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PRION DISEASE UPDATE 2009 (09)
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A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases
<http://www.isid.org>
[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 5 Oct 2009
[2] France: Institut de Veille Sanitaire - monthly statistics as of 1
Oct 2009 -- new confirmed case of vCJD
[3] US National Prion Disease Center - not updated (quarterly
statistics as of 15 May 2009)
[4] Infectious CWD prions in faeces
[5] Transmission of BSE to fish
******
[1] UK: National CJD Surveillance Unit - monthly statistics as of 5 Oct 2009
Date: Mon 5 Oct 2009
Source: UK National CJD Surveillance Unit, monthly statistics [edited]
<http://www.cjd.ed.ac.uk/figures.htm>
The number of deaths due to definite or probable vCJD cases remains
165. A total of 4 definite/probable patients are still alive, so that
the total number of definite or probable vCJD cases remains 169.
Although one new case of vCJE has been recorded this year [2009], the
overall picture is still 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, one in 2008, and so far one in 2009.
Totals for all types of CJD cases in the UK in the year 2009
-----
As of Mon 5 Oct 2009 in the UK so far this year [2009], there have
been 106 referrals, 46 cases of sporadic CJD, one case of familial
CJD, one case of iatrogenic CJD, 3 cases of GSS, and one case of vCJD.
--
Communicated by:
ProMED-mail <promed@promedmail.org>
******
[2] France: Institut de Veille Sanitaire - monthly statistics as of
Thu 1 Oct 2009 -- new confirmed case of vCJD
Date: Thu 1 Oct 2009
Source: IVS - Maladie de Creutzfeldt-Jakob et maladies apparentees
[in French, trans. & summ. Mod.CP, edited]
<http://www.invs.sante.fr/display/?doc=publications/mcj/donnees_mcj.html>
Since the update in the preceding month, the previously suspected
case has become a confirmed case, bringing the total of new cases of
vCJD confirmed in 2009 to 2.
So far in the 1st 8 months of 2009, there have been 1103 referrals,
48 cases of sporadic CJD, 8 cases of familial CJD 2 cases of
iatrogenic CJD, and 2 confirmed cases of vCJD.
A total of 25 cases of confirmed or probable vCJD have now been
recorded in France since 1997. The 25 confirmed cases comprise 13
females and 12 males. All 25 are now deceased. Their median age is 37
(between 19 and 58). Seven were resident in the Ile-de-France and 18
in the provinces. All the identified cases have been Met-Met
homozygotes. No risk factor has been identified. One of the 25 had
made frequent visit to the United Kingdom.
--
Communicated by:
ProMED-mail <promed@promedmail.org>
******
[3] US National Prion Disease Center - not updated (quarterly
statistics as of 15 May 2009)
Date: Thu 6 Aug 2009
Source: US National Prion Disease Pathology Surveillance Center [edited]
<http://www.cjdsurveillance.com/pdf/case-table.pdf>
Not updated since 15 May 2009: During the period 1 Jan 2009 to 15 May
2009, there were 116 referrals, of which 66 were classified as prion
disease, comprising 37 cases of sporadic CJD, 14 of familial CJD, and
no cases of iatrogenic CJD or vCJD. (N.B. The prion disease category
includes cases where the type determination is pending but where vCJD
has been excluded).
--
Communicated by:
ProMED-mail <promed@promedmail.org>
******
[4] Infectious CWD prions in faeces
Date: Sat 9 Sep 2009
Source: The New York Times [edited]
<http://www.nytimes.com/2009/09/10/science/10brain.html?emc=eta1>
Researchers are reporting that they have solved a long standing
mystery about the rapid spread of a fatal brain infection in deer,
elk and moose in the Midwest and West. The infectious agent, which
leads to chronic wasting disease [CWD], is spread in the feces of
infected animals long before they become ill, according to a study
published online Wednesday by the journal Nature [see below, and
<http://www.nature.com/nature/journal/vaop/ncurrent/full/nature08289.html>].
The agent is retained in the soil, where it, along with plants, is
eaten by other animals, which then become infected. The finding
explains the extremely high rates of transmission among deer, said
the study's lead author, Dr. Stanley B. Prusiner, director of the
Institute for Neurodegenerative Diseases at the University of
California, San Francisco. 1st identified in deer in Colorado in
1967, the disease is now found throughout 14 states and 2 Canadian
provinces. It leads to emaciation, staggering and death. Unlike other
animals, Dr. Prusiner said, deer give off the infectious agent, a
form of protein called a prion, from lymph tissue in their intestinal
linings up to a year before they develop the disease. By contrast,
cattle that develop a related disease, mad cow [bovine spongiform
encephalopathy], do not easily shed prions into the environment but
accumulate them in their brains and spinal tissues. There is no
evidence to date that humans who hunt, kill and eat deer have
developed chronic wasting disease. Nor does the prion that causes it
pass naturally to other animal species in the wild.
Besides bovine spongiform encephalopathy and chronic wasting disease,
the prion diseases include Creutzfeldt-Jakob, which leads to dementia
and death in humans. Each of these diseases is caused by a different
strain [of prion], and all strains behave somewhat differently. In
the case of chronic wasting disease, "it turns out prions exploit the
oldest trick in the book used by pathogens and parasites," said Mike
Miller, a veterinarian at the Colorado Division of Wildlife who is an
expert on chronic wasting disease. Each deer excretes about 2 pounds
of fecal pellets a day. As wild herds move around, or captive herds
are trucked between states, more soil becomes infected. In captive
herds, up to 90 percent of animals develop the disease, Dr. Prusiner
said. In wild herds, 1/3rd of animals can be infected.
"This is an important finding," said Judd M. Aiken, a leading prion
expert who is director of the Alberta Veterinary Research Institute
in Canada and who was not involved in the new study. "Most of us
suspected that prions might be spread in feces, but we needed proof.
The fact that prions are shed at a preclinical stage of the disease
is very significant," Dr. Aiken added.
The study was carried out in 2 parts. 1st, Dr. Miller and his team
infected 5 mule deer by feeding them brain tissue from an infected
animal. They took fecal samples before infection and at 3 to 6 months
afterward. The deer came down with chronic wasting disease 16 to 20
months later. Four to 9 months after infection, the deer began
shedding prions in low levels in their feces, even though they had no
symptoms. Surprisingly, an infected deer could shed as many prions at
this stage as would accumulate in its brain during terminal disease.
In the 2nd part of the experiment, Erdem Tamguney, an assistant
professor at Dr. Prusiner's institute, created a strain of mice with
deer-like prions in their brains. When Dr. Tamguney inoculated the
brains of these mice with feces from infected but asymptomatic deer,
half developed symptoms of chronic wasting disease. 14 out of 15
fecal samples transmitted the disease to some of the mice.
Dr. Aiken said prions tended to bind to clay in soil and to persist
indefinitely. When deer graze on infected dirt, prions that are
tightly bound to clay will persist for long periods in their
intestinal regions. So there is no chance chronic wasting disease
will be eradicated, he said. Outside the laboratory, nothing can
inactivate prions bound to soil. They are also impervious to radiation.
[Byline: Sandra Blakeslee]
--
Communicated by:
ProMED-mail Rapporteur Mary Marshall
[The reference for the article sited in the preceding newspaper
article is the following:
Title:Asymptomatic deer excrete infectious prions in faeces. Authors:
Tamguney G, Miller MW, Wolfe LL, Sirochman TM, Glidden DV, Palmer
C,Lemus A, Dearmond SJ, Prusiner SB. At Institute for
Neurodegenerative Diseases, and Department of Neurology, University
of California, San Francisco, California, 94143 USA.
Abstract: "Infectious prion diseases -- scrapie of sheep and chronic
wasting disease (CWD) of several species in the deer family -- are
transmitted naturally within affected host populations. Although
several possible sources of contagion have been identified in
excretions and secretions from symptomatic animals, the biological
importance of these sources in sustaining epidemics remains unclear.
Here we show that asymptomatic CWD-infected mule deer (_Odocoileus
hemionus_) excrete CWD prions in their faeces long before they
develop clinical signs of prion disease. Intracerebral inoculation of
irradiated deer faeces into transgenic mice overexpressing cervid
prion protein (PrP) revealed infectivity in 14 of 15 faecal samples
collected from 5 deer at 7 to 11 months before the onset of
neurological disease. Although prion concentrations in deer faeces
were considerably lower than in brain tissue from the same deer
collected at the end of the disease, the estimated total infectious
dose excreted in faeces by an infected deer over the disease course
may approximate the total contained in a brain. Prolonged faecal
prion excretion by infected deer provides a plausible natural
mechanism that might explain the high incidence and efficient
horizontal transmission of CWD within deer herds, as well as prion
transmission among other susceptible cervids." - Mod.CP]
******
[5] Transmission of BSE to fish
Date: Tue 15 Sep 2009
Source: Practical Fishkeeping [edited]
<http://www.practicalfishkeeping.co.uk/pfk/pages/item.php?news=2232>
Greek scientists have discovered that fishes can contract mad cow disease.
Evgenia Salta and coauthors published the results of their studies on
the transmissibility of bovine spongiform encephalopathy (BSE or mad
cow disease) and scrapie (another transmissible spongiform
encephalopathy, TSE) in the gilthead sea bream (_Sparus aurata_, a
species widely farmed for food) in a recent issue of the journal PLoS
ONE [see below and
<http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0006175>].
The authors divided 1600 sea bream into groups of 200 and force-fed
each group with a variety of infected, and non-infected brain
homogenates, ranging from scrapie-infected sheep, healthy control
sheep, BSE-infected cow and healthy control cow. The force-feeding
procedure was repeated fortnightly for a total of 5 treatments.
Following the inoculation period, all fish were kept on a maintenance
diet with commercial feed to prevent excessive growth and
overcrowding during the multi-year study period.
The authors observed the fishes for any signs of abnormalities in
behaviour or in swimming, and regularly examined sacrificed
individuals (at 3, 6, 8, 10, 12, 14, 16, 18, 24 months) to examine
the histology of organs such as the brain, spleen and intestine.
Finally, the authors confirmed the presence of the appropriate prion
proteins (PrP) -- the agents responsible for spongiform
encephelopathies -- using immunohistological methods.
The authors found that while the bream never displayed clinical signs
of spongiform encephelopathies during the study period, the brains of
TSE-fed fish sampled 2 years after challenge showed signs of
neurodegeneration and accumulation of deposits that reacted
positively with antibodies raised against sea bream PrP. The control
groups, fed with brains from uninfected animals, showed no such signs.
While the authors acknowledge that more studies are needed to study
infectivity and transmission of TSEs in fish, the prospect of farmed
fish being contaminated with infectious mammalian PrP, or of a prion
disease developing in farmed fish is an alarming one. They conclude
that "... the possibility that the affected sea bream brain tissue
might be infectious must be taken seriously in any consideration to
lift EU feed bans, especially those related to farmed fish."
--
Communicated by:
ProMED-mail <promed@promedmail.org>
[The paper on which the above article is based is the following:
Evaluation of the Possible Transmission of BSE and Scrapie to
Gilthead Sea Bream (Sparus aurata). By Evgenia Salta1, Cynthia
Panagiotidis2, Konstantinos Teliousis3, Spyros Petrakis1,4,
Eleftherios Eleftheriadis5, Fotis Arapoglou5, Nikolaos Grigoriadis6,
Anna Nicolaou7, Eleni Kaldrymidou3, Grigorios Krey5, Theodoros
Sklaviadis2* At: 1 Department of Pharmacology, Aristotle University
of Thessaloniki, Thessaloniki, Greece, 2 Centre for Research and
Technology-Hellas, Institute of Agrobiotechnology, Thessaloniki,
Greece, 3 Laboratory of Pathology, School of Veterinary Medicine,
Aristotle University of Thessaloniki, Thessaloniki, Greece, 4 Max
Delbruck Center for Molecular Medicine, Department of
Neuroproteomics, Berlin-Buch, Germany, 5 National Agricultural
Research Foundation, Fisheries Research Institute, Nea Peramos,
Greece, 6 B' Department of Neurology, AHEPA University Hospital,
Aristotle University of Thessaloniki, Thessaloniki, Greece, 7
Department of Business Administration, University of Macedonia,
Thessaloniki, Greece
Abstract
"In transmissible spongiform encephalopathies (TSEs), a group of
fatal neurodegenerative disorders affecting many species, the key
event in disease pathogenesis is the accumulation of an abnormal
conformational isoform (PrPSc) of the host-encoded cellular prion
protein (PrPC). While the precise mechanism of the PrPC to PrPSc
conversion is not understood, it is clear that host PrPC expression
is a prerequisite for effective infectious prion propagation.
Although there have been many studies on TSEs in mammalian species,
little is known about TSE pathogenesis in fish. Here we show that
while gilthead sea bream (_Sparus aurata_) orally challenged with
brain homogenates prepared either from a BSE infected cow or from
scrapie infected sheep developed no clinical prion disease, the
brains of TSE-fed fish sampled 2 years after challenge did show signs
of neurodegeneration and accumulation of deposits that reacted
positively with antibodies raised against sea bream PrP. The control
groups, fed with brains from uninfected animals, showed no such
signs. Remarkably, the deposits developed much more rapidly and
extensively in fish inoculated with BSE-infected material than in the
ones challenged with the scrapie-infected brain homogenate, with
numerous deposits being proteinase K-resistant. These plaque-like
aggregates exhibited congophilia and birefringence in polarized
light, consistent with an amyloid-like component. The
neurodegeneration and abnormal deposition in the brains of fish
challenged with prion, especially BSE, raises concerns about the
potential risk to public health. As fish aquaculture is an
economically important industry providing high protein nutrition for
humans and other mammalian species, the prospect of farmed fish being
contaminated with infectious mammalian PrPSc, or of a prion disease
developing in farmed fish is alarming and requires further evaluation."
Dietary consumption of fish is widely recommended because of the
beneficial effects of omega-3 polyunsaturated fatty acids on the
risks of cardiovascular and Alzheimer's diseases. Concern has been
expressed that consumption of farmed fish may provide a means of
transmission of infectious prions (such as those from cows with
bovine spongiform encephalopathy) to humans, since fish food for
optimal yield may contain up to 60 percent protein. Indeed, in some
parts of southeast Asia, fish ponds are sited under poultry pens such
that the fish can benefit from the spillage and detritus from poultry
rearing. The paper by Salfa et al. indicates that mammalian prions
under some circumstances can be transmitted to fish. It has not been
shown that these prions retain their ability to induce disease if
transmitted back to mammalian hosts via the food chain. - Mods.MHJ/CP/TY]
[see also:
Prion disease update 2009 (08) 20090908.3170
Prion disease update 2009 (07) 20090806.2783
Prion disease update 2009 (06) 20090706.2433
Prion disease update 2009 (05) 20090602.2054
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/msp/dk
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