Follow Ups | Post Followup | Back to Discussion Board | VegSource
See spam or
inappropriate posts?
Please let us know.

From: TSS ()
Date: January 15, 2007 at 7:53 pm PST



Infected and Source Flocks

As of September 30, 2006, there were 85 scrapie-infected and source flocks (48 infected and 37

source). There were a total of 116 new infected and source flocks reported for FY 2006. Figure 1

shows the number of new infected and source flocks by year. The total infected and source flock

statuses that were released in FY 2006 was 100. A total of 343 positive scrapie cases were confirmed

and reported by the National Veterinary Services Laboratories (NVSL). Of these, 70 were RSSS cases,

(collected in FY 2006 and confirmed in FY 2006 or FY 2007), and 222 positive field necropsy cases

(most of these cases were found during depopulations of scrapie exposed animals in infected/source

flocks), 14 necropsies of field cases retained long term for test evaluation, and 37 third eyelid regulatory

tests confirmed in FY 2006. Three of the field cases were goats. One goat case, in Colorado, could not

be linked to exposure in sheep as a result Colorado goats no longer meet the requirements to be

classified as low-risk goats or low-risk commercial goats for interstate movement.

Approximately 3,822 animals were indemnified comprised of 62% non-registered sheep, 30%

registered sheep, 5% non-registered goats and 3% registered goats. This represents a 26% decrease

over FY 2005 with a significant shift from registered to grade animals.

Regulatory Scrapie Slaughter Surveillance (RSSS)

RSSS was designed based on the findings of the Center for Epidemiology and Animal Health

(CEAH) Scrapie: Ovine Slaughter Surveillance (SOSS) study. The results of SOSS can be found at

RSSS started April 1, 2003. It is a targeted slaughter surveillance program which is designed to

identify infected flocks for clean-up. During FY 2006, collections increased by 9% overall and by 16%

for black and mottled faced sheep compared to FY 2005. Improvement in the overall program

effectiveness and efficiency is demonstrated by the 33% decrease in percent positive black faced sheep

compared to FY 2005 (0.67 to 0.45%, based on test results posted before November 6, 2006). During

FY 2006, 37,167 samples were collected. The distribution of these samples is shown in figure 2. There

have been 70 NVSL confirmed positive cases that were collected in FY 2006. Face colors of these

positives were 62 black and eight mottled. The percent positive by face color is shown in the figure 3


Scrapie Testing

In FY 2006, 42,823 animals were sampled for scrapie testing: 37,167 RSSS; 3,649 regulatory

field cases, 1,934 regulatory third eyelid biopsies, and 73 necropsy validations.

Animal ID

As of October 02, 2006, 118,668 sheep and goat premises have been assigned identification

numbers in the Scrapie National Generic Database. Official eartags have been issued to 96,755 of these


Note: report based on data available as of November 6, 2006


Descriptive Analysis and Scrapie Infected/Source Flocks and Investigations in FY 2006.

Dianne Norden and Charles Gaiser

Regional Epidemiologists

Veterinary Services

Infected and Source Flocks

On average, Scrapie Infected/Source flocks identified in FY 2006 had an inventory of 98 animals

(1,044), 23 animals indemnified on average (1-279), 3.45 positive animals found per flock upon flock

cleanup plans. Of all these Infected/Source flocks for which data are available, 4,441 animals were

involved in trace forward investigations. The primary breed of these flocks was predominantly blackfaced

breeds, however there were 12 white-faced flocks identified (one Shetland, four Polypay Cross,

four Southdown, three Dorset) and one flock whose primary breed was Dorper. Most of these flocks

(89.7%) underwent a standard genetics based flock plan (flock genotyped and QQ animals removed).

Other flock plans included variations on the standard genetics based flock plan (e.g. some high risk

animals retained separately from the genetically less susceptible or resistant animals after lid testing

“negative”, other flocks removed QRAV animals in addition to all QQs, and four flocks underwent a

whole flock depopulation. These flocks were primarily identified because of a positive found at

slaughter (43%). Other detection methods included trace forward of exposed animals (30%), trace back

to birth flock of positive animals (19%), investigation of clinical suspects (7%) and voluntary

surveillance (1%).


Attempts were made to trace 4,889 high risk sheep out of these Infected and Source flocks.

While some of these investigations are still ongoing (9%), 16% were untraceable and 75% were

traceable to a flock. Almost 30 (27) clinically suspicious sheep were investigated in FY 06. Seven of

these animals were ultimately diagnosed with scrapie resulting in five newly discovered Infected or

Source flocks. Nearly 37,000 (36,891) samples were collected at slaughter. Of these, 55 positive

animals were detected, and 31 were successfully traced back to their flock of origin, resulting in 27

newly discovered Infected or Source Flocks. Over 20 (22) traces are still ongoing, and two of these

positives were untraceable.

Scrapie positive animals

Of the Scrapie positive animals that were found, 75% (116) were female, and most (90%) had

lambed or aborted in their flock of origin. Most (65%) were still in their flock of birth at the time of

diagnosis. Nearly all (99.2%) of all positive animals found were QQ, of those that were QQ, most

(89.2% were QQAA). One animal has initially tested QRAA; the genotype of this animal is being

confirmed. One QRAV positive was detected in FY 2006. Most positive animals were found as part of

an Infected or Source flock depopulation (45%). Other methods of detection included RSSS traceback

(28%), traceforward investigations (20%), investigation of clinical suspects (5%), and Voluntary

Surveillance (2%). The breeds of these positives was predominantly black-faced breeds (99), but there

were 63 White-faced breeds identified (40 Southdown, 11 Polypay Cross, two Dorsets, and 10 nonspecified

white-faced or white-faced crosses). The average age of scrapie-positive animals was 3.9

years, ranging from six months to 12 years of age.

Office Note


A The Present Position with respect to Scrapie
A] The Problem

Scrapie is a natural disease of sheep and goats. It is a slow
and inexorably progressive degenerative disorder of the nervous system
and it ia fatal. It is enzootic in the United Kingdom but not in all

The field problem has been reviewed by a MAFF working group
(ARC 35/77). It is difficult to assess the incidence in Britain for
a variety of reasons but the disease causes serious financial loss;
it is estimated that it cost Swaledale breeders alone $l.7 M during
the five years 1971-1975. A further inestimable loss arises from the
closure of certain export markets, in particular those of the United
States, to British sheep.

It is clear that scrapie in sheep is important commercially and
for that reason alone effective measures to control it should be
devised as quickly as possible.

Recently the question has again been brought up as to whether
scrapie is transmissible to man. This has followed reports that the
disease has been transmitted to primates. One particularly lurid
speculation (Gajdusek 1977) conjectures that the agents of scrapie,
kuru, Creutzfeldt-Jakob disease and transmissible encephalopathy of
mink are varieties of a single "virus". The U.S. Department of
Agriculture concluded that it could "no longer justify or permit
scrapie-blood line and scrapie-exposed sheep and goats to be processed
for human or animal food at slaughter or rendering plants" (ARC 84/77)"
The problem is emphasised by the finding that some strains of scrapie
produce lesions identical to the once which characterise the human

Whether true or not. the hypothesis that these agents might be
transmissible to man raises two considerations. First, the safety
of laboratory personnel requires prompt attention. Second, action
such as the "scorched meat" policy of USDA makes the solution of the
acrapie problem urgent if the sheep industry is not to suffer



1: J Infect Dis 1980 Aug;142(2):205-8

Oral transmission of kuru, Creutzfeldt-Jakob disease, and scrapie to nonhuman primates.

Gibbs CJ Jr, Amyx HL, Bacote A, Masters CL, Gajdusek DC.

Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of sheep and goats were transmitted to squirrel monkeys (Saimiri sciureus) that were exposed to the infectious agents only by their nonforced consumption of known infectious tissues. The asymptomatic incubation period in the one monkey exposed to the virus of kuru was 36 months; that in the two monkeys exposed to the virus of Creutzfeldt-Jakob disease was 23 and 27 months, respectively; and that in the two monkeys exposed to the virus of scrapie was 25 and 32 months, respectively. Careful physical examination of the buccal cavities of all of the monkeys failed to reveal signs or oral lesions. One additional monkey similarly exposed to kuru has remained asymptomatic during the 39 months that it has been under observation.

PMID: 6997404


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

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

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

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

1997 TO 2006. SPORADIC CJD CASES TRIPLED, with phenotype
of 'UNKNOWN' strain growing. ...

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

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


MARCH 26, 2003

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

disease in the United States

Email Terry S. Singeltary:

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?

Diagnosis and Reporting of Creutzfeldt-Jakob Disease

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


Follow Ups:

Post a Followup

E-mail: (optional)


Optional Link URL:
Link Title:
Optional Image URL: