Creutzfeldt Jakob Disease CJD, TSE, Prion, Surveillance Update August 2019
Updated August 14, 2019
Year Total Referrals² Prion Disease Sporadic Familial Iatrogenic vCJD
1999 & earlier 380 230 200 27 3 0
2000 145 102 90 12 0 0
2001 209 118 110 8 0 0
2002 241 144 124 18 2 0
2003 259 160 137 21 2 0
2004 316 181 164 16 0 1³
2005 327 178 156 21 1 0
2006 365 179 159 17 1 2⁴
2007 374 210 191 19 0 0
2008 384 221 205 16 0 0
2009 398 232 210 21 1 0
2010 401 246 218 28 0 0
2011 392 238 214 24 0 0
2012 413 244 221 23 0 0
2013 416 258 223 34 1 0
2014 355 208 185 21 1 1⁵
2015 402 264 244 20 0 0
2016 396 277 248 29 0 0
2017 375 266 247 19 0 0
2018 308 222 202 17 1 0
2019 218 128 100 9 0 0
TOTAL 70746 4306⁷ 3848⁸ 420⁹ 13 4
1Listed based on the year of death or, if not available, on year of referral;
2Cases with suspected prion disease for which brain tissue was submitted;
3Disease acquired in the United Kingdom;
4Disease acquired in the United Kingdom in one case and in Saudi Arabia in the other;
5Disease possibly acquired in a Middle Eastern or Eastern European country;
6Includes 21 cases in which the diagnosis is pending, and 19 inconclusive cases;
7Includes 21 (19 from 2019) cases with type determination pending in which the diagnosis of vCJD has been excluded.
8The sporadic cases include 3748 cases of sporadic Creutzfeldt-Jakob disease (sCJD),
66 cases of Variably Protease-Sensitive Prionopathy (VPSPr) and
34 cases of sporadic Fatal Insomnia (sFI).
9Total does not include 254 Familial cases diagnosed by blood test only.
Updated August 15, 2019
Year1
CSF RT-QuIC (+) Cases
Probable2 & Definite Prion Disease Cases Submitted to NPDPSC
2016 356 461
2017 395 491
2018 420 488
2019 3 287 255
1Listed based on the year of the patient’s first CSF submission
2RT-QuIC positive without neuropathological examination
32019 data based on the date range of 1/1/2019-8/15/2019
Creutzfeldt-Jakob Disease Surveillance System Report
Definite and probable CJD, 1998-2019
As of 31 July, 2019
Year Sporadic Iatrogenic Familial GSS FFI vCJD Total
1998 22 1 0 1 0 0 24
1999 27 2 2 1 0 0 32
2000 32 0 0 3 0 0 35
2001 27 0 2 1 0 0 30
2002 31 0 2 2 0 1 36
2003 27 1 1 0 0 0 29
2004 42 0 1 1 0 0 44
2005 42 0 1 1 0 0 44
2006 39 0 1 3 1 0 44
2007 35 0 0 4 0 0 39
2008 48 0 1 0 0 0 49
2009 48 0 3 2 0 0 53
2010 35 0 3 0 0 0 38
2011 46 0 3 1 0 1 51
2012 62 0 1 0 0 0 63
2013 50 0 0 0 1 0 51
2014 51 0 4 0 1 0 56
2015 44 0 5 1 2 0 52
2016 55 1 5 1 - - 62
2017 78 - 1 1 1 - 81
2018 65 1 3 - 1 - 70
2019 20 0 - - - - 20
Total 926 6 39 23 7 2 1003
Cases with definite & probable diagnosis to date.
REFERRALS OF SUSPECT CJD DEATHS OF DEFINITE AND PROBABLE CJD
Year Referrals Year Sporadic1 Iatrogenic Genetic2 vCJD Total Deaths
1990 [53]† 1990 28 5 0 - 33
1991 75 1991 31 1 4 - 36
1992 96 1992 45 2 6 - 53
1993 79 1993 36 4 7 - 47
1994 119 1994 53 1 9 - 63
1995 87 1995 35 4 5 3 47
1996 132 1996 40 4 6 10 60
1997 163 1997 59 6 7 10 82
1998 155 1998 64 3 5 18 90
1999 170 1999 62 6 2 15 85
2000 178 2000 48 1 3 28 80
2001 179 2001 58 4 6 20 88
2002 164 2002 73 0 5 17 95
2003 162 2003 79 5 6 18 108
2004 114 2004 50 2 6 9 67
2005 124 2005 67 4 13 5 89
2006 112 2006 68 1 9 5 83
2007 119 2007 63 2 11 5 81
2008 150 2008 84 5 6 2 97
2009 153 2009 78 2 8 3 91
2010 150 2010 85 3 6 3 97
2011 158 2011 91 4 14 5 114
2012 127 2012 94 5 11 0 110
2013 152 2013 108 2 10 1 121
2014 130 2014 99 3 13 0 115
2015 140 2015 105 0 4 0 109
2016 148 2016 117 1 6 1 125
2017 159 2017 121 0 12 0 133
2018 167 2018 135 2 11 0 148
2019 89 2019 75 0 1 0 76
Total Referrals 4004 Total Deaths 2151 82 212 178 2623
† Referral figure for 1990 is from 1 May onwards * As at 12th August 2019
Summary of vCJD cases
Deaths
Deaths from definite vCJD (confirmed): 123
Deaths from probable vCJD (without neuropathological confirmation): 55
Deaths from probable vCJD (neuropathological confirmation pending): 0
Number of deaths from definite or probable vCJD (as above): 178
Alive
Number of definite/probable vCJD cases still alive: 0
Total number of definite or probable vCJD (dead and alive): 178
1 There are in addition a total of 17 cases of vPSPr (death in 1997(1 case), 2004(1), 2006(1), 2008(3), 2010(1), 2012(4), 2013(1), 2016(3), 2017(1), 2018(1)) not included in the above figures.
2 includes all genetic prion disease, including GSS.
SATURDAY, AUGUST 24, 2019
Creutzfeldt-Jakob disease surveillance in Australia: update to 31 December 2018
TUESDAY, JULY 30, 2019
Guidelines for reporting surveillance data on Transmissible Spongiform Encephalopathies (TSE) in the EU within the framework of Regulation (EC) No 999/2001 APPROVED: 9 July 2019
FRIDAY, JUNE 21, 2019
CJD TSE Prion cases update USA, Texas, Canada, and UK
MONDAY, JUNE 24, 2019
APHIS, FSIS, USDA, FDA, Transmissible Spongiform Encephalopathy TSE, BSE, CWD, Scrapie, Camel TSE Prion Disease, CJD Humans
SUNDAY, MARCH 10, 2019
National Prion Disease Pathology Surveillance Center Cases Examined¹ Updated Feb 1, 2019 Variably protease-sensitive prionopathy VPSPr
FRIDAY, JANUARY 10, 2014
vpspr, sgss, sffi, TSE, an iatrogenic by-product of gss, ffi, familial type prion disease, what it ???
Greetings Friends, Neighbors, and Colleagues,
vpspr, sgss, sffi, TSE, an iatrogenic by-product of gss, ffi, familial type prion disease, what it ???
Confucius is confused again.
I was just sitting and thinking about why there is no genetic link to some of these TSE prion sGSS, sFFi, and it’s really been working on my brain, and then it hit me today.
what if, vpspr, sgss, sffi, TSE prion disease, was a by-product from iatrogenic gss, ffi, familial type prion disease ???
it could explain the cases of no genetic link to the gss, ffi, familial type prion disease, to the family.
sporadic and familial is a red herring, in my opinion, and underestimation is spot on, due to the crude prehistoric diagnostic procedures and criteria and definition of a prion disease.
I say again, what if, iatrogenic, what if, with all these neurological disorders, with a common denominator that is increasingly showing up in the picture, called the prion.
I urge all scientist to come together here, with this as the utmost of importance about all these neurological disease that are increasingly showing up as a prion mechanism, to put on the front burners, the IATROGENIC aspect and the potential of transmission there from, with diseases/disease??? in question.
by definition, could they be a Transmissible Spongiform Encephalopathy TSE prion type disease, and if so, what are the iatrogenic chances of transmission?
this is very important, and should be at the forefront of research, and if proven, could be a monumental breakthrough in science and battle against the spreading of these disease/diseases.
the US National Library of Medicine National Institutes of Health pub-med site, a quick search of the word SPORADIC will give you a hit of 40,747. of those, there are a plethora of disease listed under sporadic. sporadic simply means (UNKNOWN).
the US National Library of Medicine National Institutes of Health pub-med site, a quick search of the word FAMILIAL will give you a hit of 921,815. of those, there are a plethora of disease listed under familial.
again, sporadic and familial is a red herring, in my opinion.
also, in my opinion, when you start have disease such as sporadic Fatal Familial Insomnia, (and or sporadic GSS, or the VPSPr type prion disease), and there is NO familial genetic linkage to the family of the diseased, I have serious questions there as to a familial type disease, and thus, being defined as such.
snip...see full text;
Friday, January 10, 2014
vpspr, sgss, sffi, TSE, an iatrogenic by-product of gss, ffi, familial type prion disease, what it ???
THURSDAY, AUGUST 08, 2019
Raccoons accumulate PrPSc after intracranial inoculation with the agents of chronic wasting disease (CWD) or transmissible mink encephalopathy (TME) but not atypical scrapie
FRIDAY, JULY 26, 2019
Chronic Wasting Disease in Cervids: Implications for Prion Transmission to Humans and Other Animal Species
WEDNESDAY, JULY 31, 2019
The agent of transmissible mink encephalopathy passaged in sheep is similar to BSE-L
MONDAY, FEBRUARY 25, 2019
MAD DOGS AND ENGLISHMEN BSE, SCRAPIE, CWD, CJD, TSE PRION A REVIEW 2019
2018 USDA ARS RESEARCH AND PRION CONFERENCE 2018
CWD CWD CWD PIGS PIGS PIGS SCRAPIE SCRAPIE SCRAPIE
Scrapie, CWD, tse prion, transmit to pigs by oral route
***> However, at 51 months of incubation or greater, 5 animals were positive by one or more diagnostic methods. Furthermore, positive bioassay results were obtained from all inoculated groups (oral and intracranial; market weight and end of study) suggesting that swine are potential hosts for the agent of scrapie. <***
>*** Although the current U.S. feed ban is based on keeping tissues from TSE infected cattle from contaminating animal feed, swine rations in the U.S. could contain animal derived components including materials from scrapie infected sheep and goats. These results indicating the susceptibility of pigs to sheep scrapie, coupled with the limitations of the current feed ban, indicates that a revision of the feed ban may be necessary to protect swine production and potentially human health. <***
***> Results: PrPSc was not detected by EIA and IHC in any RPLNs. All tonsils and MLNs were negative by IHC, though the MLN from one pig in the oral <6 5="" 6="" at="" by="" detected="" eia.="" examined="" group="" in="" intracranial="" least="" lymphoid="" month="" months="" of="" one="" pigs="" positive="" prpsc="" quic="" the="" tissues="" was="">6 months group, 5/6 pigs in the oral <6 4="" and="" group="" months="" oral="">6 months group. Overall, the MLN was positive in 14/19 (74%) of samples examined, the RPLN in 8/18 (44%), and the tonsil in 10/25 (40%).
***> Conclusions: This study demonstrates that PrPSc accumulates in lymphoid tissues from pigs challenged intracranially or orally with the CWD agent, and can be detected as early as 4 months after challenge. CWD-infected pigs rarely develop clinical disease and if they do, they do so after a long incubation period.
This raises the possibility that CWD-infected pigs could shed prions into their environment long before they develop clinical disease.
Furthermore, lymphoid tissues from CWD-infected pigs could present a potential source of CWD infectivity in the animal and human food chains.
MONDAY, NOVEMBER 26, 2018
***>The agent of chronic wasting disease from pigs is infectious in transgenic mice expressing human PRNP
FRIDAY, APRIL 20, 2018
*** Scrapie Transmits To Pigs By Oral Route, what about the terribly flawed USA tse prion feed ban?
Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies
***> Subject: Scrapie Transmits To Pigs By Oral Route, what about the terribly flawed USA tse prion feed ban? <***
MONDAY, OCTOBER 01, 2018
Update on Classical and Atypical Scrapie in Sheep and Goats: Review 2018
MONDAY, OCTOBER 1, 2018
Review: Update on Classical and Atypical Scrapie in Sheep and Goats
ZOONOSIS OF SCRAPIE TSE PRION
O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations
Emmanuel Comoy, Jacqueline Mikol, Valerie Durand, Sophie Luccantoni, Evelyne Correia, Nathalie Lescoutra, Capucine Dehen, and Jean-Philippe Deslys Atomic Energy Commission; Fontenay-aux-Roses, France
Prion diseases (PD) are the unique neurodegenerative proteinopathies reputed to be transmissible under field conditions since decades. The transmission of Bovine Spongiform Encephalopathy (BSE) to humans evidenced that an animal PD might be zoonotic under appropriate conditions. Contrarily, in the absence of obvious (epidemiological or experimental) elements supporting a transmission or genetic predispositions, PD, like the other proteinopathies, are reputed to occur spontaneously (atpical animal prion strains, sporadic CJD summing 80% of human prion cases).
Non-human primate models provided the first evidences supporting the transmissibiity of human prion strains and the zoonotic potential of BSE. Among them, cynomolgus macaques brought major information for BSE risk assessment for human health (Chen, 2014), according to their phylogenetic proximity to humans and extended lifetime. We used this model to assess the zoonotic potential of other animal PD from bovine, ovine and cervid origins even after very long silent incubation periods.
*** We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period,
***with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold long incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014),
***is the third potentially zoonotic PD (with BSE and L-type BSE),
***thus questioning the origin of human sporadic cases.
We will present an updated panorama of our different transmission studies and discuss the implications of such extended incubation periods on risk assessment of animal PD for human health.
===============
***thus questioning the origin of human sporadic cases***
===============
***our findings suggest that possible transmission risk of H-type BSE to sheep and human. Bioassay will be required to determine whether the PMCA products are infectious to these animals.
==============
***Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
***Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
PRION 2016 TOKYO
Saturday, April 23, 2016
SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016
Prion. 10:S15-S21. 2016 ISSN: 1933-6896 printl 1933-690X online
Taylor & Francis
Prion 2016 Animal Prion Disease Workshop Abstracts
WS-01: Prion diseases in animals and zoonotic potential
Juan Maria Torres a, Olivier Andreoletti b, J uan-Carlos Espinosa a. Vincent Beringue c. Patricia Aguilar a,
Natalia Fernandez-Borges a. and Alba Marin-Moreno a
"Centro de Investigacion en Sanidad Animal ( CISA-INIA ). Valdeolmos, Madrid. Spain; b UMR INRA -ENVT 1225 Interactions Holes Agents Pathogenes. ENVT. Toulouse. France: "UR892. Virologie lmmunologie MolécuIaires, Jouy-en-Josas. France
Dietary exposure to bovine spongiform encephalopathy (BSE) contaminated bovine tissues is considered as the origin of variant Creutzfeldt Jakob (vCJD) disease in human. To date, BSE agent is the only recognized zoonotic prion... Despite the variety of Transmissible Spongiform Encephalopathy (TSE) agents that have been circulating for centuries in farmed ruminants there is no apparent epidemiological link between exposure to ruminant products and the occurrence of other form of TSE in human like sporadic Creutzfeldt Jakob Disease (sCJD). However, the zoonotic potential of the diversity of circulating TSE agents has never been systematically assessed. The major issue in experimental assessment of TSEs zoonotic potential lies in the modeling of the ‘species barrier‘, the biological phenomenon that limits TSE agents’ propagation from a species to another. In the last decade, mice genetically engineered to express normal forms of the human prion protein has proved essential in studying human prions pathogenesis and modeling the capacity of TSEs to cross the human species barrier.
To assess the zoonotic potential of prions circulating in farmed ruminants, we study their transmission ability in transgenic mice expressing human PrPC (HuPrP-Tg). Two lines of mice expressing different forms of the human PrPC (129Met or 129Val) are used to determine the role of the Met129Val dimorphism in susceptibility/resistance to the different agents.
These transmission experiments confirm the ability of BSE prions to propagate in 129M- HuPrP-Tg mice and demonstrate that Met129 homozygotes may be susceptible to BSE in sheep or goat to a greater degree than the BSE agent in cattle and that these agents can convey molecular properties and neuropathological indistinguishable from vCJD. However homozygous 129V mice are resistant to all tested BSE derived prions independently of the originating species suggesting a higher transmission barrier for 129V-PrP variant.
Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
why do we not want to do TSE transmission studies on chimpanzees $
5. A positive result from a chimpanzee challenged severly would likely create alarm in some circles even if the result could not be interpreted for man.
***> I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough.
***> Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.
snip...
R. BRADLEY
Title: Transmission of scrapie prions to primate after an extended silent incubation period)
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
***> Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility. <***
Transmission of scrapie prions to primate after an extended silent incubation period
Emmanuel E. Comoy, Jacqueline Mikol, Sophie Luccantoni-Freire, Evelyne Correia, Nathalie Lescoutra-Etchegaray, Valérie Durand, Capucine Dehen, Olivier Andreoletti, Cristina Casalone, Juergen A. Richt, Justin J. Greenlee, Thierry Baron, Sylvie L. Benestad, Paul Brown & Jean-Philippe Deslys Scientific Reports volume 5, Article number: 11573 (2015) | Download Citation
Abstract
Classical bovine spongiform encephalopathy (c-BSE) is the only animal prion disease reputed to be zoonotic, causing variant Creutzfeldt-Jakob disease (vCJD) in humans and having guided protective measures for animal and human health against animal prion diseases. Recently, partial transmissions to humanized mice showed that the zoonotic potential of scrapie might be similar to c-BSE. We here report the direct transmission of a natural classical scrapie isolate to cynomolgus macaque, a highly relevant model for human prion diseases, after a 10-year silent incubation period, with features similar to those reported for human cases of sporadic CJD. Scrapie is thus actually transmissible to primates with incubation periods compatible with their life expectancy, although fourfold longer than BSE. Long-term experimental transmission studies are necessary to better assess the zoonotic potential of other prion diseases with high prevalence, notably Chronic Wasting Disease of deer and elk and atypical/Nor98 scrapie.
SNIP...
Discussion We describe the transmission of spongiform encephalopathy in a non-human primate inoculated 10 years earlier with a strain of sheep c-scrapie. Because of this extended incubation period in a facility in which other prion diseases are under study, we are obliged to consider two alternative possibilities that might explain its occurrence. We first considered the possibility of a sporadic origin (like CJD in humans). Such an event is extremely improbable because the inoculated animal was 14 years old when the clinical signs appeared, i.e. about 40% through the expected natural lifetime of this species, compared to a peak age incidence of 60–65 years in human sporadic CJD, or about 80% through their expected lifetimes. Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.
The second possibility is a laboratory cross-contamination. Three facts make this possibility equally unlikely. First, handling of specimens in our laboratory is performed with fastidious attention to the avoidance of any such cross-contamination. Second, no laboratory cross-contamination has ever been documented in other primate laboratories, including the NIH, even between infected and uninfected animals housed in the same or adjacent cages with daily intimate contact (P. Brown, personal communication). Third, the cerebral lesion profile is different from all the other prion diseases we have studied in this model19, with a correlation between cerebellar lesions (massive spongiform change of Purkinje cells, intense PrPres staining and reactive gliosis26) and ataxia. The iron deposits present in the globus pallidus are a non specific finding that have been reported previously in neurodegenerative diseases and aging27. Conversely, the thalamic lesion was reminiscent of a metabolic disease due to thiamine deficiency28 but blood thiamine levels were within normal limits (data not shown). The preferential distribution of spongiform change in cortex associated with a limited distribution in the brainstem is reminiscent of the lesion profile in MM2c and VV1 sCJD patients29, but interspecies comparison of lesion profiles should be interpreted with caution. It is of note that the same classical scrapie isolate induced TSE in C57Bl/6 mice with similar incubation periods and lesional profiles as a sample derived from a MM1 sCJD patient30.
We are therefore confident that the illness in this cynomolgus macaque represents a true transmission of a sheep c-scrapie isolate directly to an old-world monkey, which taxonomically resides in the primate subdivision (parvorder of catarrhini) that includes humans. With an homology of its PrP protein with humans of 96.4%31, cynomolgus macaque constitutes a highly relevant model for assessing zoonotic risk of prion diseases. Since our initial aim was to show the absence of transmission of scrapie to macaques in the worst-case scenario, we obtained materials from a flock of naturally-infected sheep, affecting animals with different genotypes32. This c-scrapie isolate exhibited complete transmission in ARQ/ARQ sheep (332 ± 56 days) and Tg338 transgenic mice expressing ovine VRQ/VRQ prion protein (220 ± 5 days) (O. Andreoletti, personal communication). From the standpoint of zoonotic risk, it is important to note that sheep with c-scrapie (including the isolate used in our study) have demonstrable infectivity throughout their lymphoreticular system early in the incubation period of the disease (3 months-old for all the lymphoid organs, and as early as 2 months-old in gut-associated lymph nodes)33. In addition, scrapie infectivity has been identified in blood34, milk35 and skeletal muscle36 from asymptomatic but scrapie infected small ruminants which implies a potential dietary exposure for consumers.
Two earlier studies have reported the occurrence of clinical TSE in cynomolgus macaques after exposures to scrapie isolates. In the first study, the “Compton” scrapie isolate (derived from an English sheep) and serially propagated for 9 passages in goats did not transmit TSE in cynomolgus macaque, rhesus macaque or chimpanzee within 7 years following intracerebral challenge1; conversely, after 8 supplementary passages in conventional mice, this “Compton” isolate induced TSE in a cynomolgus macaque 5 years after intracerebral challenge, but rhesus macaques and chimpanzee remained asymptomatic 8.5 years post-exposure8. However, multiple successive passages that are classically used to select laboratory-adapted prion strains can significantly modify the initial properties of a scrapie isolate, thus questioning the relevance of zoonotic potential for the initial sheep-derived isolate. The same isolate had also induced disease into squirrel monkeys (new-world monkey)9. A second historical observation reported that a cynomolgus macaque developed TSE 6 years post-inoculation with brain homogenate from a scrapie-infected Suffolk ewe (derived from USA), whereas a rhesus macaque and a chimpanzee exposed to the same inoculum remained healthy 9 years post-exposure1. This inoculum also induced TSE in squirrel monkeys after 4 passages in mice. Other scrapie transmission attempts in macaque failed but had more shorter periods of observation in comparison to the current study. Further, it is possible that there are differences in the zoonotic potential of different scrapie strains.
The most striking observation in our study is the extended incubation period of scrapie in the macaque model, which has several implications. Firstly, our observations constitute experimental evidence in favor of the zoonotic potential of c-scrapie, at least for this isolate that has been extensively studied32,33,34,35,36. The cross-species zoonotic ability of this isolate should be confirmed by performing duplicate intracerebral exposures and assessing the transmissibility by the oral route (a successful transmission of prion strains through the intracerebral route may not necessarily indicate the potential for oral transmission37). However, such confirmatory experiments may require more than one decade, which is hardly compatible with current general management and support of scientific projects; thus this study should be rather considered as a case report.
Secondly, transmission of c-BSE to primates occurred within 8 years post exposure for the lowest doses able to transmit the disease (the survival period after inoculation is inversely proportional to the initial amount of infectious inoculum). The occurrence of scrapie 10 years after exposure to a high dose (25 mg) of scrapie-infected sheep brain suggests that the macaque has a higher species barrier for sheep c-scrapie than c-BSE, although it is notable that previous studies based on in vitro conversion of PrP suggested that BSE and scrapie prions would have a similar conversion potential for human PrP38.
Thirdly, prion diseases typically have longer incubation periods after oral exposure than after intracerebral inoculations: since humans can develop Kuru 47 years after oral exposure39, an incubation time of several decades after oral exposure to scrapie would therefore be expected, leading the disease to occur in older adults, i.e. the peak age for cases considered to be sporadic disease, and making a distinction between scrapie-associated and truly sporadic disease extremely difficult to appreciate.
Fourthly, epidemiologic evidence is necessary to confirm the zoonotic potential of an animal disease suggested by experimental studies. A relatively short incubation period and a peculiar epidemiological situation (e.g., all the first vCJD cases occurring in the country with the most important ongoing c-BSE epizootic) led to a high degree of suspicion that c-BSE was the cause of vCJD. Sporadic CJD are considered spontaneous diseases with an almost stable and constant worldwide prevalence (0.5–2 cases per million inhabitants per year), and previous epidemiological studies were unable to draw a link between sCJD and classical scrapie6,7,40,41, even though external causes were hypothesized to explain the occurrence of some sCJD clusters42,43,44. However, extended incubation periods exceeding several decades would impair the predictive values of epidemiological surveillance for prion diseases, already weakened by a limited prevalence of prion diseases and the multiplicity of isolates gathered under the phenotypes of “scrapie” and “sporadic CJD”.
Fifthly, considering this 10 year-long incubation period, together with both laboratory and epidemiological evidence of decade or longer intervals between infection and clinical onset of disease, no premature conclusions should be drawn from negative transmission studies in cynomolgus macaques with less than a decade of observation, as in the aforementioned historical transmission studies of scrapie to primates1,8,9. Our observations and those of others45,46 to date are unable to provide definitive evidence regarding the zoonotic potential of CWD, atypical/Nor98 scrapie or H-type BSE. The extended incubation period of the scrapie-affected macaque in the current study also underscores the limitations of rodent models expressing human PrP for assessing the zoonotic potential of some prion diseases since their lifespan remains limited to approximately two years21,47,48. This point is illustrated by the fact that the recently reported transmission of scrapie to humanized mice was not associated with clinical signs for up to 750 days and occurred in an extreme minority of mice with only a marginal increase in attack rate upon second passage13. The low attack rate in these studies is certainly linked to the limited lifespan of mice compared to the very long periods of observation necessary to demonstrate the development of scrapie. Alternatively, one could estimate that a successful second passage is the result of strain adaptation to the species barrier, thus poorly relevant of the real zoonotic potential of the original scrapie isolate of sheep origin49. The development of scrapie in this primate after an incubation period compatible with its lifespan complements the study conducted in transgenic (humanized) mice; taken together these studies suggest that some isolates of sheep scrapie can promote misfolding of the human prion protein and that scrapie can develop within the lifespan of some primate species.
In addition to previous studies on scrapie transmission to primate1,8,9 and the recently published study on transgenic humanized mice13, our results constitute new evidence for recommending that the potential risk of scrapie for human health should not be dismissed. Indeed, human PrP transgenic mice and primates are the most relevant models for investigating the human transmission barrier. To what extent such models are informative for measuring the zoonotic potential of an animal TSE under field exposure conditions is unknown. During the past decades, many protective measures have been successfully implemented to protect cattle from the spread of c-BSE, and some of these measures have been extended to sheep and goats to protect from scrapie according to the principle of precaution. Since cases of c-BSE have greatly reduced in number, those protective measures are currently being challenged and relaxed in the absence of other known zoonotic animal prion disease. We recommend that risk managers should be aware of the long term potential risk to human health of at least certain scrapie isolates, notably for lymphotropic strains like the classical scrapie strain used in the current study. Relatively high amounts of infectivity in peripheral lymphoid organs in animals infected with these strains could lead to contamination of food products produced for human consumption. Efforts should also be maintained to further assess the zoonotic potential of other animal prion strains in long-term studies, notably lymphotropic strains with high prevalence like CWD, which is spreading across North America, and atypical/Nor98 scrapie (Nor98)50 that was first detected in the past two decades and now represents approximately half of all reported cases of prion diseases in small ruminants worldwide, including territories previously considered as scrapie free... Even if the prevailing view is that sporadic CJD is due to the spontaneous formation of CJD prions, it remains possible that its apparent sporadic nature may, at least in part, result from our limited capacity to identify an environmental origin.
P132 Aged cattle brain displays Alzheimer’s-like pathology that can be propagated in a prionlike manner
Ines Moreno-Gonzalez (1), George Edwards III (1), Rodrigo Morales (1), Claudia Duran-Aniotz (1), Mercedes Marquez (2), Marti Pumarola (2), Claudio Soto (1)
snip...
These results may contribute to uncover a previously unsuspected etiology surrounding some cases of sporadic AD. However, the early and controversial stage of the field of prion-like transmission in non-prion diseases added to the artificial nature of the animal models utilized for these studies, indicate that extrapolation of the results to humans should not be done without further experiments.
P75 Determining transmissibility and proteome changes associated with abnormal bovine prionopathy
Dudas S (1,2), Seuberlich T (3), Czub S (1,2)
In prion diseases, it is believed that altered protein conformation encodes for different pathogenic strains. Currently 3 different strains of bovine spongiform encephalopathy (BSE) are confirmed. Diagnostic tests for BSE are able to identify animals infected with all 3 strains, however, several diagnostic laboratories have reported samples with inconclusive results which are challenging to classify. It was suggested that these may be novel strains of BSE; to determine transmissibility, brain material from index cases were inoculated into cattle.
In the first passage, cattle were intra-cranially challenged with brain homogenate from 2 Swiss animals with abnormal prionopathy. The challenged cattle incubated for 3 years and were euthanized with no clinical signs of neurologic disease. Animals were negative when tested on validated diagnostic tests but several research methods demonstrated changes in the prion conformation in these cattle, including density gradient centrifugation and immunohistochemistry. Currently, samples from the P1 animals are being tested for changes in protein levels using 2-D Fluorescence Difference Gel Electrophoresis (2D DIGE) and mass spectrometry. It is anticipated that, if a prionopathy is present, this approach should identify pathways and targets to decipher the source of altered protein conformation. In addition, a second set of cattle have been challenged with brain material from the first passage. Ideally, these cattle will be given a sufficient incubation period to provide a definitive answer to the question of transmissibility.
=====prion 2018===
***however in 1 C-type challenged animal, Prion 2015 Poster Abstracts
S67 PrPsc was not detected using rapid tests for BSE.
***Subsequent testing resulted in the detection of pathologic lesion in unusual brain location and PrPsc detection by PMCA only.
*** IBNC Tauopathy or TSE Prion disease, it appears, no one is sure ***
Posted by Terry S. Singeltary Sr. on 03 Jul 2015 at 16:53 GMT
P.9.21
Molecular characterization of BSE in Canada
Jianmin Yang 1 , Sandor Dudas 2 , Catherine Graham 2 , Markus Czub 3 , Tim McAllister 1 , Stefanie Czub 1 1 Agriculture and Agri-Food Canada Research Centre, Canada; 2 National and OIE BSE Reference Laboratory, Canada; 3 University of Calgary, Canada
Background: Three BSE types (classical and two atypical) have been identified on the basis of molecular characteristics of the misfolded protein associated with the disease. To date, each of these three types have been detected in Canadian cattle. Objectives: This study was conducted to further characterize the 16 Canadian BSE cases based on the biochemical properties of there associated PrPres.
Methods: Immuno-reactivity, molecular weight, glycoform profiles and relative proteinase K sensitivity of the PrPres from each of the 16 confirmed Canadian BSE cases was determined using modified Western blot analysis.
Results: Fourteen of the 16 Canadian BSE cases were C type, 1 was H type and 1 was L type. The Canadian H and L-type BSE cases exhibited size shifts and changes in glycosylation similar to other atypical BSE cases. PK digestion under mild and stringent conditions revealed a reduced protease resistance of the atypical cases compared to the C-type cases. N terminal-specific antibodies bound to PrPres from H type but not from C or L type. The C-terminal-specific antibodies resulted in a shift in the glycoform profile and detected a fourth band in the Canadian H-type BSE.
Discussion: The C, L and H type BSE cases in Canada exhibit molecular characteristics similar to those described for classical and atypical BSE cases from Europe and Japan. This supports the theory that the importation of BSE contaminated feedstuff is the source of C-type BSE in Canada. It also suggests a similar cause or source for atypical BSE in these countries.
Discussion: The C, L and H type BSE cases in Canada exhibit molecular characteristics similar to those described for classical and atypical BSE cases from Europe and Japan.
*** This supports the theory that the importation of BSE contaminated feedstuff is the source of C-type BSE in Canada.
*** It also suggests a similar cause or source for atypical BSE in these countries. ***
see page 176 of 201 pages...tss
*** Singeltary reply ; Molecular, Biochemical and Genetic Characteristics of BSE in Canada Singeltary reply;
SUNDAY, MAY 26, 2019
Arguments for Alzheimer’s and Parkinson’s diseases caused by prions Stanley B. Prusiner
''From a large array of bioassays, we conclude that AD, PD, MSA, and the frontotemporal dementias, including PSP and CBD, are all prion diseases''
Terry S. Singeltary Sr.
posted by Terry S. Singeltary Sr. at
10:43 AM
