Excerpt from below: "The tonsils are one of the sites in the body
where, once infected, vCJD prions can accumulate (other sites include
the spleen, appendix, lymph nodes, spinal cord and brain)."
Now I am thinking, if they show in these places on humans, why wouldnt they show up in the same organs of infected animals? Hummm. Why wouldnt they, indeed. As I mentioned in a previous post, some studies have shown mad-cow prions in the flesh-meat of the infected animals, you know, the parts we eat called steaks, roasts, chops, fryers and what not.
Here the latest report on all kinds of prion diseases;
******************************
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
[With the continuing decline in the number of cases in the human
population of variant Creutzfeldt-Jakob disease -- abbreviated
previously as vCJD or CJD (new var.) in ProMED-mail -- it has been
decided to broaden the scope of the occasional ProMED-mail updates to
include some other prion-related diseases. In addition to vCJD, data
on other forms of CJD: sporadic, iatrogenic, familial, and GSS
(Gerstmann-Straussler-Scheinker disease), are included also since
they may have some relevance to the incidence and etiology of vCJD. -
Mod.CP]
In this update:
[1] UK: National CJD Surveillance Unit - monthly statistics as of 1 Jun 2009
[2] France: Institut de Veille Sanitaire - monthly statistics as of 2 Jun 2009
[3] US National Prion Disease Center - not updated, as of 31 Dec 2008
[4], [5] UK: evaluation of tonsil survey
[6] vCJD in UK assessment
******
[1] UK: National CJD Surveillance Unit - monthly statistics as of 1 Jun 2009
Date: Mon 1 Jun 2009
Source: UK National CJD Surveillance Unit, monthly statistics [edited]
The number of suspected cases of vCJD referred to the CJD
surveillance unit in Edinburgh, and the number of deaths of definite
and probable cases due to vCJD remain unchanged since the previous
monthly report; that is, the number of deaths due to definite or
probable vCJD cases remains 164. Four definite/probable patients
remain alive, bringing the total number of definite or probable vCJD
cases to 168.
This situation is consistent with the view that the vCJD outbreak in
the UK is in decline. The 1st cases were observed in 1995, and the
peak number of deaths was 28 in the year 2000, followed by 20 in
2001, 17 in 2002, 18 in 2003, 9 in 2004, 5 in 2005, 5 in 2006, 5 in
2007, only one in 2008, and none so far in 2009.
Totals for all types of CJD cases in the UK in the year 2009
------------------------------------------------------------
As of Mon 1 Jun 2009 in the UK so far this year [2009], there have
been 52 referrals, 21 cases of sporadic CJD, one case of familial
CJD, one case of iatrogenic CJD, and no cases of GSS or vCJD.
--
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[2] France: Institut de Veille Sanitaire - monthly statistics as of 2 Jun 2009
Date: Tue 2 Jun 2009
Source: IVS - Maladie de Creutzfeldt-Jakob et maladies apparentees
[in French, trans. & summ. Mod.CP, edited]
So far in 2009 there have been 609 referrals, 23 cases of sporadic
CJD, 4 cases of familial CJD and no cases of iatrogenic CJD. There is
currently one case of suspected vCJD (no details provided), but no
confirmed case of vCJD.
In total there have been 23 cases of confirmed or probable vCJD in
France, since 1992 when records began, and currently there is one
case pending.
Twelve of the confirmed cases have been male, and 11 female. The
median age is 34 years (range 19 to 58 years), and all have been
Met-Met homozygotes at codon 129 of the prion protein gene (PRNP).
Six patients were resident in the Ile-de-France and 17 in the
provinces.
--
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[3] US National Prion Disease Center - not updated, as of 31 Dec 2008
Date: Wed 31 Dec 2008
Source: US National Prion Disease Pathology Surveillance Center [edited]
No update during 2009. Totals for 2008 are: referrals - 383, prion
disease - 228, sporadic CJD - 182, familial CJD - 23, iatrogenic - 0,
vCJD - 0. (N.B. The prion disease category includes cases with type
diagnosis pending, but excluding vCJD).
--
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[4] UK: evaluation of tonsil survey
Date: Fri 22 May 2009
Source: Health Protection Agency (HPA), Health Protection Report 3(20)
[edited]
Latest results of HPA study on vCJD-related abnormal prion proteins
in extracted tonsils
-------------------------------------------------------------------
In 2004, the Health Protection Agency launched the National Anonymous
Tissue Archive (NATA) to determine prevalence of asymptomatic vCJD in
the population by looking for the prion protein associated with vCJD
in extracted tonsils. The tonsils are one of the sites in the body
where, once infected, vCJD prions can accumulate (other sites include
the spleen, appendix, lymph nodes, spinal cord and brain).
Awareness of the prevalence of vCJD in the population is important to
determine the level of public health risk and to limit the impact of
infection or plan healthcare interventions for people who may develop
the disease.
Newly published results from the study (1,2) suggest there may be
fewer undetected asymptomatic cases of vCJD in the population than
were previously expected.
The survey will eventually collect and analyse 100 000 samples of
discarded tonsil tissue but no evidence of the abnormal prion protein
has been found in any of the 63 000 tonsil samples analysed to date.
When the archive was established it was estimated that up to 50 of
the 100 000 samples could contain the abnormal prion protein.
References
----------
1. Prevalence of disease related prion protein in anonymous tonsil
specimens in Britain: a cross-sectional opportunistic survey, J
Clewley et al, BMJ 2009; 338: b1442 [see item [5] below].
2. HPA, National Press Releases: Latest research into prevalence of
vCJD consistent with findings of existing studies. HPA website:
National Press Releases, 22 May 2009 [available from
--
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[5] UK: tonsil survey interim report
Date: Thu 21 May 2009
Source: British Medical Journal (BMJ 2009; 338: b1442) [edited]
Research: Prevalence of disease related prion protein in anonymous
tonsil specimens in Britain: cross sectional opportunistic survey
----------------------------------------------------------------------
[Authors: Jonathan P Clewley, clinical scientist1, Carole M Kelly,
research epidemiologist1, Nick Andrews, statistician1, Kelly Vogliqi,
research technician1, Gary Mallinson, clinical scientist2, Maria
Kaisar, research scientist2, David A Hilton, consultant
neuropathologist3, James W Ironside, professor of clinical
neuropathology4, Philip Edwards, biomedical scientist3, Linda M
McCardle, biomedical scientist4, Diane L Ritchie, research
assistant4, Reza Dabaghian, research scientist1, Helen E Ambrose,
research scientist1, O Noel Gill, consultant epidemiologist1
1. Centre for Infections, Health Protection Agency, London NW9 5EQ
2. Bristol Institute for Transfusion Sciences, National Blood
Service, Bristol BS10 5ND
3. Department of Histopathology, Derriford Hospital, Plymouth PL6 8DH
4. National CJD Surveillance Unit, University of Edinburgh, Western
General Hospital, Edinburgh EH4 2XU]
Abstract
--------
Objective: to establish with improved accuracy the prevalence of
disease related prion protein (PrPCJD) in the population of Britain
and thereby guide a proportionate public health response to limit the
threat of healthcare associated transmission of variant
Creutzfeldt-Jakob disease (vCJD).
Design: cross sectional opportunistic survey.
Study samples: anonymised tonsil pairs removed at elective
tonsillectomy throughout England and Scotland.
Setting: National anonymous tissue archive for England and Scotland.
Main outcome measure: Presence of PrPCJD determined by using 2 enzyme
immunoassays based on different analytical principles, with further
investigation by immunohistochemistry or immunoblotting of any
samples reactive in either assay.
Results: Testing of 63 007 samples was completed by the end of
September 2008. Of these, 12 753 were from the birth cohort in which
most vCJD cases have arisen (1961-85) and 19 908 were from the
1986-95 cohort that would have been also exposed to bovine spongiform
encephalopathy through infected meat or meat products. None of the
samples tested was unequivocally reactive in both enzyme
immunoassays. Only 2 samples were reactive in one or other enzyme
immunoassay and equivocal in the other, and 9 samples were
equivocally reactive in both enzyme immunoassays. 276 samples were
initially reactive in one or other enzyme immunoassay; the repeat
reactivity rate was 15 percent or less, depending on the enzyme
immunoassay and cut-off definition. None of the samples (including
all the 276 initially reactive in enzyme immunoassay) that were
investigated by immunohistochemistry or immunoblotting was positive
for the presence of PrPCJD.
Conclusions: The observed prevalence of PrPCJD in tonsils from the
1961-95 combined birth cohort was 0/32 661 with a 95 percent
confidence interval of 0 to 113 per million. In the 1961-85 cohort,
the prevalence of zero with a 9 percent confidence interval of 0 to
289 per million was lower than, but still consistent with, a previous
survey of appendix tissue that showed a prevalence of 292 per million
with a 95 percent confidence interval of 60 to 853 per million.
Continuing to archive and test tonsil specimens, especially in older
birth cohorts, and other complementary large scale anonymous tissue
surveys, particularly of post-mortem tissues, will further refine the
calculated prevalence of PrPCJD.
--
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******
[6] vCJD in UK assessment
Date: Thu 21 May 2009
Source: British Medical Journal (BMJ 2009; 338: b435) [edited]
Editorial: prevalence of variant CJD in the UK
----------------------------------------------
The number of cases of variant Creutzfeldt-Jakob disease (vCJD) in
the United Kingdom has decreased since 2000 (1) but controversy
remains about how many people carry the infectious agent and will
eventually develop disease. In the linked study, Clewley and
colleagues add to the debate by assessing 63 007 pairs of tonsils for
the only available marker of prion disease -- the pathological,
partially protease resistant, prion protein (2). Although more than
half of the samples came from people born between 1961 and 1995, when
the risk of exposure to bovine spongiform encephalopathy (BSE)
infection was high, no convincingly positive tonsil specimens were
detected. The study estimates that the prevalence of vCJD in the
British population is zero, but with a large confidence interval of 0
to 113 per million.
This result agrees with one UK survey of 2000 tonsil specimens (3),
but it differs from another survey of 1427 tonsils and 11 247
appendices, which found that more than 10 000 people were incubating
the disease (4). However, despite the discrepancy, the 95 percent
confidence intervals of the two studies overlap, indicating that the
results do not differ significantly and that many people in the UK
may be carriers. Is that reasonable?
The chance that no one in the UK is incubating the disease, as
suggested by the lower confidence limit of Clewley and colleagues'
study (2) is unlikely because backup calculations predict up to 100
new cases of vCJD in the next 50 years (5). This prediction seems
reasonable unless most cases of vCJD were missed by surveillance in
the past years. Is that possible?
Until December 2008, all 210 people reported to have vCJD (164 in the
UK, 46 in other countries) were homozygous for methionine at the
polymorphic codon 129 of the prion protein gene (PRNP), suggesting
that genetic factors strongly influence the development of disease.
Whether people who are heterozygous for methionine and valine or
homozygous for valine at this codon (about 60 percent of the
population) will develop vCJD in the future is still unknown.
However, data from gene targeted transgenic mice indicate that these
people are also susceptible to BSE and vCJD, although incubation
periods are longer than in those who are homozygous for methionine
(6).
This notion is supported by information from 3 sources. Firstly, the
identification of preclinical vCJD in a heterozygous patient who died
of a non-neurological disorder 5 years after receiving an infected
blood transfusion (7). Secondly, the identification of prion protein
in the appendices of 2 people who were homozygous for valine at the
polymorphic codon 129 of PRNP after a retrospective tonsil and
appendix survey (8). Finally, the recently announced suspected case
of vCJD in a heterozygous patient in the UK (9). Also, brain lesions
in transgenic mice that are heterozygous for methionine and valine or
homozygous for valine on codon 129 of the PrP gene are reportedly
different from those seen in mice that are homozygous for methionine
(6). This suggests that clinical signs, neuropathological lesions,
and possibly magnetic resonance imaging scans of the brain might be
different in patients who are not homozygous for methionine, which
would make the available diagnostic criteria for vCJD inappropriate
and mean that these patients are misdiagnosed as having sporadic CJD.
However, data collected for more than 15 years in the UK and
elsewhere in Europe by national surveillance centres found no
evidence of cases of sporadic CJD in the UK that are clinically or
pathologically different from those reported in other countries,
suggesting that this scenario is highly unlikely (10).
It is still possible that in people who are heterozygous for
methionine and valine or homozygous for valine, the BSE agent is
prevented from moving from the lymphatic tissues to the central
nervous system, so that most of them do not develop clinical signs of
disease. These subclinical carriers could be sources of infection for
people who are homozygous for methionine at codon 129 of the PRNP
gene through blood transfusion and surgical procedures, including
major dental or ocular surgery.
Predicting the number of vCJD carriers in the UK is difficult for
several reasons. Firstly, the best peripheral tissue for detecting
the prion protein is not known. The best choice at the moment is
lymphoreticular tissue, but both appendix and tonsil are occasionally
negative in patients with vCJD (11,12) and in blood donors who are
infected with vCJD but do not develop disease (7). Secondly, it is
not clear how soon after infection peripheral tissues become positive
for the prion protein. Thirdly, most specimens will now be taken from
people who are not exposed to BSE. Finally, any positive or negative
results should be interpreted with caution because of the lack of a
confirmatory test on infectivity. Repeating surveys of prion protein
in tissue specimens may not yield further information unless a more
sensitive and specific test is developed. Therefore, the
precautionary measures already in force must be maintained to avoid
transmission of vCJD between humans and surveillance of disease in
the UK and in the rest of Europe should remain active.
Finally, Clewley and colleagues' negative results indicate that
public health authorities in other countries should not carry out
such studies; an enormous number of samples would be needed to yield
useful information because exposure to the BSE agent in the rest of
the world is probably much lower than in the UK.
Maurizio Pocchiari
Director of Research
Department of Cell Biology and Neurosciences
Istituto Superiore di Sanita
00161 Rome
Italy
References
----------
1. National Creutzfeldt-Jakob Disease Surveillance Unit (NCJDSU). CJD
statistics. 2009
2. Clewley JP, Kelly CM, Andrews N, Vogliqi K, Mallinson G, Kaisar M,
et al: Prevalence of disease related prion protein in anonymous
tonsil specimens in Britain: cross sectional opportunistic survey.
BMJ 2009; 338: b1442
3. Frosh A, Smith LC, Jackson CJ, Linehan JM, Brandner S, Wadsworth
JD, et al: Analysis of 2000 consecutive UK tonsillectomy specimens
for disease-related prion protein. Lancet 2004; 364: 1260-2 [abstract
available from
4. Hilton DA, Ghani AC, Conyers L, Edwards P, McCardle L, Ritchie D,
et al: Prevalence of lymphoreticular prion protein accumulation in UK
tissue samples. J Pathol 2004; 203: 733-9 [abstract available from
5. Clarke P, Ghani AC: Projections of the future course of the
primary vCJD epidemic in the UK: inclusion of subclinical infection
and the possibility of wider genetic susceptibility. JR Soc Interface
2005; 2: 19-31
6. Bishop MT, Hart P, Aitchison L, Baybutt HN, Plinston C, Thomson V,
et al: Predicting susceptibility and incubation time of
human-to-human transmission of vCJD. Lancet Neurol 2006; 5: 393-8
[abstract available from
7. Peden AH, Head MW, Ritchie DL, Bell JE, Ironside JW: Preclinical
vCJD after blood transfusion in a PRNP codon 129 heterozygous
patient. Lancet 2004; 364: 527-9 [abstract available from
8. Ironside JW, Bishop MT, Connolly K, Hegazy D, Lowrie S, Le Grice
M, et al: Variant Creutzfeldt-Jakob disease: prion protein genotype
analysis of positive appendix tissue samples from a retrospective
prevalence study. BMJ 2006; 332: 1186-8
9. Watts S: Fears raised over new vCJD wave. BBC Online 17 Dec 2008
10. Ladogana A, Puopolo M, Croes EA, Budka H, Jarius C, Collins S, et
al: Mortality from Creutzfeldt-Jakob disease and related disorders in
Europe, Australia, and Canada. Neurology 2005; 64: 1586-91. Abstract
available from
11. Wadsworth JD, Joiner S, Hill AF, Campbell TA, Desbruslais M,
Luthert PJ, et al: Tissue distribution of protease resistant prion
protein in variant Creutzfeldt-Jakob disease using a highly sensitive
immunoblotting assay. Lancet 2001; 358: 171-80 [abstract available
from
12. Brandel JP, Heath CA, Head MW, Levavasseur E, Knight R, Laplanche
JL, et al: Variant Creutzfeldt-Jakob disease in France and the
United-Kingdom: evidence for the involvement of same agent strain.
Ann Neurol (in press) [abstract available from
--
Communicated by:
ProMED-mail
[see also:
Prion disease update 2009 (04) 20090406.1337
vCJD, 5th death - Spain (Cantabria) 20090307.0953
Prion disease update 2009 (03) 20090305.0918
Prion disease update 2009 (02) 20090202.0463
Prion disease update 2009 (01) 20090108.0076
2008
----
Prion disease update 2008 (14): new vCJD wave imminent? 20081218.3980
Prion disease update 2008 (13) 20081201.3780
Prion disease update 2008 (12) 20081103.345
Prion disease update 2008 (11) 20081006.3159
vCJD, mother & son - Spain: (Leon) 20080926.3051
Prion disease update 2008 (10) 20080902.2742
vCJD - Spain: susp. 20080410.1311
Prion disease update 2008 (05) 20080408.1285
Prion disease update 2008 (01): correction 20080104.0046
Prion disease update 2008 (01) 20080102.0014
2007
----
Prion disease update 2007 (08) 20071205.3923
Prion disease update 2007 (07) 20071105.3602
Prion disease update 2007 (06) 20071003.3269
Prion disease update 2007 (05) 20070901.2879
Prion disease update 2007 (04) 20070806.2560
Prion disease update 2007 (03) 20070702.2112
Prion disease update 2007 (02) 20070604.1812
Prion disease update 2007 20070514.1542
CJD (new var.) update 2007 (05) 20070403.1130
CJD (new var.) update 2007 (04) 20070305.0780
CJD (new var.) update 2007 (03) 20070205.0455
CJD (new var.) update 2007 (02): South Korea, susp 20070115.0199
2006
----
CJD (new var.), blood transfusion risk 20061208.3468
CJD, transmission risk - Canada (ON) 20061207.3457
CJD (new var.) update 2006 (12) 20061205.3431
CJD (new var.) update 2006 (11) 20061106.3190
CJD (new var.) update 2006 (10) 20061002.2820
CJD (new var.) - Netherlands: 2nd case 20060623.1741
CJD (new var.) - UK: 3rd transfusion-related case 20060209.0432
CJD (new var.) update 2006 (02) 20060206.0386
CJD (new var.) update 2006 20060111.0101
2005
----
CJD (new var.) update 2005 (12) 20051209.3547
CJD (new var.) update 2005 (11) 20051108.3270
CJD (new var.) update 2005 (10) 20051006.2916
CJD (new var.) update 2005 (02) 20050211.0467
CJD (new var.) - UK: update 2005 (01) 20050111.0095
2004
----
CJD, genetic susceptibility 20041112.3064
CJD (new var.) - UK: update 2004 (14) 20041206.3242
CJD (new var.) - UK: update 2004 (10) 20040909.2518
CJD (new var.) - UK: update 2004 (02) 20040202.0400
CJD (new var.) - UK: update 2004 (01) 20040106.0064
CJD (new var.) - France: 8th case 20041022.2864
CJD (new var.) - France: 9th case 20041123.3138
CJD (new var.), blood supply - UK 20040318.0758
CJD (new var.), carrier frequency study - UK 20040521.1365
2003
----
CJD (new var.) - UK: update 2003 (13) 20031216.3072
CJD (new var.) - UK: update 2003 (01) 20030108.0057
2002
----
CJD (new var.) - UK: update Dec 2002 20021207.5997
CJD (new var.) - UK: update Jan 2002 20020111.3223
2001
----
CJD (new var.), incidence & trends - UK (02) 20011124.2875
CJD (new var.), incidence & trends - UK 20011115.2816
CJD (new var.) - UK: reassessment 20011029.2671
CJD (new var.) - UK: update Oct 2001 20011005.2419
CJD (new var.) - UK: regional variation (02) 20010907.2145
CJD (new var.) - UK: update Sep 2001 20010906.2134
CJD (new var.) - UK: update Aug 2001 20010808.1872
CJD (new var.) - UK: 9th Annual Report 20010628.1231
CJD (new var.) - UK: update June 2001 20010622.1188
CJD (new var.) - UK: update 3 Jan 2001 20010104.0025]
........................................cp/mj/jw
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