Washington statewide pathology surveillance for prion disease

[flatfish]

Brief Communication

Washington statewide pathology surveillance for prion disease

Camilla T. Allen, MD 1, Joshua Sonnen, MD 1, Mira J. Leslie, DVM, MPH 2, Lara Kidoguchi, MPH 2, Carrie Harris, BA 3, Pierluigi Gambetti, MD 3, Thomas J. Montine, MD, PhD 1 *

1Department of Pathology, University of Washington, Seattle
2Washington State Department of Health, Shoreline, WA
3National Prion Disease Pathology Surveillance Center, Cleveland, OH

email: Thomas J. Montine (tmontine@u.washington.edu)

*Correspondence to Thomas J. Montine, Department of Pathology, University of Washington, Harborview Medical Center, Box 359791, Seattle, WA 98104

Funded by:
National Prion Disease Pathology Surveillance Center
Centers for Disease Control
NIH; Grant Number: NIA, AG05136

Abstract
In February 2004, we initiated an epidemiological investigation within a US state to enhance autopsy surveillance for clinically suspected prion disease. During the first 30 months, 30 cases of suspected prion disease were referred from throughout Washington. Of these, 18 cases had prion disease, and all of these were classified as either familial or sporadic Creutzfeldt-Jakob disease (CJD); there was no case of variant CJD. This represents a death rate of approximately 1.1 cases of sporadic CJD per 1 million people per year in Washington. Our results do not support the hypotheses that variant CJD is an emerging illness in Washington or that sporadic CJD is more common in this state than in other regions of the world. Ann Neurol 2007



--------------------------------------------------------------------------------
Received: 9 September 2006; Revised: 9 December 2006; Accepted: 16 January 2006
Digital Object Identifier (DOI)

10.1002/ana.21096 About DOI


http://www3.interscience.wiley.com/cgi-bin/abstract/114184834/ABSTRACT



USA CJD

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


Other work presented suggested that BSE and bovine amyloidotic spongiform
encephalopathy (BASE) MAY BE RELATED. A mutation had been identified in the
prion protein gene in an AMERICAN BASE CASE THAT WAS SIMILAR IN NATURE TO A
MUTATION FOUND IN CASES OF SPORADIC CJD.


snip...


http://www.seac.gov.uk/minutes/95.pdf



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



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...


CONTINUED

[flatfish]

Sporadic CJD

The possibility that at least some cases of apparently sporadic CJD might be due to infection by sporadic cases of BSE cannot be dismissed outright. Screening programs needed to identify sporadic BSE have yet to be implemented, and we know from already extant testing programs that at least a proportion of infected animals have no symptoms and thus would never be identified in the absence of systematic testing. Thus, sporadic BSE (or for that matter, sporadic disease in any mammalian species) might be occurring on a regular basis at perhaps the same annual frequency as sporadic CJD in humans, that is, in the range of 1 case per million animals.

Whether humans might be more susceptible to atypical forms of BSE cannot be answered at this time. Experimentally transmitted BASE shows shorter incubation periods than BSE in at least 1 breed of cattle, bovinized transgenic mice, and Cynomolgus monkeys (12,13). In humanized transgenic mice, BASE transmitted, whereas typical BSE did not transmit (13). Paradoxically, the other major phenotype (H) showed an unusually long incubation period in bovinized transgenic mice (12).

The limited experimental evidence bearing on a possible relationship between BSE and sporadic CJD is difficult to interpret. The original atypical BASE strain of BSE had a molecular protein signature very similar to that of 1 subtype (type 2 M/V) of sporadic CJD in humans (5). In another study, a strain of typical BSE injected into humanized mice encoding valine at codon 129 showed a glycopattern indistinguishable from the same subtype of sporadic CJD (15). In a third study, the glycopatterns of both the H and L strains of atypical BSE evidently did not resemble any of the known sporadic CJD subtypes (12).

To these molecular biology observations can be added the epidemiologic data accumulated during the past 30 years. The hypothesis that at least some cases of apparently sporadic CJD are due to unrecognized BSE infections cannot be formally refuted, but if correct, we might expect by now to have some epidemiologic evidence linking BSE to at least 1 cluster of apparently sporadic cases of CJD. Although only a few clusters have been found (and still fewer published), every proposed cluster that has been investigated has failed to show any common exposure to bovines. For that matter, no common exposure has been shown to any environmental vehicles of infection, including the consumption of foodstuffs from bovine, ovine, and porcine sources, the 3 livestock species known to be susceptible to transmissible spongiform encephalopathies. Additional negative evidence comes from several large case-control studies in which no statistically significant dietary differences were observed between patients with sporadic CJD and controls (16,17).

On the other hand, the difficulty of establishing a link between BSE and CJD may be compounded by our ignorance of the infectious parameters of a sporadic form of BSE (e.g., host range, tissue distribution of infectivity, route of transmission, minimum infectious dose for humans, whether single or multiple). Presumably, these parameters would resemble those of variant CJD; that is, high infectivity central nervous system and lymphoreticular tissues of an infected cow find their way into products consumed by humans. Transmissions that might have occurred in the past would be difficult to detect because meat products are generally not distributed in a way that results in detectable geographic clusters.

Barring the discovery of a specific molecular signature (as in variant CJD), the most convincing clue to an association will come from the observation of trends over time of the incidence of typical and atypical BSE and of sporadic and variant CJD. With 4 diseases, each of which could have increasing, unchanging, or decreasing trends, there could be 81 (34) possible different combinations. However, it is highly likely that the trends for typical BSE and variant CJD will both decrease in parallel as feed bans continue to interrupt recycled contamination. The remaining combinations are thus reduced to 9 (32), and some of them could be highly informative.

For example, if the incidence of atypical BSE declines in parallel with that of typical BSE, its candidacy as a sporadic form of disease would be eliminated (because sporadic disease would not be influenced by current measures to prevent oral infection). If, on the other hand, atypical BSE continues to occur as typical BSE disappears, this would be a strong indication that it is indeed sporadic, and if in addition at least 1 form of what is presently considered as sporadic CJD (such as the type 2 M/V subtype shown to have a Western blot signature like BASE) were to increase, this would suggest (although not prove) a causal relationship (Figure 5).

Recognition of the different forms of BSE and CJD depends upon continuing systematic testing for both bovines and humans, but bovine testing will be vulnerable to heavy pressure from industry to dismantle the program as the commercial impact of declining BSE cases ceases to be an issue. Industry should be aware, however, of the implications of sporadic BSE. Its occurrence would necessitate the indefinite retention of all of the public health measures that exclude high-risk bovine tissues from the animal and human food chains, whereas its nonoccurrence would permit tissues that are now destroyed to be used as before, once orally acquired BSE has disappeared.



SNIP...




PLEASE READ FULL TEXT ;


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



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:


flounder9@verizon.net


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/



TSS