OIE Reference Laboratory Reports
Activities in 2011
Name of disease (or topic) for
which you are a designated OIE
Reference Laboratory:
Address of laboratory:
Scrapie
and
Chronic wasting disease
National Reference Laboratory for Scrapie and CWD
Ottawa Laboratory (Fallowfield)
Canadian Food Inspection Agency
3851 Fallowfield Road
Ottawa, Ontario,
CANADA K2H 8P9
Tel.:
613-221-4854
Fax:
613-221-6103
e-mail address:
website:
Name (including Title and
Position) of Head of Laboratory
(Responsible Official):
Name(including Title and
Position) of OIE Reference
Expert:
Aru.Balachandran@inspection.gc.ca
http://www.inspection.gc.ca/english/toce.shtml
Karen Jessett
Dr Aru Balachandran
Veterinary Science Advisor;
Head, National and OIE Reference
Laboratory for scrapie and CWD
Name (including Title and
Position) of writer of this report
(if different from above):
Annual reports of OIE Reference Centres, 2011
1
Scrapie and Chronic wasting disease
Part I: Summary of general activities related to the disease
1.
Test(s) in use/or available for the specified disease/topic at your laboratory
Our laboratory routinely uses a combination of Histopathology, PrP immunohistochemistry and Western blot as
confirmatory tests for scrapie and CWD. In addition, rapid screening tests for BSE, CWD (Biorad TeSeE SAPELISA) and scrapie (Biorad TeSeE SAP- ELISA and Biorad TeSeE sheep and goat ELISA) are used for disease
control and surveillance testing. Scrapie and CWD confirmed small ruminant and cervid samples are further
subjected to VLA discriminatory western blot testing. Confirmation and discrimination bioassays using cervid,
and ovine transgenic mice and inbred (VM and RIII) lines of mice are in place. The laboratory also performs the
PrP genotyping for scrapie susceptibility/ resistance (codon 136,154 and 171) and elk CWD (codon 132) and
white-tailed deer CWD (codon 96). Detecting bovine prohibited materials such as the brain, spinal cord and other
neural elements in mechanically separated meat (AMR) products is done routinely using histological and GFAP
immunohistochemistry methods.
Disease
Test
For
Specifity
Total
(Diagnosis & Research)
Scrapie
IHC
Antigen
PrP Sc
2341
BioRad ELISA
Antigen
PrP Sc
7662
VLA Hybrid & BioRad
TeSeE-Confirm WB
Antigen
PrP Sc
94
Genotyping sheep
Codon136,154,171
IHC
Antigen
PrP CWD
344
ELISA
Antigen
PrP CWD
1671
VLA Hybrid & BioRad
TeSeE-Confirmatory WB
Antigen
PrP CWD
189
Genotyping-Elk, whitetailed deer
Codon132, 96
BSE
ELISA
Antigen
PrP BSE
5141
AMR
IHC
Antigen
GFAP
418
CWD
2.
5394
152
Production and distribution of diagnostic reagents
While most diagnostic reagents required for scrapie and CWD testing are commercially available, we continue to
develop and maintain an archive of TSE-positive and negative reference materials for use in test development,
validation and proficiency testing programs. These materials are used nationally within our reference and network
laboratories and have been provided to countries in North and South America and Asia who are seeking to develop
TSE testing programs or validate existing programs.
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Annual reports of OIE Reference Centres, 2011
Scrapie and Chronic wasting disease
Part II: Activities specifically related to the mandate
of OIE Reference Laboratories
3.
International harmonisation and standardisation of methods for diagnostic testing or the
production and testing of vaccines
a)
Establishment and maintenance of a network with other OIE Reference Laboratories
designated for the same pathogen or disease and organisation of regular inter-laboratory
proficiency testing to ensure comparability of results
A panel of scrapie and CWD-infected and non-infected tissue blocks were provided to the OIE Reference
Laboratory for Scrapie in Argentina.
b)
Organisation of inter-laboratory proficiency testing with laboratories other than OIE
Reference Laboratories for the same pathogens and diseases to ensure equivalence of
results
To provide ongoing validation of immunohistochemistry testing as well as maintain ISO 17025 certification,
annual proficiency panels consisting of blinded, unstained slides were exchanged with United States
Department of Agriculture (USDA) and Colorado State Veterinary laboratories conducting testing for scrapie
and CWD. A panel of scrapie infected and non-infected tissue blocks was also provided to a TSE-testing
laboratory in Chile.
4.
Preparation and supply of international reference standards for diagnostic tests or vaccines
We curate an archive of scrapie and CWD-infected reference tissues from sheep, goats and a range of cervid
species for use in diagnostic test development and validation. Selected Canadian field cases of confirmed CWD
and scrapie have been inoculated into transgenic or inbred mouse strains to provide characterized and standardized
infectious reference materials. We utilize several inbred and transgenic strains of mice from international
collaborators. These include RIII and VM strains from the Medical Research Council (MRC) in the United
Kingdom, Tg338 (ovinized-PrP) mice from the National Institute for Agricultural Research (INRA) in France,
cervidized-PrP and humanized-PrP transgenic mice from the National Institutes of Health (NIH) in the United
States and bovinized-PrP transgenic mice from the Friedrich-Loeffler-Institut (FLI) in Germany. Quantitative
bioassays are conducted to determine infectivity titres of standardized inoculates for test development and
validation, as well as for the characterization of Canadian CWD and scrapie strains.
5.
Research and development of new procedures for diagnosis and control
Evaluation of immuno-PCR for the detection of ultra-low levels of pathologic prion protein: Current testing
methods for transmissible spongiform enceophalopathies (TSEs) involve the detection of abnormal prion protein
(PrPTSE) by immunochemical methods as the hallmark of infection. Novel technologies that combine higher
sensitivity detection with fast, robust, and cost-efficient protocols hold promise for future diagnostic and research
applications. Work is in progress to increase the analytical sensitivity of immuno-PCR relative to currently
approved test methods and to investigate the applicability for pre-clinical diagnosis and environmental testing.
Cervid genotyping for CWD resistance/susceptibility: Susceptibility of cervids to CWD infection has been shown
to be associated with polymorphisms in the host prion protein gene. Work is in progress to validate recently
developed high throughput methods to detect the allelic variants of elk, white-tailed deer at codons 132, and 96
respectively. This information may be used as a component of regulatory control and eradication programs.
Measures of sensitivity and specificity do not apply as per diagnostic testing of a disease/infectious agents since
this test provides the genotype of a particular animal and not infected/non-infected status. The method used to
detect these allelic variants has undergone partial Level 1 formal validation in accordance with the OIE Validation
Template (calibration, repeatability studies).
Rodent bioassays for the quantification and characterization of prion infectivity. Studies utilizing our rodent
bioassay platform continue for characterising Canadian scrapie and CWD strain variability, investigating species
barriers to infectivity and determining infectivity titres from a variety of matrices. Collaborative research projects
Annual reports of OIE Reference Centres, 2011
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Scrapie and Chronic wasting disease
are ongoing investigating the utility and validity of novel low-level detection methods such as PMCA and
immuno-PCR as well as the reductions of infectivity associated with composting infectious tissues. Research
continues towards defining the distribution of infectivity in CWD-infected cervids and if CWD is capable of
overcoming a range of species barriers. The rodent bioassay has demonstrated diagnostic utility in discriminating
between CWD, atypical and classical scrapie and BSE in diagnostic samples.
6.
Collection, analysis and dissemination of epizootiological data relevant to international disease
control
Enhanced scrapie surveillance is ongoing across Canada with the goal of better understanding the disease
prevalence and distribution. This includes continued characterization of all positive cases though IHC, western
blot and in some cases bioassay, to discriminate classical scrapie cases from atypical scrapie or potential BSE
cases in sheep. Data from this surveillance program will be collated and communicated as it becomes available.
The distribution of CWD continues to be monitored in farmed and feral cervid populations with particular interest
in detecting expanding geographical ranges and the ability of CWD to infect novel cervid species such as caribou
or reindeer.
7.
Maintenance of a system of quality assurance, biosafety and biosecurity relevant to the
pathogen and the disease concerned
The TSE-OIE Reference Laboratory operates within an ISO 17025 accredited facility. Maintenance of this
certification requires strict adherence to quality assurance guidelines with an ongoing audit process to ensure the
highest standards of testing are sustained. All samples handling and testing is done under strict TSE containment
standards in access-restricted laboratories which are subjected to a federally-mandated certification program.
8.
Provision of consultant expertise to OIE or to OIE Member Countries
Participated in a research collaboration meeting with the Prion Diseases Department of Animal, Plant and
Fisheries Quarantine and Inspection Agency, South Korea and gave a presentation on “CWD in North America :
An update” Dec 9-12.
9.
Provision of scientific and technical training to personnel from other OIE Member Countries
Dr Yoon-Hee Lee, Veterinary Researcher from the Animal, Plant and Fisheries Quarantine and Inspection Agency
in South Korea visited for 2 weeks (September 12-26) to exchange ideas in diagnostic test methodology and result
interpretation in support of a collaborative research project investigating cross-species transmission of CWD.
Dr Gabriel Pinto, from the TSE Reference Laboratory, INTA, Buenos Aires, Argentina visited May 21-24 and
received training in scrapie and CWD diagnosis.
Dr Aline Kawanami from the Department of Veterinary Pathology, FCAV-UNESP, Jaboticabal, Brazil visited
September 24-October 03 for training in diagnosis of CWD.
10. Provision of diagnostic testing facilities to other OIE Member Countries
Testing for the presence of CWD by immunohistochemistry was undertaken in a small group of samples obtained
from wild cervids in Brazil.
11. Organisation of international scientific meetings on behalf of OIE or other international bodies
None
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Annual reports of OIE Reference Centres, 2011
Scrapie and Chronic wasting disease
12. Participation in international scientific collaborative studies
A collaborative study with the Animal, Plant and Fisheries Quarantine and Inspection Agency (QIA) in South
Korea continues with the objective of characterizing South Korean and Canadian CWD strains. Transmission
studies are ongoing in cervid and transgenic mouse models. In August 2011, Dr G. Mitchell travelled to the QIA
TSE laboratory to discuss project progress and present an informal seminar to QIA scientists on the transmission
of Canadian CWD isolates to transgenic mice.
13. Publication and dissemination of information relevant to the work of OIE (including list of
scientific publications, internet publishing activities, presentations at international conferences)

Presentations at international conferences and meetings
PRION 2011, Montreal, Canada, May 16-19, 2011
Mitchell G, Shaffer P, Foster S, Ghazi D, Rendulich J, Yogasingam N, Hills B, and Balachandran A. Transmission
of Canadian CWD Isolates to Transgenic Mice.
Gao TT, Tong Y, Wong L, Xiaomei L, Balachandran A, Yogasingam N, Mitchell G, Bowlby E, and Wu J.
Thermophilic Anaerobic Digestion Degrades Scrapie Prion Protein and Transforms Specified Risk Materials into
Bioenergy.
Price LM, Braithwaite S, Balachandran A, Mitchell G, Belosevic M, and Neumann N. Detection of PrPCWD from
the Saliva, Urine and Feces of Experimentally-Infected White-Tailed Deer.
Harrington N, Rendulich J, and Balachandran A. A review of archived Canadian scrapie cases for evidence of
bovine spongiform encephalopathy.
University of Guelph Emergency Management Research Expo, Guelph, ON, Canada, Sept. 19, 2011
The RAMALT Procedure to Detect Scrapie in Sheep - Is It Painful? Menzies PI, Haley D, Yates D, Mitchell G
and Balachandran A

Scientific publications in peer-reviewed journals
Huang. H, Soutyrine. A, Rendulich. J, O’Rourke. K, Balachandran. A. Investigation of the effects of experimental
autolysis on the detection of abnormal prion protein in lymphoid and central nervous system tissues from elk and
sheep using the Western blotting method. Can.J.Vet.Res.2011. Jan. 75(1) 69-72
Blashe.T, Schenck.E.V, Balachandran.A, Miller.M.W, Langenberg.J, Frolich.K, Steibach.F. Rapid detection of
CWD PrP: Compariosn of tests designed for the detection of BSE or scrapie. Transbound Emerg Dis. 2011. Dec.
doi. 10.1111 ( Epub)
_______________
Annual reports of OIE Reference Centres, 2011
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