Sandhusker said:
I'll bet the CDC has a few PhD epidemiologists on their staff. What did they say?
In this context, a word is in order about the US testing program. After the
discovery of the first (imported) cow in 2003, the magnitude of testing was
much increased, reaching a level of >400,000 tests in 2005 (Figure 4).
Neither of the 2 more recently indigenously infected older animals with
nonspecific clinical features would have been detected without such testing,
and neither would have been identified as atypical without confirmatory
Western blots. Despite these facts, surveillance has now been decimated to
40,000 annual tests (USDA news release no. 0255.06, July 20, 2006) and
invites the accusation that the United States will never know the true
status of its involvement with BSE.
http://www.cdc.gov/ncidod/EID/vol12no12/06-0965.htm
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/ConsumerHealthDaily/view.php?StoryID=20060315-055557-1284r
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 COMMENT TO ME ON THIS ISSUE
Tuesday, September 12, 2006 11:10 AM
"Actually, Terry, I have been critical of the USDA handling of the mad cow
issue for some years,
and with Linda Detwiler and others sent lengthy detailed critiques and
recommendations to both the
USDA and the Canadian Food Agency."
http://lists.ifas.ufl.edu/cgi-bin/wa.exe?A2=ind0703&L=sanet-mg&T=0&P=8125
suppressed peer review of Harvard study October 31, 2002
http://www.fsis.usda.gov/oa/topics/BSE_Peer_Review.pdf
OIG
We also disagree with APHIS/FSIS' contention that because they have tested over 375,000 of their 446,000 estimate of high risk cattle, few in the high-risk population are being missed, including those that might be pre-screened before entering a slaughter facility's property. In our prior audit, we reported that APHIS underestimated the high-risk population; we found that this estimate should have been closer to 1 million animals (see Finding 1). We recognize that BSE samples are provided on a voluntary basis; however, APHIS should consider industry practice in any further maintenance surveillance effort. Animals unsuitable for slaughter exhibiting symptoms not inconsistent with BSE should be sampled and their clinical signs recorded. However, this cited industry practice results in rejected animals not being made available to either APHIS or FSIS veterinarians for their observation and identification of clinical signs exhibited ante mortem. Although these animals may be sampled later at other collection sites, the animals are provided post mortem without information as to relevant clinical signs exhibited ante mortem. For these reasons, we believe APHIS needs to
USDA/OIG-A/50601-10-KC Page 27
observe these animals ante mortem when possible to assure the animals from the target population are ultimately sampled and the clinical signs evaluated.
snip...
http://www.usda.gov/oig/webdocs/50601-10-KC.pdf
[GAO-05-101 ] Mad Cow Disease: FDA's Management of the Feed Ban Has Improved, but Oversight Weaknesses Continue to Limit Program Effectiveness
Size: 104986 , Score: 1000 , TEXT , PDF , SUMMARY
http://frwebgate.access.gpo.gov/cgi-bin/useftp.cgi?IPaddress=162.140.64.88&filename=d05101.txt&directory=/diskb/wais/data/gao
[2]
[GAO-05-101 ] Mad Cow Disease: FDA's Management of the Feed Ban Has Improved, but Oversight Weaknesses Continue to Limit Program Effectiveness
Size: 104986 , Score: 1000 , TEXT , PDF , SUMMARY
http://frwebgate.access.gpo.gov/cgi-bin/useftp.cgi?IPaddress=162.140.64.88&filename=d05101.txt&directory=/diskb/wais/data/gao
SCRAPIE and TSE to human UPDATE 2008 (ambiguous terms of transition and
reality set in)
Laboratory transmission studies with animal models: Since the publication of the
Opinion new data have become available with regards to L type of BSE, which
has now been identified in various EU members states (Biacabe et al., 2004;
Casalone et al., 2004; Baron et al., 2007). This TSE agent, differing from that
causing Classical BSE by its biochemical signature and transmission features in
mouse models, has been transmitted to a Tg mouse model expressing Human
M129 PRP gene (Beringue et al. 2007)2. Here again, uncertainty arises from the
limitations of these animal models for the estimation of the human species barrier.
These 'proof of principle' experiments provide data supporting the ability of TSE agents
other than those causing Classical BSE to cross the human species barrier. Even so, it is
important to remember that as mentioned in the EFSA 2007 opinion, transmission to
primates:
• "… does not allow to take into account the human gene PRNP polymorphisms
(in particular the M/V 129), that have been identified to play a major role on
relative susceptibility towards prion disease. In addition, genes other than the
PrP gene may also be influential in determining overall susceptibility to TSEs."
Despite the interests in the area, studies of the transmissibility of currently known TSE
agents using animal models will remain incomplete for several years.
In conclusion, the reply to the ToR number 2 is:
• Experimental transmissions to primate and to transgenic (Tg) mouse models
expressing the human PrP gene, are currently used as to evaluate the potential
capacity of a TSE agent to cross the human species barrier.
• TSE agents other than the Classical BSE agent from three field TSE cases (two
Classical Scrapie cases and one L type BSE case) have been demonstrated to
cross the modelled human species barrier.
http://www.defra.gov.uk/corporate/vla/science/documents/science-tse-rl-ringtrial.pdf
7 February 2008 - A Statement on the potential human health risk from
changes to classical scrapie controls(41 KB) has been published.
http://www.seac.gov.uk/statements/scrapiestatement080207.pdf
FC5.5.2 Transmission of Italian BSE and BASE Isolates in Cattle Results into a Typical BSE Phenotype and a Muscle Wasting Disease
Zanusso, G1; Lombardi, G2; Casalone, C3; D'Angelo, A4; Gelmetti, D2; Torcoli, G2; Barbieri, I2; Corona, C3; Fasoli, E1; Farinazzo, A1; Fiorini, M1; Gelati, M1; Iulini, B3; Tagliavini, F5; Ferrari, S1; Monaco, S1; Caramelli, M3; Capucci, L2 1University of Verona, Neurological and Visual Sciences, Italy; 2IZSLER, Italy; 3IZSPLVA, Italy; 4University of Turin, Animal Pathology, Italy; 5Isituto Carlo Besta, Italy
The clinical phenotype of bovine spongiform encephalopathy has been extensively reported in early accounts of the disorder. Following the introduction of statutory active surveillance, almost all BSE cases have been diagnosed on a pathological/molecular basis, in a pre-symptomatic clinical stage. In recent years, the active surveillance system has uncovered atypical BSE cases, which are characterized by distinct conformers of the PrPSc, named high-type (BSE-H) and low-type (BSE-L), whose clinicopathological phenotypes remain unknown. We recently reported two Italian atypical cases with a PrPSc type similar to BSE-L, pathologically characterized by PrP amyloid plaques. Experimental transmission to TgBov mice has recently disclosed that BASE is caused by a distinct prion strain which is extremely virulent. A major limitation of transmission studies to mice is the lack of reliable information on clinical phenotype of BASE in its natural host. In the present study, we experimentally infected Fresian/Holstein and Alpine/Brown cattle with Italian BSE and BASE isolates by i.c. route. BASE infected cattle showed survival times significantly shorter than BSE, a finding more readily evident in Fresian/Holstein, and in keeping with previous observations in TgBov mice. Clinically, BSE-infected cattle developed a disease phenotype highly comparable with that described in field BSE cases and in experimentally challenged cattle. On the contrary, BASE-inoculated cattle developed an amyotrophic disorder accompanied by mental dullness. The molecular and neuropathological profiles, including PrP deposition pattern, closely matched those observed in the original cases. This study further confirms that BASE is caused by a distinct prion isolate and discloses a novel disease phenotype in cattle, closely resembling the phenotype previous reported in scrapie-inoculated cattle *** and in some subtypes of inherited and sporadic Creutzfeldt-Jakob disease. Oral Abstracts 14
snip...
P04.27
Experimental BSE Infection of Non-human Primates: Efficacy of the Oral Route
Holznagel, E1; Yutzy, B1; Deslys, J-P2; Lasmézas, C2; Pocchiari, M3; Ingrosso, L3; Bierke, P4; Schulz-Schaeffer, W5; Motzkus, D6; Hunsmann, G6; Löwer, J1 1Paul-Ehrlich-Institut, Germany; 2Commissariat à l´Energie Atomique, France; 3Instituto Superiore di Sanità, Italy; 4Swedish Institute for Infectious Disease control, Sweden; 5Georg August University, Germany; 6German Primate Center, Germany
Background:
In 2001, a study was initiated in primates to assess the risk for humans to contract BSE through contaminated food. For this purpose, BSE brain was titrated in cynomolgus monkeys.
Aims:
The primary objective is the determination of the minimal infectious dose (MID50) for oral exposure to BSE in a simian model, and, by in doing this, to assess the risk for humans. Secondly, we aimed at examining the course of the disease to identify possible biomarkers.
Methods:
Groups with six monkeys each were orally dosed with lowering amounts of BSE brain: 16g, 5g, 0.5g, 0.05g, and 0.005g. In a second titration study, animals were intracerebrally (i.c.) dosed (50, 5, 0.5, 0.05, and 0.005 mg).
Results:
In an ongoing study, a considerable number of high-dosed macaques already developed simian vCJD upon oral or intracerebral exposure or are at the onset of the clinical phase. However, there are differences in the clinical course between orally and intracerebrally infected animals that may influence the detection of biomarkers.
Conclusions:
Simian vCJD can be easily triggered in cynomolgus monkeys on the oral route using less than 5 g BSE brain homogenate. The difference in the incubation period between 5 g oral and 5 mg i.c. is only 1 year (5 years versus 4 years). However, there are rapid progressors among orally dosed monkeys that develop simian v CJD as fast as intracerebrally inoculated animals.
The work referenced was performed in partial fulfilment of the study "BSE in primates" supported by the EU (QLK1-2002-01096).
Subject: Aspects of the Cerebellar Neuropathology in Nor98
Date: September 26, 2007 at 4:06 pm PST
P03.141
Aspects of the Cerebellar Neuropathology in Nor98
Gavier-Widén, D1; Benestad, SL2; Ottander, L1; Westergren, E1 1National Veterinary Insitute, Sweden; 2National Veterinary Institute, Norway
Nor98 is a prion disease of old sheep and goats. This atypical form of scrapie was first described in Norway in 1998. Several features of Nor98 were shown to be different from classical scrapie including the distribution of disease associated prion protein (PrPd) accumulation in the brain. The cerebellum is generally the most affected brain area in Nor98. The study here presented aimed at adding information on the neuropathology in the cerebellum of Nor98 naturally affected sheep of various genotypes in Sweden and Norway. A panel of histochemical and immunohistochemical (IHC) stainings such as IHC for PrPd, synaptophysin, glial fibrillary acidic protein, amyloid, and cell markers for phagocytic cells were conducted. The type of histological lesions and tissue reactions were evaluated. The types of PrPd deposition were characterized. The cerebellar cortex was regularly affected, even though there was a variation in the severity of the lesions from case to case. Neuropil vacuolation was more marked in the molecular layer, but affected also the granular cell layer. There was a loss of granule cells. Punctate deposition of PrPd was characteristic. It was morphologically and in distribution identical with that of synaptophysin, suggesting that PrPd accumulates in the synaptic structures. PrPd was also observed in the granule cell layer and in the white matter. *** The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.
full text ;
http://www.prion2007.com/pdf/Prion%20Book%20of%20Abstracts.pdf
NOR-98 ATYPICAL SCRAPIE USA UPDATE AS AT OCT 2007
http://nor-98.blogspot.com/
USA MAD COW CASES IN ALABAMA AND TEXAS
***PLEASE NOTE***
USA BASE CASE, (ATYPICAL BSE), AND OR TSE (whatever they are calling it today), please note that both the ALABAMA COW, AND THE TEXAS COW,
both were ''H-TYPE'', personal communication Detwiler et al Wednesday, August 22, 2007 11:52 PM. ...TSS
http://lists.ifas.ufl.edu/cgi-bin/wa.exe?A2=ind0708&L=sanet-mg&T=0&P=19779
tss