Friday, December 02, 2022

Texas Chronic Wasting Disease CWD TSE Prion Increases To 428 Confirmed To Date

Texas Chronic Wasting Disease CWD TSE Prion Increases To 428 Confirmed To Date

Biologists Stress Testing Harvests for Chronic Wasting Disease During Deer Season

DEC. 2, 2022

MEDIA CONTACT: TPWD NEWS, BUSINESS HOURS, 512-389-8030

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AUSTIN— With the recent discovery of Chronic Wasting Disease (CWD) in Kaufman County, Texas Parks and Wildlife Department (TPWD) biologists are stressing the importance of testing harvested deer taken this hunting season to curb the spread of this deadly disease.

CWD is a highly contagious and fatal neurological disease affecting members of the deer family such as white-tailed deer, mule deer, elk and moose. Hunters and landowners can voluntarily submit their harvest for free CWD testing at a TPWD check station or by contacting local wildlife biologists. 


First recognized in 1967 in captive mule deer in Colorado, CWD has since been documented in captive and/or free-ranging deer in 30 states and three Canadian provinces. To date, 428 captive or free-ranging cervids — including white-tailed deer, mule deer, red deer, and elk — in 17 Texas counties have tested positive for CWD.

Eradication of CWD is very difficult if not impossible when established in free-ranging deer populations and in the environment. Testing for CWD allows wildlife biologists and animal health officials to get a clearer picture of the prevalence and distribution of the disease across Texas. Proactive monitoring improves the state’s response time to a CWD detection and can greatly reduce the risk of the disease further spreading to neighboring captive and free-ranging populations.

Those hunting in CWD surveillance and containment zones need to know the submission requirements 


for susceptible species before hitting the field this season. Anyone hunting in an established CWD zone must bring their deer to a check station within 48 hours of harvest for testing.

There are about 30 check stations and drop boxes across the state in Kimble County, far West Texas, South Central Texas, the northwest Panhandle, Val Verde County, Hunt County, Lubbock County, Gillespie County, Limestone County and Duval County.

For more information about CWD, visit the TPWD website, the Texas Animal Health Commission website, or read about how hunters can help protect deer from CWD with a story from the Texas Parks and Wildlife Magazine.

Find TPWD veterinarians speaking about CWD on the TPWD YouTube page.


Texas CWD Confirmed High Fence Release Site Kaufman County, To Date 420 Cases Confirmed

Chronic Wasting Disease Detected at a High Fence Release Site in Kaufman County 

Nov. 28, 2022 Media Contact: TPWD News, Business Hours, 512-389-8030 

AUSTIN –Chronic Wasting Disease (CWD) was detected on a high fence release site in Kaufman County. This is the first positive detection of CWD in the county.

The white-tailed buck, harvested at a high-fence release site located in a CWD Surveillance Zone, was delivered to a Hunt County CWD check station in compliance with surveillance zone requirements. Texas Parks and Wildlife Department (TPWD) and Texas Animal Health Commission (TAHC) received notice of the CWD-positive test result from the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) on Nov. 14.
Prior to this detection, the high-fence release site was identified as a “trace herd” property to the Hunt County CWD-positive deer breeding facility reported on March 31, 2021, meaning deer were transferred from the Hunt County facility to this release site prior to discovery of CWD in that facility. Plans to conduct additional CWD investigations are underway.

“The incubation period of CWD can span years, creating disease detection and management challenges as seen in this recent detection,” said Andy Schwartz, TAHC Executive Director and State Veterinarian.
Animal health and wildlife officials will continue investigations to determine the extent of the disease within the property and mitigate risks to Texas’ CWD-susceptible species. Adequate surveillance and quick detection of CWD can help mitigate the disease’s spread.

“The discovery of CWD on this ranch is an unfortunate situation that TPWD and TAHC take very seriously,” said John Silovsky, TPWD Wildlife Division Director. “Both agencies will respond appropriately to this matter to protect the state’s susceptible species from further disease exposure. Hunters are reminded of the requirement to bring their harvested deer to the check station within 48 hours of harvest.”

First recognized in 1967 in captive mule deer in Colorado, CWD has since been documented in captive and/or free-ranging deer in 30 states and three Canadian provinces. To date, 420 captive or free-ranging cervids — including white-tailed deer, mule deer, red deer, and elk — in 17 Texas counties have tested positive for CWD. For more information on previous detections visit the CWD page on the TPWD website.

Testing for CWD allows wildlife biologists and animal health officials to get a clearer picture of the prevalence and distribution of the disease across Texas. Proactive monitoring improves the state’s response time to a CWD detection and can greatly reduce the risk of the disease further spreading to neighboring captive and free-ranging populations.

This confirmation is a good reminder to those hunting in CWD surveillance and containment zones to know the submission requirements for CWD susceptible species. Additionally, hunters outside of established surveillance and containment zones are encouraged to voluntarily submit their harvest for testing at a check station, for free, before heading home from the field. A map of TPWD check stations for all CWD zones can be found on the TPWD website.

For more information about CWD, visit the TPWD web site or the TAHC web site.


''To date, 420 captive or free-ranging cervids — including white-tailed deer, mule deer, red deer, and elk — in 17 Texas counties have tested positive for CWD.''

TAHC OFFICIAL MINUTES OF THE 413th COMMISSION MEETING TSE PRION July 26, 2022

OFFICIAL MINUTES OF THE 413th COMMISSION MEETING Texas Animal Health Commission July 26, 2022 

snip...

• Chronic Wasting Disease (CWD):

 Positive WTD Breeder Facilities: seven in 2021

o Four have been depopulated

o One breeder depopulated his breeder deer on his own in mid-April.

o One signed a Genetic Herd Plan

o One is in litigation

 Trace Herds: 303 WTD facilities with connections to a positive facility

o 221 facilities released after meeting requirements (164 Breeder & 57 Release sites/DMP)

o 24 facilities are under a Herd Plan (2 Breeder & 22 Release Sites/DMP)

o 50 facilities are pending a signed Herd Plan (4 Breeder & 46 Release Sites/DMP)

o Eight out of State

 USDA VS review of the Texas CWD HCP UPDATE

o Adoption of proposed changes to Chapter 40, Chronic Wasting Disease, up for consideration today

snip...


Counties where CWD Exposed Deer were Released


Number of CWD Exposed Deer Released by County


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). 


PRION CONFERENCE 2022 ABSTRACTS CWD TSE PrP ZOONOSIS and ENVIRONMENTAL FACTORS 

Chronic wasting disease detection in environmental and biological samples from a taxidermy site

Paulina Sotoa,b, J. Hunter Reedc, Mitch Lockwoodc, and Rodrigo Moralesa,b aDepartment of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Texas, USA; bUniversidad Bernardo O’Higgins, Santiago, Chile; cTexas Parks and Wildlife Department, Texas, USA 

Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy affecting captive and free-ranging cervids (e.g., mule deer, white-tailed deer, elk, reindeer, and moose). Nowadays, CWD is widely distributed in North America. It is suggested that CWD spreads due to direct animal contact or through exposure to contaminated environments previously inhabited by infected animals. CWD may also be spread through the movement of infected animals and carcasses. Taxidermy practices involve processing deer tissues (or whole animal carcasses). In many cases, the CWD status of processed animals is unknown. This can generate risks of disease spread and transmission. Taxidermy practices include different steps involving physical, chemical, and biological procedures. Without proper tissue handling or disposal practices, taxidermist facilities may become a focus of prion infectivity. 

Aims: In this study, we evaluated the presence of infectious prions in a taxidermy facility believed to be exposed to CWD. Detection was performed using the Protein Misfolding Cyclic Amplification (PMCA) technique in biological and inert environmental samples. Methods: We collected biological and environmental samples (plants, soils, insects, excreta, and others) from a taxidermy facility, and we tested these samples using the PMCA technique. In addition, we swabbed different surfaces possibly exposed to CWD-infected animals. For the PMCA reaction, we directly used a swab piece or 10 µL of 20% w/v homogenized samples. 
Results: The PMCA analysis demonstrated CWD seeding activity in some of the components of this facility, including insects involved in head processing, soils, and a trash dumpster. 

Conclusions: Different areas of this property were used for various taxidermy procedures. We were able to detect the presence of prions in 

i) soils that were in contact with the heads of dead animals, 

ii) insects involved in the cleaning of skulls, and 

iii) an empty dumpster where animal carcasses were previously placed. 

This is the first report demonstrating that swabbing is a helpful method to screen for prion infectivity on surfaces potentially contaminated with CWD. These findings are relevant as this swabbing and amplification strategy may be used to evaluate the disease status of other free-ranging and captive settings where there is a concern for CWD transmissions, such as at feeders and water troughs with CWD-exposed properties. This approach could have substantial implications for free-ranging cervid surveillance as well as in epidemiological investigations of CWD. 


Carrot plants as potential vectors for CWD transmission

Paulina Sotoa,b, Francisca Bravo-Risia,b, Claudio Sotoa, and Rodrigo Moralesa,b
aDepartment of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Texas, USA; bUniversidad Bernardo O’Higgins, Santiago, Chile

Prion diseases are infectious neurodegenerative disorders afflicting humans and other mammals. These diseases are generated by the misfolding of the cellular prion protein into a disease-causing isoform. Chronic wasting disease (CWD) is a prevalent prion disease affecting cervids (captive and free-range). CWD is thought to be transmitted through direct animal contact or by indirect exposure to contaminated environments. Many studies have shown that infectious prions can enter the environment through saliva, feces, or urine from infected animals and decaying carcasses. However, we do not fully understand the specific contribution of each component to disease transmission events. Plants are logical environmental components to be evaluated since they grow in environments contaminated with CWD prions and are relevant for animal and human nutrition.

Aims: The main objective of this study is to study whether prions are transported to the roots and leaves of carrots, an edible plant commonly used in the human diet and as deer bait.

Methods: We have grown carrot plants in CWD-infected soils. After 90 days, we harvested the carrots and separated them from the leaves. The experiment was controlled by growing plants in soil samples treated with brain extracts from healthy animals. These materials were interrogated for their prion seeding activity using the Protein Misfolding Cyclic Amplification (PMCA) technique. Infectivity was evaluated in mouse bioassays (intracerebral injections in Tg1536 mice). The animals were sacrificed when they showed established signs of prion disease. Animals not displaying clinical signs were sacrificed at 600 days post-inoculation.

Results: The PMCA analysis demonstrated CWD seeding activity in soils contaminated with CWD prions, as well as in carrot plants (leaves and roots) grown on them. Bioassays demonstrated that both leaves and roots contained CWD prions in sufficient quantities to induce disease (92% attack rate). As expected, animals treated with prion-infected soils developed prion disease at shorter incubation periods (and complete attack rates) compared to plant components. Animals treated with soil and plant components exposed with CWD-free brain extracts did not display prion-associated clinical signs or evidence of sub-clinical prion infection.

Conclusions: We show that edible plant components can absorb prions from CWD contaminated soils and transport them to their aerial parts. Our results indicate that plants could participate as vectors of CWD transmission. Importantly, plants designated for human consumption represent a risk of introducing CWD prions into the human food chain.

Large-scale PMCA screening of retropharyngeal lymph nodes and in white-tailed deer and comparisons with ELISA and IHC: the Texas CWD study

Rebeca Benaventea, Paulina Sotoa, Mitch Lockwoodb, and Rodrigo Moralesa
aDepartment of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Texas, USA; bTexas Park and Wildlife Department, Texas, USA

Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy that affects various species of cervids, and both free-ranging and captive animals. Until now, CWD has been detected in 3 continents: North America, Europe, and Asia. CWD prevalence in some states may reach 30% of total animals. In Texas, the first case of CWD was reported in a free-range mule deer in Hudspeth and now it has been detected in additional 14 counties. Currently, the gold standard techniques used for CWD screening and detection are ELISA and immunohistochemistry (IHC) of obex and retropharyngeal lymph nodes (RPLN). Unfortunately, these methods are known for having a low diagnostic sensitivity. Hence, many CWD-infected animals at pre-symptomatic stages may be misdiagnosed. Two promising in vitro prion amplification techniques, including the real-time quaking-induced conversion (RT-QuIC) and the protein misfolding cyclic amplification (PMCA) have been used to diagnose CWD and other prion diseases in several tissues and bodily fluids. Considering the low cost and speed of RT-QuIC, two recent studies have communicated the potential of this technique to diagnose CWD prions in RPLN samples. Unfortunately, the data presented in these articles suggest that identification of CWD positive samples is comparable to the currently used ELISA and IHC protocols. Similar studies using the PMCA technique have not been reported.

Aims: Compare the CWD diagnostic potential of PMCA with ELISA and IHC in RPLN samples from captive and free-range white-tailed deer. Material and Methods: In this study we analyzed 1,003 RPLN from both free-ranging and captive white-tailed deer collected in Texas. Samples were interrogated with the PMCA technique for their content of CWD prions. PMCA data was compared with the results obtained through currently approved techniques.

Results: Our results show a 15-fold increase in CWD detection in free-range deer compared with ELISA. Our results unveil the presence of prion infected animals in Texas counties with no previous history of CWD. In the case of captive deer, we detected a 16% more CWD positive animals when compared with IHC. Interestingly, some of these positive samples displayed differences in their electroforetic mobilities, suggesting the presence of different prion strains within the State of Texas.

Conclusions: PMCA sensitivity is significantly higher than the current gold standards techniques IHC and ELISA and would be a good tool for rapid CWD screening.


PRION CONFERENCE 2022 ABSTRACTS CWD TSE PrP ZOONOSIS 

Transmission of prion infectivity from CWD-infected macaque tissues to rodent models demonstrates the zoonotic potential of chronic wasting disease.

Samia Hannaouia, Ginny Chenga, Wiebke Wemheuerb, Walter J. Schulz-Schaefferb, Sabine Gilcha, and Hermann M. Schätzla 

Aims: Chronic wasting disease (CWD) is a prion disease of cervids. Its rapid geographic expansion, shedding of infectivity and persistence in the environment for many years are of concern for humans. Here, we provide the first evidence by transmission experiments to different transgenic mouse models and bank voles that Cynomolgus macaques inoculated via different routes with CWD-positive cervid tissues harbor infectious prions that elicit clinical disease in rodents.

Material and Methods: We used tissue materials from macaques inoculated with CWD to inoculate transgenic mice overexpressing cervid PrPCfollowed by transmission into bank voles. We used RT-QuIC, immunoblot and PET blot analysis to assess brains, spinal cords, and tissues of the gastrointestinal tract (GIT) for the presence of prions.

Results: Our results show that of the macaque materials that induced clinical disease in transgenic mice,73% were from the CNS (46% spinal cord and 27% brain), and 27% were from the spleen, although attack rates were low around 20%. Clinical mice did not display PK-resistant PrPSc(PrPres) in immunoblot, but showed low-levels of prion seeding activity. Transmission into bank voles from clinical transgenic mice led to a 100% attack rate with typical PrPressignature in immunoblot, which was different from that of voles inoculated directly with CWD or scrapie prions. High-level prion seeding activity in brain and spinal cord and PrPresdeposition in the brain were present. Remarkably, we also found prion seeding activity in GIT tissues of inoculated voles. Second passage in bank voles led to a 100% attack rate in voles inoculated with brain, spinal cord and small intestine material from first round animals, with PrPresin immunoblot, prion seeding activity, and PrPresdeposition in the brain. Shortened survival times indicate adaptation in the new host. This also shows that prions detected in GIT tissues are infectious and transmissible. Transmission of brain material from sick voles back to cervidized mice revealed transmission in these mice with a 100% attack rate, and interestingly, with different biochemical signature and distribution in the brain.

Conclusions: Our findings demonstrate that macaques, considered the best model for the zoonotic potential of prions, were infected upon CWD challenge, including oral one. The disease manifested as atypical in macaques and transgenic mice, but with infectivity present at all times, as unveiled in the bank vole model with an unusual tissue tropism.

Transmission of Cervid Prions to Humanized Mice Demonstrates the Zoonotic Potential of CWD

Samia Hannaouia, Irina Zemlyankinaa, Sheng Chun Changa, Maria Immaculata Arifina, Vincent Béringueb, Debbie McKenziec, Hermann M. Schatzla, and Sabine Gilcha

Aims: Chronic wasting disease (CWD), a prion disease of cervids, spreads efficiently among wild and farmed animals. Potential transmission to humans of CWD is a growing concern due to its increasing prevalence. Here, we aimed to determine the zoonotic potential of CWD using a mouse model for human prion diseases.

Material and Methods: Transgenic mice overexpressing human PrPChomozygous for methionine at codon 129 (tg650) were inoculated intracerebrally with brain homogenates of white-tailed deer infected with Wisc-1/CWD1 or 116AG CWD strains. Mice were monitored for clinical signs and were euthanized at terminal disease. Brains were tested by RT-QuIC, western blot upon PK digestion, and immunohistochemistry; fecal homogenates were analyzed by RT-QuIC. Brain/spinal cord and fecal homogenates of CWD-inoculated tg650 mice were inoculated into tg650 mice or bank voles. Brain homogenates of bank voles inoculated with fecal homogenates of CWD-infected tg650 mice were used for second passage in bank voles.

Results: Here, we provide the strongest evidence supporting the zoonotic potential of CWD prions, and their possible phenotype in humans. Inoculation of mice expressing human PrPCwith deer CWD isolates (strains Wisc-1 and 116AG) resulted in atypical clinical manifestations in > 75% of the mice, with myoclonus as leading clinical sign. Most of tg650 brain homogenates were positive for seeding activity in RT-QuIC. Clinical disease and presentation was transmissible to tg650 mice and bank voles. Intriguingly, protease-resistant PrP in the brain of tg650 mice resembled that found in a familial human prion disease and was transmissible upon passage. Abnormal PrP aggregates upon infection with Wisc-1 were detectable in thalamus, hypothalamus, and midbrain/pons regions.

Unprecedented in human prion disease, feces of CWD-inoculated tg650 mice harbored prion seeding activity and infectious prions, as shown by inoculation of bank voles and tg650 with fecal homogenates.

Conclusions: This is the first evidence that CWD can infect humans and cause disease with a distinctive clinical presentation, signature, and tropism, which might be transmissible between humans while current diagnostic assays might fail to detect it. These findings have major implications for public health and CWD-management.


p.s. there is a great deal of latest science on cwd in the above url link to the Prion 2022 conference...terry

TUESDAY, NOVEMBER 29, 2022 

Texas CWD Confirmed High Fence Release Site Kaufman County, To Date 420 Cases Confirmed 


WEDNESDAY, NOVEMBER 30, 2022 

USDA Bovine Spongiform Encephalopathy BSE, Scrapie, CWD, Testing and Surveillance 2022 A Review of History 


1985

Evidence That Transmissible Mink Encephalopathy Results from Feeding Infected Cattle Over the next 8-10 weeks, approximately 40% of all the adult mink on the farm died from TME. 

snip... 

The rancher was a ''dead stock'' feeder using mostly (>95%) downer or dead dairy cattle... 




THURSDAY, FEBRUARY 03, 2022 

Transmissible Mink Encephalopathy TME, Atypical L-Type BSE PrP, and typical C-Type BSE, which came first, the cart or the horse? 



WEDNESDAY, JANUARY 12, 2022 

Bovine Spongiform Encephalopathy BSE TSE Prion Origin USA, what if?


Monday, November 14, 2022 

Prion Diseases in Dromedary Camels (CPD) 2022 Review 


THURSDAY, NOVEMBER 10, 2022 

Annual Report of the Scientific Network on BSE‐TSE 2022 



SUNDAY, OCTOBER 16, 2022 

USDA Transmissible Spongiform Encephalopathy TSE Prion Action Plan National Program 103 Animal Health 2022-2027 



FRIDAY, DECEMBER 02, 2022 

Creutzfeldt Jacob Disease CJD TSE Prion December 2022 Annual Update



Terry S. Singeltary Sr.

posted by Terry S. Singeltary Sr. at 4:24 PM

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