Association Study of the M132L Single Nucleotide Polymorphism With Susceptibility to Chronic Wasting Disease in Korean Elk: A Meta-Analysis
In-Soon Roh1†, Yong-Chan Kim2,3†, Sae-Young Won2,3, Kyung-Je Park 1 , Hoo-Chang Park 1 , Ji-Yong Hwang1 , Hae-Eun Kang1 , Hyun-Joo Sohn1 * and Byung-Hoon Jeong2,3 * 1 Reference Laboratory for Chronic Wasting Disease (CWD), Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Gimcheon, South Korea, 2 Korea Zoonosis Research Institute, Jeonbuk National University, Iksan, South Korea, 3 Department of Bioactive Material Sciences and Institute for Molecular Biology and Genetics, Jeonbuk National University, Jeonju, South Korea
Chronic wasting disease (CWD) is a deleterious brain proteinopathy caused by a pathogenic form of prion protein (PrPSc), which is converted from a benign form of prion protein (PrPC) encoded by the prion protein gene (PRNP). In elk, the M132L single nucleotide polymorphism (SNP) of the PRNP gene likely plays a pivotal role in susceptibility to CWD. However, the association of the M132L SNP with susceptibility to CWD has not been evaluated in Korean elk to date. To estimate the association of the M132L SNP with susceptibility to CWD in Korean elk, we investigated the genotype and allele frequencies of the M132L SNP by amplicon sequencing and performed association analysis between CWD-positive and CWD-negative elk. In addition, we performed a meta-analysis to evaluate the association between the M132L SNP and susceptibility to CWD in quantitatively synthesized elk populations. Furthermore, we estimated the effect of the M132L SNP on elk PrP using in silico programs, including PolyPhen-2, PROVEAN, AMYCO and Swiss-PdbViewer. We did not identify a significant association between the M132L SNP of PRNP and susceptibility to CWD in Korean elk. The meta-analysis also did not identify a strong association between the M132L SNP of PRNP and susceptibility to CWD in quantitatively synthesized elk populations. Furthermore, we did not observe significant changes in structure, amyloid propensity or electrostatic potential based on the M132L SNP in elk PrP. To the best of our knowledge, this was the first report of an association analysis and meta-analysis in Korean elk and quantitatively synthesized elk populations, respectively.
Keywords: Elk (Cervus canadensis), prion, CWD, PRNP, M132L, polymorphism, SNP, meta-analysis
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In Korea, >12,000 elk are bred to obtain meat and antlers as food and medicine, respectively (https://www.mafra.go.kr). Korean elk were originally imported from North America, and CWD in Korean elk has been reported sporadically (17). Given that CWD is a highly infectious prion disease and can be transmitted by peripheral body fluids, including urine, tears and saliva, it is very important to breed elk that are genetically resistant to CWD for preemptive control of CWD (18). However, the M132L SNP, one of the important genetic factors of CWD, has not been investigated in Korean elk to date.
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In total, 796 CWD-negative elk and 186 CWD-positive elk were included in the meta-analysis.
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CONCLUSION
We investigated the M132L SNP of the elk PRNP gene in Korean elk and performed association analysis between CWD-positive and CWD-negative elk for the first time. We did not observe a significant association between the M132L SNP of the PRNP gene and susceptibility to CWD in Korean elk. The meta-analysis also did not identify a strong association between the M132L SNP and susceptibility to CWD in quantitatively synthesized elk populations. Furthermore, we did not find significant changes in structure, amyloid propensity or electrostatic potential according to the M132L SNP in elk PrP using in silico analyses. To the best of our knowledge, this was the first report of an association analysis and meta-analysis in Korean elk and quantitatively synthesized elk populations, respectively.
FULL PAPER
Additional Cases of Chronic Wasting Disease in Imported Deer in Korea
Tae-Yung KIM, Hyun-Joo SHON, Yi-Seok JOO, Un-Kyong MUN, Kyung-Sun KANG, Yong-Soon LEE
Abstract
Chronic Wasting Disease (CWD), which had previously occurred only in the U.S.A. and Canada, broke out in a farm at Chungbuk, Korea from imported Canadian deer (Aug. 8, 2001). CWD distribution, through surveillance and epidemiologic investigations, was reported for 93 deer (43 from the CWD originating farm and 50 imported with the CWD originating farm's deer) out of 144 deer (72 from the CWD originating farm and 72 imported with the CWD originating farm's deer) that were breeding at 30 different farms. On Oct. 4 and Oct. 8, 2001, additional cases of CWD were investigated. As a result of slaughtering cohabitating deer, it was verified that other imported deer from Canada were also infected with CWD. Since it was thought that this might cause horizontal transmission, 93 deer imported from Canada in 1997 and 130 cohabitating Korean deer were slaughtered and examined. There were no infected Korean deer, but CWD re-occurred on Nov. 20, 2004 and is still under investigation.
Chronic Wasting Disease (CWD) is a transmissible spongiform encephalopathy (TSE). The infectious agents are hypothesized to be prions (infectious proteins without associated nucleic acids). Similar to the vertical [2, 3, 4] and horizontal [5, 8, 9, 11, 12] transmissions of scrapies, it rarely manifests vertical transmission and usually horizontal transmission is made between cervids with signs of excessive salivation, loss of balance, and neurosis before death. It is known to only infect between cervids, not humans, cows, sheep, etc.
Since CWD has only occurred in the U.S. (originating in 1967) and Canada (originating in 1996), research of the disease has been actively studied in those countries. It has not been listed as a reportable disease to the OIE yet, and only Canada controls CWD as a legal communicable disease. According to news of the CWD outbreak, Korea immediately stopped import of Canadian and American deer and their products (Dec. 12, 2000) and requested an investigation in the corresponding countries. As a result, the Canadian government reported that 23 deer in 1994 and 72 deer in 1997 were exported to Korea from a CWD affected farm (Jan. 1, 2001).
Therefore, in order to investigate the 144 deer (72 originating from the CWD affected farm and 72 transported with the CWD affected farm’s deer) that were imported from Canada in 1997, approximately 2,000 veterinary offices examined 149,502 deer bred in 11,777 deer farms in Korea for symptoms and external appearance between Jan. 12 and Feb. 15, 2001. No abnormalities were found.
During the above investigations, 102 (48 from the CWD originating farms and 54 imported with the CWD originating farm’s deer) out of 144 deer were traced back to those imported from Canada in 1997. There were no abnormalities in symptoms or external appearance in the 102 heads. But between Jan. 1997 and Jan. 2002, including the advanced surmise period (60 months: incubation period + safety period), during which time no clinical disorders were confirmed by Canadian authorities, 48 deer from the CWD originating farms were specially managed (Mar. 13, 2001).
On July 20, 2001, during the special management (movement restrictions, disinfection, observation, etc.) period, a farm reported the death of imported deer, which turned out to be CWD. For this reason, all imported Canadian deer and all Korean deer that were born from domestic deer and that cohabited with Canadian imported deer were slaughtered and examined. Nine out of 144 Canadian imported deer were judged as having CWD.
Although only imported deer turned out to have CWD in Korea, as a 3rd CWD originating country, CWD outbreak case and communicable CWD control grasped in the research. In addition, vertical and horizontal transmission of CWD was examined by slaughtering and inspecting all deer that cohabited with Canadian deer.
* CORRESPONDENCE TO: LEE, Y.-S., Department of Veterinary Public Health, College of Veterinary Medicine, Seoul National University, San 56–1, Shilim 9 dong, Kwanak-ku, 151–742, Seoul, Republic of Korea.
MATERIALS AND METHODS
Animals: In this study, 93 elk imported from Canada in 1997 as well as 130 Korean deer (born from domestic deer) cohabiting with them at 30 farms in 7 different provinces were slaughtered and tested. All had been raised in either open ranches or stockyards with formulated feed for deer. CWD diagnosis: The brain was cut longitudinally, onehalf of the brain was fixed in 10% neutral buffered formalin, and the remainder of the brain was frozen. The formalinfixed portion of the brain was cut into 2–4 mm wide coronal sections. Sections of the various anatomic sites (6–7 sec-tions per animal) of the cerebrum, cerebellum, brainstem (including the obex), and cervical spinal cord were subjected to routine histopathology, embedded in paraplast, and split into 3 µm sections. The sections were stained with hematoxylin and eosin (HE) and by an immunohistochemical (IHC) method [6] for detection of PrPsc using a formic acid pretreatment. Two different primary antibodies were used, including F89/160.1.5 and F99/97.6.1 (VMRD, U.S.A.). These antibodies would identify PrP sequences conserved in most mammalian species in which natural TSEs have been reported [7].
For immunodetection of PrPsc, a western blot method was used on the frozen portion of the brain (obex). PrPsc was purified as previously described [1]. The purified PrP was subjected to electrophoresis on 12% polyacrylamide gels and then transferred to a polyvinylidene difluoride (PVDF) membrane. After non-specific binding was blocked with 3% bovine serum albumin, the membrane was incubated with monoclonal antibodies F89/160.1.5 and F99/97.6.1 (VMRD, U.S.A.) diluted to 5 µg/ml and then with anti mouse IgG conjugated-HRP (KPL, Maryland U.S.A.), followed by development in chemiluminescent substrate (ECL, U.K.) and visualization on Biomax MR film (Kodak). The positive control used recombinant PrP that was expressed in E. coli BL21 (Prionics AG, Switzerland).
RESULTS
CWD outbreak situation based on the farms’ death report: Korea had imported 1,017 deer (119, 495, 162, 238, and 3 deer in 1993, 1994, 1995, 1997, and 2003) from Canada since 1993. The status of the imported deer from the CWD affected farm is shown in Table 1.
One hundred and two (48 from a CWD affected farm and 54 imported with the CWD affected farm’s deer) out of 144 deer imported from Canada in 1997 were traced back, and 93 (43 from the CWD affected farm and 50 imported with the CWD affected farm’s deer) of them were slaughtered. Eight deer (4 from the CWD affected farm and 4 imported with the CWD affected farm’s deer) had fallen dead and 43 were missing. One hundred and thirty cohabitating Korean deer were also slaughtered. As a result, only 9 deer (5 from the CWD affected farm and 4 imported with the CWD affected farm’s deer) from Canada were infected with CWD.
In addition, the Canadian government further reported on Apr. 19, 2002 and Mar. 20, 2001 that additional 4 deer in 1994 and 30 deer in 1995 were exported to Korea from the CWD affected farm. However, all we could do was observe the symptoms and external appearance of all deer (149,502 deer bred at 11,117 deer farms) in Korea between Jan. 2 and Feb. 15, 2001, as opposed to back tracing the 27 deer in 1994 and 30 deer in 1995, because it was impossible to trace the importer. Table 2 indicates the result of farm’s death report.
First CWD outbreak (1 head) farm (Chungbuk B): On July 20, 2001, one deer (from the CWD affected farm in Canada, coupon number D50Y) fell dead in Buljung-myun, Goisan-gun, Chungbuk (Table 2). It was judged as CWD by the National Veterinary Research & Quarantine Service on July 30, 2001. To confirm whether this disease was CWD or not, as the first case in Korea, a request was made to the Canadian Food Inspection Agency’s (CFIA) ADRI in Canada on July 30, 2001. As a result, it was confirmed as CWD on Aug. 8, 2001.
In order to investigate the possibilities of vertical and horizontal transmission, 44 cohabitating cervids were slaughtered. They were 40 elk, including 8 deer from the CWD affected farm in Canada (one had fallen dead), and 4 deer, two red deer and two Formosan deer, imported with the CWD affected farm’s deer. They indicated no symptoms, showing no transmission among them at the farm. Second CWD outbreak (6 heads) farm (Chungbuk A): A second outbreak occurred at Chungbuk A farm in Ochangmyun, Chungwon-gun, Chungbuk (Table 2). Out of the deer imported in March 1997 from the CWD affected farm in Canada, one deer (coupon number 1BY) fell dead on Sept. 20, 2001 and another deer (coupon number E190Y) on Oct. 4, 2001. They were diagnosed as CWD positive by the National Veterinary Research & Quarantine Service on Oct. 4 and Oct. 8, 2001.
After inspecting all 20 (5 from the CWD affected farm and 15 imported with the CWD affected farm’s deer) of the slaughtered deer, 4 deer (one [coupon number E190Y] from the CWD affected farm and 3 [coupon numbers G48, G49, and Y229] imported with the CWD affected farm’s deer) were diagnosed as positive.
Active survey of imported deer for CWD: According to the finding of CWD positive cases in the deer imported with the CWD originating farm’s deer, it became clear there was a serious danger of horizontal transmission. Therefore, on Oct. 30, 2001, it was decided that the deer imported from Canada in 1997 should be slaughtered and inspected to detect whether or not CWD had been transmitted to Korean deer.
As a result of slaughtering and inspecting 62 deer (32 from the CWD affected farm in Canada and 30 imported with the CWD affected farm’s deer) at 28 farms between Oct. 26, 2001 and the end of 2001, 2 out of the 62 deer turned out to be CWD positive (Table 3).
In the Chungbuk C farm, 9 deer (4 from a CWD affected farm in Canada and 5 imported with the CWD affected farm’s deer) were slaughtered and inspected on Oct. 26, 2001. As a result, one deer (coupon number E1750) from the CWD affected farm was diagnosed as CWD positive on Dec. 7, 2001. Forty-two Korean breeding deer cohabitating with imported deer were also slaughtered and examined, but were diagnosed as CWD negative on Feb. 23, 2002.
In the Chungbuk D farm, 3 deer imported with the CWD originating farm’s deer were slaughtered and inspected on Nov. 12, 2001. As a result, one deer (coupon number 447Y) was diagnosed as CWD positive on Dec. 7, 2001. The other 55 cohabitating Korean breeding deer were slaughtered and found to be CWD negative on Apr. 24, 2002. This farm was managed by the daughter-in-law of the owner of the Chungbuk A farm, where the second CWD outbreak occurred. According to the investigation, the CWD positive deer was found to have been moved from the Chungbuk A farm before the disease occurred.
CWD diagnosis and advanced surmise: The entire brain (cerebrum, thalamus, midbrain, pons, bulbar, medulla, spinalis, cerebellum, lymph nodes, tonsils, 3rd palpebra) was utilized for the laboratory diagnosis and subjected to histopathological examination, immunohistochemistry, and western blotting (Figs. 1 and 2). Mixed F89 and F99, 5 µg/ ml each, was used as the antibody. Details of the diagnosis results for the 9 cases are shown in Table 4.
Clinical observations were made of all deer imported from Canada and Korean breeding deer during the advanced surmise period. In the advanced surmise period, consumption of feed, chronic atrophy, withdrawal from the group loss of body condition, changes in behavior, hyperexcitability, hyperesthesia, serious deglutition, grinding of the teeth, polydisia/polyuria, and pneumonia were monitored. The inspection was conducted on slaughtered deer that were more than 2 years old and neurotic.
Distribution of imported deer and management of deer farms: Investigation of the importers and breeding farms of the deer imported from Canada in 1997 indicated that the deer were breeding at a total of 30 different farms through selling or reselling. CWD occurred in 4 out of these farms. Based on the investigation, it became clear that one farm imported the Canadian deer and initially sold to 9 different farms, and a second sale was made to 17 farms, followed by a third sale to 3 farms (Fig. 3).
Prion disease has recently become a worldwide issue. A Standing Committee on the Food Chain and Animal Health (SSC) meeting (Nov. 29–30, 2001) concluded that prion infectivity could be reduced in the ground for 3 years, although it would not completely disappear. In Iceland, a farm where prion disease occurred was closed for 3 years, cleaned and disinfected by flame and other disinfectants, and the top soil was removed in order to prevent prion diseases [10]. For this reason, Chungbuk A and Chungbuk D farms were closed because their topography was difficult to manage for communicable disease control. For the Chungbuk B and Chungbuk C farms, more than 30 cm of top soil was removed and soil disinfection by 2N NaOH was conducted a minimum of 3 times every 2–3 weeks. Breeding was restarted after disease prevention measures using a flamethrower. Thereafter, no clinical problems were reported until now.
Four out of 26 farms abandoned their deer breeding business as a result of slaughtered and inspected Canadian deer, which turned out to be CWD negative. The Communicable Disease Control Department conducts regular disinfection and clinical observations for the other farms. There have been no signs or additional infections of CWD (Table 5).
DISCUSSION
A total of 129 deer (deer/year: 27/1994, 30/1995, and 72/ 1997) were imported from the CWD originating farm in Canada. None of the 57 deer imported in 1994 and 1995 fell dead during the advanced surmise period, 60 months, and were confirmed to have no clinical disorders by Canadian authorities and no clinical matters examined. Korean deer were raised for 3.5 years with 144 deer imported in 1997, during which time only 9 of the imported deer became infected. Five of them were imported from the CWD affected farm in Canada and the other 4 were gathered at the CWD affected farm (SK 3 farm) for quarantine and shipped to Korea on the same boat.
It can be considered that horizontal CWD transmission took place, but it is still unclear whether only 4 of the cohabitating Canadian deer became infected. Therefore, Korean authorities should exchange further information on the number of quarantine certificates and coupons with the Canadian Communicable Disease Control Department in order to reinvestigate whether only 5 deer were raised at the CWD affected farm, with the other 4 deer being raised at a CWD free farm, or whether the disease was transmitted during shipping. Furthermore, why cohabitating Korean deer were not infected by CWD is considered to be a subject for further research.
The Korean Communicable Disease Control Department did its best to prevent the spread of CWD, but failed to trace back 43 out of 144 deer imported from Canada in 1997. Among these, 25 deer were from the CWD affected farm and 18 deer were imported with the deer from the CWD affected farm (Table 5). The department is currently investigating a new case of CWD found on Nov. 20, 2004 to determine whether it is a deer that was missing in 2001, or a vertically or horizontally transmitted deer. ACKNOWLEDGMENTS. This work was supported by the National Veterinary Research & Quarantine Service, Anyang 430–016, Korea.
REFERENCES...snip...end
Korea Chronic Wasting Disease CWD TSE PrP Update Increase of Positive Cases and Polymorphisms of the prion-related protein gene
Vet Rec. 2022 Feb;190(4):e940. doi: 10.1002/vetr.940. Epub 2021 Sep 25.
Polymorphisms of the prion-related protein gene are strongly associated with cervids' susceptibility to chronic wasting disease
In-Soon Roh 1, Yong-Chan Kim 2 3, Hyo-Jin Kim 1, Sae-Young Won 2 3, Min-Ju Jeong 2 3, Ji-Yong Hwang 1, Hae-Eun Kang 1, Hyun-Joo Sohn 1, Byung-Hoon Jeong 2 3
PMID: 34562285 DOI: 10.1002/vetr.940
Abstract
Background: Chronic wasting disease (CWD) is a cervid prion disease that is caused by abnormal prion protein (PrPSc ). Recent studies have reported that prion family genes showed a strong association with the susceptibility of several types of prion diseases. To date, an association study of the prion-related protein gene (PRNT) has not been performed in any type of cervid prion disease.
Methods: In the present study, we investigated PRNT polymorphisms in large deer, including 235 elk, 257 red deer and 150 sika deer. We compared genotype, allele and haplotype frequencies of PRNT polymorphisms between CWD-negative animals and CWD-positive animals to find an association of PRNT polymorphisms with the susceptibility of CWD.
Results: We found a total of five novel single nucleotide polymorphisms (SNPs) in the cervid PRNT gene. Interestingly, we observed significantly different distributions of genotypes and allele frequencies of three PRNT SNPs, including c.108C>T, c.159+30C>T and c.159+32A>C, between CWD-negative and CWD-positive red deer. In addition, significant differences of two haplotype frequencies in red deer were found between the CWD-negative and CWD-positive groups. However, the association identified in the red deer was not found in elk and sika deer.
Conclusion: To the best of our knowledge, this report is the first to describe the strong association of PRNT SNPs with the susceptibility of CWD.
INTRODUCTION
Chronic wasting disease (CWD) is a prion-related transmissible spongiform encephalopathy of cervids such as scrapie in sheep and goats, bovine spongiform encephalopathy (BSE) in cattle and Creutzfeldt-Jakob disease (CJD),fatal familial insomnia and Gerstmann-Straussler-Scheinker syndrome in humans.1-12 CWD is transmitted horizontally and vertically through abnormal prion protein (PrPSc), which originates from normal prion protein (PrPc). Since CWD was first reported in the USA in 1967, intercontinental propagation has also occured from America to Asia and Europe13-19 In addition, CWD transmission to non-human primates and squirrel monkeys indicates the possibility of CWD as a zoonotic disease.20,21 AS threats of CWD to humans have increased, achieving an exact understanding of the molecular mechanism of CWD is highly desirable.
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METHODS
Subjects
A total of 642 brain samples, including 235 elk, 257 red deer and 150 sika deer, were provided from animal farms in the Republic of Korea including Chungnam, Gyeongnam and Jeonnam Provinces where CWD occurred. CWD tests were performed on all brain samples by the Animal and Plant Quarantine Agency (APQA) in the Republic of Korea using HerdChek BSE-Scrapie Antigen Kit (IDEXX, USA) and conventional western blot analysis.
IN 235 elks, 22 elks (9.4%) were infected with CWD.
IN 257 red deer, 78 red deer (30.4%) were infected with CWD.
IN 150 sika deer, 16 sika deer (10.7%) were infected with CWD.
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IN CONCLUSION, we first investigated PRNT polymorphisms and found five novel PRNT SNPs. We identified significantly different genotype, allele and haplotype frequencies between CWD-negative and CWD-positive red deer. To the best of our knowledge, this report is the first to describe the strong association of PRNT SNPs with CWD susceptibility in red deer.
Keywords: CWD; PRND; PRNP; PRNT; SNP; SPRN; cervid; prion; prion gene family.
© 2021 British Veterinary Association.
Introduced into the Republic of Korea through the inadvertent importation of asymptomatic but infected elk [11],
A case of chronic wasting disease in an elk imported to Korea from Canada.
Sohn HJ, Kim JH, Choi KS, Nah JJ, Joo YS, Jean YH, Ahn SW, Kim OK, Kim DY, Balachandran A J Vet Med Sci. 2002 Sep; 64(9):855-8.
CWD was subsequently detected in farmed elk populations in 2001, 2004 and 2005 [12].
Additional cases of Chronic Wasting Disease in imported deer in Korea. Kim TY, Shon HJ, Joo YS, Mun UK, Kang KS, Lee YS J Vet Med Sci. 2005 Aug; 67(8):753-9.
Additional cases were later observed in farmed red deer, sika deer, and several cross-bred deer during investigations in 2010 and 2016 [4].
Sohn HJ, Roh IS, Kim HJ, et al., editors. Epidemiology of chronic wasting disease in Korea. Prion. Philadelphia, PA, USA:
Farmed and feral sika deer exist in other regions of Asia, North America, and Europe [13],
McCullough DR, Takatsuki S, Kaji K. Sika deer: biology and management of native and introduced populations. Tokyo: Springer; 2009.
although natural CWD transmission to this species has not yet been documented beyond the Republic of Korea.
In several regions of the world, the range of feral sika deer overlaps with other cervids, and hybridization with congeneric species such as red deer is known to occur [13,14].
McCullough DR, Takatsuki S, Kaji K. Sika deer: biology and management of native and introduced populations. Tokyo: Springer; 2009. [
Additionally, sika deer may be farmed to maintain broodstock for game ranches or for the production of venison and antler velvet, and may be cross-bred or housed with CWD-susceptible cervid species in this context.
see;
Prion. 2020; 14(1): 271–277.
Published online 2020 Dec 10. doi: 10.1080/19336896.2020.1857038
PMCID: PMC7734081
PMID: 33300452
Experimental oral transmission of chronic wasting disease to sika deer (Cervus nippon)
Korea Chronic Wasting Disease CWD TSE Prion additional cases were observed in red deer, sika deer, and their crossbred deer in 2010 and 2016
In Korea, CWD was only confirmed in elk in 2001, 2004, and 2005 [13]; however, additional cases were observed in red deer, sika deer, and their crossbred deer in 2010 and 2016 [14]. Therefore, it is important to prevent CWD recurrence in the Republic of Korea, and farmers that have experienced a CWD outbreak are required to disinfect the farm before reintroducing the cervids. Thus, farmers require a disinfectant solution that is marketed and readily available to effectively inactivate prions.
[14] Sohn HJ, Roh IS, Kim HJ, et al. Epidemiology of chronic wasting disease in Korea. Prion. 2106;10 (supp1):S16–S17
WS-03: Epidemiology of chronic wasting disease in Korea
Hyun Joo Sohn
In Soon Roh
Hyo Jin Kim
Tae Young Suh
Kyung Je Park
Hoo Chang Park
Byounghan Kim
Foreign Animal Disease Division (FADD), Animal and Plant Quarantine Agency (QIA), Gimcheon, Korea
Transmissible spongiform encephalopathy (TSE) is a fatal neurodegenerative disorder, which is so-called as prion diseases due to the causative agents (PrPSc). TSEs are believed to be due to the template-directed accumulation of disease-associated prion protein, generally designated PrPSc. Based on export information of Chronic wasting disease (CWD) suspected elk from Canada to Korea, CWD surveilance program was initiated by the Ministry of Agriculture, Food and Rural Affairs (MAFRA) in 2001. CWD control measures included stamping out of all animals in the affected farm, and through cleaning and disinfection of the premises. In addition, nationwide clinical surveillance of Korean native cervid and improved measures to ensure reporting of CWD suspect cases were implemented. Total of 9 elks were found to be affected. CWD was designated as a notifiable disease under the Act for Prevention of Livestock Epidemics in 2002. Additional CWD cases– 12 elks and 2 elks – were diagnosed in 2004 and 2005. On 2010, 6 elks, 7 sika deer, one red deer and 5 cross-breeds were confirmed as positive. Further epidemiological investigations showed that these CWD outbreaks were linked to the importation of elks from Canada in 1994 based on circumstantial evidences. CWD is the prion disease that is known spread horizontally. The experimental studies have shown that PrPCWD is capable of transmitting CWD through saliva and blood. We conducted sPMCA and animal biosassy using contaminated soils in the playground of farm 2 which considered horizontal transmission between cervid and have been confirmed infectious PrPCWD. This result suggests PrPCWD shedding in the CWD contaminated soil is progressive through the disease course.
Keywords: CWD, soil, sPMCA
Additional Cases of Chronic Wasting Disease in Imported Deer in Korea
Tae-Yung KIM1,3), Hyun-Joo SHON2), Yi-Seok JOO2), Un-Kyong MUN2), Kyung-Sun KANG3) and Yong-Soon LEE3)* 1)Animal Health Division, Ministry of Agriculture & Forestry, Kwacheon 427–760, 2)National Veterinary Research & Quarantine Service, Anyang 430–016 and 3)Department of Veterinary Public Health, College of Veterinary Medicine, Seoul National University, Seoul 151– 742, Korea (Received 21 January 2005/Accepted 27 May 2005)
ABSTRACT.
Chronic Wasting Disease (CWD), which had previously occurred only in the U.S.A. and Canada, broke out in a farm at Chungbuk, Korea from imported Canadian deer (Aug. 8, 2001). CWD distribution, through surveillance and epidemiologic investigations, was reported for 93 deer (43 from the CWD originating farm and 50 imported with the CWD originating farm’s deer) out of 144 deer (72 from the CWD originating farm and 72 imported with the CWD originating farm’s deer) that were breeding at 30 different farms. On Oct. 4 and Oct. 8, 2001, additional cases of CWD were investigated. As a result of slaughtering cohabitating deer, it was verified that other imported deer from Canada were also infected with CWD. Since it was thought that this might cause horizontal transmission, 93 deer imported from Canada in 1997 and 130 cohabitating Korean deer were slaughtered and examined. There were no infected Korean deer, but CWD re-occurred on Nov. 20, 2004 and is still under investigation. KEY WORDS: Chronic Wasting Disease (CWD), horizontal transmission. J. Vet. Med. Sci. 67(8): 753–759, 2005
Strain Characterization of the Korean CWD Cases in 2001 and 2004
Yoon-Hee LEE1), Hyun-Joo SOHN1)*, Min-Jeong KIM1), Hyo-Jin KIM1), Won-Yong LEE1), Eun-Im YUN1), Dong-Seob TARK1), In-Soo CHO1) and Aru BALACHANDRAN2) 1)Animal, Plant and Fisheries Quarantine and Inspection Agency, Ministry for Food, Agriculture, Forestry and Fisheries, Anyang 430–757, Republic of Korea 2)National and OIE Reference Laboratory for Scrapie and CWD, Ottawa Laboratory Fallowfield, Ottawa, Canadian Food Inspection Agency, Ottawa, Ontario K2H 8P9, Canada (Received 22 February 2012/Accepted 14 August 2012/Published online in J-STAGE 28 August 2012)
ABSTRACT.
Chronic wasting disease (CWD) has been recognized as a naturally occurring prion disease in North American deer (Odocoileus species), Rocky Mountain elk (Cervus elaphus nelsoni) and moose (Alces alces). The disease was confirmed only in elk in the Republic of Korea in 2001, 2004 and 2005. Epidemiological investigations showed that CWD was introduced via importation of infected elk from Canada between 1994 and 1997. In spite of the increasing geographic distribution and host range of CWD, little is known about the prion strain (s) responsible for distinct outbreaks of the disease. We carried out strain characterization, using transgenic mice overexpressing elk prion protein, including clinical assessment, pathological examination and biochemical analyses, in brain tissues derived following primary through tertiary transmissions. The final incubation period was shortened to approximately 130 dpi due to adaptation. Biochemical profiles remained identical between passages. Lesion profiling in recipient mice brains showed similar patterns of vacuolation scores and intensity. It is clear that there were no biochemical or histopathological differences in Korean CWD cases in 2001 and 2004, suggesting a single strain was responsible for the outbreaks.
KEY WORDS: CWD, Republic of Korea, strain characterization. doi: 10.1292/jvms.12-0077; J. Vet. Med. Sci. 75(1): 95–98, 2013
A Case of Chronic Wasting Disease in an Elk Imported to Korea from Canada
Hyun-Joo SOHN1), Jae-Hoon KIM1)*, Kang-Seuk CHOI1), Jin-Ju NAH1), Yi-Seok JOO1), Young-Hwa JEAN1), Soo-Whan AHN1), Ok-Kyung KIM1), Dae-Yong KIM2) and Aru BALACHANDRAN3) 1)National Veterinary Research and Quarantine Service, Anyang 430–824, 2)Department of Pathology, College of Veterinary Medicine, Seoul National University, Suwon 441–744, Korea and 3)Animal Disease Research Institute, Canadian Food Inspection Agency, Nepean, Ontario, Canada (Received 13 March 2002/Accepted 8 May 2002)
ABSTRACT.
A seven-year-old male elk (Cervus elaphus nelsoni) was euthanized and necropsied after having a 3-week history of body weight loss, emaciation, excessive salivation, teeth grinding, fever, anorexia, and respiratory distress. The elk was imported into Korea from Canada on March 9, 1997. Gross pathologic findings were restricted to a diffuse fibrinous pneumonia. Microscopic lesions included mild neuronal vacuolation and spongiform change in the neuropil of selected brain stem nuclei and generalized astrocytosis. Immunohistochemistry for protease-resistant prion protein (PrPres) was positive in all brain sections but more pronounced in the section of the obex of the medulla. And the PrP res was also detected by western immunoblotting in the brain and spinal cord. All the remaining elk and deer that had been in contact with this elk were destroyed and negative for chronic wasting disease (CWD). To our knowl edge, this is the first case of CWD occurring outside of the U.S.A. and Canada.
KEY WORDS: chronic wasting disease, elk, immunohistochemistry. J. Vet. Med. Sci. 64(9): 855–858, 2002
KOREA CWD TSE Prion
CWD outbreaks in farmed animals were reported in 2001, 2004, 2005, 2010, and *2016 in the Republic of Korea.
Korean CWD was introduced by elk imported from Canada in 1997.
CWD outbreaks in farmed animals were reported in 2001, 2004, 2005, 2010, and ***2016 in the Republic of Korea.
The Korean water deer is the dominant species of wild deer in Korea, with approximately 620 thousand heads (8.0 heads/100 ha) [9].
*2016 in the Republic of Korea.
I LACK A REPORT ON THAT~!???
i have asked about it to Korea officials and scientist, with no reply to date...so, total count on Chronic Wasting Disease CWD TSE Prion in Korea, your guess is good as mine, especially through 2019, ...terry
Between 1996 and 2002, chronic wasting disease was diagnosed in 39 herds of farmed elk in Saskatchewan in a single epidemic. All of these herds were depopulated as part of the Canadian Food Inspection Agency's (CFIA) disease eradication program. Animals, primarily over 12 mo of age, were tested for the presence CWD prions following euthanasia. Twenty-one of the herds were linked through movements of live animals with latent CWD from a single infected source herd in Saskatchewan, 17 through movements of animals from 7 of the secondarily infected herds.
***The source herd is believed to have become infected via importation of animals from a game farm in South Dakota where CWD was subsequently diagnosed (7,4). A wide range in herd prevalence of CWD at the time of herd depopulation of these herds was observed. Within-herd transmission was observed on some farms, while the disease remained confined to the introduced animals on other farms.
KOREA CWD TSE PRION
Chronic Wasting Disease (CWD) outbreaks and surveillance program in the Republic of Korea Chronic Wasting Disease (CWD) outbreaks and surveillance program in the Republic of Korea
Hyun-Joo Sohn, Yoon-Hee Lee, Min-jeong Kim, Eun-Im Yun, Hyo-Jin Kim, Won-Yong Lee, Dong-Seob Tark, In- Soo Cho, Foreign Animal Disease Research Division, National Veterinary Research and Quarantine Service, Republic of Korea
Chronic wasting disease (CWD) has been recognized as an important prion disease in native North America deer and Rocky mountain elks. The disease is a unique member of the transmissible spongiform encephalopathies (TSEs), which naturally affects only a few species. CWD had been limited to USA and Canada until 2000.
On 28 December 2000, information from the Canadian government showed that a total of 95 elk had been exported from farms with CWD to Korea.
These consisted of 23 elk in 1994 originating from the so-called "source farm" in Canada, and 72 elk in 1997, which had been held in pre export quarantine at the "source farm".
Based on export information of CWD suspected elk from Canada to Korea, CWD surveillance program was initiated by the Ministry of Agriculture and Forestry (MAF) in 2001.
All elks imported in 1997 were traced back, however elks imported in 1994 were impossible to identify.
CWD control measures included stamping out of all animals in the affected farm, and thorough cleaning and disinfection of the premises.
In addition, nationwide clinical surveillance of Korean native cervids, and improved measures to ensure reporting of CWD suspect cases were implemented.
*Total of 9 elks were found to be affected. CWD was designated as a notifiable disease under the Act for Prevention of Livestock Epidemics in 2002.
*Additional CWD cases - 12 elks and 2 elks - were diagnosed in 2004 and 2005.
*Since February of 2005, when slaughtered elks were found to be positive, all slaughtered cervid for human consumption at abattoirs were designated as target of the CWD surveillance program.
Currently, CWD laboratory testing is only conducted by National Reference Laboratory on CWD, which is the Foreign Animal Disease Division (FADD) of National Veterinary Research and Quarantine Service (NVRQS).
*In July 2010, one out of 3 elks from Farm 1 which were slaughtered for the human consumption was confirmed as positive.
*Consequently, all cervid - 54 elks, 41 Sika deer and 5 Albino deer - were culled and one elk was found to be positive.
Epidemiological investigations were conducted by Veterinary Epidemiology Division (VED) of NVRQS in collaboration with provincial veterinary services.
*Epidemiologically related farms were found as 3 farms and all cervid at these farms were culled and subjected to CWD diagnosis.
*Three elks and 5 crossbreeds (Red deer and Sika deer) were confirmed as positive at farm 2.
All cervids at Farm 3 and Farm 4 - 15 elks and 47 elks - were culled and confirmed as negative.
Further epidemiological investigations showed that these CWD outbreaks were linked to the importation of elks from Canada in 1994 based on circumstantial evidences.
*In December 2010, one elk was confirmed as positive at Farm 5.
*Consequently, all cervid - 3 elks, 11 Manchurian Sika deer and 20 Sika deer - were culled and one Manchurian Sika deer and seven Sika deer were found to be positive.
This is the first report of CWD in these sub-species of deer.
*Epidemiological investigations found that the owner of the Farm 2 in CWD outbreaks in July 2010 had co-owned the Farm 5.
*In addition, it was newly revealed that one positive elk was introduced from Farm 6 of Jinju-si Gyeongsang Namdo.
All cervid - 19 elks, 15 crossbreed (species unknown) and 64 Sika deer - of Farm 6 were culled, but all confirmed as negative.
: Corresponding author: Dr. Hyun-Joo Sohn (+82-31-467-1867, E-mail: shonhj@korea.kr) 2011 Pre-congress Workshop: TSEs in animals and their environment 5
FULL PAPER
Additional Cases of Chronic Wasting Disease in Imported Deer in Korea
Tae-Yung KIM, Hyun-Joo SHON, Yi-Seok JOO, Un-Kyong MUN, Kyung-Sun KANG, Yong-Soon LEE Author information Keywords: Chronic Wasting Disease (CWD), horizontal transmission JOURNALS FREE ACCESS 2005 Volume 67 Issue 8 Pages 753-759
Abstract
Chronic Wasting Disease (CWD), which had previously occurred only in the U.S.A. and Canada, broke out in a farm at Chungbuk, Korea from imported Canadian deer (Aug. 8, 2001). CWD distribution, through surveillance and epidemiologic investigations, was reported for 93 deer (43 from the CWD originating farm and 50 imported with the CWD originating farm's deer) out of 144 deer (72 from the CWD originating farm and 72 imported with the CWD originating farm's deer) that were breeding at 30 different farms. On Oct. 4 and Oct. 8, 2001, additional cases of CWD were investigated. As a result of slaughtering cohabitating deer, it was verified that other imported deer from Canada were also infected with CWD. Since it was thought that this might cause horizontal transmission, 93 deer imported from Canada in 1997 and 130 cohabitating Korean deer were slaughtered and examined. There were no infected Korean deer, but CWD re-occurred on Nov. 20, 2004 and is still under investigation.
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DISCUSSION
Fig. 3. Present status of farms that sold or resold imported Canadian elk in 1997.
A total of 129 deer (deer/year: 27/1994, 30/1995, and 72/ 1997) were imported from the CWD originating farm in Canada, None ofthe 57 deer imported in 1994 and 1995 fell dead during the advanced surmise period, 60 months, and were confirmed to have no clinical disorders by Canadian authorities and no clinical matters examined. Korean deer were raised for 3.5 years with 144 deer imported in 1997, during which time only 9 of the imported deer became infected, Five of them were imported from the CWD affected farm in Canada and the other 4 were gathered at the CWD affected farm (SK 3 farm) for quarantine and shipped to Korea on the same boat.
It can be considered that horizontal CWD transmission took place, but it is still unclear whether only 4 of the cohabitating Canadian deer became infected. Therefore, Korean authorities should exchange further information on the number of quarantine certificates and coupons with the Canadian Communicable Disease Control Department in order to re— investigate whether only 5 deer were raised at the CWD affected farm, with the other 4 deer being raised at a CWD free farm, or whether the disease was transmitted during shipping. Furthermore, why cohabitating Korean deer were not infected by CWD is considered to be a subject for further research.
The Korean Communicable Disease Control Department did its best to prevent the spread of CWD, but failed to trace back 43 out of 144 deer imported from Canada in 1997,
CHRONIC WASTING DISEASE CASES IN KOREA 759
Among these, 25 deer were from the CWD affected farm and 18 deer were imported with the deer from the CWD affected farm (Table 5). The department is currently investigating a new case of CWD found on Nov, 20, 2004 to determine whether it is a deer that was missing in 2001, or a vertically or horizontally transmitted deer.
ACKNOWLEDGMENTS, This work was supported by the National Veterinary Research & Quarantine Service, Anyang 430-016, Korea.
REFERENCES
Strain Characterization of the Korean CWD Cases in 2001 and 2004
Yoon-Hee LEE1), Hyun-Joo SOHN1)*, Min-Jeong KIM1), Hyo-Jin KIM1), Won-Yong LEE1), Eun-Im YUN1), Dong-Seob TARK1), In-Soo CHO1) and Aru BALACHANDRAN2)
1)Animal, Plant and Fisheries Quarantine and Inspection Agency, Ministry for Food, Agriculture, Forestry and Fisheries, Anyang 430–757, Republic of Korea
2)National and OIE Reference Laboratory for Scrapie and CWD, Ottawa Laboratory Fallowfield, Ottawa, Canadian Food Inspection Agency, Ottawa, Ontario K2H 8P9, Canada
(Received 22 February 2012/Accepted 14 August 2012/Published online in J-STAGE 28 August 2012)
ABSTRACT. Chronic wasting disease (CWD) has been recognized as a naturally occurring prion disease in North American deer (Odocoileus species), Rocky Mountain elk (Cervus elaphus nelsoni) and moose (Alces alces). The disease was confirmed only in elk in the Republic of Korea in 2001, 2004 and 2005. Epidemiological investigations showed that CWD was introduced via importation of infected elk from Canada between 1994 and 1997. In spite of the increasing geographic distribution and host range of CWD, little is known about the prion strain (s) responsible for distinct outbreaks of the disease. We carried out strain characterization, using transgenic mice overexpressing elk prion protein, including clinical assessment, pathological examination and biochemical analyses, in brain tissues derived following primary through tertiary transmissions. The final incubation period was shortened to approximately 130 dpi due to adaptation. Biochemical profiles remained identical between passages. Lesion profiling in recipient mice brains showed similar patterns of vacuolation scores and intensity. It is clear that there were no biochemical or histopathological differences in Korean CWD cases in 2001 and 2004, suggesting a single strain was responsible for the outbreaks.
Chronic wasting disease (CWD) has been recognized as an important prion disease in North American deer and Rocky mountain elk [13]. This disease was confirmed only in elk in the Republic of Korea in 2001, 2004 and 2005 [7, 10]. Additional CWD cases were observed in red deer, sika deer, and crossbred sika and red deer in 2010 (unpublished data). However, these cases were not included in the present study, which focuses only on elk CWD. Recently, using a model of transgenic mice overexpressing mule deer prion, the possibility of at least two CWD strains existing in North American cervids was raised [1]. More evidence on the two distinct CWD strains that originated from the mule deer was suggested using the ferret model [9] and from Syrian hamster model studies, and the emergence of a new “wasting strain” (WST) would appear to have occurred in white-tailed deer [2]. Epidemiological investigations showed that CWD was introduced to the Korean peninsula via importation of infected elk from Canada in 1994, 1995 and 1997 [7]. It is possible that more than one strain might have been introduced from Canada, although a Canadian retrospective study underway shows no emergence of other phenotypes so far (Dr. Gordon Mitchell, personal comm.).
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KEY WORDS: CWD, Republic of Korea, strain characterization.
doi: 10.1292/jvms.12-0077; J. Vet. Med. Sci. 75(1): 95–98, 2013
see full text;
A Case of Chronic Wasting Disease in an Elk Imported to Korea from Canada
Hyun-Joo SOHN, Jae-Hoon KIM, Kang-Seuk CHOI, Jin-Ju NAH, Yi-Seok JOO, Young-Hwa JEAN, Soo-Whan AHN, Ok-Kyung KIM, Dae-Yong KIM, Aru BALACHANDRAN Author information Keywords: chronic wasting disease, elk, immunohistochemistry JOURNALS FREE ACCESS 2002 Volume 64 Issue 9 Pages 855-858
Abstract A seven-year-old male elk (Cervus elaphus nelsoni) was euthanized and necropsied after having a 3-week history of body weight loss, emaciation, excessive salivation, teeth grinding, fever, anorexia, and respiratory distress. The elk was imported into Korea from Canada on March 9, 1997. Gross pathologic findings were restricted to a diffuse fibrinous pneumonia. Microscopic lesions included mild neuronal vacuolation and spongiform change in the neuropil of selected brain stem nuclei and generalized astrocytosis. Immunohistochemistry for protease-resistant prion protein (PrPres) was positive in all brain sections but more pronounced in the section of the obex of the medulla. And the PrPres was also detected by western immunoblotting in the brain and spinal cord. All the remaining elk and deer that had been in contact with this elk were destroyed and negative for chronic wasting disease (CWD). To our knowledge, this is the first case of CWD occurring outside of the U.S.A. and Canada.
References (11)
see full text
P-147 Infection and detection of PrPCWD in soil from CWD infected farm in Korea
Hyun Joo Sohn, Kyung Je Park, In Soon Roh, Hyo Jin Kim, Hoo Chang Park, Byounghan Kim
Animal and Plant Quarantine Agency (QIA), Korea
Transmissible spongiform encephalopathy (TSE) is a fatal neurodegenerative disorder, which is so-called as prion diseases due to the causative agents (PrPSc). TSEs are believed to be due to the template-directed accumulation of disease-associated prion protein, generally designated PrPSc. Chronic wasting disease (CWD) is the prion disease that is known spread horizontally. CWD has confirmed last in Republic of Korea in 2010 since first outbreak of CWD in 2001. The environmental reservoirs mediate the transmission of this disease. The significant levels of infectivity have been detected in the saliva, urine, and feces of TSE-infected animals. Using serial protein misfolding cyclic amplification (sPMCA), we developed a detection method for CWD PrPSc in soil from CWD affected farm in 2010. We found to detect PrPSc in soil from CWD infected farm, but not detect PrPSc in soil of wild cervid habitats and normal cervid farm in Korea. We also tried the bioassay on transgenic mice overexpressing elk prion protein (TgElk mice) to confirm infectivity of CWD-infected farm soil and washing solution of it. As the results, there was the presence of infectious prions in them. The attack rates were each 12.5% (1/8, soil) and 100% (6/6, soil washing solution). Our method appears to be a very useful technique for monitoring PrPSc levels in environmental conditions.
P-153
Experimental oral transmission of chronic wasting disease to sika deer (Cervus nippon)
Gordon Mitchell1, Hyun-Joo Sohn2, Yoon-Hee Lee2, Antanas Staskevicius1, Nishandan Yogasingam1, Ines Walther1, In-Soo Cho2, Aru Balachandran1
1National & OIE Reference Laboratory for Scrapie and CWD, Canadian Food Inspection Agency, Ottawa, Ontario, Canada; 2Animal, Plant and Fisheries Quarantine and Inspection Agency, Ministry for Food, Agriculture, Forestry and Fisheries, Anyang, Republic of Korea
Chronic wasting disease (CWD) persists in North American cervids, and epidemiological evidence indicates CWD was introduced into the Republic of Korea approximately twenty years ago through the importation of an infected elk (Cervus elaphus) from Canada. Additional cases of CWD have since been detected in Korean elk, and recently for the first time in their farmed sika deer (Cervus nippon). Sika deer are also found in regions of North America and Europe, although natural transmission to these populations has not been detected. Understanding the pathogenesis of CWD in this species is therefore essential to developing diagnostic and disease control strategies.
Six sika deer were orally inoculated with a brain homogenate prepared from a farmed Canadian elk with clinical CWD. Four deer developed clinical signs consistent with CWD and were euthanized between 21 and 24 months post-inoculation (mpi). Two deer were removed from the study due to intercurrent disease, at 4 and 11 mpi. At necropsy, an array of tissues and bodily fluids were sampled and preliminary testing of brainstem and lymphoid tissue by ELISA, immunohistochemistry and western blot confirmed CWD transmission. Aggregates of pathological prion protein (PrPCWD) were detected in the retropharyngeal lymph nodes, but not brainstem of the deer sampled at 4 mpi. All other deer, including the deer tested at 11 mpi, displayed marked PrPCWD accumulation in brainstem and lymphoid tissues. Further immunohistochemical analysis of tissues from sika deer with clinical disease revealed widespread PrPCWD deposition in Iymphoreticular tissues, central and peripheral nervous systems, the gastrointestinal tract and neuroendocrine tissues. Western blot molecular profiles in sika deer brainstem samples were similar to the original elk inoculum. Ante-mortem biopsy of recto-anal mucosal associated lymphoid tissue, tested using immunohistochemistry, detected infected sika deer prior to the onset of clinical disease. These findings corroborate studies in other cervids, identifying early and widespread PrPCWD accumulation in tissues following oral inoculation. Efficient transmission of CWD to sika deer dictates a precautionary approach when exposing this species to environments or other cervids potentially infected with CWD.
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chronic wasting disease cwd tse prion in cervid, is like mad cow disease on steroids in so many different ways, it's frightening...terry
zoonosis zoonotic cervid tse prion cwd to humans, preparing for the storm
***An alternative to modeling the species barrier is the cell-free conversion assay which points to CWD as the animal prion disease with the greatest zoonotic potential, after (and very much less than) BSE..116***
Distribution of PrPCWD in tissues of CWD affected sika deer using RT-QuIC following experimental oral transmission
HJ Sohna, KJ Parka, YR Lee a, HC Parka, and G Mitchell b
a Foreign animal disease division (FADD), Animal and Plant Quarantine Agency (APQA), Gimcheon, Korea; b National & OIE Reference Laboratory for Scrapie and CWD, Canadian Food Inspection Agency, Ottawa, Ontario, Canada
Aims: Chronic wasting disease (CWD) is the only prion disease affecting free-ranging animals, reported in North America, South Korea and Scandinavia. Unlike in most other prion diseases, CWD agents are shed in blood, saliva, urine and feces which most likely contributes to the horizontal transmission between cervid species. Using NaPTA precipitation and real-time quaking-induced conversion (NaPTA/RT-QuIC) or only RT-QuIC, we established an ultrasensitive detection method for PrPCWD in the various tissues and body fluids of CWD affected sika deer following experimental oral transmission.
Material and Methods: Two Sika deer were orally inoculated with a brain homogenate (5 g) prepared from a farmed Canadian elk with clinical CWD. Deer were euthanized due to intercurrent disease or following the development of signs consistent with terminal CWD.
An array of tissues was collected and stored frozen, and were tested for the presence of PrPCWD by RT-QuIC or NaPTA/RT-QuIC.
Results: Primary oral transmission of CWD from elk to sika deer occurred in all inoculated animals, and was detected by RT-QuIC. Consistent with other cervids in the terminal stages of CWD, pathological prions were distributed throughout the central nervous system and lymphoid tissues including spleen. PrPCWD was also detected in the urinary system (kidney, urinary bladder, urine), salivary system (salivary glands and saliva), heart and skin. Detection in the skin occurred after collagenase treatment, and PrPCWD in the urinary system was associated with renal nerve plexus.
Conclusions: CWD transmits efficiently from elk to sika deer via the oral route. Widespread detection of PrPCWD by RT-QuIC suggests that, similar to other cervid species, infectivity is distributed throughout a wide range of tissues in sika deer with clinical CWD.
Funded by: Animal and Plant Quarantine Agency
Grant number: B-154085-2022-24-01
Detection of PrPCWD in ear skin from CWD affected cervid
HJ Sohn, KJ Park, HC Park, YR Lee, and HE Kang
Foreign animal disease division (FADD), Animal and Plant Quarantine Agency (APQA), Gimcheon, Korea
Aims: Chronic wasting disease (CWD) is the only prion disease affecting free-ranging animals, reported in North America, South Korea and Scandinavia. Using real-time quaking-induced conversion (RT-QuIC), we established an ultrasensitive detection method for PrPCWD to determine the availability of using ear skin for preclinical diagnosis, here we report RT-QuIC assays of ear skin samples from cervid. In addition, we confirmed infectivity of four RT-QuIC positive skins thorough Tg Elk mouse bioassay.
Material and Methods: CWD-derived samples were obtained from animals at different clinical stage in Korean cervid farm. This classification of clinical stage was assigned based on post mortem diagnosis of PrPCWD detection in RPLN, tonsil and obex.
An array of tissues was collected and prepared 10% ear homogenate of farmed Korean cervid and then were tested for the presence of PrPCWD by RT-QuIC after incubated collagenase (2 mg/ml) and phospholipase (1.6 umol) 37°C for 1 hr. To confirm ear skin infectivity, we inoculated 4 RT-QuIC positive tissues into Tg elk mice (n = 6 per group) by intracranial route.
Results: PrPCWD is not evenly distributes in cervid ear and detects in seven out of eight cervid at late pre-symptomatic stage. The average ThT fluorescence unit in ear skin gave rapid increase within 11 h in just two cervid of the last end-stage. All inoculated groups showed 80 ~ 100% attack rates and developed the disease during survival times.
Conclusions: Based on our data, we were confirmed in PrPCWD detection and infectivity from CWD infected cervid ear skin. And raising the possibility that simple ear-punch biopsies might be used for CWD antemortem monitoring.
Funded by: Animal and Plant Quarantine Agency
Grant number: B-154085-2022-24-01
SUNDAY, JULY 14, 2019
Korea Chronic Wasting Disease CWD TSE Prion additional cases were observed in red deer, sika deer, and their crossbred deer in 2010 and 2016, beyond that, anyone's guess
FRIDAY, DECEMBER 23, 2022
House and Senate Send Important Chronic Wasting Disease Legislation to President’s Desk
TUESDAY, DECEMBER 20, 2022
TEXAS CHRONIC WASTING DISEASE CWD TSE PRION TOTALS JUMP TO 444 CONFIRMED TO DATE
Terry S. Singeltary Sr.
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