Surveillance for variant CJD: should more children with neurodegenerative diseases have autopsies? Singeltary Review
Original article
Surveillance for variant CJD: should more children with neurodegenerative diseases have autopsies?
Christopher Verity1, Anne Marie Winstone1, Robert Will2, Alison Powell1, Peter Baxter3, Carlos de Sousa4, Paul Gissen4, Manju Kurian5, John Livingston6, Robert McFarland7, Suvankar Pal2, Michael Pike8, Richard Robinson9, Evangeline Wassmer10, Sameer Zuberi11
Author affiliations
Abstract Objectives
To report investigations performed in children with progressive neurodegenerative diseases reported to this UK study.
Design Since 1997 paediatric surveillance for variant Creutzfeldt-Jakob disease (vCJD) has been performed by identifying children aged less than 16 years with progressive intellectual and neurological deterioration (PIND) and searching for vCJD among them.
Setting The PIND Study obtains case details from paediatricians who notify via the British Paediatric Surveillance Unit.
Participants Between May 1997 and October 2017, a total of 2050 cases meeting PIND criteria had been notified and investigated.
Results Six children had vCJD. 1819 children had other diagnoses, made in 12 cases by antemortem brain biopsy and in 15 by postmortem investigations. 225 children were undiagnosed: only 3 had antemortem brain biopsies and only 14 of the 108 who died were known to have had autopsies; postmortem neuropathological studies were carried out in just 10% (11/108) and only two had prion protein staining of brain tissue. Of the undiagnosed cases 43% were known to come from Asian British families.
Conclusions Most of the notified children had a diagnosis other than vCJD to explain their neurological deterioration. None of the undiagnosed cases had the clinical phenotype of vCJD but brain tissue was rarely studied to exclude vCJD. Clinical surveillance via the PIND Study remains the only practical means of searching for vCJD in UK children.
snip...
Discussion Principal findings Postmortems and diagnosis The diagnosis was made without brain biopsy or postmortem neuropathology in 99% of the whole diagnosed group of children with PIND. Only 24 children in the diagnosed group were known to have had postmortem examinations. However, these did help to make the diagnosis in 15 cases. It is therefore a concern that only 14 of the 108 undiagnosed children who died were known to have had postmortem studies and in three of these the brain was not examined.
Falling autopsy rates have been noted in adults and children.14–16 Burton and Underwood14 reported that the overall autopsy rate in the UK in 1979 was 42.7%, falling to 15.3% in 2001. In 2015, Turnbull et al17 found that the mean autopsy rate in the UK was 0.69%: hospital autopsy rates in children’s hospital NHS trusts ranged from 0% to 21%. A recent systematic review18 of postmortem examinations in perinatal and paediatric settings stated, ‘…PM examinations result in clinically significant findings in 22%–76% of cases…’
Possible hidden vCJD It is reassuring that the majority of notified UK children who met the PIND criteria had a diagnosis other than vCJD to explain their deterioration. However, 225 of them had no diagnosis—could some of them have vCJD? A previous short report by the PIND Study19 provided reassurance about this and the current data reinforce the view that there is no evidence of hidden vCJD in undiagnosed children with PIND; none fulfilled the sensitive and specific diagnostic criteria for ‘probable’ vCJD (see table 3).20
VIEW INLINE VIEW POPUP Table 3 Current diagnostic criteria for vCJD as reported by Heath et al20 in 2010
However, it is a concern that prion protein staining of brain tissue was carried out in just two of the undiagnosed cases as this is the only way to completely exclude the diagnosis of vCJD.21 Blood and urine tests for diagnosing vCJD have been developed, but are not sufficiently validated for routine clinical use.22–24
Ethnicity and consanguinity The PIND Study has reported that the greatest numbers of cases come from areas where there are relatively large populations of Pakistani origin.7 These new data confirm that a large proportion of Study children are Asian British (29% in the diagnosed group and 43% in the undiagnosed group compared with 7.5% in the general population of England and Wales in 201111). There were high rates of consanguinity—in the families of undiagnosed children of Pakistani origin with PIND it was 89%: possibly they have inherited neurodegenerative diseases that have not yet been characterised. These diseases may become evident as new diagnostic investigations are available.
Strengths and weaknesses of the PIND Study The Study uses the well-established health surveillance mechanism of the BPSU.8 The PIND Study Expert Group includes representatives from the NCJDRSU and provides an independent opinion about the diagnosis in every reported case. There is multisource ascertainment and the reporting is not restricted to cases admitted to hospital. The Study has confirmed the diagnosis of more than 190 known neurological disorders and has published case series of the diagnosed groups.25–28
The BPSU relies on the voluntary support of consultant paediatricians: it does not provide complete ascertainment of cases and it is not always possible to obtain all the relevant data. When PIND cases are diagnosed they are not systematically followed up by the Study and follow-up has to be discontinued eventually in undiagnosed cases.
UK surveillance for prion diseases is carried out by the NCJDRSU, the team that first identified this new disease.1 The NCJDRSU relies on a network of neurologists, psychiatrists, neuropathologists and other clinical specialists who report adults with suspected vCJD. Because vCJD cases could be hidden among the multitude of rare neurodegenerative diseases of childhood a system of direct referral of suspected vCJD cases would not be reliable. The PIND Study therefore has to work via local paediatricians and other specialists to screen all the children in the UK with PIND.
Policy implications and future research There has been increasing use of minimally invasive postmortem investigations in infants and children. Postmortem MRI can provide useful diagnostic information29–31 and may identify significant neuropathology in infants and children.32 Storage of blood and other relevant tissues for metabolic and/or genetic studies is very important; several PIND Study children have been diagnosed via the UK and Ireland Deciphering Developmental Disorders Study.33 Some children with undiagnosed PIND might be eligible for inclusion in the 100 000 Genomes Project.34 Because of the recent advances in genetics undiagnosed children should be referred for an up-to-date opinion from a clinical geneticist.
The recent identification of the first patient with vCJD who was MV heterozygous at PRNP codon 129 reinforces the need for continued vCJD surveillance,3 particularly as a study of archived appendix samples from UK hospitals published in 2013 indicated that approximately 1 in 2000 of the UK population is carrying abnormal prion protein in the gastrointestinal tract.35
Should more children with neurodegenerative diseases have autopsies? In this study, an underlying diagnosis had been made in the majority of children in whom investigations of their neurodegenerative diseases had been completed; in 99% of these 1819 cases the diagnosis was reached before death without the need for brain biopsies or autopsies. Thus, the PIND Study does not provide evidence that autopsies should be performed more frequently in most children with neurodegenerative diseases meeting the Study criteria. However, if such children have been carefully investigated before death and are still undiagnosed there is a case for recommending postmortem studies. There are different considerations when trying to confirm or exclude vCJD, as this can only be done with certainty by neuropathological study. If postmortem studies of brain tissue were always performed after children died of undiagnosed neurodegenerative diseases then vCJD would be detected and there would be no need for the PIND Study. However, the undiagnosed children in the Study rarely underwent antemortem or postmortem pathological examination of brain tissue and this seems unlikely to change. Therefore, in the absence of an alternative validated vCJD screening test the PIND Study remains the only practical means of performing systematic surveillance for vCJD in UK children.
Acknowledgments Many thanks to the paediatricians who notify cases, to Mr Richard Lynn and Mr Jacob Avis of the BPSU and to the PIND Expert Group: PB, CdS, PG, MK, JL, RM, SP, MP, RR, EW, RW, Dr John Wilson and SZ.
References
This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See:
SERIOUS QUESTION PLEASE ???
***>CONCERN HERE, WHAT ABOUT TSE PRION DISEASE, WHAT ABOUT ACUTE FLACCID MYELITIS IN US CHILDREN, could this be a tse prion disease?
has anyone checked?
seems the spinal cord is specifically effected with acute flaccid myelitis, or AFM, and with this new TSE Prion study out about vCJD, this is why i bring this question to the table, not trying to freak anyone out, just a serious question?
SEE;
***> AFM affects the nervous system, specifically the spinal cord, which can cause the muscles and reflexes in the body not to work normally.
compared to new TSE Prion study that states ;
***> It is noteworthy that macaques developed an original, yet undescribed myelopathic syndrome associating demyelination and pseudo-necrotic lesions of spinal cord, brainstem and optical tract without affecting encephalon, which is rather evocative of spinal cord disease than prion disease in human medicine.
***>These observations strongly suggest that the spectrum of human prion diseases may extend the current field restricted to the phenotypes associated to protease-resistant PrP, and may notably include spinal cord diseases.
Acute Flaccid Myelitis in U.S. Children
CDC continues to receive reports of children with acute flaccid myelitis (AFM), a rare but serious condition. CDC is working hard to find the causes of these AFM cases. Learn more about AFM and symptoms that require immediate medical care.
Parents may be hearing about children in the United States who suddenly became weak in their arms or legs from a condition called acute flaccid myelitis, or AFM. This condition is not new, but the increase in cases we saw starting in 2014 is new. There are different possible causes, such as viruses, environmental toxins, and genetic disorders. AFM affects the nervous system, specifically the spinal cord, which can cause the muscles and reflexes in the body not to work normally.
10/21/2018 Acute Flaccid Myelitis in U.S. Children | Features | CDC
From August 2014 through September 2018, CDC has received information on a total of 386 confirmed cases of AFM across the US; most of the cases have occurred in children.
Even with an increase in cases since 2014, AFM remains a very rare condition. Less than one in a million people in the United States get AFM each year.
While we don’t know the cause of most of the AFM cases, it’s always important to practice disease prevention steps, such as staying up-to-date on vaccines, washing your hands, and protecting yourself from mosquito bites. Learn more about CDC’s investigation of AFM.
While we don’t know if effective in preventing AFM, washing your hands often is one of the best ways to avoid getting sick and spreading germs to other people.
In August 2014, CDC was made aware of an increased number of people, mostly children, with AFM. Since then, we’ve been working hard to better understand AFM, what puts people at risk of getting it, and the possible causes. AFM remains rare (less than one in a million people), even with the recent increase in cases. However, AFM is serious, and we don’t yet know what causes most people to get it or how to protect people from getting AFM. As we continue to learn about AFM, we urge parents to seek medical care right away if their child develops symptoms of AFM.
Symptoms of AFM
AFM is rare, but it can lead to serious neurologic problems. You should seek medical care right away if you or your child develops any of these symptoms:
weakness and loss of muscle tone and reflexes in the arms or legs
facial droop or weakness
difficulty moving the eyes
drooping eyelids
difficulty swallowing
slurred speech
Infections That Can Cause Conditions like AFM
Certain viruses, such as poliovirus and West Nile virus, may sometimes lead to conditions like AFM. You can protect yourself and your children from these viruses by:
10/21/2018 Acute Flaccid Myelitis in U.S. Children | Features | CDC
Making sure you are all up to date on polio vaccinations.
Protecting against bites from mosquitoes, which can carry West Nile virus, by using mosquito repellent, staying indoors at dusk and dawn (when bites are more common), and removing standing or stagnant water near your home (where mosquitoes can breed).
What CDC Is Doing About AFM
CDC has been investigating AFM since we were made aware of an increased number of people with this condition in August 2014.
We have done extensive lab testing on specimens from patients, but have not determined what caused most of these people to get AFM. It is unclear what pathogen (germ) or immune response caused the arm or leg weakness and paralysis. AFM may have a variety of possible causes such as viruses, environmental toxins, and genetic disorders.
We are continuing to learn as much as we can about AFM by looking at each case to figure out what puts people at risk of getting this condition and what is causing it. Also, we are urging doctors to be alert for patients with symptoms of AFM and to report suspected cases to their health departments.
If you would like to learn more about what CDC is doing, please visit CDC’s AFM in the United States website. If you would like to learn more about AFM, please visit CDC’s acute flaccid myelitis website.
Unexpected prion phenotypes in experimentally transfused animals: predictive models for humans?
Emmanuel E. Comoy, Jacqueline Mikol & Jean-Philippe Deslys
Pages 162-169 | Received 06 Jul 2018, Accepted 24 Jul 2018, Accepted author version posted online: 06 Aug 2018, Published online: 16 Aug 2018
ABSTRACT
The recently reevaluated high prevalence of healthy carriers (1/2,000 in UK) of variant Creutzfeldt-Jakob Disease (v-CJD), whose blood might be infectious, suggests that the evolution of this prion disease might not be under full control as expected.
After experimental transfusion of macaques and conventional mice with blood derived from v-CJD exposed (human and animal) individuals, we confirmed in these both models the transmissibility of v-CJD, but we also observed unexpected neurological syndromes transmissible by transfusion: despite their prion etiology confirmed through transmission experiments, these original cases would escape classical prion diagnosis, notably in the absence of detectable abnormal PrP with current techniques.
It is noteworthy that macaques developed an original, yet undescribed myelopathic syndrome associating demyelination and pseudo-necrotic lesions of spinal cord, brainstem and optical tract without affecting encephalon, which is rather evocative of spinal cord disease than prion disease in human medicine.
These observations strongly suggest that the spectrum of human prion diseases may extend the current field restricted to the phenotypes associated to protease-resistant PrP, and may notably include spinal cord diseases.
KEYWORDS: (5-10): prion, vCJD, macaque, mouse, spinal cord disease, myelopathy, transfusion, abnormal PrP, demyelination, spongiform change
This article refers to:
Additional information
Funding
The original laboratory work was funded by European Commission [Fifth Framework Programme, QLK1-CT-2002-01096], French Research Funding Agency (Agence Nationale de la Recherche, ANR) [ANR-10-BLAN-1330 01], Health Canada [4500216567] and MacoPharma.
***> It is noteworthy that macaques developed an original, yet undescribed myelopathic syndrome associating demyelination and pseudo-necrotic lesions of spinal cord, brainstem and optical tract without affecting encephalon, which is rather evocative of spinal cord disease than prion disease in human medicine.
***> These observations strongly suggest that the spectrum of human prion diseases may extend the current field restricted to the phenotypes associated to protease-resistant PrP, and may notably include spinal cord diseases.
TUESDAY, AUGUST 7, 2018
Unexpected prion phenotypes in experimentally transfused animals: predictive models for humans?
MONDAY, NOVEMBER 06, 2017
Experimental transfusion of variant CJD-infected blood reveals previously uncharacterised prion disorder in mice and macaque
FRIDAY, OCTOBER 05, 2018
More Politicians and Very Young People Struck Down With Creutzfeldt Jakob Disease CJD mad cow type TSE Prion USA
Sunday, September 16, 2018
Mother to Offspring Transmission of TSE PRION DISEASE and risk factors there from
WEDNESDAY, SEPTEMBER 05, 2018
Edmonton woman one of the youngest diagnosed with CJD at 35 years old and pregnant
Volume 2: Science
4. The link between BSE and vCJD
4.29 The evidence discussed above that vCJD is caused by BSE seems overwhelming. Uncertainties exist about the cause of CJD in farmers, their wives and in several abattoir workers. It seems that farmers at least might be at higher risk than others in the general population. 1 Increased ascertainment (ie, increased identification of cases as a result of greater awareness of the condition) seems unlikely, as other groups exposed to risk, such as butchers and veterinarians, do not appear to have been affected.
***The CJD in farmers seems to be similar to other sporadic CJD in age of onset, in respect to glycosylation patterns, and in strain-typing in experimental mice.
***Some farmers are heterozygous for the methionine/valine variant at codon 129, and their lymphoreticular system (LRS) does not contain the high levels of PrPSc found in vCJD.
*** It remains a remote possibility that when older people contract CJD from BSE the resulting phenotype is like sporadic CJD and is distinct from the vCJD phenotype in younger people.
BSEINQUIRY
***>Some farmers are heterozygous for the methionine/valine variant at codon 129, and their lymphoreticular system (LRS) does not contain the high levels of PrPSc found in vCJD.<***
SATURDAY, JUNE 23, 2018
***> Diagnosis of Methionine/Valine Variant Creutzfeldt-Jakob Disease by Protein Misfolding Cyclic Amplification
Volume 24, Number 7—July 2018
2006-2007
HUMAN and ANIMAL TSE Classifications i.e. mad cow disease and the UKBSEnvCJD only theory
TSEs have been rampant in the USA for decades in many species, and they all have been rendered and fed back to animals for human/animal consumption. I propose that the current diagnostic criteria for human TSEs only enhances and helps the spreading of human TSE from the continued belief of the UKBSEnvCJD only theory in 2007. With all the science to date refuting it, to continue to validate this myth, will only spread this TSE agent through a multitude of potential routes and sources i.e. consumption, surgical, blood, medical, cosmetics etc. I propose as with Aguzzi, Asante, Collinge, Caughey, Deslys, Dormont, Gibbs, Ironside, Manuelidis, Marsh, et al and many more, that the world of TSE Transmissible Spongiform Encephalopathy is far from an exact science, but there is enough proven science to date that this myth should be put to rest once and for all, and that we move forward with a new classification for human and animal TSE that would properly identify the infected species, the source species, and then the route. This would further have to be broken down to strain of species and then the route of transmission would further have to be broken down. Accumulation and Transmission are key to the threshold from subclinical to clinical disease, and of that, I even believe that physical and or blunt trauma may play a role of onset of clinical symptoms in some cases, but key to all this, is to stop the amplification and transmission of this agent, the spreading of, no matter what strain. BUT, to continue with this myth that the U.K. strain of BSE one strain in cows, and the nv/v CJD, one strain in humans, and that all the rest of human TSE is one single strain i.e. sporadic CJD (when to date there are 6 different phenotypes of sCJD), and that no other animal TSE transmits to humans, to continue with this masquerade will only continue to spread, expose, and kill, who knows how many more in the years and decades to come. ONE was enough for me, My Mom, hvCJD, DOD 12/14/97 confirmed, which is nothing more than another mans name added to CJD, like CJD itself, Jakob and Creutzfeldt, or Gerstmann-Straussler-Scheinker syndrome, just another CJD or human TSE, named after another human. WE are only kidding ourselves with the current diagnostic criteria for human and animal TSE, especially differentiating between the nvCJD vs the sporadic CJD strains and then the GSS strains and also the FFI fatal familial insomnia strains or the ones that mimics one or the other of those TSE? Tissue infectivity and strain typing of the many variants of the human and animal TSEs are paramount in all variants of all TSE. There must be a proper classification that will differentiate between all these human TSE in order to do this. With the CDI and other more sensitive testing coming about, I only hope that my proposal will some day be taken seriously.
My name is Terry S. Singeltary Sr. and I am no scientist, no doctor and have no PhDs, but have been independently researching human and animal TSEs since the death of my Mother to the Heidenhain Variant of Creutzfeldt Jakob Disease on December 14, 1997 'confirmed'. ...END
Diagnosis and Reporting of Creutzfeldt-Jakob Disease
Singeltary, Sr et al. JAMA.2001; 285: 733-734. Vol. 285 No. 6, February 14, 2001 JAMA Diagnosis and Reporting of Creutzfeldt-Jakob Disease
To the Editor:
In their Research Letter, Dr Gibbons and colleagues1 reported that the annual US death rate due to Creutzfeldt-Jakob disease (CJD) has been stable since 1985. These estimates, however, are based only on reported cases, and do not include misdiagnosed or preclinical cases. It seems to me that misdiagnosis alone would drastically change these figures. An unknown number of persons with a diagnosis of Alzheimer disease in fact may have CJD, although only a small number of these patients receive the postmortem examination necessary to make this diagnosis. Furthermore, only a few states have made CJD reportable. Human and animal transmissible spongiform encephalopathies should be reportable nationwide and internationally.
Terry S. Singeltary, Sr Bacliff, Tex
1. Gibbons RV, Holman RC, Belay ED, Schonberger LB. Creutzfeldt-Jakob disease in the United States: 1979-1998. JAMA. 2000;284:2322-2323.
Diagnosis and Reporting of Creutzfeldt-Jakob Disease
Singeltary, Sr et al. JAMA.2001; 285: 733-734.
BRITISH MEDICAL JOURNAL
BMJ
U.S. Scientist should be concerned with a CJD epidemic in the U.S., as well...
02 January 2000
Terry S Singeltary
retired
US scientists develop a possible test for BSE
BMJ 1999; 319 doi: https://doi.org/10.1136/bmj.319.7220.1312b (Published 13 November 1999) Cite this as: BMJ 1999;319:1312
Rapid responses Response
Re: vCJD in the USA * BSE in U.S.
15 November 1999
Terry S Singeltary
NA
medically retired
January 28, 2003; 60 (2) VIEWS & REVIEWS
Monitoring the occurrence of emerging forms of Creutzfeldt-Jakob disease in the United States
Ermias D. Belay, Ryan A. Maddox, Pierluigi Gambetti, Lawrence B. Schonberger
First published January 28, 2003, DOI: https://doi.org/10.1212/01.WNL.0000036913.87823.D6
Abstract
Transmissible spongiform encephalopathies (TSEs) attracted increased attention in the mid-1980s because of the emergence among UK cattle of bovine spongiform encephalopathy (BSE), which has been shown to be transmitted to humans, causing a variant form of Creutzfeldt-Jakob disease (vCJD). The BSE outbreak has been reported in 19 European countries, Israel, and Japan, and human cases have so far been identified in four European countries, and more recently in a Canadian resident and a US resident who each lived in Britain during the BSE outbreak. To monitor the occurrence of emerging forms of CJD, such as vCJD, in the United States, the Centers for Disease Control and Prevention has been conducting surveillance for human TSEs through several mechanisms, including the establishment of the National Prion Disease Pathology Surveillance Center. Physicians are encouraged to maintain a high index of suspicion for vCJD and use the free services of the pathology center to assess the neuropathology of clinically diagnosed and suspected cases of CJD or other TSEs.
Received May 7, 2002. Accepted August 28, 2002.
RE-Monitoring the occurrence of emerging forms of Creutzfeldt-Jakob disease in the United States
Terry S. Singeltary, retired (medically)
Published March 26, 2003
26 March 2003
Terry S. Singeltary, retired (medically) CJD WATCH
I lost my mother to hvCJD (Heidenhain Variant CJD). I would like to comment on the CDC's attempts to monitor the occurrence of emerging forms of CJD. Asante, Collinge et al [1] have reported that BSE transmission to the 129-methionine genotype can lead to an alternate phenotype that is indistinguishable from type 2 PrPSc, the commonest sporadic CJD. However, CJD and all human TSEs are not reportable nationally. CJD and all human TSEs must be made reportable in every state and internationally. I hope that the CDC does not continue to expect us to still believe that the 85%+ of all CJD cases which are sporadic are all spontaneous, without route/source. We have many TSEs in the USA in both animal and man. CWD in deer/elk is spreading rapidly and CWD does transmit to mink, ferret, cattle, and squirrel monkey by intracerebral inoculation. With the known incubation periods in other TSEs, oral transmission studies of CWD may take much longer. Every victim/family of CJD/TSEs should be asked about route and source of this agent. To prolong this will only spread the agent and needlessly expose others. In light of the findings of Asante and Collinge et al, there should be drastic measures to safeguard the medical and surgical arena from sporadic CJDs and all human TSEs. I only ponder how many sporadic CJDs in the USA are type 2 PrPSc?
Reply to Singletary Ryan A. Maddox, MPH Other Contributors: Published March 26, 2003
Mr. Singletary raises several issues related to current Creutzfeldt- Jakob disease (CJD) surveillance activities. Although CJD is not a notifiable disease in most states, its unique characteristics, particularly its invariably fatal outcome within usually a year of onset, make routine mortality surveillance a useful surrogate for ongoing CJD surveillance.[1] In addition, because CJD is least accurately diagnosed early in the course of illness, notifiable-disease surveillance could be less accurate than, if not duplicative of, current mortality surveillance.[1] However, in states where making CJD officially notifiable would meaningfully facilitate the collection of data to monitor for variant CJD (vCJD) or other emerging prion diseases, CDC encourages the designation of CJD as a notifiable disease.[1] Moreover, CDC encourages physicians to report any diagnosed or suspected CJD cases that may be of special public health importance (e.g., vCJD, iatrogenic CJD, unusual CJD clusters).
As noted in our article, strong evidence is lacking for a causal link between chronic wasting disease (CWD) of deer and elk and human disease,[2] but only limited data seeking such evidence exist. Overall, the previously published case-control studies that have evaluated environmental sources of infection for sporadic CJD have not consistently identified strong evidence for a common risk factor.[3] However, the power of a case-control study to detect a rare cause of CJD is limited, particularly given the relatively small number of subjects generally involved and its long incubation period, which may last for decades. Because only a very small proportion of the US population has been exposed to CWD, a targeted surveillance and investigation of unusual cases or case clusters of prion diseases among persons at increased risk of exposure to CWD is a more efficient approach to detecting the possible transmission of CWD to humans. In collaboration with appropriate local and state health departments and the National Prion Disease Pathology Surveillance Center, CDC is facilitating or conducting such surveillance and case- investigations, including related laboratory studies to characterize CJD and CWD prions.
Mr. Singletary also expresses concern over a recent publication by Asante and colleagues indicating the possibility that some sporadic CJD cases may be attributable to bovine spongiform encephalopathy (BSE).[4] The authors reported that transgenic mice expressing human prion protein homozygous for methionine at codon 129, when inoculated with BSE prions, developed a molecular phenotype consistent with a subtype of sporadic CJD. Although the authors implied that BSE might cause a sporadic CJD-like illness among persons homozygous for methionine, the results of their research with mice do not necessarily directly apply to the transmission of BSE to humans. If BSE causes a sporadic CJD-like illness in humans, an increase in sporadic CJD cases would be expected to first occur in the United Kingdom, where the vast majority of vCJD cases have been reported. In the United Kingdom during 1997 through 2002, however, the overall average annual mortality rate for sporadic CJD was not elevated; it was about 1 case per million population per year. In addition, during this most recent 6-year period following the first published description of vCJD in 1996, there was no increasing trend in the reported annual number of UK sporadic CJD deaths.[3, 5] Furthermore, surveillance in the UK has shown no increase in the proportion of sporadic CJD cases that are homozygous for methionine (Will RG, National CJD Surveillance Unit, United Kingdom, 2003; personal communication).
References
1. Gibbons RV, Holman RC, Belay ED, Schonberger LB. Diagnosis and reporting of Creutzfeldt-Jakob disease. JAMA 2001;285:733-734.
2. Belay ED, Maddox RA, Gambetti P, Schonberger LB. Monitoring the occurrence of emerging forms of Creutzfeldt-Jakob disease in the United States. Neurology 2003;60:176-181.
3. Belay ED. Transmissible spongiform encephalopathies in humans. Annu Rev Microbiol 1999;53:283-314.
4. Asante EA, Linehan JM, Desbruslais M, et al. BSE prions propagate as either variant CJD-like or sporadic CJD-like prion strains in transgenic mice expressing human prion protein. EMBO J 2002;21:6358-6366.
5. The UK Creutzfeldt-Jakob Disease Surveillance Unit. CJD statistics. Available at: http://www.cjd.ed.ac.uk/figures.htm. Accessed February 18, 2003.
Competing Interests: None declared.
doi:10.1016/S1473-3099(03)00715-1 Copyright © 2003 Published by Elsevier Ltd. Newsdesk
Tracking spongiform encephalopathies in North America
Xavier Bosch
Available online 29 July 2003.
Volume 3, Issue 8, August 2003, Page 463
“My name is Terry S Singeltary Sr, and I live in Bacliff, Texas. I lost my mom to hvCJD (Heidenhain variant CJD) and have been searching for answers ever since. What I have found is that we have not been told the truth. CWD in deer and elk is a small portion of a much bigger problem.” ............................
FRIDAY, JUNE 29, 2018
Vaccines, TSE, Prion, risk factors?
***> see HISTORY great debate here <***
BSE, CJD, and Baby foods (the great debate 1999 to 2005)
SATURDAY, OCTOBER 06, 2018
Evaluation of iatrogenic risk of CJD transmission associated with corneal transplantation
SATURDAY, SEPTEMBER 22, 2018
Emerging Diseases, Infection Control & California Dental Practice Act
THURSDAY, OCTOBER 04, 2018
Case Western Reserve researchers to examine skin prions in fatal neurodegenerative disease $2.9 million NIH grant focuses on transmission and diagnostic testing
WEDNESDAY, JULY 04, 2018
CREUTZFELDT-JAKOB DISEASE: GUIDELINES FOR SOCIAL WORKERS IN ENGLAND June 2018
MONDAY, JUNE 18, 2018
Ecuador Six Case series of Creutzfeldt-Jakob disease in a third-level hospital in Quito
THURSDAY, OCTOBER 04, 2018
Cervid to human prion transmission 5R01NS088604-04 Update
WEDNESDAY, SEPTEMBER 26, 2018
JAVMA In Short Update USDA announces detection of atypical BSE
MONDAY, OCTOBER 01, 2018
Update on Classical and Atypical Scrapie in Sheep and Goats: Review 2018
HUMAN MAD COW DISEASE nvCJD TEXAS CASE NOT LINKED TO EUROPEAN TRAVEL CDC
Sunday, November 23, 2014
Confirmed Variant Creutzfeldt-Jakob Disease (variant CJD) Case in Texas
Updated: October 7, 2014
CDC and the Texas Department of State Health Services (DSHS) have completed the investigation of the recently reported fourth vCJD case in the United States. It confirmed that the case was in a US citizen born outside the Americas and indicated that the patient's exposure to the BSE/vCJD agent most likely occurred before he moved to the United States; the patient had resided in Kuwait, Russia and Lebanon. The completed investigation did not support the patient's having had extended travel to European countries, including the United Kingdom, or travel to Saudi Arabia. The specific overseas country where this patient’s infection occurred is less clear largely because the investigation did not definitely link him to a country where other known vCJD cases likely had been infected.
https://www.cdc.gov/ncidod/dvrd/vcjd/other/confirmed-case-in-texas.htm
https://vcjd.blogspot.com/2014/11/confirmed-variant-creutzfeldt-jakob.html
WEDNESDAY, SEPTEMBER 26, 2018
A new variant of Creutzfeldt-Jakob disease in the UK 1995 revisited 2018 a review of science
THURSDAY, OCTOBER 04, 2018
National Prion Disease Pathology Surveillance Center Cases Examined¹ (September 18, 2018)
THURSDAY, SEPTEMBER 27, 2018
Amydis Awarded Prion Disease Grant from NIH
TUESDAY, SEPTEMBER 4, 2018
USA CJD, BSE, SCRAPIE, CWD, TSE PRION END OF YEAR REPORTS September 4, 2018
prepare for the storm...
Tuesday, March 20, 2018
Variably protease-sensitive prionopathy (VPSPr), sporadic creutzfeldt jakob disease sCJD, the same disease, what if?
O3 Experimental studies on prion transmission barrier and TSE pathogenesis in large animals
Rosa Bolea(1), Acín C(1)Marín B(1), Hedman C(1), Raksa H(1), Barrio T(1), Otero A(1), LópezPérez O(1), Monleón E(1),Martín-Burriel(1), Monzón M(1), Garza MC(1), Filali H(1),Pitarch JL(1), Garcés M(1), Betancor M(1), GuijarroIM(1), GarcíaM(1), Moreno B(1),Vargas A(1), Vidal E(2), Pumarola M(2), Castilla J(3), Andréoletti O(4), Espinosa JC(5), Torres JM(5), Badiola JJ(1).
1Centro de Investigación en Encefalopatías y Enfermedades Transmisibles Emergentes, VeterinaryFaculty, Universidad de Zaragoza; Zaragoza,Spain.2 RTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB) 3 4 INRA, ÉcoleVétérinaire, Toulouse, France.5CIC bioGUNE, Prion researchlab, Derio, Spain CISA- INIA, Valdeolmos, Madrid 28130, Spain.
Experimental transmission of Transmissible Spongiform Encephalopathies (TSE) has been understood and related with several factors that could modify the natural development of these diseases. In fact, the behaviour of the natural disease does not match exactly in each animal, being modified by parameters such as the age at infection, the genotype, the breed or the causative strain. Moreover, different TSE strains can target different animal species or tissues, what complicate the prediction of its transmissibility when is tested in a different species of the origin source. The aim of the experimental studies in large animals is to homogenize all those factors, trying to minimize as much as possible variations between individuals. These effects can be flattened by experimental transmission in mice, in which a specific strain can be selected after several passages. With this objective, several experimental studies in large animals have been developed by the presenter research team.
Classical scrapie agent has been inoculated in cow, with the aim of demonstrate the resistance or susceptibility of this species to the first well known TSE; Atypical scrapie has been inoculated in sheep (using several routes of infection), cow and pig, with the objective of evaluating the potential pathogenicity of this strain; Classical Bovine Spongiform Encephalopathy (BSE) has been inoculated in goats aiming to demonstrate if the genetic background of this species could protect against this strain; goat BSE and sheep BSE have been inoculated in goats and pigs respectively to evaluate the effect of species barrier; and finally atypical BSE has been inoculated in cattle to assess the transmissibility properties of this newly introduced strain.
Once the experiments have been carried out on large animal species, a collection of samples from animals studied were inoculated in different types of tg mice overexpressing PrPcin order to study the infectivity of the tissues, and also were studied using PMCA.
In summary, the parameters that have been controlled are the species, the strain, the route of inoculation, the time at infection, the genotype, the age, and the environmental conditions.
To date,
***> eleven of the atypical scrapie intracerebrally inoculated sheep have succumbed to atypical scrapie disease;
***> six pigs to sheep BSE;
***> one cow to classical scrapie;
***> nine goats to goat BSE and
***> five goats to classical BSE.
***> PrPSC has been demonstrated in all cases by immunohistochemistry and western blot.
=====> PRION CONFERENCE 2018
WITH the recent findings that Scrapie will transmit to Macaque by or route, that Scrapie and CWD TSE Prion will transit to pigs orally, recent outbreak documented of TSE Prion Disease in Dromedary Camels, Algeria, atypical TSE Prion still being documented, and again just recently in the USA, of another atypical BSE case, and this discovery was only documented by testing 20k head of cattle from some 100M head of cattle in any given year in the USA, the continued denial that atypical BSE and atypical Scrapie are a transmissible disease (science has shown otherwise) this is concerning to me. Science and scientific policy makers have forgotten what Gibbs, Gajdusek, Hadlow, Alper, Zigas, even Gordon with the infamous Scrapie vaccine blunder, a discovery of valuable importance, and so many others i am failing to remember now, what some found long ago, like Dr. Gibbs, he tried to warn us about scrapie zoonosis potential, yet that went ignored for decades and decades. we/scientist/officials/the world, knows the USA FDA PART 589 TSE PRION FEED ban has failed terribly, the BSE testing has failed terribly, and the surveillance there from has failed, SRM removal breaches, all proven by the OIG or the GAO, and others. But yet, we find ourselves now debating the issue of these same risk factors for scrapie, the same risk factors that we all knew were there, with science staring us in the face, we still deny scientific facts all in the name of corporate interest. let's not continue to make these same mistakes. human and animal life is at stake here. we must remove corporate/government/lobbyist interest from the scientific policy making and regulations there from for the TSE Prion, all of them. ...Terry S. Singeltary SR.
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.
==============
https://prion2015.files.wordpress.com/2015/05/prion2015abstracts.pdf
***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.
http://www.tandfonline.com/doi/abs/10.1080/19336896.2016.1163048?journalCode=kprn20
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.
http://www.tandfonline.com/doi/abs/10.1080/19336896.2016.1163048?journalCode=kprn20
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.
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R. BRADLEY
https://web.archive.org/web/20170126051158/http://collections.europarchive.org/tna/20080102222950/http://www.bseinquiry.gov.uk/files/yb/1990/09/23001001.pdf
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.
http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=313160
***> 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.
Singeltary on Scrapie and human transmission way back, see;
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
BSE INQUIRY
1979
SILENCE ON CJD AND SCRAPIE
1980
SILENCE ON CJD AND SCRAPIE
*** 1981 NOVEMBER
1: J Infect Dis 1980 Aug;142(2):205-8
Oral transmission of kuru, Creutzfeldt-Jakob disease, and scrapie to nonhuman primates.
Gibbs CJ Jr, Amyx HL, Bacote A, Masters CL, Gajdusek DC.
Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of sheep and goats were transmitted to squirrel monkeys (Saimiri sciureus) that were exposed to the infectious agents only by their nonforced consumption of known infectious tissues. The asymptomatic incubation period in the one monkey exposed to the virus of kuru was 36 months; that in the two monkeys exposed to the virus of Creutzfeldt-Jakob disease was 23 and 27 months, respectively; and that in the two monkeys exposed to the virus of scrapie was 25 and 32 months, respectively. Careful physical examination of the buccal cavities of all of the monkeys failed to reveal signs or oral lesions. One additional monkey similarly exposed to kuru has remained asymptomatic during the 39 months that it has been under observation.
snip...
The successful transmission of kuru, Creutzfeldt-Jakob disease, and scrapie by natural feeding to squirrel monkeys that we have reported provides further grounds for concern that scrapie-infected meat may occasionally give rise in humans to Creutzfeldt-Jakob disease.
PMID: 6997404
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6997404&dopt=Abstract
12/10/76
AGRICULTURAL RESEARCH COUNCIL REPORT OF THE ADVISORY COMMITTE ON SCRAPIE
Office Note CHAIRMAN: PROFESSOR PETER WILDY
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A The Present Position with respect to Scrapie A] The Problem Scrapie is a natural disease of sheep and goats. It is a slow and inexorably progressive degenerative disorder of the nervous system and it ia fatal. It is enzootic in the United Kingdom but not in all countries. The field problem has been reviewed by a MAFF working group (ARC 35/77). It is difficult to assess the incidence in Britain for a variety of reasons but the disease causes serious financial loss; it is estimated that it cost Swaledale breeders alone $l.7 M during the five years 1971-1975. A further inestimable loss arises from the closure of certain export markets, in particular those of the United States, to British sheep. It is clear that scrapie in sheep is important commercially and for that reason alone effective measures to control it should be devised as quickly as possible. Recently the question has again been brought up as to whether scrapie is transmissible to man. This has followed reports that the disease has been transmitted to primates.
One particularly lurid speculation (Gajdusek 1977) conjectures that the agents of scrapie, kuru, Creutzfeldt-Jakob disease and transmissible encephalopathy of mink are varieties of a single "virus". The U.S. Department of Agriculture concluded that it could "no longer justify or permit scrapie-blood line and scrapie-exposed sheep and goats to be processed for human or animal food at slaughter or rendering plants" (ARC 84/77)" The problem is emphasised by the finding that some strains of scrapie produce lesions identical to the once which characterise the human dementias" Whether true or not. the hypothesis that these agents might be transmissible to man raises two considerations. First, the safety of laboratory personnel requires prompt attention. Second, action such as the "scorched meat" policy of USDA makes the solution of the acrapie problem urgent if the sheep industry is not to suffer grievously.
snip...
76/10.12/4.6
Nature. 1972 Mar 10;236(5341):73-4.
Transmission of scrapie to the cynomolgus monkey (Macaca fascicularis).
Gibbs CJ Jr, Gajdusek DC. Nature 236, 73 - 74 (10 March 1972); doi:10.1038/236073a0
Transmission of Scrapie to the Cynomolgus Monkey (Macaca fascicularis)
C. J. GIBBS jun. & D. C. GAJDUSEK National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland
SCRAPIE has been transmitted to the cynomolgus, or crab-eating, monkey (Macaca fascicularis) with an incubation period of more than 5 yr from the time of intracerebral inoculation of scrapie-infected mouse brain. The animal developed a chronic central nervous system degeneration, with ataxia, tremor and myoclonus with associated severe scrapie-like pathology of intensive astroglial hypertrophy and proliferation, neuronal vacuolation and status spongiosus of grey matter. The strain of scrapie virus used was the eighth passage in Swiss mice (NIH) of a Compton strain of scrapie obtained as ninth intracerebral passage of the agent in goat brain, from Dr R. L. Chandler (ARC, Compton, Berkshire).
Nature. 1972 Mar 10;236(5341):73-4.
Transmission of scrapie to the cynomolgus monkey (Macaca fascicularis).
Gibbs CJ Jr, Gajdusek DC. Nature 236, 73 - 74 (10 March 1972); doi:10.1038/236073a0
Transmission of Scrapie to the Cynomolgus Monkey (Macaca fascicularis)
C. J. GIBBS jun. & D. C. GAJDUSEK National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland
SCRAPIE has been transmitted to the cynomolgus, or crab-eating, monkey (Macaca fascicularis) with an incubation period of more than 5 yr from the time of intracerebral inoculation of scrapie-infected mouse brain. The animal developed a chronic central nervous system degeneration, with ataxia, tremor and myoclonus with associated severe scrapie-like pathology of intensive astroglial hypertrophy and proliferation, neuronal vacuolation and status spongiosus of grey matter. The strain of scrapie virus used was the eighth passage in Swiss mice (NIH) of a Compton strain of scrapie obtained as ninth intracerebral passage of the agent in goat brain, from Dr R. L. Chandler (ARC, Compton, Berkshire).
why do we not want to do TSE transmission studies on chimpanzees $
IN CONFIDENCE
TRANSMISSION TO CHIMPANZEES
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5. A positive result from a chimpanzee challenged severely 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
full text ;
RB3.20
IN CONFIDENCE
TRANSMISSION TO CHIMPANZEE
1. Kuru and CJD have been successfully transmitted to chimpanzees but scrapie and TME have not.
2. We cannot say that scrapie will not transmit to chimpanzees. There are several scrapie strains and I am not aware that all have been tried (that would have to be from mouse passaged material). Nor has a wide enough range of field isolates subsequently strain typed in mice been inoculated by the appropriate routes (i/c, i/p and i v);
3. I believe the proposed experiment to determine transmissibility, if conducted, would only show the susceptibility or resistance of the chimpanzee to infection/disease by the routes used and the result could not be interpreted for the predictability of the susceptibility for man. Proposals for prolonged oral exposure of chimpanzees to milk from cattle were suggested a long while ago and rejected.
4. In view of Dr Gibbs‘ probable use of Chimpazees Mr Wells‘ comments (enclosed) are pertinent. I have yet to receive a direct communication from Dr Schellekers but before any collaboration or provision of material we should identify the Gibbs' proposals and objectives.
5. A positive result from a chimpanzee challenged severely 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.
A negative result would take a lifetime to determine but that would be a shorter period than might be available for human exposure and it would still not answer the question regarding mans' susceptibility. In the meantime no doubt the negativity would be used defensively. It would however be counterproductive if the experiment finally became positive- We may learn more about public reactions following next Monday‘s meeting. CVO (+ Mr. Wells’ comments)
Dr. T W A Little
Dr. B J Shreeve
R Bradley September 1990
90/9.23/1/1
Wednesday, February 16, 2011
IN CONFIDENCE
SCRAPIE TRANSMISSION TO CHIMPANZEES
IN CONFIDENCE
Terry S. Singeltary Sr.
posted by Terry S. Singeltary Sr. at
11:49 AM
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