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FOIA MAD SHEEP MAD RIVER VALLEY UPDATE NOVEMBER 13, 2007

flounder

Well-known member
FOIA MAD SHEEP MAD RIVER VALLEY


Tuesday, November 13, 2007

DECLARATION OF EXTRAORDINARY EMERGENCY BECAUSE OF AN ATYPICAL T.S.E. (PRION DISEASE) OF FOREIGN ORIGIN IN THE UNITED STATES [Docket No. 00-072-1]


To: [email protected]


CC: [email protected]; [email protected];


Re: FOIA APPEAL 07-566 DECLARATION OF EXTRAORDINARY EMERGENCY BECAUSE OF AN ATYPICAL T.S.E. (PRION DISEASE) OF FOREIGN ORIGIN IN THE UNITED STATES [Docket No. 00-072-1]



November 13, 2007


Greetings Garfield O. Daley, Acting FOIA Director, and USDA et al,



http://foiamadsheepmadrivervalley.blogspot.com/



TSS
 

Tex

Well-known member
terry, are there tests that are common for scrapies and are there scrapies free stock you can purchase?
 

flounder

Well-known member
Tex said:
terry, are there tests that are common for scrapies and are there scrapies free stock you can purchase?


figure 7 breaks testing down a bit ;

http://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/downloads/monthly_scrapie_rpt.pps



Submitted to: Veterinary Record
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 29, 2003
Publication Date: May 22, 2004
Citation: Bender, S., Alverson, J., Herrmann, L.M., O'Rourke, K.I. 2004.
Histamine as an aid to biopsy of third eyelid lymphoid tissue in sheep.
Veterinary Record. 154: 662-663.

Interpretive Summary: A novel technique was developed to facilitate the
collection of third eyelid tissue samples in sheep for use in diagnosis of
scrapie, a transmissible spongiform encephalopathy. Histamine eyedrops were
used prior to tissue biopsy to enhance the tissue, thereby making the biopsy
procedure easier, and the sample collected of sufficient quality for an
accurate diagnosis of scrapie. The use of histamine eyedrops will increase
the accuracy of preclinical scrapie diagnosis in third eyelid tissue and
will be of use to field veterinarians, animal health regulatory agencies,
and the sheep industry.
Technical Abstract: Diagnosis of ovine scrapie, a transmissible spongiform
encephalopathy, by third eyelid lymphoid tissue biopsy and PrPSc assay has
been described. One of the biggest drawbacks to implementing routine field
use of the third eyelid test has been obtaining adequate numbers of lymphoid
follicles in each tissue biopsy for disease diagnosis. We describe a
technique for enhancing third eyelid lymphoid tissue using histamine
eyedrops that improved biopsy collection of third eyelid tissue with
increased numbers of lymphoid follicles and did not interfere with PrPSc
detection by immunohistochemistry assay.



http://www.aphis.usda.gov/vs/highlights/section3/section3-19.html


http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=148966


Research Project: NONINVASIVE ANTEMORTEM OCULAR FUNCTION SCREENING TEST FOR
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES


http://www.ars.usda.gov/research/projects/projects.htm?accn_no=409741



Title: COMPARISON OF TWO AUTOMATED IMMUNOHISTOCHEMICAL PROCEDURES FOR THE
DIAGNOSIS OF SCRAPIE IN DOMESTIC SHEEP AND CHRONIC WASTING DISEASE IN NORTH
AMERICAN WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS) AND MULE DEER
(ODOCOILEUS HEMI

Authors

Baszler, T - WSU
Kiupel, M - MICHIGAN ST UNIV
Williams, E - UNIV OF WYOMING
Thomsen, B - USDA APHIS
Gidlewski, T - USDA APHIS
Montgomery, D - TX VET MED DIAG LAB
O`ROURKE, KATHERINE
Hall, S - USDA APHIS


Submitted to: Journal of Veterinary Diagnostic Investigation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 3, 2005
Publication Date: March 3, 2006
Citation: Baszler, T.V., Kiupel, M., Williams, E.S., Thomsen, B.V.,
Gidlewski, T., Montgomery, D.L., O'Rourke, K.I., Hall, S.M. 2006. Comparison
of two automated immunohistochemical procedures for the diagnosis of scrapie
in domestic sheep and chronic wasting disease in north American white-tailed
deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus). Journal
of Veterinary Diagnostic Investigation. 18(2):147-155.

Interpretive Summary: Scrapie and chronic wasting disease are prion
disorders in which a marker protein accumulates in the lymph nodes and brain
of affected sheep, deer, and elk. Diagnosis can be performed by
immunohistochemistry assay, in which preserved tissue sections are treated
with antibodies to the marker protein and detected with compounds that
produce a color change. The assay can be performed on a number of automated
systems. In this paper, the authors describe the comparison between two
commercially available systems for detection of the marker protein.
Concordance between the systems was 98.6% for lymph nodes and 99.9% for
brain. The results indicate that the systems are equivalent. These findings
indicate that laboratories will be able to test samples using either piece
of equipment, following final approval of the test format by USDA APHIS.
Technical Abstract: Scrapie and chronic wasting disease are transmissible
spongiform encephalopathies of sheep and cervid ruminants respectively.
These diseases are often diagnosed by immunohistochemistry using one or a
cocktail of two monoclonal antibodies on an automated immunostainer that
delivers commercially available detection reagents in sequence with
intervening washing steps. Automated immunohistochemistry allows federal
contract laboratories in different parts of the US to test large numbers of
samples using a standard uniform protocol. Testing by the USDA Animal Plant
Health Inspection Service (APHIS) has been conducted with equipment and
reagents marketed by Ventana Medical Systems. A recent survey revealed that
the autostainer and reagents marketed by the DAKO Corporation were commonly
used in veterinary diagnostic laboratories and adaptation of the testing to
that equipment would allow these laboratories to participate in the national
testing program without purchasing additional equipment. A trial to
determine concordance between the two autostainers was conducted with
tissues from sheep and two species of deer exposed to transmissible
spongiform encephalopathies. Discordance between the methods was minimal and
there were no significant qualitative differences. Equal performance of the
two platforms in a semi-quantitative grading classification of tissues
considered positive supported the conclusion that the systems perform
similarly.



http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=188399


http://www.aphis.usda.gov/vs/ceah/ncahs/nahms/sheep/SOSSphase2.pdf



Research Project: OVINE PRION & VIRAL INFECTIONS: SCRAPIE & OVINE PROGRESSIVE PNEUMONIA, DIAGNOSIS & CONTROL
Location: Animal Diseases Research


2005 Annual Report

1.What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? What does it matter?
The economic losses to the sheep industry due to ovine scrapie can be reduced by a coordinated program of live animal testing, replacement with sheep of lower susceptibility, and reducing transmission within the flock. Scrapie is a transmissible spongiform encephalopathy associated with deposition of an abnormal isoform of a mammalian glycoprotein, the prion protein, in tissues throughout the sheep. The highest level of accumulation is in the brain, although detectable levels are found in lymphoid tissues and placenta/fetal tissues. Detection of prions in peripheral lymphoid tissue can be used to identify and cull infected animals early in infection. Further, the susceptibility of sheep to clinical scrapie and to accumulation of prions is under genetic control. Quantitative determination of the level of protection associated with commonly occurring genotypes could enable producers and regulatory programs to integrate protective genetics with elimination of infected stock to reduce the amount of disease in U.S. flocks. Control of all domestic prion diseases is important in reducing trade barriers for U.S. sheep and germplasm and for assuring the present and future global markets for cattle. Ovine progressive pneumonia virus causes persistent viral infection and development of multi-organ inflammatory disease in some animals. The infection rates in US sheep flocks range from 9 to 49%. A variable and unpredictable percentage of infected animals will progress to clinical disease with high viral titers and increased risk of transmission to flockmates. This project has produced a serologic test for the disease. The current project includes development of a vaccine to reduce infected animals and identification of genes associated with decreased transmission in infected sheep. Sheep scrapie is a member of a group of diseases that includes bovine spongiform encephalopathy (BSE). Sheep scrapie is associated with minor direct losses to the industry. However, loss of international markets for sheep and sheep germplasm and loss of the domestic access to rendering facilities are major economic losses to the industry. Control programs based on epidemiology alone have failed to control the spread of scrapie throughout the U.S. since the disease was introduced in 1947. A control program based on a live animal diagnostic test supplemented by introduction of replacement stock of lower genetic susceptibility is urgently needed. Transmission barriers of these diseases are not understood. Therefore, the presence of any of these diseases within the U.S. represents a continuous threat for emergence in animals not yet found to have been infected in the U.S. The occurrence of BSE in U.S. cattle has caused economic losses in the U.S. cattle domestic market and the world markets. Animals with clinical signs of ovine progressive pneumonia virus represent the main risk of virus transmission because disease progression is associated with much higher virus loads than is nonprogressive persistent infection. Therefore, the immunogenetic basis of disease pathogenesis is an important consideration in SRLV research. The most significant problem associated with SRLV infection is the inability to determine which animals will progress to severe clinical disease and death. Our objectives are to reduce the clinical disease rates and viremia levels through a vaccination program targeting the type 1 immune responses and to determine the immunogenetics associated with this response. SRLV research will lead to methods for the induction of immunologic control and genetic predictors of animals with a low potential for transmission if infected. Our research concerning the transmissible encephalopathies and small ruminant lentiviruses address the following elements of our National Program in Animal Production, Product Value and Safety. Our research encompasses the National Program Initiative 103 Animal Health at 100%, and our research components include pathogen detection and diagnostics, animal immunology, mechanism of disease, genetic resistance to disease, and strategies to control infectious and non-infectious diseases.


2.List the milestones (indicators of progress) from your Project Plan.
Year 1 (FY2002)

Validate diagnostic and genetic tests; IHC test validation studies and PrP genotype continue from previous CRIS.

Define transmission route. Continue study on effect of maternal disease status and fetal genotype of PrP-Sc in placenta. Initiate studies on effect of pregnancy and placenta on PrP-Sc.

Initiate blood transfusion study. Complete methods for detecting and quantitating PrP-C and PrP-Sc in dissociated lymph nodes.

Induce type 1 response to CAEV and MVV. Immunize goats with plasmid DNA expressing CAEV env and boost with SU-FIA. Isolate and characterize wild type CAEV for challenge and challenge-immunized goats.

Identify MVV resistant MHC class II haplotypes. Complete titration and isotypes of antibodies from Dubois sheep.

Year 2 (FY2003)

Continue validation of IHC tests.

Continue studies on effect of pregnancy and placenta on PrP-Sc.

Continue FACS and IHC analysis of lymph node cells for PrP-C and PrP-Sc.

Continue examination of postchallenge parameters. Construct and characterize a recombinant plasmid expressing MVV8534 env.

Complete T cell proliferation assays and divide sheep.

Year 3 (FY2004)

Complete validation of IHC tests.

Complete studies on effect of pregnancy and placenta on PrP-Sc.

Complete FACS and IHC analysis of lymph node cells for PrP-C and PrP-Sc.

Continue examination of postchallenge parameters. Construct and characterize a recombinant plasmid expressing MVV8534 env.

Year 4 (FY2005)

Initiate studies on rapid, high volume diagnostic testing; complete PrP genotype study.

Complete study on effect of maternal disease status and fetal genotype of PrP-Sc in placenta Initiate studies on regulation of PrP-C by estrous cycle and pregnancy.

Complete PrP-C distribution and quantitation in peripheral blood cells; initiate immunomagnetic bead enrichment studies if indicated.

Immunize sheep with plasmid DNA expressing MVV8534 env and boost with MVV SU-FIA. Challenge immunized goats with MVV8534.

Complete PCR-RFLP of OvLa DRB-1 alleles.

Year 5 (FY2006)

Complete PrP-Sc rapid test development and transfer technology.

Complete studies on regulation of PrP-C by estrous cycle and pregnancy.

Complete blood transfusion study.

Continue examination of postchallenge parameters.

Identify OvLa DRB-1 alleles that associate with type 1 responses. Identify MMV-free sheep with appropriate DRB-1 haplotypes and challenge with MVV8534.


3a.List the milestones that were scheduled to be addressed in FY 2005. For each milestone, indicate the status: fully met, substantially met, or not met. If not met, why.

Initiate studies on rapid, high volume diagnostic testing; complete PrP genotype study.
Milestone Substantially Met

Complete study on effect of maternal disease status and fetal genotype of PrP-Sc in placenta Initiate studies on regulation of PrP-C by estrous cycle and pregnancy.
Milestone Substantially Met

Complete PrP-C distribution and quantitation in peripheral blood cells; initiate immunomagnetic bead enrichment studies if indicated.
Milestone Fully Met

Immunize sheep with plasmid DNA expressing MVV8534 env and boost with MVV SU-FIA. Challenge immunized sheep with MVV8534.
Milestone Not Met

Complete PCR-RFLP of OvLa DRB-1 alleles.
Milestone Fully Met


3b.List the milestones that you expect to address over the next 3 years (FY 2006, 2007, and 2008). What do you expect to accomplish, year by year, over the next 3 years under each milestone?
Year 5, 6 and 7 milestones are listed below with a description of the anticipated outcomes. The entire project will be completed during FY 2006, and a new project will be developed to undergo OSQR review, and subsequent implementation beginning FY 2007.

Year 5 (FY2006)

Complete rapid scrapie test development and transfer technology.

Complete PrP genotype study in goats.

Complete sequencing of expressed OvLa MHC Class II DRB-1 alleles.

Continue oral scrapie transmission study in goats.

Potential impact: A rapid test for scrapie will facilitate diagnosis. A map of the PrP gene and the mutations for goats will aid in determining if certain genotypes are more susceptible or resistant to scrapie once challenge experiments are initiated. Characterization of the expressed OvLa MHC Class II DRB1 alleles will allow development of a rapid high-throughput system for typing sheep.

Year 6 (FY 2007)

Continue oral scrapie transmission study in goats.

Initiate experimental inoculation of OPPV into sheep with specific OvLa MHC Class II DRB-1 expressed alleles.

Develop rapid MHC Class II DRB1-1 typing tests.

Potential impact: Data on oral transmission of scrapie to goats will aid in determining the impact of goats on scrapie transmission to sheep flocks in the US. Development of a rapid MHC Class II DRB1 typing test will allow rapid screening of sheep for specific MHC Class II types followed by experimental inoculation of OPPV.

Year 7 (FY 2008)

Continue experimental inoculation of OPPV into sheep with specific OvLa MHC Class II DRB-1 expressed alleles.

Initiate TSE strain studies.

Complete oral scrapie transmission study in goats.

Potential impact: Examining strains of scrapie will aid in understanding transmission of sheep scrapie. Data on oral transmission of scrapie to goats will aid in determining the impact of goats on scrapie transmission to sheep flocks in the US. Monitoring of experimental inoculation of OPPV into sheep with specific MHC Class II DRB1 types will allow associations to be made between disease progression and specific MHC Class II DRB1 types.


4a.What was the single most significant accomplishment this past year?
We found that multiple fetuses in the uterus of a pregnant ewe have an effect on PrPSc accumulation in the placental tissue. We previously showed that if a sheep fetus has a scrapie-resistant genotype, PrPSc does not accumulate in the placenta tissue of scrapie-infected ewes. We have now found, however, the placenta tissue associated with a fetus of a scrapie-resistant genotype can accumulate PrPSc if it is positioned next to a fetus of a scrapie susceptible genotype in utero in scrapie infected ewes. This has potential impact to the sheep industry in relying on the genetics to breed for resistance to scrapie.


4b.List other significant accomplishments, if any.
When applying OPPV diagnostic tests to the field, it is necessary to identify the immunodominant antigen in OPPV-infected sheep. One publication has resulted from identifying the surface envelope glycoprotein (SU) as the B-lymphocyte immunodominant antigen in mature OPPV-infected sheep. Because the CAEV cELISA detects anti-SU antibodies, this result ensures that most mature OPPV-infected sheep will have measurable titers of anti-SU antibodies which can be detected in the CAEV cELISA This result has direct implications for the sheep industry in terms of accurate OPPV diagnostic testing using the CAEV cELISA.

Previous studies have shown that sheep with Prnp diploid genotypes of AA, QR and AA, RR at codons 136, 171, respectively, are more resistant to scrapie. However, it is unknown whether breeding toward these scrapie-resistant Prnp diploid genotypes would affect lamb production traits. ADRU is currently collaborating with University of Wyoming (5348-32000-019-03S) to show that breeding flocks toward the scrapie resistant PrP genotypes does not influence lamb production. Results of this research have yielded one publication and has impact on the sheep industry.

We previously showed that if a sheep fetus has a scrapie-resistant genotype, PrPSc does not accumulate in the placenta tissue of scrapie-infected ewes. Another question we wanted to address, which relates to sheep with scrapie-resistant Prnp diploid genotypes, is whether ewes with scrapie resistant PrP genotypes born from scrapie-infected ewes will accumulate PrPSc in their placental tissue after being bred back to a ram with a scrapie susceptible PrP genotype. In addition, ADRU and North Dakota State University (5348-32000-019-04S) are collaborating to evaluate the natural passage of scrapie through a flock with Prnp diploid genotypes at 136 of AV and VV. Since this flock is the first documented case of valine 136-based scrapie in the U.S., it is extremely important to understand the Prnp genetics of all flock mates and the transmission of valine 136-based scrapie.


4c.List any significant activities that support special target populations.
None.


4d.Progress report.
None


5.Describe the major accomplishments over the life of the project, including their predicted or actual impact.
A practical live animal test for scrapie and preclinical postmortem tests for scrapie were developed and transferred to the regulatory agencies for use in the US. Monoclonal antibodies useful in assays on routinely formalin fixed tissue from infected sheep, deer, elk, cattle, humans, mink, domestic cats and a wide variety of captive wildlife potentially exposed to prion diseases were developed. Mechanisms for preventing transmission of scrapie through genetic selection of sires were demonstrated. Along with sire testing, genetic testing in bred ewes will ensure less transmission of scrapie from ewe to lamb.

The specific immune cells in lymph nodes involved in PrPSc accumulation remain unknown. Therefore, we analyzed lymph nodes for the presence of PrPSc and macrophage or follicular dendritic cell (FDC) markers using dual immunohistochemistry. Results indicated that lymph node follicular macrophages acquire PrPSc by phagocytosis of CD21+ FDC processes and process full-length PrPSc to N-terminally truncated PrPSc. These data provide the first knowledge in determining the pathogenesis of sheep scrapie in FDC and macrophages.

A new caprine arthritis-encephalitis virus (CAEV) competitive inhibition enzyme-linked immunosorbent assay (cELISA) had previously been developed. We tested 200 goat sera for the presence of CAEV antibodies using cELISA against the standard of comparison, immunoprecipitations (IP) of [S35] methionine-labeled CAEV lysate. The CAEV cELISA validation resulted in 100% sensitivity and 96.4% specificity against the standard of comparison. By annually testing goats for CAEV using cELISA, a CAEV-free herd could be established.

Because of the high sensitivity and specificity of the CAEV cELISA in goats, validation of the CAEV cELISA in sheep also ensued. By using IP of [S35] methionine-labeled OPPV lysate as the comparable standard, detection of serum antibodies to ovine progressive pneumonia virus (OPPV) in sheep using the CAEV cELISA yielded a sensitivity 98.6% and a specificity of 96.9%. This indicates that one diagnostic test, the CAEV cELISA, can be utilized for detection of small ruminant lentiviruses.

When applying the CAEV cELISA diagnostic test to the field, it is necessary to identify OPPV field strains. We isolated 7 new OPPV field strains from the colostrum cells of 10 OPPV-infected sheep. We characterized and compared the surface envelope glycoprotein (SU) deduced amino acid sequences from these sheep against previously characterized OPPV, CAEV and maedi-visna virus strains. The new OPPV field strains had high sequence identity to OPPV and CAEV strains more than MVV strains. This result is important for future CAEV cELISA testing of U.S. sheep and sheep outside the U.S. infected with OPPV or MVV, respectively.

Standardized, validated diagnostic tests are needed for eradication of scrapie. In FY2001-FY2003, a cooperative ARS-APHIS-state test validation program resulted in submission of samples from more than 2,000 sheep. These samples are being used to validate the third eyelid live animal test, the postmortem immunohistochemistry test, and to develop novel rapid, high throughput tests suitable for slaughter surveillance. A panel of internationally accepted tests suitable for diagnostic and surveillance purposes will result.

Control of scrapie and the small ruminant lentiviruses (SRLV) directly benefits small farms that raise sheep and goats for supplementary income. Direct and indirect losses to these producers because of these diseases are significant. Control programs that include identification of infected flocks and animals should reduce the economic consequences of SRLV and prion diseases.


6.What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end-user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products?
Two monoclonal antibodies to the prion protein and their use in combination as detection reagents for prions have been patented. Both antibodies are commercially available. Only non-exclusive licenses have been offered, to insure the widest possible use of these reagents in diagnostics, industry, and research. The antibodies are in use internationally and collaborative programs to train personnel in Canada, Mexico, and China are in progress. The preclinical test for scrapie has been transferred to the National Veterinary Services Laboratory. APHIS has established a national testing network, through which veterinary and state diagnostic laboratories will apply the technology under contract with APHIS. CAEV cELISA will be licensed and commercially available in the U.S. in 6-12 months.


7.List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: List your peer reviewed publications below).
1. Scrapie: Prions in the Placenta of AAQQ and AAQR sheep. Invited presentation at American Sheep Industry Convention, Reno, NV, January 28, 2005.

2. Prion accumulation in the sheep placenta / Goat scrapie genotyping project. Invited presentation at USAHA Sheep and Goat Committee, United States Animal Health Association Annual Meeting, Greensboro, NC, October 24, 2005.

3. Sheep scrapie: maternal and fetal genetics. Invited presentation at Animal Prion Diseases and the Americas, Ames, IA, October 14-16, 2005.

4. Using host immunogenetics as a prediction tool for ovine progressive pneumonia virus clinical disease. Invited presentation at the American Sheep Industry Convention, Reno, NV, January 2005.

5. Natural Sheep Scrapie: What have we learned? Invited presentation to the Department of Chemistry and Biochemistry at the University of Denver, Denver, CO, November 2004.

6. Predicting ovine progressive pneumonia virus loads using MHC Class II DRB1 immunogenetics. Invited presentation at the United States Animal Health Association Sheep and Goat Committee, Greensboro, NC, October 2004.

7. Lack of Natural Ovine Progressive Pneumonia Virus Transmission from OPPV-Infected Ewes to Their Lambs. Presentation at the Keystone Symposia HIV Pathogenesis, Banff, Canada, April 2005.


Review Publications
Alverson, J. 2005. Data sheet for scrapie. Animal Health and Production Compendium. Available: http://www.cabicompendium.org/ahpc/home.asp


Alexander, B.M., Stobart, R.H., Russell, W.C., Orourke, K.I., Lewis, G.S., Logan, J.R., Duncan, J.R., Moss, G.E. 2005. The incidence of genotypes at codon 171 of the prion protein gene (prnp) in five breeds of sheep and production traits of ewes associated with those genotypes. Journal of Animal Science. 83(2):455-459.


Herrmann, L.M., Mcguire, T.C., Hotzel, I., Lewis, G.S., Knowles Jr, D.P. 2005. Surface envelope glycoprotein is b-lymphocyte immunodominant in sheep naturally infected with ovine progressive pneumonia virus. Clinical and Diagnostic Laboratory Immunology. 12(6):797-800.


Herrmann, L.M. 2005. Needles: To Re-use or Not to Re-use?. Sheep Industry News. 9(5):2.


Johnson, M.L., Evoniuk, J.M., Stoltenow, C.L., Orourke, K.I., Redmer, D.A. 2005. Development of an assay to determine single nucleotide polymorphisms (snp) in the prion gene for the diagnosis of genetic susceptibility to scrapie in sheep. American Society of Animal Science. 56:151.


Evoniuk, J.M., Stoltenow, C.L., O'Rourke, K.I., Moore, B.L., Redmer, D.A. 2005. Assessment of the genetic risk and impact of lateral transmission in a valine-associated scrapie outbreak in sheep. American Journal of Veterinary Research. 66:)1-6.


http://www.ars.usda.gov/research/projects/projects.htm?ACCN_NO=405202&fy=2005


http://www.idexx.com/aboutidexx/pressroom/releases/20060313pr.jsp



However, a fairly new study out ;

Rapid testing leads to the underestimation of the scrapie prevalence in an affected sheep and goat flock

Claudia Reckzeha, b, Christine Hoffmanna, Anne Buschmanna, Silke Budac, Klaus-Dieter Budrasc, Karl-Friedrich Recklingd, Steffi Bellmannd, Hartmut Knobloche, Georg Erhardtf, Reinhard Friesb and Martin H. Groschupa, ,
aFriedrich-Loeffler-Institut, Institute for Novel and Emerging Diseases, Insel Riems, Germany
bInstitute of Meat Hygiene and Technology, Faculty of Veterinary Medicine, Freie Universität Berlin, Germany
cInstitute of Veterinary Anatomy, Freie Universität Berlin, Germany
dLandesuntersuchungsamt für Gesundheits-, Umwelt- und Verbraucherschutz, Stendal, Germany
eVeterinär- und Lebensmittelüberwachungsamt des Landkreises Anhalt-Zerbst, Germany
fDepartment of Animal Breeding and Genetics, Justus-Liebig University of Giessen, Germany

Available online 8 April 2007.



Abstract
To obtain a more detailed understanding of the prevalence of classical scrapie infections in a heavily affected German sheep flock (composed of 603 sheep and 6 goats), we analysed 169 sheep and 6 goats that carried the genotypes susceptible to the disease and that were therefore culled following discovery of the index case. The initial tests were performed using the Biorad TeSeE ELISA and reactive results were verified by official confirmatory methods (OIE-immunoblot and/or immunohistochemistry (IHC)) to demonstrate the deposition of scrapie-associated PrPSc in the brain stem (obex). This approach led to the discovery of 40 additional subclinically scrapie-infected sheep. Furthermore, peripheral lymphatic and nervous tissue samples of the 129 sheep and 6 goats with a negative CNS result were examined by IHC in order to identify any preclinical infections which had not already spread to the central nervous system (CNS). Using this approach we found 13 additional sheep with PrPSc depositions in the gut-associated lymph nodes (GALT) as well as in the enteric nervous system. Moreover, in most of these cases PrPSc was also deposited in the spleen and in the retropharyngeal and superficial cervical lymph nodes. Taken together, these results show a 30.3% infection prevalence in this scrapie-affected flock. Almost 7.4% of the infected animals harboured PrPSc exclusively in the peripheral lymphatic and nervous tissue and were therefore missed by the currently used testing strategy.

Keywords: Preclinical scrapie; Immunohistochemistry; Lymphoid tissue


Corresponding author at: Institute for Novel and Emerging Infectious Diseases at the Friedrich-Loeffler-Institut, Boddenblick 5a, 17493 Greifswald, Germany. Tel.: +49 38351 7163; fax: +49 38351 7191


http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TD6-4NFH0BB-3&_user=10&_coverDate=08%2F31%2F2007&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10
&md5=21d6b63c1b05ee634c418ebc13b515a4


1: Vet J. 2007 Jun 14; [Epub ahead of print]Links
Lack of PrP(sc) immunostaining in intracranial ectopic lymphoid follicles in a sheep with concomitant non-suppurative encephalitis and Nor98-like atypical scrapie: A case report.Vidal E, Tortosa R, Costa C, Benavides J, Francino O, Sánchez-Robert E, Pérez V, Pumarola M.
Priocat Laboratory, CReSA, Autonomous University of Barcelona, 08193 Bellaterra (Cerdanyola del Vallès), Spain.

During active surveillance for transmissible spongiform encephalopathies (TSEs) in sheep, an initial reactor was detected using a rapid test on a brain sample. Immunohistochemistry confirmed an atypical TSE presentation that closely resembled the previously described Nor98 cases. Sequencing of the prnp gene confirmed the ARQ/AHQ genotype with the L141F mutation at codon 141 associated with this phenotype. The head, including the brain and cranial lymphoid tissues, was sampled and examined thoroughly. Non-purulent encephalitis, with ectopic lymphoid follicle formation within the brain, was diagnosed concomitant to the TSE. When scrapie-associated prion protein (PrP(sc)) deposition was studied by immunohistochemistry there was a noticeable lack of lymphotropism. The distribution of PrP(sc) in the brain differed considerably from that of classical scrapie cases. Astrogliosis and microgliosis were demonstrated by histochemical procedures.

PMID: 17574883 [PubMed - as supplied by publisher]


http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=17574883&ordinalpos=
3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_Results
Panel.Pubmed_RVDocSum

Scrapie free purchase ??? maybe Australia and New Zealand, but i would not hold my breath here for a scrapie free flock just yet. they do have a program.


it's a voluntary program.


http://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/free-certi.shtml


http://permanent.access.gpo.gov/lps3025/fsvsfcp.html

http://www.sheepusa.org/?page=site/get_file&print=1&file_id=7409273a5daaa6e46508712e0368f53c

http://www.sheep101.info/201/biosecurity.html




USA NOR-98 SCRAPIE UPDATE AUGUST 31, 2007 RISES TO 5 DOCUMENTED CASES


http://nor-98.blogspot.com/


Government Accountability Project




https://www.blogger.com/comment.g?blogID=3995372399492420922&postID=295754279213239559




TSS
 

flounder

Well-known member
FY 2007 Priorities – Diagnostic Testing
• Evaluate rectal biopsy for
live animal diagnosis
• Convert RSSS to ELISA
screening test
• Finalize MOU with ARS for
further characterization of
positive samples



http://www.animalagriculture.org/proceedings/2007/Tuesday/2%20Sheep%20and%20Goat%20Health/1%20Alecia%20Naugle.pdf


TSS
 

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