Prion disease update 2012

isfidThe number of deaths due to definite or probable vCJD as of Mon 7 May 2012 remains 176. No definite/probable patient remains alive, so the total number of definite or probable vCJD cases (dead and alive) remains 176.
The overall picture remains consistent with the view that the vCJD
outbreak in the UK is in decline, albeit now with a pronounced tail.
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, 3 in 2009, 3 in
2010, 5 in 2011, and none so far in 2012

Totals for all types of CJD cases in the UK in the year 2012
During 2012 so far [as of 7 May 2012], there have been 35 referrals,
23 fatal cases of sporadic CJD, none of GSS
[Gerstmann-Straussler-Scheinker disease], one case of familial CJD, no
cases of vCJD, and no cases of iatrogenic CJD.

Since records began in 1990, there have been 2921 referrals, 1329
fatal cases of sporadic CJD, 176 cases of vCJD, 95 cases of familial
CJD, 68 cases of iatrogenic CJD, and 45 cases of GSS.

Communicated by:

[These data are consistent with the conclusion that the vCJD outbreak
in the UK is in decline. – Mod.CP

The interactive HealthMap/ProMED map for the UK is available at:
<> – CopyEd.EJP]

[2] CJD risk – Health professionals
Date: 12 Apr 2012
Source: Eurosurveillance, Volume 17, Issue 15, 12 April 2012;
surveillance and outbreak reports [edited]
Health professions and risk of sporadic Creutzfeldt-Jakob disease,
Summary and conclusions:
In 2009, a pathologist with sporadic Creutzfeldt-Jakob Disease (sCJD)
was reported to the Spanish registry. This case prompted a request for
information on health-related occupation in sCJD cases from countries
participating in the European Creutzfeldt Jakob Disease Surveillance
network (EuroCJD).

Responses from registries in 21 countries revealed that of 8321
registered cases, 65 physicians or dentists, 2 of whom were
pathologists, and another 137 health care workers had been identified
with sCJD. 5 countries reported 15 physicians and 68 other health
professionals among 2968 controls or non-cases, suggesting no relative
excess of sCJD among health care professionals. A literature review
revealed: (i) 12 case or small case-series reports of 66 health
professionals with sCJD, and (ii) 5 analytical studies on
health-related occupation and sCJD, where statistically significant
findings were solely observed for persons working at physicians’
offices (odds ratio: 4.6 (95 CI: 1.2-17.6)).

We conclude that a wide spectrum of medical specialities and health
professions are represented in sCJD cases and that the data analysed
do not support any overall increased occupational risk for health
professionals. Nevertheless, there may be a specific risk in some
professions associated with direct contact with high human-infectivity

[Reported by: Alcalde-Cabero E, Almazin-Isla J, Brandel JP, Breithaupt
M, Catarino J, Collins S, Hayback J, Hoftberger R, Kahana E, Kovacs
GG, Ladogana A, Mitrova E, Molesworth A, Nakamura Y, Pocchiari M,
Popovic M, Ruiz-Tovar M, Taratuto AL, van Duijn C, Yamada M, Will RG,
Zerr I, de Pedro Cuesta J.]

Communicated by:

[These results are consistent with the view that sporadic CJD is
rarely if ever transmissible. – Mod.CP

The interactive HealthMap/ProMED map for Spain is available at:
<> – CopyEd.EJP]

[3] CJD surveillance in Denmark
Eurosurveillance, Volume 17, Issue 15, 12 April 2012; Surveillance and
outbreak reports [edited]
Description and analysis of 12 years of surveillance for
Creutzfeldt-Jakob disease in Denmark
Summary and conclusions:
Prospective surveillance of Creutzfeldt-Jakob disease (CJD) was
initiated in Denmark in 1997, following the observation of variant CJD
[vCJD] in the United Kingdom. Demographic, clinical and diagnostic
information was collected for each patient with clinical suspicion of

Here we describe the methods for surveillance and the observed
outcomes between 1 Jan 1997 and 31 Dec 2008. A total of 83 patients
were classified as sporadic CJD, 47 were definite diagnoses, 34
probable and 2 possible. This resulted in a mean incidence of 1.26
patients with probable and definite sporadic CJD per million
inhabitants. Two sporadic CJD patients were found to have a genetic
variant of unknown significance: (thr201Ser) and Glu200Asp). One
patient was diagnosed with Gerstmann-Straussler-Scheinker [GSS]
syndrome. No patients were classified as having variant, iatrogenic or
familial CJD.

The Danish surveillance system, like those in other countries, has a
multidisciplinary approach, which is labour-intensive and
time-consuming but ensures the most complete set of information
possible. With this approach we think that patients with variant CJD
would have been detected had they occurred in Denmark. Certain aspects
of CJD surveillance need further discussion at European level and
beyond, in order to find a balance between efficiency of the systems
and accuracy of surveillance data.

[Reported by: Gubbels S, Bacci S, Laursen H, Hogenhaven H, Cowan S,
Molbak K, Christiansen M.]

Communicated by:

[These observations are consistent with the view that all confirmed
cases of vCJD have a direct connection with the original outbreak in
the UK. – Mod.CP

The interactive HealthMap/ProMED map for Denmark is available at:
<> – CopyEd.EJP]

[4] Elk faeces
Date: Sun 1 Apr 2012
Source: Journal of Wildlife Disease, 2012, vol. 48 no. 2 425-434
Detection of PPrPCWD in feces from Rocky Mountain elk
Chronic wasting disease (CWD) is a transmissible spongiform
encephalopathy affecting captive and free-ranging cervids. Currently,
tests for CWD in live animals involve relatively invasive procedures
to collect lymphoid tissue biopsies and examine them for
CWD-associated, protease-resistant cervid prion protein (PrPCWD)
detected by immunohistochemistry (IHC).

We adapted an ultrasensitive prion detection system, protein
misfolding cyclic amplification (PMCA), to detect PrPCWD in Rocky
Mountain elk (_Cervus elaphus nelson_) feces. Our PMCA reproducibly
detected a 1.2 x 10 to the 7th dilution of PrPCWD (a 10 percent
infected brain homogenate diluted 1.2 x 10 to the 6th-fold into 10
percent fecal homogenates), equivalent to approximately 100 pg of
PrPCWD/g of feces. We developed a semiquantitative scoring system
based on the first PMCA round at which PrPCWD was detected and fit a
nonlinear regression curve to our serial dilutions to correlate PMCA
scores with known PrPCWD concentrations.

We used this PMCA scoring system to detect PrPCWD and estimate its
concentration in feces from free-ranging elk from Rocky Mountain
National Park, Colorado. We compared our results to PrPCWD IHC of
rectoanal mucosa-associated lymphoid tissue and obex from the same
animals. The PMCA successfully detected PrPCWD in feces from elk that
were positive by IHC, with estimated prion loads from 100 to 5000 pg
PrPCWD/g of feces. These data show for the 1st time PrPCWD in feces
from naturally exposed free-ranging elk and demonstrate the potential
of PMCA as a new, noninvasive CWD diagnostic tool to complement IHC.

[Reported by: Bruce Pulford and 11 others]

Communicated by:
Terry S. Singeltary Sr.

[The distinctive event in prion disease is the conversion of the
native prion protein into the disease-associated misfolded protein. A
novel technology has been developed to mimic the prion conversion
process in vitro. This procedure, named protein misfolding cyclic
amplification (PMCA), conceptually analogous to DNA amplification by
polymerase chain reaction (PCR), has important applications for
research and diagnosis. The rational behind PMCA and some of the many
potential applications of this novel technology are describe in detail
as well as its application in automatic and serial modes that have
been developed with a view to improving disease diagnosis. (See:
Protein misfolding cyclic amplification for diagnosis and prion
propagation studies. By Castilla J, Sao¡ P, Morales R, Abid K,
Maundrell K, Soto C, in Methods Enzymol. 2006;412:3-21, and Castilla
J, Saa P, Hetz C, Soto C (2005) In vitro generation of infectious
scrapie prions. Cell 121: 195-206). – Mod.CP

The interactive HealthMap/ProMED map for Colorado is available at:
<> – CopyEd.EJP]

[5] USA BSE case
Date: Fri 27 Apr 2012
Source: CIDRAP News [edited]
US BSE cow was lame before culling
A report yesterday from the US Department of Agriculture (USDA) to the
World Organization for Animal Health (OIE) contained some new details
about a California dairy cow that recently tested positive for an
atypical form of bovine spongiform encephalopathy (BSE), the 1st US
case detected since 2006. Earlier reports didn’t say whether the cow
had any signs of clinical disease or how old it was, but the OIE
report says the cow was culled for lameness and that it was 10 years
and 7 months old.

The cow was tested for BSE after it was slaughtered as part of routine
surveillance for the disease. The carcass was set to be rendered but
will now be destroyed. The report said the source of the disease is
unknown and could have resulted from a random mutation. The cow was
from Tulare County, located in California’s Central Valley south of
Fresno. The cow’s age means it was born after the United States 1st
banned use of cattle protein in feed for cattle and other ruminants in
1997, but before a broader ban went into effect in 2009 that bars
certain cattle materials from all animal feed.

However, veterinary health experts said earlier this week that the
very rare, atypical BSE the cow had isn’t typically linked to
consumption of contaminated feed. Health officials have said the
California case poses no threat to the nation’s food supply.

Communicated by:

[The interactive HealthMap/ProMED map for California is available at:
<> – CopyEd.EJP]

[6] APHIS US BSE case update
Date: Wed 2 May 2012
Source: APHIS Online (Animal and Public Health Information System)
Update from APHIS Regarding a Detection of BSE in the US
On 24 Apr 2012, USDA’s Animal and Plant Health Inspection Service
confirmed the nation’s 4th case of bovine spongiform encephalopathy
(BSE) in an animal that was sampled for the disease at a rendering
facility in central California. This animal was never presented for
slaughter for human consumption, so at no time presented a risk to the
food supply, or to human health in the United States.

Through its continuing epidemiological investigation, APHIS — in
collaboration with the California Department of Food and Agriculture
(CDFA) — has identified that one progeny born to the positive cow in
the last 2 years was stillborn, and another has been located on a site
in another state. That animal has been appraised, humanely euthanized,
and sampled for BSE at the National Veterinary Services Laboratories
in Ames, Iowa. Test results for that animal are negative for BSE. No
birth cohort cattle have been located through the investigation.

A hold order has been placed on all cattle at a 2nd dairy (dairy 2)
that is associated with the dairy of the initial positive cow (also
called the index dairy). Both dairies remain under quarantine.
Inventories of both the index dairy and dairy 2 have been completed by
CDFA. Records are still being matched and validated to determine if
any at-risk cattle may be present.

In addition, a calf ranch where the initial positive cow was raised 10
years ago is being investigated.

The Food and Drug Administration (FDA) and CDFA continue the
investigation of feed records at the index dairy, rendering facility
and calf ranch. To date, 10 feed firms have been identified as
suppliers for the index dairy during the time period of interest. At
the rendering facility, feed investigators confirmed that all domestic
distribution of meat and bone meal meets federal labeling

The USDA will continue to work closely with the CDFA and the FDA to
provide additional information as it is available.

The United States has a longstanding system of 3 interlocking
safeguards against BSE that protects public and animal health in the
United States, the most important of which is the removal of specified
risk materials — or the parts of an animal that would contain BSE
should an animal have the disease — from all animals presented for
slaughter in the United States. The 2nd safeguard is a strong feed ban
that protects cattle from the disease. The 3rd safeguard — which led
to this detection — is our ongoing BSE surveillance program that
allows USDA to detect the disease if it exists at very low levels in
the U.S. cattle population.

Communicated by:
Terry S. Singeltary Sr.

Sobre snmv