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Research Project: Study of Atypical BSE 2006 Annual Report

flounder

Well-known member
Subject: Research Project: Study of Atypical BSE 2006 ARS Annual Report
Date: January 13, 2007 at 3:16 pm PST

Research Project: Study of Atypical Bse
Location: Virus and Prion Diseases of Livestock

2006 Annual Report

4d.Progress report.
This report serves to document research conducted under a specific cooperative agreement between ARS and the Italian Reference Centre for Animal TSE (CEA) at the Istituto Zooprofilattico Sperimentale, Turin, Italy. Additional details of research can be found in the report for the parent project 3625-32000-073-00D, Transmission, Differentiation, and Pathobiology of Transmissible Spongiform Encephalopathies (TSEs).

The aim of the cooperative research project is (i) to compare the U.S. Bovine Spongiform Encephalopathy (BSE) isolates and the atypical BSE isolates identified in Italy and (ii) to determine whether diagnostic methods routinely used at the USDA are able to identify atypical BSE cases.

Within FY06, formalin fixed and frozen brain materials from animals with typical and atypical Italian (BASE) BSE have been sent by CEA to the USDA-ARS-NADC laboratory in Ames, IA. The serial brain material sections of BSE and BASE (consecutively numbered) will be analyzed in Ames using the USDA immunohistochemistry (IHC) protocol. To evaluate its reproducibility in Italian laboratories and to standardize the method, the USDA IHC protocol is being established at the CEA neuropathology laboratory. As soon as the Ventana NexES IHC Staining System is available to the CEA, the same samples (different cut numbers) will be examined by the CEA using the CEA in-house and the USDA IHC protocol.

In order to evaluate the USDA Western blot method, about 2 gram of typical Italian BSE and about 2 gram of atypical BASE brain tissue have been sent to the USDA-ARS-NADC laboratory. These samples and U.S. typical and atypical BSE samples have been analyzed in parallel using both the USDA and CEA Western blot methods and three different monoclonal antibodies (6H4, P4, SAF 84). These studies were performed during the visit by a CEA collaborator to the USDA-ARS-NADC. The latter studies revealed that both the Italian and USDA extraction and Western blot methods allowed the identification of the typical and atypical BSE samples tested.


http://www.ars.usda.gov/research/projects/projects.htm?ACCN_NO=408490&showpars=true&fy=2006




ATYPICAL BSE BACKGROUND HISTORY USA


Research Project: Study of Atypical Bse

Location: Virus and Prion Diseases of Livestock

Project Number: 3625-32000-073-07
Project Type: Specific C/A


Start Date: Sep 15, 2004
End Date: Sep 14, 2007


Objective:
The objective of this cooperative research project with Dr. Maria Caramelli from the Italian BSE Reference Laboratory in Turin, Italy, is to conduct comparative studies with the U.S. bovine spongiform encephalopathy (BSE) isolate and the atypical BSE isolates identified in Italy. The studies will cover the following areas: 1. Evaluation of present diagnostics tools used in the U.S. for the detection of atypical BSE cases. 2. Molecular comparison of the U.S. BSE isolate and other typical BSE isolates with atypical BSE cases. 3. Studies on transmissibility and tissue distribution of atypical BSE isolates in cattle and other species.

Approach:
This project will be done as a Specific Cooperative Agreement with the Italian BSE Reference Laboratory, Istituto Zooprofilattico Sperimentale del Piemonte, in Turin, Italy. It is essential for the U.S. BSE surveillance program to analyze the effectiveness of the U.S diagnostic tools for detection of atypical cases of BSE. Molecular comparisons of the U.S. BSE isolate with atypical BSE isolates will provide further characterization of the U.S. BSE isolate. Transmission studies are already underway using brain homogenates from atypical BSE cases into mice, cattle and sheep. It will be critical to see whether the atypical BSE isolates behave similarly to typical BSE isolates in terms of transmissibility and disease pathogenesis. If transmission occurs, tissue distribution comparisons will be made between cattle infected with the atypical BSE isolate and the U.S. BSE isolate. Differences in tissue distribution could require new regulations regarding specific risk material (SRM) removal.


http://www.ars.usda.gov/research/projects/projects.htm?ACCN_NO=408490




2005 Annual Report


4d.Progress report.
This report serves to document research conducted under a specific cooperative agreement between ARS and the Italian Reference Centre for Animal TSE (CEA) at the Istituto Zooprofilattico Sperimentale, Turin, Italy. Additional details of research can be found in then report for the parent project 3625-32000-073-00D, Transmission, Differentiation, and Pathobiology of Transmissible Spongiform Encephalopathies. The aim of the cooperative research project conducted by the CEA and ARS is to compare the U.S. bovine spongiform encephalopathy (BSE) isolate and the bovine amyloidotic spongiform encephalopathy isolates (BASE) identified in Italy. The first objective was to determine whether diagnostic methods routinely used by USDA are able to identify the Italian BASE cases. For this purpose, CEA received the immunohistochemistry (IHC) protocol developed by APHIS-USDA. The IHC protocol was reproduced and standardized in the CEA laboratory and will be applied to the Italian BSE and BASE cases. Furthermore, fixed brainstem sections and frozen brainstem material from Italian BSE and BASE cases will be sent to ARS for analysis using USDA IHC and Western blot (WB) methods. These studies will enable us to determine whether the present diagnostic tools (IHC and WB) employed at the USDA will be able to detect the Italian BASE cases and also enable us to compare Italian BSE and BASE with the U.S. BSE cases.


http://www.ars.usda.gov/research/projects/projects.htm?ACCN_NO=408490&showpars=true&fy=2005




Volume 12, Number 12–December 2006


PERSPECTIVE

On the Question of Sporadic

or Atypical Bovine SpongiformEncephalopathy and

Creutzfeldt-Jakob Disease

Paul Brown,* Lisa M. McShane,† Gianluigi Zanusso,‡ and Linda Detwiler§

Strategies to investigate the possible existence of sporadic

bovine spongiform encephalopathy (BSE) require

systematic testing programs to identify cases in countries

considered to have little or no risk for orally acquired disease,

or to detect a stable occurrence of atypical cases in

countries in which orally acquired disease is disappearing.

To achieve 95% statistical confidence that the prevalence

of sporadic BSE is no greater than 1 per million (i.e., the

annual incidence of sporadic Creutzfeldt-Jakob disease

[CJD] in humans) would require negative tests in 3 million

randomly selected older cattle. A link between BSE and

sporadic CJD has been suggested on the basis of laboratory

studies but is unsupported by epidemiologic observation.

Such a link might yet be established by the discovery

of a specific molecular marker or of particular combinations

of trends over time of typical and atypical BSE and various

subtypes of sporadic CJD, as their numbers are influenced

by a continuation of current public health measures that

exclude high-risk bovine tissues from the animal and

human food chains.


SNIP...



PLEASE READ FULL TEXT ;


http://www.cdc.gov/ncidod/EID/vol12no12/06-0965.htm?s_cid=eid06_0965_e





3:00 Afternoon Refreshment Break, Poster and Exhibit Viewing in the Exhibit
Hall


3:30 Transmission of the Italian Atypical BSE (BASE) in Humanized Mouse

Models Qingzhong Kong, Ph.D., Assistant Professor, Pathology, Case Western Reserve
University

Bovine Amyloid Spongiform Encephalopathy (BASE) is an atypical BSE strain
discovered recently in Italy, and similar or different atypical BSE cases
were also reported in other countries. The infectivity and phenotypes of
these atypical BSE strains in humans are unknown. In collaboration with
Pierluigi Gambetti, as well as Maria Caramelli and her co-workers, we have
inoculated transgenic mice expressing human prion protein with brain
homogenates from BASE or BSE infected cattle. Our data shows that about half
of the BASE-inoculated mice became infected with an average incubation time
of about 19 months; in contrast, none of the BSE-inoculated mice appear to
be infected after more than 2 years. ***These results indicate that BASE is
transmissible to humans and suggest that BASE is more virulent than
classical BSE in humans.

6:30 Close of Day One


http://www.healthtech.com/2007/tse/day1.asp



SEE STEADY INCREASE IN SPORADIC CJD IN THE USA FROM
1997 TO 2006. SPORADIC CJD CASES TRIPLED, with phenotype
of 'UNKNOWN' strain growing. ...


http://www.cjdsurveillance.com/resources-casereport.html




There is a growing number of human CJD cases, and they were presented last
week in San Francisco by Luigi Gambatti(?) from his CJD surveillance
collection.

He estimates that it may be up to 14 or 15 persons which display selectively
SPRPSC and practically no detected RPRPSC proteins.


http://www.fda.gov/ohrms/dockets/ac/06/transcripts/1006-4240t1.htm


http://www.fda.gov/ohrms/dockets/ac/06/transcripts/2006-4240t1.pdf





JOURNAL OF NEUROLOGY

MARCH 26, 2003


RE-Monitoring the occurrence of emerging forms of Creutzfeldt-Jakob

disease in the United States


Email Terry S. Singeltary:


[email protected]


I lost my mother to hvCJD (Heidenhain Variant CJD). I would like to

comment on the CDC's attempts to monitor the occurrence of emerging

forms of CJD. Asante, Collinge et al [1] have reported that BSE

transmission to the 129-methionine genotype can lead to an alternate

phenotype that is indistinguishable from type 2 PrPSc, the commonest

sporadic CJD. However, CJD and all human TSEs are not reportable

nationally. CJD and all human TSEs must be made reportable in every

state and internationally. I hope that the CDC does not continue to

expect us to still believe that the 85%+ of all CJD cases which are

sporadic are all spontaneous, without route/source. We have many TSEs in

the USA in both animal and man. CWD in deer/elk is spreading rapidly and

CWD does transmit to mink, ferret, cattle, and squirrel monkey by

intracerebral inoculation. With the known incubation periods in other

TSEs, oral transmission studies of CWD may take much longer. Every

victim/family of CJD/TSEs should be asked about route and source of this

agent. To prolong this will only spread the agent and needlessly expose

others. In light of the findings of Asante and Collinge et al, there

should be drastic measures to safeguard the medical and surgical arena

from sporadic CJDs and all human TSEs. I only ponder how many sporadic

CJDs in the USA are type 2 PrPSc?


http://www.neurology.org/cgi/eletters/60/2/176#535



Diagnosis and Reporting of Creutzfeldt-Jakob Disease

Singeltary, Sr et al. JAMA.2001; 285: 733-734.

http://jama.ama-assn.org/



BRITISH MEDICAL JOURNAL


BMJ


http://www.bmj.com/cgi/eletters/319/7220/1312/b#EL2


BMJ


http://www.bmj.com/cgi/eletters/320/7226/8/b#EL1




USA BSE OIG 2006


http://www.usda.gov/oig/webdocs/50601-10-KC.pdf



CDC DR. PAUL BROWN TSE EXPERT COMMENTS 2006


The U.S. Department of Agriculture was quick to assure the public earlier
this week that the third case of mad cow disease did not pose a risk to
them, but what federal officials have not acknowledged is that this latest
case indicates the deadly disease has been circulating in U.S. herds for at
least a decade.

The second case, which was detected last year in a Texas cow and which USDA
officials were reluctant to verify, was approximately 12 years old.

These two cases (the latest was detected in an Alabama cow) present a
picture of the disease having been here for 10 years or so, since it is
thought that cows usually contract the disease from contaminated feed they
consume as calves. The concern is that humans can contract a fatal,
incurable, brain-wasting illness from consuming beef products contaminated
with the mad cow pathogen.

"The fact the Texas cow showed up fairly clearly implied the existence of
other undetected cases," Dr. Paul Brown, former medical director of the
National Institutes of Health's Laboratory for Central Nervous System
Studies and an expert on mad cow-like diseases, told United Press
International. "The question was, 'How many?' and we still can't answer
that."

Brown, who is preparing a scientific paper based on the latest two mad cow
cases to estimate the maximum number of infected cows that occurred in the
United States, said he has "absolutely no confidence in USDA tests before
one year ago" because of the agency's reluctance to retest the Texas cow
that initially tested positive.

USDA officials finally retested the cow and confirmed it was infected seven
months later, but only at the insistence of the agency's inspector general.

"Everything they did on the Texas cow makes everything USDA did before 2005
suspect," Brown said. ...snip...end


http://www.upi.com/


CDC - Bovine Spongiform Encephalopathy and Variant Creutzfeldt ...
Dr. Paul Brown is Senior Research Scientist in the Laboratory of Central
Nervous System ... Address for correspondence: Paul Brown, Building 36, Room
4A-05, ...


http://www.cdc.gov/ncidod/eid/vol7no1/brown.htm





PAUL BROWN M.D.

http://www.fda.gov/ohrms/dockets/dockets/02n0273/02n-0273-c000490-vol40.pdf




[Docket No. 03-025IFA] FSIS Prohibition of the Use of Specified Risk
Materials for Human Food and Requirement for the Disposition of
Non-Ambulatory Disabled Cattle

http://www.fsis.usda.gov/OPPDE/Comments/03-025IFA/03-025IFA-2.pdf


[Docket No. FSIS-2006-0011] FSIS Harvard Risk Assessment of Bovine
Spongiform Encephalopathy (BSE)


http://www.fsis.usda.gov/OPPDE/Comments/2006-0011/2006-0011-1.pdf




THE SEVEN SCIENTIST REPORT ***


http://www.fda.gov/ohrms/dockets/dockets/02n0273/02n-0273-EC244-Attach-1.pdf




9 December 2005
Division of Dockets Management (RFA-305)

SEROLOGICALS CORPORATION
James J. Kramer, Ph.D.
Vice President, Corporate Operations

http://www.fda.gov/ohrms/dockets/dockets/02n0273/02n-0273-c000383-01-vol35.pdf




Embassy of Japan
http://www.fda.gov/ohrms/dockets/dockets/02n0273/02N-0273-EC240.htm




Dockets Entered on December 22, 2005
2005D-0330, Guidance for Industry and FDA Review Staff on Collection of
Platelets
by Automated ... EC 203, McDonald's Restaurants Corporation, Vol #:, 34 ...
http://www.fda.gov/ohrms/dockets/dailys/05/Dec05/122205/122205.htm


03-025IF 03-025IF-631 Linda A. Detwiler [PDF]
Page 1. 03-025IF 03-025IF-631 Linda A. Detwiler Page 2. Page 3. Page 4.
Page 5. Page 6. Page 7. Page 8. Page 9. Page 10. Page 11. Page 12.
http://www.fsis.usda.gov/OPPDE/Comments/03-025IF/03-025IF-631.pdf


03-025IF 03-025IF-634 Linda A. Detwiler [PDF]
Page 1. 03-025IF 03-025IF-634 Linda A. Detwiler Page 2.
Page 3. Page 4. Page 5. Page 6. Page 7. Page 8.
http://www.fsis.usda.gov/OPPDE/Comments/03-025IF/03-025IF-634.pdf


Page 1 of 17 9/13/2005 [PDF]
... 2005 6:17 PM To: [email protected] Subject: [Docket
No. 03-025IFA]
FSIS Prohibition of the Use of Specified Risk Materials for Human Food ...
http://www.fsis.usda.gov/OPPDE/Comments/03-025IFA/03-025IFA-2.pdf



03-025IFA 03-025IFA-6 Jason Frost [PDF]
... Zealand Embassy COMMENTS ON FEDERAL REGISTER 9 CFR Parts 309 et al
[Docket No. 03-
025IF] Prohibition of the Use of Specified Risk Materials for Human Food and
...
http://www.fsis.usda.gov/OPPDE/Comments/03-025IFA/03-025IFA-6.pdf


In its opinion of 7-8 December 2000 (EC 2000), the SSC ... [PDF]
Page 1. Linda A. Detwiler, DVM 225 Hwy 35 Red Bank, New Jersey 07701 Phone:
732-741-2290
Cell: 732-580-9391 Fax: 732-741-7751 June 22, 2005 FSIS Docket Clerk US ...

http://www.fsis.usda.gov/OPPDE/Comments/03-025IF/03-025IF-589.pdf





Terry S. Singeltary SR.
P.O. Box 42
Bacliff, Texas USA 77518
 

flounder

Well-known member
Subject: Bovine Spongiform Encephalopathy Order Code RL32199 Updated September 20, 2006
Date: January 15, 2007 at 8:05 pm PST

Order Code RL32199

Bovine Spongiform Encephalopathy

(BSE, or “Mad Cow Disease”):

Current and Proposed Safeguards

Updated September 20, 2006

Sarah A. Lister

Specialist in Public Health and Epidemiology

Domestic Social Policy Division

Geoffrey S. Becker

Specialist in Agricultural Policy

Resources, Science, and Industry Division


FULL TEXT 55 PAGES ;


http://ncseonline.org/NLE/CRSreports/06Oct/RL32199.pdf




LIVESTOCK AND PRODUCTS ANNUAL REPORT 2006

http://www.fas.usda.gov/gainfiles/200607/146208314.pdf




IMPORT AND EXPORT

http://www.usaha.org/committees/reports/2006/report-ie-2006.pdf




Final Case Summeries

May 02, 2006 Alabama BSE Investigation—Final Epidemiology Report

http://www.aphis.usda.gov/newsroom/hot_issues/bse/downloads/EPI_Final5-2-06.pdf




http://www.scienceblog.com/cms/feds_confirm_mad_cow_in_alabama_10204.html



http://www.prwatch.org/node/4624



http://www.microbes.info/forums/index.php?showtopic=306




Aug 30, 2005 USDA Texas BSE Investigation—Final Epidemiology Report

http://www.aphis.usda.gov/newsroom/hot_issues/bse/downloads/bse_final_epi_report8-05.pdf




TSS REPORT ON 2ND TEJAS MAD COW Mon, 22 Nov 2004 17:12:15 -0600 (the one
that did NOT get away, thanks to the Honorable Phyllis Fong)


-------- Original Message -------- Subject: Re: BSE 'INCONCLUSIVE' COW from
TEXAS ???
Date: Mon, 22 Nov 2004 17:12:15 -0600
From: "Terry S. Singeltary Sr."
To: Carla Everett
References: <[log in to unmask]>
<[log in to unmask] us>


Greetings Carla,still hear a rumor;

Texas single beef cow not born in Canada no beef entered the food chain?

and i see the TEXAS department of animal health is ramping up forsomething,
but they forgot a url for update?I HAVE NO ACTUAL CONFIRMATION YET...can you
confirm???terry

==============================
==============================


-------- Original Message -------- Subject: Re: BSE 'INCONCLUSIVE' COW from
TEXAS ???
Date: Fri, 19 Nov 2004 11:38:21 -0600
From: Carla Everett
To: "Terry S. Singeltary Sr."
References: <[log in to unmask]>


The USDA has made a statement, and we are referring all callers to the USDA
web site. We have no informationabout the animal being in Texas. CarlaAt
09:44 AM 11/19/2004, you wrote:>Greetings Carla,>>i am getting
unsubstantiated claims of this BSE 'inconclusive' cow is from>TEXAS. can you
comment on this either way please?>>thank you,>Terry S. Singeltary Sr.>>
===================
===================


-------- Original Message -------- Subject: Re: BSE 'INCONCLUSIVE' COW from
TEXAS ???
Date: Mon, 22 Nov 2004 18:33:20 -0600
From: Carla Everett
To: "Terry S. Singeltary Sr."
References: <[log in to unmask]>
<[log in to unmask] us>
<[log in to unmask]> <[log in to unmask]
us> <[log in to unmask]>


our computer department was working on a place holder we could postUSDA's
announcement of any results. There are no results to be announced tonightby
NVSL, so we are back in a waiting mode and will post the USDA
announcementwhen we hear something.At 06:05 PM 11/22/2004, you wrote:>why
was the announcement on your TAHC site removed?>>Bovine Spongiform
Encephalopathy:>November 22: Press Release title here >>star image More BSE
information>>>>terry>>Carla Everett wrote:>>>no confirmation on the U.S.'
inconclusive test...>>no confirmation on location of
animal.>>>>>>==========================
==========================

THEN, 7+ MONTHS OF COVER-UP BY JOHANN ET AL! no doubt about it now $$$


NO, it's not pretty, hell, im not pretty, but these are the facts, take em
or leave em, however, you cannot change them.

with kindest regards,

I am still sincerely disgusted and tired in sunny Bacliff, Texas USA 77518

Terry S. Singeltary Sr.


FULL 130 LASHINGS TO USDA BY OIG again
http://www.usda.gov/oig/webdocs/50601-10-KC.pdf


Link: TSS


http://lists.ifas.ufl.edu/cgi-bin/wa.exe?A2=ind0612&L=sanet-mg&T=0&P=23557



Feb 06, 2004 Washington State Investigation—Final Epidemiology Report

http://www.aphis.usda.gov/newsroom/hot_issues/bse/downloads/WashingtonState_epi_final3-04.pdf



Secretary's Advisory Committee Recommendations

Feb 13, 2004 Secretary’s Advisory Committee Report

http://www.aphis.usda.gov/newsroom/hot_issues/bse/downloads/SAC-Report2-13-04.pdf



Feb 02, 2004 International Review Team (IRT) Report

http://www.aphis.usda.gov/newsroom/hot_issues/bse/downloads/US_BSE_Report2-2-04.pdf


http://www.aphis.usda.gov/newsroom/hot_issues/bse/surveillance/bse_disease_surv.shtml




To be published in the Proceedings of the
Fourth International Scientific Congress in
Fur Animal Production. Toronto, Canada,
August 21-28, 1988

Evidence That Transmissible Mink Encephalopathy
Results from Feeding Infected Cattle

R.F. Marsh* and G.R. Hartsough

•Department of Veterinary Science, University of Wisconsin-Madison, Madison,
Wisconsin 53706; and ^Emba/Creat Lakes Ranch Service, Thiensville, Wisconsin 53092

ABSTRACT
Epidemiologic investigation of a new incidence of
transmissible mink encephalopathy (TME) in Stetsonville, Wisconsin
suggests that the disease may have resulted from feeding infected
cattle to mink. This observation is supported by the transmission of
a TME-like disease to experimentally inoculated cattle, and by the
recent report of a new bovine spongiform encephalopathy in
England.

INTRODUCTION

Transmissible mink encephalopathy (TME) was first reported in 1965 by Hartsough
and Burger who demonstrated that the disease was transmissible with a long incubation
period, and that affected mink had a spongiform encephalopathy similar to that found in
scrapie-affecied sheep (Hartsough and Burger, 1965; Burger and Hartsough, 1965).
Because of the similarity between TME and scrapie, and the subsequent finding that the
two transmissible agents were indistinguishable (Marsh and Hanson, 1969), it was
concluded that TME most likely resulted from feeding mink scrapie-infecied sheep.
The experimental transmission of sheep scrapie to mink (Hanson et al., 1971)
confirmed the close association of TME and scrapie, but at the same time provided
evidence that they may be different. Epidemiologic studies on previous incidences of
TME indicated that the incubation periods in field cases were between six months and
one year in length (Harxsough and Burger, 1965). Experimentally, scrapie could not be
transmitted to mink in less than one year.
To investigate the possibility that TME may be caused by a (particular strain of
scrapie which might be highly pathogenic for mink, 21 different strains of the scrapie
agent, including their sheep or goat sources, were inoculated into a total of 61 mink.
Only one mink developed a progressive neurologic disease after an incubation period of
22 mon..s (Marsh and Hanson, 1979). These results indicated that TME was either caused
by a strain of sheep scrapie not yet tested, or was due to exposure to a scrapie-like agent
from an unidentified source.

OBSERVATIONS AND RESULTS

A New Incidence of TME. In April of 1985, a mink rancher in Stetsonville, Wisconsin
reported that many of his mink were "acting funny", and some had died. At this time, we
visited the farm and found that approximately 10% of all adult mink were showing
typical signs of TME: insidious onset characterized by subtle behavioral changes, loss of
normal habits of cleanliness, deposition of droppings throughout the pen rather than in a
single area, hyperexcitability, difficulty in chewing and swallowing, and tails arched over
their _backs like squirrels. These signs were followed by progressive deterioration of
neurologic function beginning with locomoior incoordination, long periods of somnolence
in which the affected mink would stand motionless with its head in the corner of the
cage, complete debilitation, and death. Over the next 8-10 weeks, approximately 40% of
all the adult mink on the farm died from TME.
Since previous incidences of TME were associated with common or shared feeding
practices, we obtained a careful history of feed ingredients used over the past 12-18
months. The rancher was a "dead stock" feeder using mostly (>95%) downer or dead dairy
cattle and a few horses. Sheep had never been fed.

Experimental Transmission. The clinical diagnosis of TME was confirmed by
histopaihologic examination and by experimental transmission to mink after incubation
periods of four months. To investigate the possible involvement of cattle in this disease
cycle, two six-week old castrated Holstein bull calves were inoculated intracerebrally
with a brain suspension from affected mink. Each developed a fatal spongiform
encephalopathy after incubation periods of 18 and 19 months.

DISCUSSION
These findings suggest that TME may result from feeding mink infected cattle and
we have alerted bovine practitioners that there may exist an as yet unrecognized
scrapie-like disease of cattle in the United States (Marsh and Hartsough, 1986). A new
bovine spongiform encephalopathy has recently been reported in England (Wells et al.,
1987), and investigators are presently studying its transmissibility and possible
relationship to scrapie. Because this new bovine disease in England is characterized by
behavioral changes, hyperexcitability, and agressiveness, it is very likely it would be
confused with rabies in the United Stales and not be diagnosed. Presently, brains from
cattle in the United States which are suspected of rabies infection are only tested with
anti-rabies virus antibody and are not examined histopathologically for lesions of
spongiform encephalopathy.
We are presently pursuing additional studies to further examine the possible
involvement of cattle in the epidemiology of TME. One of these is the backpassage of
our experimental bovine encephalopathy to mink. Because (here are as yet no agent-
specific proteins or nucleic acids identified for these transmissible neuropathogens, one
means of distinguishing them is by animal passage and selection of the biotype which
grows best in a particular host. This procedure has been used to separate hamster-
adapted and mink-udapted TME agents (Marsh and Hanson, 1979). The intracerebral
backpassage of the experimental bovine agent resulted in incubations of only four months
indicating no de-adaptation of the Stetsonville agent for mink after bovine passage.
Mink fed infected bovine brain remain normal after six months. It will be essential to
demonstrate oral transmission fiom bovine to mink it this proposed epidemiologic
association is to be confirmed.

ACKNOWLEDGEMENTS
These studies were supported by the College of Agricultural and Life Sciences,
University of Wisconsin-Madison and by a grant (85-CRCR-1-1812) from the United
States Department of Agriculture. The authors also wish to acknowledge the help and
encouragement of Robert Hanson who died during the course of these investigations.

REFERENCES
Burger, D. and Hartsough, G.R. 1965. Encephalopathy of mink. II. Experimental and
natural transmission. J. Infec. Dis. 115:393-399.
Hanson, R.P., Eckroade, R.3., Marsh, R.F., ZuRhein, C.M., Kanitz, C.L. and Gustatson,
D.P. 1971. Susceptibility of mink to sheep scrapie. Science 172:859-861.
Hansough, G.R. and Burger, D. 1965. Encephalopathy of mink. I. Epizoociologic and
clinical observations. 3. Infec. Dis. 115:387-392.
Marsh, R.F. and Hanson, R.P. 1969. Physical and chemical properties of the
transmissible mink encephalopathy agent. 3. ViroL 3:176-180.
Marsh, R.F. and Hanson, R.P. 1979. On the origin of transmissible mink
encephalopathy. In Hadlow, W.J. and Prusiner, S.P. (eds.) Slow transmissible
diseases of the nervous system. Vol. 1, Academic Press, New York, pp 451-460.
Marsh, R.F. and Hartsough, G.R. 1986. Is there a scrapie-like disease in cattle?
Proceedings of the Seventh Annual Western Conference for Food Animal Veterinary
Medicine. University of Arizona, pp 20.
Wells, G.A.H., Scott, A.C., Johnson, C.T., Cunning, R.F., Hancock, R.D., Jeffrey, M.,
Dawson, M. and Bradley, R. 1987. A novel progressive spongiform encephalopathy
in cattle. Vet. Rec. 121:419-420.

MARSH

http://www.bseinquiry.gov.uk/files/mb/m09/tab05.pdf



In Confidence - Perceptions of unconventional slow virus diseases
of animals in the USA - APRIL-MAY 1989 - G A H Wells


http://www.bseinquiry.gov.uk/files/mb/m11b/tab01.pdf


TSS
 
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