veterinarian
Snip…
See the full text with maps, graphs, much more, excellent data…
https://bit.ly/3xL16Gm
Since 2012, CWD has been detected in wild deer in just 7 counties in Texas and is only established in the western panhandle and far west Texas.
In that same period of time, captive deer breeders have exposed almost half of Texas counties to CWD.
https://bit.ly/3xL16Gm
As of August 2023, 116 Texas counties have received possibly infected breeder deer that cannot be located, putting more than 140,000 landowners at risk of the disease.
https://bit.ly/3xL16Gm
ECONOMIC VALUES OF WHITE-TAILED DEER IN TEXAS
2022 SURVEY: PART I
http://web.archive.org/web/20230809171452/https://nri.tamu.edu/media/3702/economic-values-of-white-tailed-deer-in-texas-2022-survey-part-i.pdf
Don't mess Texas, or with Mother Nature in Texas, but, seems things went terribly wrong down here in Texas with CWD, be careful what you ask for;
TEXAS CWD STRAIN
“Wow,” he said. “Unlike anything we've seen before.”
The disease devastating deer herds may also threaten human health
Scientists are exploring the origins of chronic wasting disease before it becomes truly catastrophic.
Rae Ellen Bichell
Image credit: David Parsons/Istock
April 8, 2019
This story was published in collaboration with the Mountain West News Bureau, a collaboration between Wyoming Public Media, Boise State Public Radio in Idaho, KUER in Salt Lake City and KRCC and KUNC in Colorado.
SNIP...
One day in late February, in their laboratory in Fort Collins, Colorado, Wagner and Zabel compared the prions from the brains of CWD-infected deer in Texas with those of elk in Colorado. They want to know if the proteins were all mangled in the same way, or not. “If they are different, this would suggest that we have different strain properties, which is evidence as we're building our case that we might have multiple strains of CWD circulating in the U.S.,” says Wagner.
Step one is to see if they’re equally easy to destroy using a chemical called guanidine. The shape of a prion dictates everything, including the way it interacts with an animal’s cells and the ease with which chemicals can unfold it.
“Moment of truth,” said Wagner, as she and Zabel huddled around a computer, waiting for results to come through. When they did, Zabel was surprised.
“Wow,” he said. “Unlike anything we've seen before.”
The prions from the Texas deer were a lot harder to destroy than the ones from the Colorado elk. In fact, the guanidine barely damaged them at all. “We’ve never seen that before in any prion strain, which means that it has a completely different structure than we've ever seen before,” says Zabel. And that suggests that it might be a very different kind of chronic wasting disease. The researchers ran the same test on another Texas deer, with the same results.
Now, these are only the preliminary results from a few animals. Wagner and Zabel have a lot more experiments to do. But if future tests come to the same conclusion, it would support their hypothesis that there are multiple strains of chronic wasting disease out there, all with different origins. That, in turn, could mean that this disease will become even trickier to manage than it already is.
And, Zabel adds, there’s something else. “If it's still evolving, it may still evolve into a form that could potentially, eventually affect humans,” he says.
Zabel is not the only one worried about that possibility.
OSTERHOLM, THE EPIDEMIOLOGIST from Minnesota, is also concerned. He directs the Center for Infectious Disease Research and Policy at the University of Minnesota, and is serving a one-year stint as a “Science Envoy for Health Security” with the U.S. State Department. In February, he told Minnesota lawmakers that when it comes to chronic wasting disease, we are playing with fire. “You are going to hear from people that this is not going to be a problem other than a game farm issue. You're going to hear from people that it's not going to transmit to people, and I hope they're right, but I wouldn't bet on it,” he said. “And if we lose this one and haven’t done all we can do, we will pay a price.”
If that wasn’t warning enough, he added: “Just remember what happened in England.”
He was talking about mad cow disease. Decades ago, Osterholm got involved in studying the potential for the newly emerging condition — bovine spongiform encephalopathy, or BSE for short — to be transmitted to humans.
At that point, researchers had yet to document a prion disease in animals that could infect people. They did, however, have a few pieces of the puzzle. For one, work in Papua New Guinea had shown that people could transmit prion diseases to each other if they practiced cannibalism, especially of the brain-eating variety. They also knew that BSE was spreading quickly between cattle. Osterholm says he and others worried that the more widespread it became, the more chances it might have to change into something that could sicken people.
“A lot of people thought that it was an overreaction,” says Osterholm. “Then, of course, in 1996, 10 years later, we recognized that in fact transmission had occurred.” Variant Creutzfeldt-Jakob disease, as the illness is called when it appears in human beings, has infected about 230 people worldwide. Osterholm says he feels like he’s having déjà vu, except that instead of mad cow, now it’s chronic wasting disease that’s spreading in animals, with the potential to cross the species barrier to infect humans.
SNIP...SEE FULL TEXT;
https://www.hcn.org/articles/wildlife-the-disease-devastating-deer-herds-may-also-threaten-human-health-science
TEXAS CWD STRAIN
77. Assessing chronic wasting disease strain differences in free-ranging cervids across the United States
Kaitlyn M. Wagnera, Caitlin Ott-Connb, Kelly Strakab, Bob Dittmarc, Jasmine Battend, Robyn Piercea, Mercedes Hennessya, Elizabeth Gordona, Brett Israela, Jenn Ballarde and Mark D Zabela
aPrion Research Center at Colorado State University; bMichigan Department of Natural Resources; cTexas Parks and Wildlife Department; dMissouri Department of Conservation, 5. Arkansas Game and Fish Commission CONTACT Kaitlyn M. Wagner miedkait@rams.colostate.edu
ABSTRACT
Background/Introduction: Chronic wasting disease (CWD) is an invariably fatal prion disease affecting captive and free-ranging cervids, including white-tailed deer, mule deer, moose, elk, and reindeer. Since the initial description of the disease in the 1960’s, CWD has spread to 23 states, 3 Canadian Provinces, South Korea, Norway and, most recently, Finland. While some outbreaks of CWD were caused by transport of infected animals from endemic regions, the origin of CWD in other epizootics is unclear and has not been characterized. Previous studies have shown that there are two distinct strains of CWD. However, the continuous spread and the unclear origin of several outbreaks warrant continued surveillance and further characterization of strain diversity.
Materials and Methods: To address these knowledge gaps, we used biochemical tests to assess strain differences between CWD outbreaks in Michigan, Texas, Missouri, and Colorado, USA. Brain or lymph node samples were homogenized and digested in 50 µg/mL proteinase K (PK). These samples were then run on a Western blot to assess glycoform ratio and electrophoretic mobility. Texas samples were digested in 100 µg/mL PK. To assess conformational stability, brain or lymph node homogenates were incubated in increasing concentrations of guanidine hydrochloride from 0 M to 4 M in 0.5 M increments. Samples were then precipitated in methanol overnight, washed and PK digested in 50 µg/mL PK before slot blotting.
Results: Our results have found significant differences in glycoform ratio between CWD from Michigan and Colorado, but no differences were observed in conformational stability assays. Interestingly, when testing our CWD isolates from Texas to analyse electrophoretic mobility and glycoform ratio, we found that these samples did not exhibit the characteristic band shift when treated with PK, but PK resistant material remained. Additionally, results from our conformational stability assay demonstrate a unique profile of these Texas isolates. Testing of samples from Missouri is currently underway.
Conclusions: Thus far, our data indicate that there are strain differences between CWD circulating in Michigan and CWD in Colorado and provide important insight into CWD strain differences between two non-contiguous outbreaks. We have also identified a unique strain of CWD in Texas with biochemical strain properties not seen in any of our other CWD isolates. These results highlight the importance of continued surveillance to better understand this devastating disease. These results have important implications for CWD emergence, evolution and our understanding of prion strain heterogeneity on the landscape.
http://www.tandfonline.com/doi/full/10.1080/19336896.2019.1615197
Texas Game Wardens Bust Illegal Deer Operations Across the State Feb. 27, 2025
Media Contact: TPWD News, Business Hours, 512-389-8030
AUSTIN – A recent investigation by Texas Game Wardens resulted in approximately 1,200 pending charges and 22 suspects from across the state involved in the deer breeding industry and black-market wildlife trade.
The suspects and charges are associated with three deer breeding facilities, ten release sites, one deer management pen and three illegal facilities not registered in the Texas Wildlife Information Management Services (TWIMS) database, meaning they were operating or receiving deer in violation of registration requirements and disease monitoring protocols.
https://tpwd.texas.gov/newsmedia/releases/?req=20250227b
Texas Game Wardens Bust Illegal Deer Operations Across the State Feb. 27, 2025
https://chronic-wasting-disease.blogspot.com/2025/02/texas-game-wardens-bust-illegal-deer.html
TUESDAY, FEBRUARY 25, 2025
TEXAS ANIMAL HEALTH COMMISSION 423rd Commission Meeting CWD Update February 25, 2025
https://chronic-wasting-disease.blogspot.com/2025/02/texas-animal-health-commission-423rd.html
CWD Status Captive Herds
https://www.aphis.usda.gov/sites/default/files/status-of-captive-herds.pdf
THURSDAY, APRIL 24, 2025
***> US Captive CWD Positive Herds Update April 2025
https://chronic-wasting-disease.blogspot.com/2025/04/us-captive-cwd-positive-herds-update.html
Detection of chronic wasting disease prions in soil at an illegal white-tailed deer carcass disposal site
Published online: 06 Jun 2025
Abstract
Chronic wasting disease (CWD) is a contagious prion disorder affecting cervids such as deer, elk, caribou, and moose, causing progressive and severe neurological degeneration followed by eventual death. As CWD prions (PrPSc) accumulate in the body, they are shed through excreta and secreta, as well as through decomposing carcasses. Prions can persist in the environment for years, posing significant concerns for ongoing transmission to susceptible cervids and pose an unknown risk to sympatric species. We used a validated protocol for real-time quaking-induced conversion (RT-QuIC) in vitro prion amplification assay to detect prions in soil collected within and around an illegal white-tailed deer (Odocoileus virginianus, WTD) carcass disposal site and associated captive WTD farm in Beltrami County, Minnesota. We detected PrPSc in 26 of 201 soil samples across 15 locations within the illegal disposal site and one on the farm that housed the cervids. Importantly, a subset of RT-QuIC positive soil samples was collected from soils where carcasses were recovered, providing direct evidence that environmental contamination resulted from this illegal activity. These findings reveal that improper cervid carcass disposal practices may have important implications for ongoing CWD transmission through the environment.
Snip…
Conclusions
Using RT-QuIC, we detected PrPSc in 26 of 201 soil samples collected across 16 locations on public land where WTD carcasses had been disposed and the captive facility from where they originated. Within the disposal site, 25 out of 124 soil samples (20%) tested positive for PrPSc. Among those positive detections, 17, or 68%, were collected from locations where CWD-positive WTD remains had been previously recovered. This environmental investigation demonstrates how improper cervid carcass disposal practices can result in persistent environmental contamination, posing a potential risk to wildlife health. Given that disposal of livestock on the landscape is a common practice among producers [Citation54–56], these findings underscore the need for improved disposal practices and further investigation of environmental impacts. Expanding on this area of environmental research is crucial as the geographic range of CWD continues to expand [Citation57]. The use of RT-QuIC for prion detection in environmental samples offers an exciting advancement to environmental surveillance for prions, though as we demonstrate here and in Grunklee et al. [Citation41], assay optimization and validation for use with different environmental samples, including new soil types, is still necessary. Further enhancements to RT-QuIC and other methodologies for prion detection will facilitate more opportunities to explore the persistence, degradation, transport, and remediation of environmental prions.
https://www.tandfonline.com/doi/full/10.1080/19336896.2025.2514947
SUNDAY, MAY 05, 2024
Chronic Wasting Disease, Cervid Captive Herd CWD Infection rates, Zoonosis, and Environmental Risk Factors
https://chronic-wasting-disease.blogspot.com/2024/05/chronic-wasting-disease-cervid-captive.html
http://chronic-wasting-disease.blogspot.com/2017/04/
***> at present, no PrPC allele conferring absolute resistance in cervids has been identified.
J Gen Virol. 2017 Nov; 98(11): 2882–2892.
Published online 2017 Oct 23. doi: 10.1099/jgv.0.000952
Estimating chronic wasting disease susceptibility in cervids using real-time quaking-induced conversion
Chronic wasting disease (CWD) resistance in cervids is often characterized as decreased prevalence and/or protracted disease progression in individuals with specific alleles; at present, no PrPC allele conferring absolute resistance in cervids has been identified.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5845664/pdf/jgv-98-2882.pdf
SUNDAY, MAY 04, 2025
Texas Senate Bill 2651 establishment of a pilot program to breed deer resistant to CWD TSE Prion, what could go wrong?
https://chronic-wasting-disease.blogspot.com/2025/05/texas-senate-bill-2651-establishment-of_4.html
Texas S.B. 2843 Directs TPWD to conduct a comprehensive study of current measures to control chronic wasting disease (CWD) in deer
Trying to legislate CWD is what got Texas in this CWD mess to begin with, how did that work out$$$ Legislators and Politicians need to stay away and let TPWD and TAHC et try and contain this mess that Legislators and Politicians got us in, called CWD TSE Prion…terry
https://chronic-wasting-disease.blogspot.com/2025/04/texas-sb-2843-directs-tpwd-to-conduct.html
Friday, February 21, 2025
LEGISLATING CWD TSE Prion, Bills to release Genetically Modified Cervid into the wild, what could go wrong?
https://chronic-wasting-disease.blogspot.com/2025/02/legislating-cwd-tse-prion-bills-to.html
Texas CWD Update May 2025
WEDNESDAY, MAY 14, 2025
Texas CWD TSE Prion Cases Rises to 1099 Confirmed Cases To Date
Entries CWD Positives
Positive Number CWD Positive Confirmation Date Free Range Captive County Source Species Sex Age
1099 5/5/25 Breeder Deer Gillespie Facility #14 White-tailed Deer M 4.9 1098 4/24/25 Breeder Deer Zavala Facility #23 White-tailed Deer F 7.8 1097 4/24/25 Breeder Deer Zavala Facility #23 White-tailed Deer F 7.8 1096 4/17/25 Breeder Release Site Zavala N/A White-tailed Deer M 10.5 1095 4/3/25 Breeder Deer Kimble Facility #26 White-tailed Deer F 2.5 1094 4/3/25 Breeder Deer Kimble Facility #26 White-tailed Deer F 6.5 1093 4/3/25 Breeder Deer Kimble Facility #26 White-tailed Deer F 3.5 1092 4/3/25 Breeder Deer Frio Facility #24 White-tailed Deer F 1.7 1091 4/3/25 Breeder Deer Frio Facility #24 White-tailed Deer F 1.7 1090 4/3/25 Breeder Deer Frio Facility #24 White-tailed Deer F 3.7 1089 4/3/25 Breeder Deer Frio Facility #24 White-tailed Deer F 5.7 1088 4/3/25 Breeder Deer Frio Facility #24 White-tailed Deer F 5.7 1087 4/3/25 Breeder Deer Frio Facility #24 White-tailed Deer F 7.7 1086 4/3/25 Breeder Deer Frio Facility #24 White-tailed Deer F 3.7 1085 4/3/25 Breeder Deer Frio Facility #24 White-tailed Deer F 3.7 1084 3/19/25 Free Range El Paso N/A Mule Deer M 6.5 1083 3/14/25 Breeder Deer Frio Facility #24 White-tailed Deer M 1.7 1082 2/27/25 Breeder Deer Kaufman Facility #36 White-tailed Deer F 0.5 1081 2/27/25 Breeder Deer Kaufman Facility #36 White-tailed Deer M 1.5 1080 2/21/25 Breeder Deer Gillespie Facility #15 White-tailed Deer M 2.5 1079 2/19/25 Breeder Deer Frio Facility #24 White-tailed Deer M 1.4 1078 2/13/25 Breeder Release Site Medina Facility #3 Elk F 4 1077 1/14/25 Breeder Deer Frio Facility #24 White-tailed Deer F 2.5 1076 1/14/25 Breeder Deer Frio Facility #24 White-tailed Deer M 1.5 1075 1/14/25 Breeder Deer Frio Facility #24 White-tailed Deer M 1.5 1074 1/24/25 Breeder Deer Zavala Facility #23 White-tailed Deer F 1.5 1073 1/24/25 Breeder Deer Zavala Facility #23 White-tailed Deer F 4.5 1072 1/24/25 Breeder Deer Zavala Facility #23 White-tailed Deer M 2.5 1071 1/24/25 Breeder Deer Zavala Facility #23 White-tailed Deer M 2.5 1070 1/24/25 Breeder Deer Zavala Facility #23 White-tailed Deer M 3.5 1069 2/4/25 Breeder Release Site Brown N/A White-tailed Deer F 2.6 1068 1/23/25 Breeder Release Site Sutton N/A White-tailed Deer M 6.5 1067 1/23/25 Breeder Release Site Medina Facility #3 White-tailed Deer M 5.5 1066 1/24/25 Breeder Release Site Hunt N/A White-tailed Deer M 2.5 1065 1/14/25 Breeder Release Site Zavala N/A White-tailed Deer M 5.5 1064 1/14/25 Breeder Release Site Zavala N/A White-tailed Deer M 5.5 1063 1/16/25 Free Range Hudspeth N/A Mule Deer M 8.5 1062 1/7/25 Breeder Deer Real Facility #29 White-tailed Deer F 3.4 1061 12/26/24 Breeder Release Site Brown N/A White-tailed Deer F 3.5
Snip…see full list of CWD Positives;
https://tpwd.texas.gov/huntwild/wild/diseases/cwd/positive-cases/listing-cwd-cases-texas.phtml
https://chronic-wasting-disease.blogspot.com/2025/05/texas-cwd-tse-prion-cases-rises-to-1099.html
December 2024
***> TEXAS CWD TSE PRION POSITIVE SAMPLES BY CALENDAR YEAR JANUARY 1 TO DECEMBER 31 2024 TOTAL TO DATE 1061 CASES CONFIRMED
Texas CWD total by calendar years
https://chronic-wasting-disease.blogspot.com/2024/12/texas-cwd-tse-prion-positive-samples-by.html
May 2024
Texas TAHC TPWD Confirm 132 More Cases of CWD TSE PrP
Jumps from 663 in March, to 795 Positive In May 2024, wow!
https://tpwd.texas.gov/huntwild/wild/diseases/cwd/positive-cases/listing-cwd-cases-texas.phtml#texasCWD
https://chronic-wasting-disease.blogspot.com/2024/05/texas-tahc-tpwd-confirm-132-more-cases.html
TPWD CWD Tracking
https://tpwd.texas.gov/huntwild/wild/diseases/cwd/positive-cases/listing-cwd-cases-texas.phtml#texasCWD
Counties where CWD Exposed Deer were Released
https://tpwd.texas.gov/documents/257/CWD-Trace-OutReleaseSites.pdf
Number of CWD Exposed Deer Released by County
https://tpwd.texas.gov/documents/258/CWD-Trace-OutReleaseSites-NbrDeer.pdf
TRUCKING CWD
“CWD spreads among wild populations at a relatively slow rate, limited by the natural home range and dispersed nature of wild animals.”
NOW HOLD YOUR HORSES, Chronic Wasting Disease CWD of Cervid can spread rather swiftly, traveling around 50 MPH, from the back of truck and trailer, and Here in Texas, we call it ‘Trucking CWD’…
Preventive Veterinary Medicine Volume 234, January 2025, 106385
Use of biosecurity practices to prevent chronic wasting disease in Minnesota cervid herds
Vehicles or trailers that entered the farm were used to transport other live cervids, cervid carcasses, or cervid body parts in past 3 years in 64.3 % (95 % CI 46.3–82.3) of larger elk/reindeer herds compared to 13.6 % (95 % CI 4.7–22.4) of smaller deer herds.
Snip…
Identifying the exact pathway of initial CWD transmission to cervid herds is often not possible, in part due to many potential pathways of transmission for the infection, including both direct and indirect contact with infected farmed or wild cervids (Kincheloe et al., 2021). That study identified that transmissions from infected farmed cervids may occur from direct contact with the movement of cervids from one herd to another and from indirect contact with the sharing of equipment, vehicles, clothing, reproductive equipment, and potentially through semen or embryos.
https://www.sciencedirect.com/science/article/abs/pii/S016758772400271X
***> Department records indicate that within the last five years (since January 1, 2020), 30 deer breeding facilities where CWD has been confirmed transferred a total of 8,799 deer to 249 additional deer breeding facilities and 487 release sites located in a total of 144 counties in Texas. <***
https://www.sos.state.tx.us/texreg/pdf/backview/0411/0411adop.pdf
Texas Kimble County Farm Chronic Wasting Disease CWD TSE Prion Approximate Herd Prevalence 12%
SUMMARY MINUTES OF THE 407th COMMISSION MEETING Texas Animal Health Commission
September 22, 2020
Chronic Wasting Disease (CWD):
A new CWD positive breeding herd was disclosed in February 2020 in Kimble County. This herd depopulation was completed in July 2020. Including the two index positive deer, an additional eight more positive deer were disclosed (approximate herd prevalence 12%). Since July 2015 and prior to this discovery, five positive captive breeder herds have been disclosed and four of those are in Medina County. One herd in Lavaca and three herds in Medina County were depopulated leaving one large herd in Medina County that is managed on a herd plan. A new zone was established in Val Verde County in December 2019 as a result of a positive free-ranging White-tailed Deer (WTD). A second positive WTD was also disclosed in February 2020 in the same area.
SUMMARY MINUTES OF THE 407th COMMISSION MEETING – 9/22/2020
Scrapie: The flock identified in April 2016 remains under quarantine in Hartley County.
https://www.tahc.texas.gov/agency/meetings/minutes/SummaryMinutes_CommMtg_2020-09-22
http://web.archive.org/web/20201017124040/https://www.tahc.texas.gov/agency/meetings/minutes/SummaryMinutes_CommMtg_2020-09-22.pdf
Chronic Wasting Disease in Texas A Real Disease with Proven Impacts
Produced by a coalition of concerned hunters, landowners, & conservationists (last update 1/2025)
https://storymaps.arcgis.com/stories/b93f528938ac48e9b56dcc79953cbec0
Aug 18, 2021
Oh, Deer
Heading Off a Wildlife Epidemic
CWD poses a significant threat to the future of hunting in Texas. Deer population declines of 45 and 50 percent have been documented in Colorado and Wyoming. A broad infection of Texas deer populations resulting in similar population impacts would inflict severe economic damage to rural communities and could negatively impact land markets. Specifically, those landowners seeking to establish a thriving herd of deer could avoid buying in areas with confirmed CWD infections. As they do with anthrax-susceptible properties, land brokers may find it advisable to inquire about the status of CWD infections on properties that they present for sale. Prospective buyers should also investigate the status of the wildlife on prospective properties. In addition, existing landowners should monitor developments as TPWD crafts management strategies to identify and contain this deadly disease.
Dr. Gilliland (c-gilliland@tamu.edu) is a research economist with the Texas Real Estate Research Center at Texas A&M University.
https://www.recenter.tamu.edu/articles/tierra-grande/oh-d
TEXAS BREEDER DEER ESCAPEE WITH CWD IN THE WILD, or so the genetics would show?
OH NO, please tell me i heard this wrong, a potential Texas captive escapee with cwd in the wild, in an area with positive captive cwd herd?
apparently, no ID though. tell me it ain't so please...
23:00 minute mark
''Free Ranging Deer, Dr. Deyoung looked at Genetics of this free ranging deer and what he found was, that the genetics on this deer were more similar to captive deer, than the free ranging population, but he did not see a significant connection to any one captive facility that he analyzed, so we believe, Ahhhhhh, this animal had some captive ahhh, whatnot.''
https://youtu.be/aoPDeGL6mpQ?t=1384
Commission Agenda Item No. 5 Exhibit B
DISEASE DETECTION AND RESPONSE RULES
PROPOSAL PREAMBLE
1. Introduction.
snip...
A third issue is the accuracy of mortality reporting. Department records indicate that for each of the last five years an average of 26 deer breeders have reported a shared total of 159 escapes. Department records for the same time period indicate an average of 31 breeding facilities reported a shared total of 825 missing deer (deer that department records indicate should be present in the facility, but cannot be located or verified).
https://tpwd.texas.gov/business/feedback/meetings/2022/1104/agenda/item.phtml?item=5
On January 21, 2017 a tornado took down thousands of feet of fence for a 420-acre illegal deer enclosure in Lamar County that had been subject to federal and state investigation for illegally importing white-tailed deer into Mississippi from Texas (a CWD positive state). Native deer were free to move on and off the property before all of the deer were able to be tested for CWD. Testing will be made available for a period of three years for CWD on the property and will be available for deer killed within a 5-mile radius of the property on a voluntary basis.
https://www.mdwfp.com/media/254796/2016-17-deer-report.pdf
“It is interesting to note that, in 2001, the State of Texas shifted its deer management strategies toward the same leanings that Kroll has suggested for Wisconsin. In Texas, the change was brought about via heavy lobbying from the high-fence deer ranching industry. This pressure helped convince the Texas Parks and Wildlife to change their regulations and allow private landowners to select the own deer biologists.”
http://www.texasmonthly.com/story/which-side-fence-are-you
Chronic Wasting Disease in Texas
A Real Disease with Proven Impacts
Produced by a coalition of concerned hunters, landowners, & conservationists (last update 08/2023)
Snip…
Since 2012, CWD has been detected in wild deer in just 7 counties in Texas and is only established in the western panhandle and far west Texas.
In that same period of time, captive deer breeders have exposed almost half of Texas counties to CWD.
Deer held in captive breeding facilities are confined to much tighter spaces, and have intimate contact with many more animals on a daily basis. By far the greatest factor in amplifying the spread of CWD is the artificial movement of these animals, shipped in livestock trailers hundreds of miles, far outside of their natural home range, and ultimately released to co-mingle with wild deer.
Each year, Texas captive deer breeders liberate 20,000-30,000 deer from their pens to the wild.
For every deer breeding facility where a CWD positive deer is discovered, an epidemiological investigation is conducted by the Texas Parks & Wildlife Department and the Texas Animal Health Commission to determine how many other deer may have been exposed to the disease and where they have been shipped. Because of the prolific artificial movement of captive deer, one deer with CWD can impact hundreds of other facilities and ranches across the state.
Unfortunately, released deer in Texas are not required to retain any kind of visible identification (an ear tag), and for this reason, the vast majority of released deer cannot be relocated for testing.
As of August 2023, 116 Texas counties have received possibly infected breeder deer that cannot be located, putting more than 140,000 landowners at risk of the disease.
Snip
The state of Texas has been testing for CWD since 2002. Since that time, more than 302,360 captive and free range deer have been tested.
From 2015-2022, more than 127,000 samples were collected from hunter-harvested and roadkill deer. This sampling rate and risk-based distribution provides scientists confidence that they would have detected the disease if it existed at a very low prevalence (<1%) in any given region at the time sampling began.
Snip…
We have learned from other states where CWD has been present the longest, that a constant increase in the prevalence of the disease may lead to a significant decline in the deer population. When disease prevalence exceeds 20%, deer populations have declined by up to 50%. In some areas of Colorado, where CWD has been present since 1985, mule deer abundance has declined by 45% since that time, despite adequate habitat and no hunting ( Miller et al. 2008 ). Similarly, the South Converse Game Unit in Wyoming has documented CWD prevalence exceeding 50% and has seen an approximate 50% decline in mule deer populations.
Snip…
Rural Economies
Deer hunting is the lifeblood of rural Texas. White-tailed deer hunting is by far the most impactful segment of the hunting economy, representing $4.3 billion, according to a recent Texas A&M Study. And while deer breeders represent a very small segment of that economy (less than 5%), they represent one of the greatest risks. ( Full Texas A&M Report )
Real Estate
Rural land prices are largely driven by recreational buyers with hunting as a top land amenity. Without deer hunting, many of these properties will be worth much less.
Conservation Funding
Deer hunters are the largest funders of wildlife conservation in Texas through excise taxes on firearms, ammunition, and gear along with active membership supporting and funding conservation organizations. If deer hunting suffers due to CWD, all wildlife in Texas lose.
Culture & Health
Texas’ native deer herd has iconic value for all Texans. Deer hunting brings families together, creates camaraderie in communities, and serves to connect Texans to nature. There is no better protein than wild, locally harvested, non-GMO and totally organic venison. A healthy deer herd leads to healthy Texans and a healthy and prosperous Texas.
Snip…
This isn't a disease for our lifetime. It's a disease for our grandchildren's lifetime.
- Dr. Bob Dittmar, Former Texas State Wildlife Veterinarian
Snip…
See the full text with maps, graphs, much more, excellent data…
https://bit.ly/3xL16Gm
Since 2012, CWD has been detected in wild deer in just 7 counties in Texas and is only established in the western panhandle and far west Texas.
In that same period of time, captive deer breeders have exposed almost half of Texas counties to CWD.
https://bit.ly/3xL16Gm
As of August 2023, 116 Texas counties have received possibly infected breeder deer that cannot be located, putting more than 140,000 landowners at risk of the disease.
https://bit.ly/3xL16Gm
ECONOMIC VALUES OF WHITE-TAILED DEER IN TEXAS
2022 SURVEY: PART I
http://web.archive.org/web/20230809171452/https://nri.tamu.edu/media/3702/economic-values-of-white-tailed-deer-in-texas-2022-survey-part-i.pdf
Don't mess Texas, or with Mother Nature in Texas, but, seems things went terribly wrong down here in Texas with CWD, be careful what you ask for;
TEXAS CWD STRAIN
“Wow,” he said. “Unlike anything we've seen before.”
The disease devastating deer herds may also threaten human health
Scientists are exploring the origins of chronic wasting disease before it becomes truly catastrophic.
Rae Ellen Bichell
Image credit: David Parsons/Istock
April 8, 2019
This story was published in collaboration with the Mountain West News Bureau, a collaboration between Wyoming Public Media, Boise State Public Radio in Idaho, KUER in Salt Lake City and KRCC and KUNC in Colorado.
SNIP...
One day in late February, in their laboratory in Fort Collins, Colorado, Wagner and Zabel compared the prions from the brains of CWD-infected deer in Texas with those of elk in Colorado. They want to know if the proteins were all mangled in the same way, or not. “If they are different, this would suggest that we have different strain properties, which is evidence as we're building our case that we might have multiple strains of CWD circulating in the U.S.,” says Wagner.
Step one is to see if they’re equally easy to destroy using a chemical called guanidine. The shape of a prion dictates everything, including the way it interacts with an animal’s cells and the ease with which chemicals can unfold it.
“Moment of truth,” said Wagner, as she and Zabel huddled around a computer, waiting for results to come through. When they did, Zabel was surprised.
“Wow,” he said. “Unlike anything we've seen before.”
The prions from the Texas deer were a lot harder to destroy than the ones from the Colorado elk. In fact, the guanidine barely damaged them at all. “We’ve never seen that before in any prion strain, which means that it has a completely different structure than we've ever seen before,” says Zabel. And that suggests that it might be a very different kind of chronic wasting disease. The researchers ran the same test on another Texas deer, with the same results.
Now, these are only the preliminary results from a few animals. Wagner and Zabel have a lot more experiments to do. But if future tests come to the same conclusion, it would support their hypothesis that there are multiple strains of chronic wasting disease out there, all with different origins. That, in turn, could mean that this disease will become even trickier to manage than it already is.
And, Zabel adds, there’s something else. “If it's still evolving, it may still evolve into a form that could potentially, eventually affect humans,” he says.
Zabel is not the only one worried about that possibility.
OSTERHOLM, THE EPIDEMIOLOGIST from Minnesota, is also concerned. He directs the Center for Infectious Disease Research and Policy at the University of Minnesota, and is serving a one-year stint as a “Science Envoy for Health Security” with the U.S. State Department. In February, he told Minnesota lawmakers that when it comes to chronic wasting disease, we are playing with fire. “You are going to hear from people that this is not going to be a problem other than a game farm issue. You're going to hear from people that it's not going to transmit to people, and I hope they're right, but I wouldn't bet on it,” he said. “And if we lose this one and haven’t done all we can do, we will pay a price.”
If that wasn’t warning enough, he added: “Just remember what happened in England.”
He was talking about mad cow disease. Decades ago, Osterholm got involved in studying the potential for the newly emerging condition — bovine spongiform encephalopathy, or BSE for short — to be transmitted to humans.
At that point, researchers had yet to document a prion disease in animals that could infect people. They did, however, have a few pieces of the puzzle. For one, work in Papua New Guinea had shown that people could transmit prion diseases to each other if they practiced cannibalism, especially of the brain-eating variety. They also knew that BSE was spreading quickly between cattle. Osterholm says he and others worried that the more widespread it became, the more chances it might have to change into something that could sicken people.
“A lot of people thought that it was an overreaction,” says Osterholm. “Then, of course, in 1996, 10 years later, we recognized that in fact transmission had occurred.” Variant Creutzfeldt-Jakob disease, as the illness is called when it appears in human beings, has infected about 230 people worldwide. Osterholm says he feels like he’s having déjà vu, except that instead of mad cow, now it’s chronic wasting disease that’s spreading in animals, with the potential to cross the species barrier to infect humans.
SNIP...SEE FULL TEXT;
https://www.hcn.org/articles/wildlife-the-disease-devastating-deer-herds-may-also-threaten-human-health-science
TEXAS CWD STRAIN
77. Assessing chronic wasting disease strain differences in free-ranging cervids across the United States
Kaitlyn M. Wagnera, Caitlin Ott-Connb, Kelly Strakab, Bob Dittmarc, Jasmine Battend, Robyn Piercea, Mercedes Hennessya, Elizabeth Gordona, Brett Israela, Jenn Ballarde and Mark D Zabela
aPrion Research Center at Colorado State University; bMichigan Department of Natural Resources; cTexas Parks and Wildlife Department; dMissouri Department of Conservation, 5. Arkansas Game and Fish Commission CONTACT Kaitlyn M. Wagner miedkait@rams.colostate.edu
ABSTRACT
Background/Introduction: Chronic wasting disease (CWD) is an invariably fatal prion disease affecting captive and free-ranging cervids, including white-tailed deer, mule deer, moose, elk, and reindeer. Since the initial description of the disease in the 1960’s, CWD has spread to 23 states, 3 Canadian Provinces, South Korea, Norway and, most recently, Finland. While some outbreaks of CWD were caused by transport of infected animals from endemic regions, the origin of CWD in other epizootics is unclear and has not been characterized. Previous studies have shown that there are two distinct strains of CWD. However, the continuous spread and the unclear origin of several outbreaks warrant continued surveillance and further characterization of strain diversity.
Materials and Methods: To address these knowledge gaps, we used biochemical tests to assess strain differences between CWD outbreaks in Michigan, Texas, Missouri, and Colorado, USA. Brain or lymph node samples were homogenized and digested in 50 µg/mL proteinase K (PK). These samples were then run on a Western blot to assess glycoform ratio and electrophoretic mobility. Texas samples were digested in 100 µg/mL PK. To assess conformational stability, brain or lymph node homogenates were incubated in increasing concentrations of guanidine hydrochloride from 0 M to 4 M in 0.5 M increments. Samples were then precipitated in methanol overnight, washed and PK digested in 50 µg/mL PK before slot blotting.
Results: Our results have found significant differences in glycoform ratio between CWD from Michigan and Colorado, but no differences were observed in conformational stability assays. Interestingly, when testing our CWD isolates from Texas to analyse electrophoretic mobility and glycoform ratio, we found that these samples did not exhibit the characteristic band shift when treated with PK, but PK resistant material remained. Additionally, results from our conformational stability assay demonstrate a unique profile of these Texas isolates. Testing of samples from Missouri is currently underway.
Conclusions: Thus far, our data indicate that there are strain differences between CWD circulating in Michigan and CWD in Colorado and provide important insight into CWD strain differences between two non-contiguous outbreaks. We have also identified a unique strain of CWD in Texas with biochemical strain properties not seen in any of our other CWD isolates. These results highlight the importance of continued surveillance to better understand this devastating disease. These results have important implications for CWD emergence, evolution and our understanding of prion strain heterogeneity on the landscape.
http://www.tandfonline.com/doi/full/10.1080/19336896.2019.1615197
Texas Game Wardens Bust Illegal Deer Operations Across the State Feb. 27, 2025
Media Contact: TPWD News, Business Hours, 512-389-8030
AUSTIN – A recent investigation by Texas Game Wardens resulted in approximately 1,200 pending charges and 22 suspects from across the state involved in the deer breeding industry and black-market wildlife trade.
The suspects and charges are associated with three deer breeding facilities, ten release sites, one deer management pen and three illegal facilities not registered in the Texas Wildlife Information Management Services (TWIMS) database, meaning they were operating or receiving deer in violation of registration requirements and disease monitoring protocols.
https://tpwd.texas.gov/newsmedia/releases/?req=20250227b
Texas Game Wardens Bust Illegal Deer Operations Across the State Feb. 27, 2025
https://chronic-wasting-disease.blogspot.com/2025/02/texas-game-wardens-bust-illegal-deer.html
TUESDAY, FEBRUARY 25, 2025
TEXAS ANIMAL HEALTH COMMISSION 423rd Commission Meeting CWD Update February 25, 2025
https://chronic-wasting-disease.blogspot.com/2025/02/texas-animal-health-commission-423rd.html
CWD Status Captive Herds
https://www.aphis.usda.gov/sites/default/files/status-of-captive-herds.pdf
THURSDAY, APRIL 24, 2025
***> US Captive CWD Positive Herds Update April 2025
https://chronic-wasting-disease.blogspot.com/2025/04/us-captive-cwd-positive-herds-update.html
Detection of chronic wasting disease prions in soil at an illegal white-tailed deer carcass disposal site
Published online: 06 Jun 2025
Abstract
Chronic wasting disease (CWD) is a contagious prion disorder affecting cervids such as deer, elk, caribou, and moose, causing progressive and severe neurological degeneration followed by eventual death. As CWD prions (PrPSc) accumulate in the body, they are shed through excreta and secreta, as well as through decomposing carcasses. Prions can persist in the environment for years, posing significant concerns for ongoing transmission to susceptible cervids and pose an unknown risk to sympatric species. We used a validated protocol for real-time quaking-induced conversion (RT-QuIC) in vitro prion amplification assay to detect prions in soil collected within and around an illegal white-tailed deer (Odocoileus virginianus, WTD) carcass disposal site and associated captive WTD farm in Beltrami County, Minnesota. We detected PrPSc in 26 of 201 soil samples across 15 locations within the illegal disposal site and one on the farm that housed the cervids. Importantly, a subset of RT-QuIC positive soil samples was collected from soils where carcasses were recovered, providing direct evidence that environmental contamination resulted from this illegal activity. These findings reveal that improper cervid carcass disposal practices may have important implications for ongoing CWD transmission through the environment.
Snip…
Conclusions
Using RT-QuIC, we detected PrPSc in 26 of 201 soil samples collected across 16 locations on public land where WTD carcasses had been disposed and the captive facility from where they originated. Within the disposal site, 25 out of 124 soil samples (20%) tested positive for PrPSc. Among those positive detections, 17, or 68%, were collected from locations where CWD-positive WTD remains had been previously recovered. This environmental investigation demonstrates how improper cervid carcass disposal practices can result in persistent environmental contamination, posing a potential risk to wildlife health. Given that disposal of livestock on the landscape is a common practice among producers [Citation54–56], these findings underscore the need for improved disposal practices and further investigation of environmental impacts. Expanding on this area of environmental research is crucial as the geographic range of CWD continues to expand [Citation57]. The use of RT-QuIC for prion detection in environmental samples offers an exciting advancement to environmental surveillance for prions, though as we demonstrate here and in Grunklee et al. [Citation41], assay optimization and validation for use with different environmental samples, including new soil types, is still necessary. Further enhancements to RT-QuIC and other methodologies for prion detection will facilitate more opportunities to explore the persistence, degradation, transport, and remediation of environmental prions.
https://www.tandfonline.com/doi/full/10.1080/19336896.2025.2514947
SUNDAY, MAY 05, 2024
Chronic Wasting Disease, Cervid Captive Herd CWD Infection rates, Zoonosis, and Environmental Risk Factors
https://chronic-wasting-disease.blogspot.com/2024/05/chronic-wasting-disease-cervid-captive.html
THURSDAY, APRIL 24, 2025
US Captive CWD Positive Herds Update April 2025
https://chronic-wasting-disease.blogspot.com/2025/04/us-captive-cwd-positive-herds-update.html
US Captive CWD Positive Herds Update April 2025
https://chronic-wasting-disease.blogspot.com/2025/04/us-captive-cwd-positive-herds-update.html
terry
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