From: TSS ()
Subject: Experimental transmission of atypical scrapie to sheep
Date: August 31, 2007 at 8:27 am PST
Experimental transmission of atypical scrapie to sheep
Marion M Simmons1, Timm Konold1, Hugh A Simmons3, Yvonne I Spencer1,
Richard Lockey1, John Spiropoulos1, Sharon Everitt2 , Derek Clifford3
1Department of Pathology, Veterinary Laboratories Agency – Weybridge,
Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK.
2Department of Molecular Pathogenesis and Genetics, Veterinary
Laboratories Agency – Weybridge, Woodham Lane, New Haw, Addlestone,
Surrey KT15 3NB, UK.
3Animal Services Unit, Veterinary Laboratories Agency – Weybridge,
Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK.
Corresponding author: Marion M Simmons
m.m.simmons@vla.defra.gsi.gov.uk
MMS: m.m.simmons@vla.defra.gsi.gov.uk
TK: t.konold@vla.defra.gsi.gov.uk
HAS: h.a.simmons@vla.defra.gsi.gov.uk
YIS: y.i.spencer@vla.defra.gsi.gov.uk
RL: r.lockey@vla.defra.gsi.gov.uk
JS: j.spiropoulos@vla.defra.gsi.gov.uk
SE: s.everitt@vla.defra.gsi.gov.uk
DC: d.clifford@vla.defra.gsi.gov.uk
Abstract
Background
Active surveillance for transmissible spongiform encephalopathies in small
ruminants has been an EU regulatory requirement since 2002. A number of
European countries have subsequently reported cases of atypical scrapie,
similar to previously published cases from Norway, which have pathological
and molecular features distinct from classical scrapie. Most cases have
occurred singly in flocks, associated with genotypes considered to be more
resistant to classical disease. Experimental transmissibility of such isolates
has been reported in certain ovinised transgenic mice, but has not previously
been reported in the natural host. Information on the transmissibility of this
agent is vital to ensuring that disease control measures are effective and
proportionate.
Results
This report presents the successful experimental transmission, in 378 days, of
atypical scrapie to a recipient sheep of homologous genotype with
preservation of the pathological and molecular characteristics of the donor.
This isolate also transmitted to ovinised transgenic mice (Tg338) with a
murine phenotype indistinguishable from that of Nor 98.
Conclusions
This result strengthens the opinion that these cases result from a distinct
strain of scrapie agent, which is potentially transmissible in the natural host
under field conditions.
snip...
This study confirms that ‘atypical scrapie’ is transmissible within the natural
host species, via the intracerebral route, without alteration of the pathological
and molecular characteristics. This is the first report from a larger study which
will explore more widely the effect of the PrP gene on the experimental
susceptibility and resultant phenotype following intracerebral or oral challenge
with this type of scrapie isolate.
Conclusion
At present the significance of this result, in terms of the transmissibility or
pathogenicity under ‘field conditions’ of this agent strain in any species
remains speculative, but it supports the need for appropriate control measures
protecting both the animal and the human food chain to encompass atypical
scrapie cases specifically.
http://www.biomedcentral.com/content/pdf/1746-6148-3-20.pdf
From: "Terry S. Singeltary Sr."
Sent: Tuesday, August 21, 2007 9:50 AM
Subject: TWO MORE Nor98 atypical Scrapie cases detected in USA bringing
total to 3 cases to date
Infected and Source Flocks
As of June 30, 2007, there were .....
snip...
One field case and one validation case were consistent with Nor-98 scrapie.
http://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/downloads/monthly_scrapie_rpt.pps
IN the February 2007 Scrapie report it only mentions ;
''One case was consistent with Nor98 scrapie.''
http://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/
(please note flocks of origin were in WY, CO, AND CA. PERSONAL COMMUNCATIONS
USDA, APHIS, VS ET AL. ...TSS)
NOR98 SHOWS MOLECULAR FEATURES REMINISCENT OF GSS
http://lists.ifas.ufl.edu/cgi-bin/wa.exe?A2=ind0708&L=sanet-mg&T=0&P=14553
An evaluation of scrapie surveillance in the United States
http://lists.ifas.ufl.edu/cgi-bin/wa.exe?A2=ind0708&L=sanet-mg&T=0&P=3427
FOIA REQUEST FOR ATYPICAL TSE INFORMATION ON VERMONT SHEEP
http://lists.ifas.ufl.edu/cgi-bin/wa.exe?A2=ind0708&L=sanet-mg&T=0&P=10451
Terry S. Singeltary Sr.
P.O. Box 42
Bacliff, Texas USA 77518
