Working Document on Camel Prion Disease (CPrD) 14/09/2020
Content: I. Introduction II. Camel prion disease III. Case definition IV. Epidemiological surveillance V. Biosafety VI. Capacity building VII. Early warning and response VIII. Risk factors IX. Knowledge Gaps X. References
I. Introduction
Camel prion disease (CPrD) is the last disease described in the family of prion diseases [1]. To date, it has been recognized only in Middle East of Algeria and in the neighboring region of Tunisia [2]. However, there are no known other initiatives of prion diseases surveillance in camels worldwide. CPrD might actually be limited to the already known geographic area in North Africa or spread undetected in other Countries, as a consequence of the movements of dromedaries along trans-Saharan commercial routes, the import/export trade flows of living animals and the traditional extensive and nomadic rearing systems.
According to the discussions in recent meetings of REMESA and OIE which indicated the need to extend the knowledge on CPrD spread in Countries where camels are extensively reared and considered as a part of the domestic livestock [3], and according to the initiative from CAMENET member countries to assess the risk in the CAMENET region, this working document aims to provide countries with the main technical and scientific knowledge necessary to implement surveillance programs on camel prion disease in its own territory. Basic information contained in this document may also be helpful for the possible design of contingency plans.
The present working document is an 'alive' document. It should be regularly reviewed and updated as further information becomes available.
II. Camel prion disease1
Camel prion disease (CPrD) was diagnosed in 2018 in three adult camels showing clinical signs at the ante-mortem inspection at an abattoir in the region of Ouargla (Algeria) [1]. According to the published report symptoms suggesting prion disease occurred in 3.1% of dromedaries brought for slaughter to the Ouargla abattoir in 2015–2016. More recently, in 2019, the same disease was reported in the region of Tataouine (Tunisia) [2]. CPrD adds to the group of animal prion diseases,
1 Modified from the OIE Bulletin: https://oiebulletin.com/wp-content/uploads/2019/12/OIE-NewsDecember-2019-Camel-priondisease.pdf?utm_source=World+Organisation+for+Animal+Health+%E2%80%93+OIE+Bulletin&utm_c ampaign=388d499799- EMAIL_CAMPAIGN_2019_12_05_09_06&utm_medium=email&utm_term=0_7694a173d1- 388d499799-54758659
including scrapie in sheep and goats, chronic wasting disease (CWD) in cervids and Bovine spongiform encephalopathy (BSE) in cattle. As of today, very limited epidemiological information is available about the prevalence, geographical distribution and mode of transmission of the disease.
The involvement of lymphoid tissue in prion replication, observed both in the Algerian and Tunisian cases [1,2], is suggestive of a peripheral pathogenesis, which is thought to be a prerequisite for prion shedding into the environment. As with other animal prion diseases, such as scrapie and CWD, in which lymphoid tissues are extensively involved and horizontal transmission occurs efficiently under natural conditions, the detection of prion proteins in lymph nodes is suggestive of the infectious nature of CPrD and concurs to hypothesize the potential impact of CPrD on animal health. No evidence is currently available with which to argue for the relevance of CPrD for human health. However, no absolute species barrier exists in prion diseases and minimizing the exposure of humans to prion-infected animal products is an essential aspect of public health protection.
The worldwide camel population is ~35 million head, 88% of which is found in Africa [4]. The camel farming system is evolving rapidly, and these animals represent vital sources of meat, milk and transportation for millions of people living in the most arid regions of the world. This makes it necessary to assess the risk for animal and human health and to develop evidence-based policies to control and limit the spread of the disease in animals, and to minimize human exposure. As a first step, the awareness of Veterinary Services about CPrD and its diagnostic capacity needs to be improved in all countries where dromedaries are part of the domestic livestock.
Since the first description of CPrD, the OIE promoted discussions on the impact of this new disease through the OIE Scientific Commission for Animal Diseases (Scientific Commission). It evaluated if CPrD should be considered an ‘emerging disease’ based on the criteria listed in the Terrestrial Animal Health Code. The OIE Scientific Commission noted that limited surveillance data were available on the prevalence of CPrD and that the evidence was not enough to measure, at that time, the impact of the disease on animal or public health. Therefore, it was concluded that, with the current knowledge, CPrD did not currently meet the criteria to be considered an emerging disease.
Nonetheless, it was emphasized that CPrD should be considered as a new disease not to be overlooked and called for the collection of further scientific evidence through research and surveillance in the affected countries and in countries with dromedary camel populations to measure the impact of the disease. As new scientific evidence becomes available, the OIE Scientific Commission will reassess whether this disease should be considered as an emerging disease. At the regional level, CPrD was first discussed in the 18th Joint Permanent Committee of the Mediterranean Animal Health Network (REMESA) held in Cairo, Egypt, in June 2019 and at the 15th Conference of the OIE Regional Commission for the Middle East in November. During this conference, the CAMENET launched a wide-ranging proposal for training, coordinated surveillance and research on CPrD. In addition, the ERFAN (Enhancing Research for Africa Network), a platform aimed at enhancing scientific cooperation between Africa and Italy, during its 2nd ERFAN meeting for North Africa, presented a project on CPrD with the objective of increasing CPrD coordinated surveillance in North Africa.
The OIE, through its Reference Laboratories for prion diseases, and by involving the above scientific initiatives, is keeping a close watch on the evolution of the disease to gather scientific evidence and to allow a proper and more thorough assessment of the risk associated with this novel disease.
III. Case definition
Clinical criteria
The clinical manifestations of CPrD cases from Algeria included weight loss, behavioral abnormalities and neurologic symptoms, such as tremors, aggressiveness, hyper excitability, abnormal and excessive movement of the neck and head, hesitant and uncertain gait, ataxia of the hind limbs, occasional falls, and difficulty getting up as the disease progresses.
As of today, in Algeria, CPrD has been reported in animals over 9 years of age [1]. However, two CPrD-affected animals aging 3 years have been recently diagnosed from Tunisia [Agrimi, personal communication].
Therefore, animals of ≥3 years of age, with abnormal behavior and neurological symptoms, in which rabies and other diseases causing neurological symptoms have been ruled out, should be considered as clinically suspects.
Laboratory criteria
Although the vacuolation of neurons and neutrophil (spongiform degeneration) is frequently detected, it is not an obligatory neuropathologic feature of prion disease. The presence of astrogliosis and micro-gliosis, although not specific histologic alteration to the prion diseases, are more constantly seen. The lack of a lymphocytic inflammatory response is also an important characteristic. In the CPrD cases studied to date spongiosis is faint. Therefore, CPrD diagnosis cannot rely purely on histopathology, but PrPSc detection in the brain is crucial for a proper diagnostic assessment [5]. The detection of disease specific PrP (PrPSc) is obtained by means of:
− Western blot
− Immunohistochemistry
In addition to the detection of PrPSc by immunohistochemistry (IHC) and Western blot, the socalled "rapid tests", mainly based on the ELISA technique, have been developed and extensively used in Europe for the surveillance of prion diseases in cattle and small ruminants. Rapid tests are used as screening approaches in active surveillance and usually require confirmation of positive samples by confirmatory Western blot or IHC [5].
Epidemiological criteria
Epidemiological criteria to be considered include: i) reporting in the area of neurological signs in camels for which diagnostic investigations for other diseases causing nervous symptoms were negative or inconclusive; ii) import of camels from areas where CPrD cases have been reported. Case classification It is still early for a formal case classification of CPrD. Nevertheless, a preliminary classification is required for the time being and can be refined gradually as knowledges progress.
1. Possible case: any dromedary of ≥3 years of age with one of the following clinical signs:
a. Behavioral abnormalities including aggressiveness and tendency to kick and bite
b. Nervous signs such as tremors and hyper excitability
c. Abnormal and excessive movement of the neck and head, hesitant and uncertain gait, ataxia of the hind limbs.
d. Downer camels, defined as any animal of ≥3 years of age that is recumbent, lying down on chest or side and unable to get up or stand unassisted. There are many possible reasons for an animal staying down. However, diagnostic investigations for prion diseases in downer cattle represented a crucial step of BSE surveillance in Europe. The relevance of downers animals for CPrD surveillance is not known, but it deserves to be investigated.
2. Probable case: any camel of ≥3 years of age, meeting the clinical criteria and with epidemiological link to a known infected area.
3. Confirmed case: any camel meeting the laboratory criteria for case confirmation, whether it fulfils the clinical criteria or not.
IV. Epidemiological surveillance
Different types of surveillance do exist. Regular reporting of disease cases by competent authorities is called passive surveillance. It involves passive notification by surveillance sites and there is no active search for cases. Active Surveillance occurs when competent authorities proactively look for disease cases.
The type of surveillance for a particular disease depends on the attributes of that disease (e.g. risk for animals and humans) and the objectives of the surveillance.
Until 1999, BSE surveillance in Europe was limited to the notification of clinically suspected cases by farmers and veterinarians to the veterinary authorities (passive surveillance). However, because passive surveillance relies solely on the reporting of clinical suspects and is dependent on many factors, including perceived consequences on the farm and diagnostic competence, it is not necessarily consistent or reliable. In Europe, underreporting has been an important constraint in the passive surveillance of BSE. To optimize the identification of positive animals, improve the surveillance data and increase the consumers' confidence, those populations of cattle that were identified as at increased risk of having BSE were actively targeted within national surveillance systems. In Europe, the population of all healthy slaughtered cattle over 18 months of age were submitted, for several years, to active surveillance by diagnostic rapid tests.
Although active surveillance on healthy slaughtered animals is able to increase the sensitivity of surveillance and to provide a more complete estimate of disease frequency, it is costlier and more labor intensive. In the context of CAMENET Countries, its implementation can be possibly considered, if needed, as a further step.
In the framework of the present program, CPrD surveillance should be targeted to:
1. suspected cases found at farms, pastures or slaughterhouses
2. animals "at risk" of ≥3 years of age, such as:
✓ fallen stock which have died or been killed, not in the framework of an epidemic
✓ emergency slaughtered animals, downer dromedaries.
V. Biosafety
In prion-affected animals, the highest concentration of prions is found in the central nervous system (CNS), therefore caution must be exerted when handling CNS samples. In BSE-affected cattle, more than 90% prion infectivity is found in the CNS, while in scrapie and CWD, prions are spread in the cerebrospinal fluid, spleen/lymph nodes, lung, liver, kidney, placenta, etc. [6]. Preliminary results in CPrD show that, beside the CNS, prions are detected also in lymphoid tissue [1].
Depending on the country, animal prions are classified in the risk class 2 or 3, with scrapie always included in class 2 and BSE in 2/3 or 3 [6,7]. Prions are normally, not transmitted via respiratory route [7].
Risk assessment is required to work with prions and biosafety protocols need to be developed for both laboratory work and sampling activity in the field.
The main risks are wounds from cutting, inoculation or accidental ingestion. Personal protective equipment and ad hoc procedures need to be developed to minimize these risks. Prions are resistant to chemicals and procedures traditionally used for decontaminating classical infectious agents. They are very resistant to chemical and physical agents and are very persistent in contaminated environments [7].
Therefore, working area for prions should be separated from other activities and frequently decontaminated. Cleaning and decontamination procedures of equipment and work surfaces, as well as waste management, take on strategic importance in protecting workers' health and the environment [7].
The absence of a complete and formally certifiable decontamination procedure due to the unavailability of analytical methods capable of detecting traces of the agent in the work environment, makes incineration still the safest method for the elimination of prion-contaminated material. Where possible, therefore, disposable materials should be used, disposed of by incineration. Instruments and other material should be dedicated to prions and left in the prion area
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[7]. As for non-disposable materials, such as laboratory equipment, refrigerators, computers, these should be dedicated and appropriately and necessarily decontaminated through the use of NaOH, NaClO or autoclaving at high temperatures, before being disposed of. Decontamination protocols suggest using solutions of NaOH 2N or NaClO with 20.000 ppm of active chlorine for the decontamination of laboratory surfaces, instruments, etc. Alternatively, heat-resistant materials can be submitted to autoclave with gravity replacement or steam input at 134 ° C for at least 30 min [8] (Table. 1).
Equipment
1. Immerse the equipment in a solution of 1N NaOH (40 g per liter of water) or NaClO with 20,000 ppm of free chlorine for at least one hour; remove the equipment from the solution and put them in gravity replacement or steam injection autoclave at 134 °C for at least 30 min.
2. Immerse the equipment in a solution of 2N NaOH or NaClO with 20,000 ppm of free chlorine for at least one hour. Wash the equipment thoroughly in water. Surfaces (lab benches, hoods, etc.)
Use 2 N NaOH solution (80 grams per liter of water) for at least one hour or, alternatively, NaClO solution with 20,000 ppm of free chlorine for at least one hour. It is always advisable to protect the surfaces with absorbent and waterproof material as a precaution to limit contamination.
Histological preparations
The tissues to be used for histological examination are decontaminated by immersing them in 96% formic acid for 1 h. This precaution reduces the risk of infection resulting from accidents during microtome cutting procedures.
Table 1. Decontamination procedures for instruments (in decreasing order of efficiency), surfaces and samples for histology.
VI. Capacity building
In the present context, capacity building is addressed to build and strengthen organizational and technical capacities for laboratory staff and field veterinarians, in its own role, to recognize CPrD, take part in surveillance activities and carry out laboratory diagnosis. At the same time, personnel from Competent Authorities can acquire basic information and knowledge for the design and implementation of possible contingency plans.
Training is a crucial component of capacity building. It aims at:
- improving the capacity of field Veterinarians to identify CPrD suspect cases
- building and strengthening the capacity of laboratory diagnosis of CPrD
- providing National Veterinary Services basic knowledge for risk analysis, early warning and contingency plans development
- providing practical experience on laboratory methods for the diagnosis and investigation of CPrD
Training programs can be done in-country or in a reference laboratory such as ISS and/or IZSPLVD. Training consists of two components:
Training programmes will include:
1) Courses for field veterinarians, laboratory staff and veterinary services personnel
a) Prion diseases of humans and animals
- Basic concepts on prions and prion diseases of humans and animals: nature of the causative agents, pathogenesis, risk for humans and animals
- Epidemiology and surveillance of animal prion diseases
- Diagnosis of animal prion diseases
- Biosafety guidelines to protect both the personnel and the environment (biocontainment)
b) Camel Prion Disease
- Clinical diagnosis of CPrD and recognition of suspected cases
- Surveillance
- Sampling at post-mortem in slaughterhouses, incinerator facility, farm or other collection site, storage and transport to the lab
- Data collection by using standardized forms
- Audiovisual aids for CPrD
- Communication protocols
2) Courses for laboratory staff
- Laboratory methods and techniques for CPrD diagnosis and research (OIE-approved methods, rapid tests and others)
- Characterization of prion strains: laboratory techniques and interpretation of results
- Analysis of the PrP gene (PRNP)* [1,9]
- Laboratory equipment
- Biosafety and biocontainment procedures under laboratory conditions
VII. Early warning and response
Due to its geographical location, the Middle East is under risk of transboundary animal diseases from Africa and Asia. No information is available on CPrD in the region but the presence of camels and their import from neighboring countries suggest extending the knowledge on CPrD spread also in this geographic area.
Based on the current limited knowledge, CPrD does not meet the OIE criteria to be considered an emerging disease. However, the suspect of its transmissibility under field conditions makes emergency preparedness and contingency planning important tools for its control, in case CPrD is found.
In the present context, only the basic principles of early warning and response planning for CPrD are provided.
Emergency preparedness planning for emergency diseases introduction is comprised of two main components: 1) early warning and 2) early response [10].
* Sequence analyses in prion diseases cannot be applied for diagnosis since prions are devoid of nucleic acid. However, PrP sequence analysis is important because in sheep, goat and deer, PRNP polymorphisms have a strong influence on prion susceptibility/resistance.
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1. Early warning.
It includes all actions (disease surveillance, reporting and epidemiological analysis) aimed at the rapid detection and assessment of the introduction of the disease. In particular, an effective early warning system should comprise:
- updated diagnostic capacities
- effective surveillance systems
- access to and analysis of real-time data
- efficient epidemiological support
- efficient and multidirectional reporting systems
- suitable and efficient organization of the various components of the system
2. Early response.
It comprises the effective and rapid implementation of all measures needed to contain the outbreak and to eliminate it progressively. This goal is achieved through the development of national contingency plans. These include:
- national coordination - Strategical operation plan with an effective control center, well identified key roles and efficient/effective communication
- risk assessment - assessing the risk associated with importation and spread of the disease
- efficient access to and analysis of continuously updated data
- communicating with veterinary and food sector services as well as with public health sector (if public health issues arise)
- when capacity building is not available at national level, a regional capacity-sharing system should be established
- animal health management and public health management (if needed) - Involvement and participation of all stakeholders, including breeders’ associations. Information and education are crucial
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- public information and the media - Providing a transparent information and establishing a strong emergency response system is key in improving the confidence and reassurance of public
- rapid and efficient communicating with OIE and international organizations also for possible foreign technical and economic support.
VIII. Risk Factors
Prion diseases present in animals with different origins:
- as putatively spontaneous diseases, such as atypical/Nor98 scrapie of sheep and goats and in atypical BSE (in its L-type and H-type forms)
- as infectious, but not contagious diseases, such as classical BSE, where the disease is only transmitted via infected feedstuff and cattle behave as dead-end hosts being not able to transmit the disease to healthy animals
- as infectious and contagious disease, such as scrapie or CWD, where the disease spreads from infected to healthy animals in the flock.
Our limited knowledge on CPrD prevents to definitely classify this new disease into the previous categories. However, the involvement of lymphoid tissue observed in the first cases is suggestive of the infectious and contagious nature of the disease.
No information is available about possible relationship between CPrD and other animal prion diseases. Although the origin of CPrD from another prion disease cannot be ruled out, as of today, the presence of other prion diseases is not considered a risk factor for CPrD.
No information is available about the distribution of infectivity in tissues of CPrD-affected animals. Although the detection of PrPSc in the nervous system and lymphoid tissue is reminiscent of what is usually seen in sheep scrapie, no conclusion can be drown at this stage about the risk of CPrD-affected animals.
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Given the limitless of current knowledge, the following list of risk factors for CPrD should be only regarded as indicative and needed to be updated and refined as knowledges progress.
1. Potential import risk factors
a. Import of dromedaries from infected areas.
b. Incursion of free-ranging infected dromedaries through permeable country borders.
c. Import of dromedaries’ products, included meat and bone meal produced with dromedaries' offals, from infected areas.
d. Potential incursion of disease by importation of contaminated camels feed with meat and bone meal produced with dromedaries' offals.
2. Potential risk factors within the country
e. Presence of camels (susceptible animals).
f. Absence of an effective surveillance system for prion diseases
g. Type of production system:
✓ extensive breeding systems with different dromedary herds sharing common pastures and limited effectiveness of surveillance
✓ nomadic movements of animals along distances with limited effectiveness of surveillance
✓ intensive breeding system with the use of processed camel proteins in feedstuff
h. Processing of camel's offal for the production of animal by products
i. Absence of animal identification and traceability systems.
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Potential risk factors for humans
To date, no information is available on the risk of CPrD for humans.
Given the limited knowledge of the molecular basis of the "barrier" existing in the transmission of prion diseases between different species, measures have been adopted in Europe to minimize the exposure of humans to any prion diseases.
Therefore, the consumption of central nervous system and lymphoid tissue from CPrD-infected camels should be avoided as precautionary measure.
IX. Knowledge gaps
Multiple areas of understanding and knowledge of CPrD need to be investigated to fill the many existing gaps. Among the others:
- Origin of CPrD - Is CPrD a newly emerged disease or it is a long existing but unrecognized disease of dromedaries?
- Geographic distribution of CPrD.
- CPrD strain characterization - Does CPrD have any relationship with other animal prion diseases? Similarities and differences with other animal prion strains.
- Is CPrD sporadic or infectious? This is of relevance for animal health and strongly affects the control measures.
- Pathogenesis and prion/infectivity distribution in dromedary tissues - This is of relevance for animal and human risk.
- Risk for other camelids and other animal species
- Risk for humans
- CPrD epidemiology and risk factors
- Others
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X. References
1. Babelhadj B, Di Bari MA, Pirisinu L, Chiappini B, Gaouar SBS, Riccardi G, Marcon S, Agrimi U, Nonno R, Vaccari G. Prion Disease in Dromedary Camels, Algeria. Emerging Infectious Diseases. Vol. 24, No. 6, June 2018
2. OIE Representation in Africa - News: "June 2019 - 18th meeting of the REMESA Joint Permanent Committee in Egypt (Cairo) [abridged, edited] http://www.rrafrica.oie.int/en/news/20190627.html
3. World Organization for Animal Health. OIE Bulletin, December, 2019. https://oiebulletin.com/wp-content/uploads/2019/12/OIE-News-December-2019-Camelpriondisease.pdf?utm_source=World+Organisation+for+Animal+Health+%E2%80%93+OIE+Bu lletin&utm_campaign=388d499799- EMAIL_CAMPAIGN_2019_12_05_09_06&utm_medium=email&utm_term=0_7694a173d 1-388d499799-54758659
4. Food and Agriculture Organization of the United Nations. Live animals [cited 2017 Nov 10]. http://www.fao.org/faostat/en/#data/QA
5. Bovine Spongiform encephalopathy, Chapter 3.4.5, OIE Manual of Diagnostic Tests and Vaccines for Terrestrial Animals. Updated 2016
6. World Health Organization (2010). Tables on Tissue Infectivity Distribution in Transmissible Spongiform Encephalopathies. WHO/EMP/QSM/2010.
7. Health and Safety Executive (HSE) Advisory Committee on Dangerous Pathogens. The Approved List of Biological Agents. 2013 Edition available via http://www.hse.gov.uk/pubns/misc208.pdf
8. Leunda A, Van Vaerenbergh B, Baldo A, Roels S, Herman P (2013) Laboratory activities involving transmissible spongiform encephalopathy causing agents. Risk assessment and biosafety recommendations in Belgium. Prion 7:5, 420–433.
9. Kaluz S, Kaluzova M, Flint AP. Sequencing analysis of prion genes from red deer and camel. Gene. 1997; 199:283–6.
10. Sinan Aktas. Emergency preparedness: formulation and implementation of animal health contingency plans in the Middle East. World Organization for Animal Health. https://www.oie.int/doc/ged/D2963.PDF
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List of contributors: ADAFSA, UAE ISS, Italy IZSPLVA, Italy Salama Almuhairi Abdelamlik Khalafalla Mohamed Alhosani Oum Kalthoum Bensalah Hassan Zakaria Umberto Agrimi Gabriele Vaccari Michele Di Bari Romolo Nonno Laura Pirisinu Barbara Chiappini Ilaria Vanni Claudia D'Agostino Cristina Casalone Giuseppe Ru
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''Since the first description of CPrD, the OIE promoted discussions on the impact of this new disease through the OIE Scientific Commission for Animal Diseases (Scientific Commission). It evaluated if CPrD should be considered an ‘emerging disease’ based on the criteria listed in the Terrestrial Animal Health Code. The OIE Scientific Commission noted that limited surveillance data were available on the prevalence of CPrD and that the evidence was not enough to measure, at that time, the impact of the disease on animal or public health. Therefore, it was concluded that, with the current knowledge, CPrD did not currently meet the criteria to be considered an emerging disease.''
***> SEEMS TO ME that the OIE et al likes to wait until a terrible animal disease is well established, spread around the world, and at the brink of being discovered and documented as a zoonosis disease before considering it a zoonosis zoonotic disease, before considering it a emerging disease. damn shame, and we will address that at the bottom of this report..terry
Monday, September 14, 2020
Assessing the aggregated probability of entry of a novel prion disease agent into the United Kingdom
■ The prevalence of CPD in camels in the region of interest - 3.1% (based on Babelhadj et al. (2018))
■ The incidence and prevalence of CPD in camel products, derived from:
MONDAY, NOVEMBER 30, 2020
REPORT OF THE MEETING OF THE OIE SCIENTIFIC COMMISSION FOR ANIMAL DISEASES Paris, 9–13 September 2019 BSE, TSE, PRION
10.2. Prion disease in dromedary camels
The Commission was informed that, in May 2019, the OIE received an immediate notification from Tunisia of a case of camel prion disease (CPD) as an emerging disease. The OIE did not publish the immediate notification in accordance with the Commission recommendation of February 2019 that more evidence should be collected to assess whether this disease should be considered as an emerging disease as defined in the Glossary of the Terrestrial Code.
The Commission noted that Tunisia has become the second country after Algeria to detect a case of CPD within a year. After analysing the information available, the Commission was concerned about the limited surveillance information on the disease to make an assessment on the need to consider it as an emerging disease. However, the Commission reiterated its position that CPD should be considered as a new disease and should not be overlooked. The Commission encouraged Member Countries to gather surveillance and research information on this disease in countries with important dromedary camel populations to measure the impact of the disease, and to provide new scientific evidence to the Commission, when it becomes available, to reassess CPD as an emerging disease.
Scientific Commission/September 2019 15
The Commission was informed that CAMENET is drafting a preparedness and response plan, including epidemiological surveillance for CPD, that would be discussed with CAMENET members during the Conference of the OIE Regional Commission in the Middle East to be held in Abu Dhabi, United Arab Emirates, in November 2019. The purpose of the preparedness and response plan will be to assist countries in prevention, early detection and timely response to the disease and facilitate countries being well prepared for this threat.
Camel prion disease: a possible emerging disease in dromedary camel populations?
The identification of a new prion disease in dromedary camels in Algeria and Tunisia, called camel prion disease (CPD), extends the spectrum of animal species naturally susceptible to prion diseases and opens up new research areas for investigation.
Camel prion disease was identified in 2018 in adult camels showing clinical signs at the ante mortem inspection at slaughterhouses in the region of Ouargla (Algeria), and in 2019 in the region of Tataouine (Tunisia). It adds to the group of existing animal prion diseases, including scrapie in sheep and goats, chronic wasting disease (CWD) in cervids and BSE (mainly in bovines). The detection of a new prion disease in the dromedary population requires attention and investigation needs to be carried out to assess the risks of this disease to animal and public health. As of today, very limited epidemiological information is available to assess the prevalence, geographical distribution and dynamic of the transmission of the disease.
Based on the clinical signs suggesting prion disease, CPD seems to have occurred in 3.1% of the dromedaries brought to the abattoir in Ouargla. Pathognomonic neurodegeneration and disease specific prion protein (PrPSc) were detected in brain tissue from three symptomatic animals (source: CDC article wwwnc.cdc.gov/eid/article/24/6/17-2007_article).
In May 2019, the OIE received a report from Tunisia on a single case of a 12-year-old slaughtered dromedary camel showing neurological signs confirmed as CPD by the Istituto Superiore di Sanità (ISS) based in Italy.
©B. Babelhadj/University Kasdi Merbah, Algeria www.oiebulletin.com 2
Is camel prion disease transmissible in natural conditions?
The involvement of lymphoid tissue in prion replication, observed both in the Algeria and Tunisia cases, is suggestive of a peripheral pathogenesis, which is thought to be a prerequisite for prion shedding into the environment. As with other animal prion diseases, such as scrapie and CWD, in which lymphoid tissues are extensively involved and horizontal transmission occurs efficiently under natural conditions, the detection of prion proteins in lymph nodes is suggestive of the infectious nature of CPD and concurs to hypothesise the potential impact of CPD on animal health. No evidence is currently available with which to argue for the relevance of CPD for human health. However, no absolute species barrier exists in prion diseases and minimising the exposure of humans to prion-infected animal products is an essential aspect of public health protection. As for the relationship between CPD and other animal prion diseases, preliminary analyses suggest that CPD prions have a different molecular signature from scrapie and BSE.
Actions on the follow up of CPD
Since the first description of CPD, the OIE promoted discussions on the impact of this new disease through the OIE Scientific Commission for Animal Diseases (Scientific Commission). The Scientific Commission consulted two OIE ad hoc Groups, one on BSE risk status evaluation of Members and the other on camelids. It analysed the information available from the Algeria and Tunisia cases to evaluate if CPD should be considered an ‘emerging disease’ based on the criteria listed in the Terrestrial Animal Health Code1 . The OIE Scientific Commission noted that limited surveillance data were available on the prevalence of CPD and that the evidence was not sufficient to measure, at that time, the impact of the disease on animal or public health. Therefore, it was concluded that, with the current knowledge, CPD did not currently meet the criteria to be considered an emerging disease. Nonetheless, it was emphasised that CPD should be considered as a new disease not to be overlooked and called for the collection of further scientific evidence through research and surveillance in the affected countries and in countries with dromedary camel populations to measure the impact of the disease. As new scientific evidence becomes available, the OIE Scientific Commission will reassess whether this disease should be considered as an emerging disease.
The worldwide camel population is ~35 million head (FAO, 2019), 88% of which is found in Africa. The camel farming system is evolving rapidly, and these animals represent vital sources of meat, milk and transportation for millions of people living in the most arid regions of the world. This makes it necessary to assess the risk for animal and human health and to develop evidence-based policies to control and limit the spread of the disease in animals, and to minimise human exposure. As a first step, the awareness of Veterinary Services about CPD and its diagnostic capacity needs to be improved in all countries where dromedaries are part of the domestic livestock.
At the regional level, CPD was first discussed in the 18th Joint Permanent Committee of the Mediterranean Animal Health Network (REMESA) held in Cairo, Egypt, in June 2019 where an expert 1 a new occurrence in an animal of a disease, infection or infestation, causing a significant impact on animal or public health resulting from a) a change of a known pathogenic agent or its spread to a new geographic area or species, or b) a previously unrecognised pathogenic agent or disease diagnosed for the first time
www.oiebulletin.com 3
from ISS, Italy, shared the knowledge available on the new disease with the 15 REMESA Member Countries. The discussion highlighted the need to strengthen surveillance systems in order to collect epidemiological data to inform the risk assessments. The results of these risk assessments will support the implementation of evidence-based policies to manage the risks in both animals and humans. CPD was recently discussed at the 15th Conference of the OIE Regional Commission for the Middle East in November. During this conference, the CAMENET (Camel Middle East Network) launched a wide ranging proposal for training, coordinated surveillance and research on CPD. In addition, the ERFAN (Enhancing Research for Africa Network), a platform aimed at enhancing scientific cooperation between Africa and Italy, during its 2nd ERFAN meeting for North Africa, presented a project on CPD with the objective of increasing CPD coordinated surveillance in North Africa.
The OIE, through its Reference Laboratories for prion diseases, and by involving the above scientific initiatives, is keeping a close watch on the evolution of the disease to gather scientific evidence and to allow a proper and more thorough assessment of the risk associated with this novel disease.
◼ December 2019
15th Conference of the OIE Regional Commission for the Middle East
Abu Dhabi, United Arab Emirates, 10 to 14 November 2019
FINAL REPORT
snip...
Prion disease in dromedary camels:
a possible emerging risk for the Middle East?
24. Dr Salama Al Muhairi from the Veterinary Laboratories Division of the Abu Dhabi Agriculture and Food Safety Authority and Dr Umberto Agrimi from the Italian National Health Institute, gave a joint presentation providing the Regional Commission with general information on the CAMENET and its activities along with the state of the art in terms of the current knowledge and the missing information regarding prion disease in dromedary camels. They also provided the region with suggestions to address the gaps through research, including the support that CAMANET could provide to gather scientific evidences to allow a proper and better assessment of the risk associated to the disease. They also provided suggestions of activities that countries could start implementing to start addressing this issue.
25. The OIE Regional Commission for the Middle East noted that:
- Many information still missing regarding camel prion disease, tracking back its cause is very difficult, and it is almost impossible to figure out its origin. It is not even clear if its origin is linked to another prion animal disease. Its epidemiology is also unknown;
- Preliminary results suggest that the prion strain of the prion camel disease is different from scrapie and BSE;
- It is a problematic disease as so far there are no diagnostic or preclinical tests available, nor treatments;
- Member Countries must be careful when interpreting clinical signs alone as several diseases manifest through neurological symptoms;
- Considering the unknown contagious nature of the disease, Member Countries still need to be prepared to manage possible positive results and thus, it is key to start working on developing a formal contingency plan, clearly detailing the procedures to be followed if facing an outbreak;
- A proposal of working document was provided by CAMENET to address the main areas of support such as: research, surveillance, capacity building and preparedness, as well as risk assessment;
- Italy through the European Reference Laboratory and the OIE Reference Laboratory for prion diseases are ready to collaborate with CAMENET to better support countries.
2.4. Camel prion disease
Gabriele Vaccari (Istituto Superiore di Sanità. Department of Food Safety, Nutrition and Veterinary Public Health, Italy) presented the newly described prion disease in dromedary camels. A recent publication by Babelhadj et al. (2018) jointly produced by researchers of the Istituto Superiore di Sanità and Algerian colleagues from the École Normale Supérieure de Ouargla and the Laboratoire PPABIONUT Physiologie, Physiopathologie et Biochimie de la Nutrition, Université de Tlemcen, described a prion disease in camel slaughtered at an abattoir in the city of Ouargla, in the centre of Algeria, a condition observed by a local veterinarian for the last five years. Three adult female camels showing clinical signs and one adult female apparently healthy were sampled and tested, confirming the diagnosis by detecting pathognomonic neurodegeneration and disease-specific PrPSc in brain tissues from dromedary camels and designate it as camel prion disease (CPD). A retrospective study of clinical suspects submitted for slaughter to the same abattoir indicated a 3.1% prevalence of animals showing neurological signs suggestive of the disease. The presentation of the disease suggests an acquired nature of CPD. The abundant extraneuronal pathogenesis may also suggest that CPD is a contagious disease. Molecular investigations show differences between CPD and BSE or scrapie; however, is not possible to exclude any potential link. Further studies are being conducted to characterize the prion strain of CPD and to ascertain the PRNP gene variability on dromedary populations. A case-control study in the region is also planned.
Volume 24, Number 6—June 2018
Research
Prion Disease in Dromedary Camels, Algeria
Baaissa Babelhadj, Michele Angelo Di Bari, Laura Pirisinu, Barbara Chiappini, Semir Bechir Suheil Gaouar, Geraldina Riccardi, Stefano Marcon, Umberto Agrimi, Romolo Nonno, and Gabriele VaccariComments to Author Author affiliations: Ecole Normale Superieure Ouargla Laboratoire de Protection des Écosystèmes en Zones Arides et Semi Arides University Kasdi Merbah Ouargla, Ouargla, Algeria (B. Babelhadj); Istituto Superiore di Sanità Department of Food Safety, Nutrition and Veterinary Public Health, Rome, Italy (M.A. Di Bari, L. Pirisinu, B. Chiappini, G. Riccardi, S. Marcon, U. Agrimi, R. Nonno, G. Vaccari); Laboratoire de Physiopathologie et Biochimie de la Nutrition University Abou Bekr Bélkaid, Tlemcen, Algeria (S.B.S. Gaouar)
Abstract
Prions cause fatal and transmissible neurodegenerative diseases, including Creutzfeldt-Jakob disease in humans, scrapie in small ruminants, and bovine spongiform encephalopathy (BSE). After the BSE epidemic, and the associated human infections, began in 1996 in the United Kingdom, general concerns have been raised about animal prions. We detected a prion disease in dromedary camels (Camelus dromedarius) in Algeria. Symptoms suggesting prion disease occurred in 3.1% of dromedaries brought for slaughter to the Ouargla abattoir in 2015–2016. We confirmed diagnosis by detecting pathognomonic neurodegeneration and disease-specific prion protein (PrPSc) in brain tissues from 3 symptomatic animals. Prion detection in lymphoid tissues is suggestive of the infectious nature of the disease. PrPSc biochemical characterization showed differences with BSE and scrapie. Our identification of this prion disease in a geographically widespread livestock species requires urgent enforcement of surveillance and assessment of the potential risks to human and animal health.
snip...
Discussion
We describe a prion disease in dromedary camels, designated as camel prion disease (CPD), that we detected during routine antemortem inspection at the Ouargla slaughterhouse in Algeria. Retrospective analysis indicated a 3.1% prevalence of animals with neurologic signs suggestive of the disease in dromedaries brought for slaughter. That figure appears to be reliable given that clinical suspicion was confirmed in all 3 animals undergoing laboratory analysis. However, because prion diseases are characterized by long incubation periods and the age at which the disease becomes apparent (>8 years) is more advanced than the age at which most dromedaries are slaughtered (<5 years), the prevalence found in the older animals is probably higher than the actual prevalence (excluding younger animals).
The spectrum of animal species susceptible to prion disease is large. However, only in ruminants belonging to the Bovidae and Cervidae families do prion diseases behave as infectious and naturally occurring conditions. Dromedaries are not ruminants (suborder Ruminantia) but rather are Tylopoda, a suborder of Artiodactyla, which also includes the 2-humped camel (Camelus bactrianus), wild Bactrian camel (C. ferus), llamas (Lama glama), alpacas (Vicugna pacos), and vicuñas (V. vicugna) (21). The presence of a prion disease in dromedaries extends the spectrum of animal species naturally susceptible to prion diseases to taxa different from those already known and opens up new research areas on the ecology and the host–pathogen relationship of prion diseases.
Whether CPD is an infectious disease in natural conditions is a key question. In scrapie and CWD, in which lymphoid tissues are extensively involved, the horizontal transmission in natural conditions is efficient. In contrast, when the peripheral lymphoid tissues are not substantially involved, as in cattle BSE, atypical/Nor98 scrapie, and most human prion diseases, the horizontal transmission appears to be inefficient. This inefficiency usually is explained by assuming the in vivo dissemination of PrPSc to the periphery as a prerequisite to facilitate prion shedding into the environment (22). Although we obtained samples from a single animal, our detection of PrPSc in all lymph nodes available suggests an abundant extraneural pathogenesis and, along with the notable prevalence of clinical cases at the slaughterhouse, concurs to suggest the infectious nature of CPD. These observations also suggest that the disease has an acquired rather than spontaneous onset.
The origin of CPD is unknown. It might be a disease unique to dromedaries or a malady deriving from transmission of a prion disease from another species. It is worth noting that meat and bone meal has been exported from the United Kingdom worldwide, and after the ban on feeding animals with ruminant protein in 1988, export to the Third World had soared to 30,000 tons (23) in 1991. Thus, the possibility that BSE-infected feed could have reached North Africa cannot be ruled out. However, even if the risk for BSE has not been formally assessed in Algeria and an official surveillance system for animal prion diseases is lacking, BSE is unlikely to appear in dromedaries without evidence in cattle populations. Moreover, dromedaries are mostly raised with no use of feedstuff. Lastly, the PrPSc biochemical signature in CPD clearly differs from that of BSE or sheep-passaged BSE. Although host factors are known to be able to alter the PrPSc signature during interspecies transmission, the BSE profile generally has been preserved in species accidentally or experimentally affected. In principle, CPD also might have derived from scrapie. Dromedaries often are raised along with sheep and goats, sharing common pastures. However, although the absence of an effective surveillance system prevents drawing any conclusions, scrapie has never been reported in Algeria, and a field survey in northeastern Algeria could not provide evidence of the disease (24). Moreover, the PrPSc signature of CPD differed from the classical scrapie case used for comparison (Figure 3). To help clarify the origin and nature of CPD, bioassays in a panel of rodent models are ongoing for a thorough prion strain characterization.
Thumbnail of Dromedary camels gathering and scavenging the waste dumps in the desert near an oil extraction plant. (Ahead of print - Video available in finalized issue) Video 3. Dromedary camels gathering and scavenging the waste dumps in the desert near an oil extraction plant. (Ahead of print - Video available in finalized issue)
Future investigations of the geographic distribution of CPD will help clarify its origin. If the disease is confined to the dromedary populations of the Ouargla region, a localized event of transmission could be hypothesized. Common-source scrapie epidemics in sheep and goats occurred in the United Kingdom and Italy as a consequence of the use of accidentally contaminated vaccines (25,26). However, in the Ouargla region, no vaccination program has been implemented for infectious disease prophylaxis in dromedaries. Intriguingly, dromedary breeders indicate that the only food source other than pasture available to dromedaries in the Ouargla region are the waste dumps widespread in the desert near the oil extraction plants, where dromedaries and small ruminants gather and scavenge (Video 3). The possibility that dromedaries acquired the disease from eating prion-contaminated waste needs to be considered.
Tracing the origin of prion diseases is challenging. In the case of CPD, the traditional extensive and nomadic herding practices of dromedaries represent a formidable factor for accelerating the spread of the disease at long distances, making the path of its diffusion difficult to determine. Finally, the major import flows of live animals to Algeria from Niger, Mali, and Mauritania (27) should be investigated to trace the possible origin of CPD from other countries.
Camels are a vital animal species for millions of persons globally. The world camel population has a yearly growth rate of 2.1% (28). In 2014, the population was estimated at ≈28 million animals, but this number is probably underestimated. Approximately 88% of camels are found in Africa, especially eastern Africa, and 12% are found in Asia. Official data reported 350,000 dromedaries in Algeria in 2014 (28).
On the basis of phenotypic traits and sociogeographic criteria, several dromedary populations have been suggested to exist in Algeria (29). However, recent genetic studies in Algeria and Egypt point to a weak differentiation of the dromedary population as a consequence of historical use as a cross-continental beast of burden along trans-Saharan caravan routes, coupled with traditional extensive/nomadic herding practices (30).
Such genetic homogeneity also might be reflected in PRNP. Studies on PRNP variability in camels are therefore warranted to explore the existence of genotypes resistant to CPD, which could represent an important tool for CPD management as it was for breeding programs for scrapie eradication in sheep.
In the past 10 years, the camel farming system has changed rapidly, with increasing setup of periurban dairy farms and dairy plants and diversification of camel products and market penetration (13). This evolution requires improved health standards for infectious diseases and, in light of CPD, for prion diseases.
The emergence of another prion disease in an animal species of crucial importance for millions of persons worldwide makes it necessary to assess the risk for humans and develop evidence-based policies to control and limit the spread of the disease in animals and minimize human exposure. The implementation of a surveillance system for prion diseases would be a first step to enable disease control and minimize human and animal exposure. Finally, the diagnostic capacity of prion diseases needs to be improved in all countries in Africa where dromedaries are part of the domestic livestock.
Dr. Babelhadj is a veterinarian working at the École Normale Supérieure Ouargla and at the Laboratory for the Protection of Ecosystems in Arid and Semi-arid Zones, University Kasdi Merbah Ouargla, Algeria. His primary research interests include the study of infectious diseases and zootechnical performance of dromedaries.
Thursday, August 1, 2019
Camel prion disease detected in Tunisian camels Camel prion disease detected in Tunisian camels
A novel prion disease first reported in three dromedary camels in Algeria in 2018 has now been detected in dromedaries in Tunisia, the second country to be affected within a year, ProMED Mail, the online reporting system of the International Society for Infectious Diseases, reported yesterday.
The Tunisian detection and the latest information about the disease, called camel prion disease (CPD) and sometimes referred to as "mad camel disease", came from a presentation at the Mediterranean Animal Health Network meeting, held in Cairo on Jun 26 and 27. According to the meeting presentation, CPD is spreading rapidly in the Ouargla region of Algeria where the disease was first identified in older camels at a slaughterhouse.
The scientists who presented at the meeting also said preliminary results suggest that the CPD prion is different from scrapie and bovine spongiform encephalitis (BSE, or "mad cow disease").
A comment from the ProMED Mail moderator Arnon Shimshony, DVM, associate professor of veterinary medicine at Hebrew University of Jerusalem, notes that the area where CPD was first found in Algeria is about 174 miles from the Tunisian border.
In the initial report on the first detection in Algerian camels, published in April 2018 in Emerging Infectious Diseases, described disease-specific prion protein in brain tissues from symptomatic camels, including positive samples in lymph nodes, suggesting infection. The moderator also requested more details about the detections in Tunisia, including location, clinical signs, and ages and origins of affected camels. Jul 29 ProMED Mail post Apr 18, 2018, CIDRAP News story "'Mad camel' disease? New prion infection causes alarm"
***> NEW TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHY TSE PRION DISEASE (MAD CAMEL DISEASE) IN A NEW SPECIES <***
NEW OUTBREAK OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHY TSE PRION DISEASE IN A NEW SPECIES
Subject: Prion Disease in Dromedary Camels, Algeria
Our identification of this prion disease in a geographically widespread livestock species requires urgent enforcement of surveillance and assessment of the potential risks to human and animal health.
Wednesday, May 30, 2018
Dromedary camels in northern Africa have a neurodegenerative prion disease that may have originated decades ago
***> IMPORTS AND EXPORTS <***
***> SEE MASSIVE AMOUNTS OF BANNED ANIMAL PROTEIN AKA MAD COW FEED IN COMMERCE USA DECADES AFTER POST BAN
Saturday, April 14, 2018
Dromedary Camels Algeria Prion (Mad Camel Disease) TSE BSE MRR Import Export Risk Factors Excluding Grains and Plants
Dromedary Camels Algeria Prion (Mad Camel Disease) TSE BSE MRR Import Export Risk Factors Excluding Grains and Plants
(Grains and Plants Materials Could Harbor the Transmissible Spongiform Encephalopathy TSE Prion agent...TSS)
Dromedary Camels Algeria Prion (Mad Camel Disease) TSE BSE MRR Import Export Risk Factors Excluding Grains and Plants
''Since the first description of CPrD, the OIE promoted discussions on the impact of this new disease through the OIE Scientific Commission for Animal Diseases (Scientific Commission). It evaluated if CPrD should be considered an ‘emerging disease’ based on the criteria listed in the Terrestrial Animal Health Code. The OIE Scientific Commission noted that limited surveillance data were available on the prevalence of CPrD and that the evidence was not enough to measure, at that time, the impact of the disease on animal or public health. Therefore, it was concluded that, with the current knowledge, CPrD did not currently meet the criteria to be considered an emerging disease.''
SEEMS TO ME that the OIE et al likes to wait until a terrible animal disease is well established, spread around the world, and at the brink of being discovered and documented as a zoonosis disease before considering it a zoonosis zoonotic disease, before considering it a emerging disease. damn shame, and we will address that at the bottom of this report..terry
OIE and Zoonotic Zoonosis of the Transmissible Spongiform Encephalopathy TSE Prion disease
Chronic Wasting Disease TSE Prion of Cervid
*** URGENT CWD UPDATE Friday, January 17, 2014
FINALLY, 12 years later, the OIE becomes concerned with CWD to humans, not that I did not try and warn them 12 years ago. ...kind regards, terry
Friday, January 17, 2014 Annual report of the Scientific Network on BSE-TSE EFSA, Question No EFSA-Q-2013-01004, approved on 11 December 2013
*** Further, it was addressed that recently discussions have being held at OIE level on Chronic Wasting Disease of cervids.
2002 Singeltary vs O.I.E. on CWD to human risk factor ;
Subject: Re: CWD AMERICA ???
Date: Fri, 12 Jul 2002 19:10:18 +0200
From: "INFORMATION DEPT"
Organization: O.I.E
To: "Terry S. Singeltary Sr."
References: <3d2f0169 .3="" wt.net=""> <012901c229b2 ad43bb90="" f00000a=""> 3D2F2358.5010700@wt.net
I agree with you Dr Terry. The OIE, namely the International Animal Health Code Commission is working on making proposals to Member Countries to change the OIE lists so to avoid some the problems mentioned in you e-mail. This will take at least two years before adoption by the International Committee. For BSE, countries asked the OIE to post information on BSE on the OIE web site.
Personally, I am interested in Chronic Wasting Disease and I follow what is distributed through ProMed. Delegates of OIE Member Countries can propose diseases to be added to the list.
Kind regards. Karim Ben Jebara
----- Original Message -----
From: "Terry S. Singeltary Sr."
To: "INFORMATION DEPT"
Sent: Friday, July 12, 2002 8:43 PM
Subject: Re: CWD AMERICA ???
>>> *** Further, it was addressed that recently discussions have being held at OIE level on Chronic Wasting Disease of cervids. <<<
> hello Dr. Jebara,
>
> many thanks for your swift and kind reply.
>
> if i am not mistaken, it was the same email address.
> it was 3 or 4 weeks ago i wrote, as it is, i don't
> save 'sent' emails anymore, unless very important.
>
> my main concern (besides the fact that a potential TSE
> has been in the USA cattle for some time, but the APHIS
> do not test to find), is that the CWD could very well be
> transmitting to humans, and i just did not see to much
> posted about it on OIE site.
>
> > Coming back to your question, Chronic Wasting Disease is not an OIE
>
> > listed disease. Please see OIE disease lists at
>
> http://www.oie.int/eng/maladies/en_classification.htm#ListeA).
>
> why is this TSE (CWD) not listed and followed as with BSE ?
>
> Article 1.1.3.2.
> 1. Countries shall make available to other countries, through the
> OIE, whatever information is necessary to minimise the spread of
> important animal diseases and to assist in achieving better worldwide
> control of these diseases.
>
> http://www.oie.int/eng/normes/MCode/A_00005.htm
>
> The USA CWD is an important animal disease.
>
> why is it not followed?
>
> > The decision to add or delete a disease from the OIE lists, come
>
> > through proposals made by Member Countries and it has to be adopted by
>
> > the International Committee.
>
> i _urgently_ suggest a proposal to the OIE to follow this disease very
> closely, and to propose _more_ testing in the USA for TSEs in the USA
> cattle...
>
> kindest regards,
> terry
>
> INFORMATION DEPT wrote:
>
> > Dear Sir,
> >
> > This is the first time that I receive your e-mail. To whom have you written
> > in the OIE or to which address?
> >
> > Coming back to your question, Chronic Wasting Disease is not an OIE listed
> > disease. Please see OIE disease lists at
> > http://www.oie.int/eng/maladies/en_classification.htm#ListeA).
> >
> > Countries should report to the OIE any disease even is not listed in the
> > OIE's lists in some conditions (example: an exceptional epidemiological
> > event). Please read Chapter 1.1.3 of the International animal health code to
> > have more information on disease notification and epidemiological
> > information agreed by OIE Member Countries at :
> > http://www.oie.int/eng/normes/MCode/A_00005.htm
> >
> > The decision to add or delete a disease from the OIE lists, come through
> > proposals made by Member Countries and it has to be adopted by the
> > International Committee.
> >
> > Hope that I answered to your question.
> >
> > Best regards.
> >
> > Dr Karim Ben Jebara
> > Head
> > Animal Health Information Department
> > OIE
> >
> >
> >
> > ----- Original Message -----
> > From: "Terry S. Singeltary Sr."
> > To:
> > Sent: Friday, July 12, 2002 6:18 PM
> > Subject: CWD AMERICA ???
> >
> >
> >
> >>I WROTE TO OIE RECENTLY ASKING 'WHY OIE DOES NOT FOLLOW CWD IN
> >>AMERICA' ? with no reply ? i am still seeking an answer ?
> >>
> >>many thanks,
> >>and kind regards,
> >>terry
=====================
Chronic Wasting Disease CWD TSE Prion Zoonosis Zoonotic Update 2021
Cervid to human prion transmission
Kong, Qingzhong
Case Western Reserve University, Cleveland, OH, United States
Prion disease is transmissible and invariably fatal. Chronic wasting disease (CWD) is the prion disease affecting deer, elk and moose, and it is a widespread and expanding epidemic affecting 22 US States and 2 Canadian provinces so far. CWD poses the most serious zoonotic prion transmission risks in North America because of huge venison consumption (>6 million deer/elk hunted and consumed annually in the USA alone), significant prion infectivity in muscles and other tissues/fluids from CWD-affected cervids, and usually high levels of individual exposure to CWD resulting from consumption of the affected animal among often just family and friends. However, we still do not know whether CWD prions can infect humans in the brain or peripheral tissues or whether clinical/asymptomatic CWD zoonosis has already occurred, and we have no essays to reliably detect CWD infection in humans.
We hypothesize that:
(1) The classic CWD prion strain can infect humans at low levels in the brain and peripheral lymphoid tissues;
(2) The cervid-to-human transmission barrier is dependent on the cervid prion strain and influenced by the host (human) prion protein (PrP) primary sequence;
(3) Reliable essays can be established to detect CWD infection in humans; and
(4) CWD transmission to humans has already occurred. We will test these hypotheses in 4 Aims using transgenic (Tg) mouse models and complementary in vitro approaches.
Aim 1 will prove that the classical CWD strain may infect humans in brain or peripheral lymphoid tissues at low levels by conducting systemic bioassays in a set of humanized Tg mouse lines expressing common human PrP variants using a number of CWD isolates at varying doses and routes. Experimental human CWD samples will also be generated for Aim 3.
Aim 2 will test the hypothesis that the cervid-to-human prion transmission barrier is dependent on prion strain and influenced by the host (human) PrP sequence by examining and comparing the transmission efficiency and phenotypes of several atypical/unusual CWD isolates/strains as well as a few prion strains from other species that have adapted to cervid PrP sequence, utilizing the same panel of humanized Tg mouse lines as in Aim 1.
Aim 3 will establish reliable essays for detection and surveillance of CWD infection in humans by examining in details the clinical, pathological, biochemical and in vitro seeding properties of existing and future experimental human CWD samples generated from Aims 1-2 and compare them with those of common sporadic human Creutzfeldt-Jakob disease (sCJD) prions.
Aim 4 will attempt to detect clinical CWD-affected human cases by examining a significant number of brain samples from prion-affected human subjects in the USA and Canada who have consumed venison from CWD-endemic areas utilizing the criteria and essays established in Aim 3. The findings from this proposal will greatly advance our understandings on the potential and characteristics of cervid prion transmission in humans, establish reliable essays for CWD zoonosis and potentially discover the first case(s) of CWD infection in humans.
Public Health Relevance
There are significant and increasing human exposure to cervid prions because chronic wasting disease (CWD, a widespread and highly infectious prion disease among deer and elk in North America) continues spreading and consumption of venison remains popular, but our understanding on cervid-to-human prion transmission is still very limited, raising public health concerns. This proposal aims to define the zoonotic risks of cervid prions and set up and apply essays to detect CWD zoonosis using mouse models and in vitro methods. The findings will greatly expand our knowledge on the potentials and characteristics of cervid prion transmission in humans, establish reliable essays for such infections and may discover the first case(s) of CWD infection in humans.
International Conference on Emerging Diseases, Outbreaks & Case Studies & 16th Annual Meeting on Influenza March 28-29, 2018 | Orlando, USA
Qingzhong Kong
Case Western Reserve University School of Medicine, USA
Zoonotic potential of chronic wasting disease prions from cervids
Chronic wasting disease (CWD) is the prion disease in cervids (mule deer, white-tailed deer, American elk, moose, and reindeer). It has become an epidemic in North America, and it has been detected in the Europe (Norway) since 2016. The widespread CWD and popular hunting and consumption of cervid meat and other products raise serious public health concerns, but questions remain on human susceptibility to CWD prions, especially on the potential difference in zoonotic potential among the various CWD prion strains. We have been working to address this critical question for well over a decade. We used CWD samples from various cervid species to inoculate transgenic mice expressing human or elk prion protein (PrP). We found infectious prions in the spleen or brain in a small fraction of CWD-inoculated transgenic mice expressing human PrP, indicating that humans are not completely resistant to CWD prions; this finding has significant ramifications on the public health impact of CWD prions. The influence of cervid PrP polymorphisms, the prion strain dependence of CWD-to-human transmission barrier, and the characterization of experimental human CWD prions will be discussed.
Speaker Biography Qingzhong Kong has completed his PhD from the University of Massachusetts at Amherst and Post-doctoral studies at Yale University. He is currently an Associate Professor of Pathology, Neurology and Regenerative Medicine. He has published over 50 original research papers in reputable journals (including Science Translational Medicine, JCI, PNAS and Cell Reports) and has been serving as an Editorial Board Member on seven scientific journals. He has multiple research interests, including public health risks of animal prions (CWD of cervids and atypical BSE of cattle), animal modeling of human prion diseases, mechanisms of prion replication and pathogenesis, etiology of sporadic Creutzfeldt-Jacob disease (CJD) in humans, normal cellular PrP in the biology and pathology of multiple brain and peripheral diseases, proteins responsible for the α-cleavage of cellular PrP, as well as gene therapy and DNA vaccination.
Prion Conference 2018 Abstracts
BSE aka MAD COW DISEASE, was first discovered in 1984, and it took until 1995 to finally admit that BSE was causing nvCJD, the rest there is history, but that science is still evolving i.e. science now shows that indeed atypical L-type BSE, atypical Nor-98 Scrapie, and typical Scrapie are all zoonosis, zoonotic for humans, there from.
HOW long are we going to wait for Chronic Wasting Disease, CWD TSE Prion of Cervid, and zoonosis, zoonotic tranmission to humans there from?
Studies have shown since 1994 that humans are susceptible to CWD TSE Prion, so, what's the hold up with making CWD a zoonotic zoonosis disease, the iatrogenic transmissions there from is not waiting for someone to make a decision.
Prion Conference 2018 Abstracts
P190 Human prion disease mortality rates by occurrence of chronic wasting disease in freeranging cervids, United States
Abrams JY (1), Maddox RA (1), Schonberger LB (1), Person MK (1), Appleby BS (2), Belay ED (1)
(1) Centers for Disease Control and Prevention (CDC), National Center for Emerging and Zoonotic Infectious Diseases, Atlanta, GA, USA (2) Case Western Reserve University, National Prion Disease Pathology Surveillance Center (NPDPSC), Cleveland, OH, USA.
Background
Chronic wasting disease (CWD) is a prion disease of deer and elk that has been identified in freeranging cervids in 23 US states. While there is currently no epidemiological evidence for zoonotic transmission through the consumption of contaminated venison, studies suggest the CWD agent can cross the species barrier in experimental models designed to closely mimic humans. We compared rates of human prion disease in states with and without CWD to examine the possibility of undetermined zoonotic transmission.
Methods
Death records from the National Center for Health Statistics, case records from the National Prion Disease Pathology Surveillance Center, and additional state case reports were combined to create a database of human prion disease cases from 2003-2015. Identification of CWD in each state was determined through reports of positive CWD tests by state wildlife agencies. Age- and race-adjusted mortality rates for human prion disease, excluding cases with known etiology, were determined for four categories of states based on CWD occurrence: highly endemic (>16 counties with CWD identified in free-ranging cervids); moderately endemic (3-10 counties with CWD); low endemic (1-2 counties with CWD); and no CWD states. States were counted as having no CWD until the year CWD was first identified. Analyses stratified by age, sex, and time period were also conducted to focus on subgroups for which zoonotic transmission would be more likely to be detected: cases <55 years old, male sex, and the latter half of the study (2010-2015).
Results
Highly endemic states had a higher rate of prion disease mortality compared to non-CWD states (rate ratio [RR]: 1.12, 95% confidence interval [CI] = 1.01 - 1.23), as did low endemic states (RR: 1.15, 95% CI = 1.04 - 1.27). Moderately endemic states did not have an elevated mortality rate (RR: 1.05, 95% CI = 0.93 - 1.17). In age-stratified analyses, prion disease mortality rates among the <55 year old population were elevated for moderately endemic states (RR: 1.57, 95% CI = 1.10 – 2.24) while mortality rates were elevated among those ≥55 for highly endemic states (RR: 1.13, 95% CI = 1.02 - 1.26) and low endemic states (RR: 1.16, 95% CI = 1.04 - 1.29). In other stratified analyses, prion disease mortality rates for males were only elevated for low endemic states (RR: 1.27, 95% CI = 1.10 - 1.48), and none of the categories of CWD-endemic states had elevated mortality rates for the latter time period (2010-2015).
Conclusions
While higher prion disease mortality rates in certain categories of states with CWD in free-ranging cervids were noted, additional stratified analyses did not reveal markedly elevated rates for potentially sensitive subgroups that would be suggestive of zoonotic transmission. Unknown confounding factors or other biases may explain state-by-state differences in prion disease mortality.
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P172 Peripheral Neuropathy in Patients with Prion Disease
Wang H(1), Cohen M(1), Appleby BS(1,2)
(1) University Hospitals Cleveland Medical Center, Cleveland, Ohio (2) National Prion Disease Pathology Surveillance Center, Cleveland, Ohio.
Prion disease is a fatal progressive neurodegenerative disease due to deposition of an abnormal protease-resistant isoform of prion protein. Typical symptoms include rapidly progressive dementia, myoclonus, visual disturbance and hallucinations. Interestingly, in patients with prion disease, the abnormal protein canould also be found in the peripheral nervous system. Case reports of prion deposition in peripheral nerves have been reported. Peripheral nerve involvement is thought to be uncommon; however, little is known about the exact prevalence and features of peripheral neuropathy in patients with prion disease.
We reviewed autopsy-proven prion cases from the National Prion Disease Pathology Surveillance Center that were diagnosed between September 2016 to March 2017. We collected information regarding prion protein diagnosis, demographics, comorbidities, clinical symptoms, physical exam, neuropathology, molecular subtype, genetics lab, brain MRI, image and EMG reports. Our study included 104 patients. Thirteen (12.5%) patients had either subjective symptoms or objective signs of peripheral neuropathy. Among these 13 patients, 3 had other known potential etiologies of peripheral neuropathy such as vitamin B12 deficiency or prior chemotherapy. Among 10 patients that had no other clear etiology, 3 (30%) had familial CJD. The most common sCJD subtype was MV1-2 (30%), followed by MM1-2 (20%). The Majority of cases wasere male (60%). Half of them had exposure to wild game. The most common subjective symptoms were tingling and/or numbness of distal extremities. The most common objective finding was diminished vibratory sensation in the feet. Half of them had an EMG with the findings ranging from fasciculations to axonal polyneuropathy or demyelinating polyneuropathy.
Our study provides an overview of the pattern of peripheral neuropathy in patients with prion disease. Among patients with peripheral neuropathy symptoms or signs, majority has polyneuropathy. It is important to document the baseline frequency of peripheral neuropathy in prion diseases as these symptoms may become important when conducting surveillance for potential novel zoonotic prion diseases.
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P177 PrP plaques in methionine homozygous Creutzfeldt-Jakob disease patients as a potential marker of iatrogenic transmission
Abrams JY (1), Schonberger LB (1), Cali I (2), Cohen Y (2), Blevins JE (2), Maddox RA (1), Belay ED (1), Appleby BS (2), Cohen ML (2)
(1) Centers for Disease Control and Prevention (CDC), National Center for Emerging and Zoonotic Infectious Diseases, Atlanta, GA, USA (2) Case Western Reserve University, National Prion Disease Pathology Surveillance Center (NPDPSC), Cleveland, OH, USA.
Background
Sporadic Creutzfeldt-Jakob disease (CJD) is widely believed to originate from de novo spontaneous conversion of normal prion protein (PrP) to its pathogenic form, but concern remains that some reported sporadic CJD cases may actually be caused by disease transmission via iatrogenic processes. For cases with methionine homozygosity (CJD-MM) at codon 129 of the PRNP gene, recent research has pointed to plaque-like PrP deposition as a potential marker of iatrogenic transmission for a subset of cases. This phenotype is theorized to originate from specific iatrogenic source CJD types that comprise roughly a quarter of known CJD cases.
Methods
We reviewed scientific literature for studies which described PrP plaques among CJD patients with known epidemiological links to iatrogenic transmission (receipt of cadaveric human grown hormone or dura mater), as well as in cases of reported sporadic CJD. The presence and description of plaques, along with CJD classification type and other contextual factors, were used to summarize the current evidence regarding plaques as a potential marker of iatrogenic transmission. In addition, 523 cases of reported sporadic CJD cases in the US from January 2013 through September 2017 were assessed for presence of PrP plaques.
Results
We identified four studies describing 52 total cases of CJD-MM among either dura mater recipients or growth hormone recipients, of which 30 were identified as having PrP plaques. While sporadic cases were not generally described as having plaques, we did identify case reports which described plaques among sporadic MM2 cases as well as case reports of plaques exclusively in white matter among sporadic MM1 cases. Among the 523 reported sporadic CJD cases, 0 of 366 MM1 cases had plaques, 2 of 48 MM2 cases had kuru plaques, and 4 of 109 MM1+2 cases had either kuru plaques or both kuru and florid plaques. Medical chart review of the six reported sporadic CJD cases with plaques did not reveal clinical histories suggestive of potential iatrogenic transmission.
Conclusions
PrP plaques occur much more frequently for iatrogenic CJD-MM cases compared to sporadic CJDMM cases. Plaques may indicate iatrogenic transmission for CJD-MM cases without a type 2 Western blot fragment. The study results suggest the absence of significant misclassifications of iatrogenic CJD as sporadic. To our knowledge, this study is the first to describe grey matter kuru plaques in apparently sporadic CJD-MM patients with a type 2 Western blot fragment.
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P180 Clinico-pathological analysis of human prion diseases in a brain bank series
Ximelis T (1), Aldecoa I (1,2), Molina-Porcel L (1,3), Grau-Rivera O (4), Ferrer I (5), Nos C (6), Gelpi E (1,7), Sánchez-Valle R (1,4)
(1) Neurological Tissue Bank of the Biobanc-Hospital ClÃnic-IDIBAPS, Barcelona, Spain (2) Pathological Service of Hospital ClÃnic de Barcelona, Barcelona, Spain (3) EAIA Trastorns Cognitius, Centre Emili Mira, Parc de Salut Mar, Barcelona, Spain (4) Department of Neurology of Hospital ClÃnic de Barcelona, Barcelona, Spain (5) Institute of Neuropathology, Hospital Universitari de Bellvitge, Hospitalet de Llobregat, Barcelona (6) General subdirectorate of Surveillance and Response to Emergencies in Public Health, Department of Public Health in Catalonia, Barcelona, Spain (7) Institute of Neurology, Medical University of Vienna, Vienna, Austria.
Background and objective:
The Neurological Tissue Bank (NTB) of the Hospital Clínic-Institut d‘Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain is the reference center in Catalonia for the neuropathological study of prion diseases in the region since 2001. The aim of this study is to analyse the characteristics of the confirmed prion diseases registered at the NTB during the last 15 years.
Methods:
We reviewed retrospectively all neuropathologically confirmed cases registered during the period January 2001 to December 2016.
Results:
176 cases (54,3% female, mean age: 67,5 years and age range: 25-86 years) of neuropathological confirmed prion diseases have been studied at the NTB. 152 cases corresponded to sporadic Creutzfeldt-Jakob disease (sCJD), 10 to genetic CJD, 10 to Fatal Familial Insomnia, 2 to GerstmannSträussler-Scheinker disease, and 2 cases to variably protease-sensitive prionopathy (VPSPr). Within sCJD subtypes the MM1 subtype was the most frequent, followed by the VV2 histotype.
Clinical and neuropathological diagnoses agreed in 166 cases (94%). The clinical diagnosis was not accurate in 10 patients with definite prion disease: 1 had a clinical diagnosis of Fronto-temporal dementia (FTD), 1 Niemann-Pick‘s disease, 1 Lewy Body‘s Disease, 2 Alzheimer‘s disease, 1 Cortico-basal syndrome and 2 undetermined dementia. Among patients with VPSPr, 1 had a clinical diagnosis of Amyotrophic lateral sclerosis (ALS) and the other one with FTD.
Concomitant pathologies are frequent in older age groups, mainly AD neuropathological changes were observed in these subjects.
Discussion:
A wide spectrum of human prion diseases have been identified in the NTB being the relative frequencies and main characteristics like other published series. There is a high rate of agreement between clinical and neuropathological diagnoses with prion diseases. These findings show the importance that public health has given to prion diseases during the past 15 years. Continuous surveillance of human prion disease allows identification of new emerging phenotypes. Brain tissue samples from these donors are available to the scientific community. For more information please visit:
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P192 Prion amplification techniques for the rapid evaluation of surface decontamination procedures
Bruyere-Ostells L (1), Mayran C (1), Belondrade M (1), Boublik Y (2), Haïk S (3), Fournier-Wirth C (1), Nicot S (1), Bougard D (1)
(1) Pathogenesis and control of chronic infections, Etablissement Français du Sang, Inserm, Université de Montpellier, Montpellier, France. (2) Centre de Recherche en Biologie cellulaire de Montpellier, CNRS, Université de Montpellier, Montpellier, France. (3) Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Université Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France.
Aims:
Transmissible Spongiform Encephalopathies (TSE) or prion diseases are a group of incurable and always fatal neurodegenerative disorders including Creutzfeldt-Jakob diseases (CJD) in humans. These pathologies include sporadic (sCJD), genetic and acquired (variant CJD) forms. By the past, sCJD and vCJD were transmitted by different prion contaminated biological materials to patients resulting in more than 400 iatrogenic cases (iCJD). The atypical nature and the biochemical properties of the infectious agent, formed by abnormal prion protein or PrPTSE, make it particularly resistant to conventional decontamination procedures. In addition, PrPTSE is widely distributed throughout the organism before clinical onset in vCJD and can also be detected in some peripheral tissues in sporadic CJD. Risk of iatrogenic transmission of CJD by contaminated medical device remains thus a concern for healthcare facilities. Bioassay is the gold standard method to evaluate the efficacy of prion decontamination procedures but is time-consuming and expensive. Here, we propose to compare in vitro prion amplification techniques: Protein Misfolding Cyclic Amplification (PMCA) and Real-Time Quaking Induced Conversion (RT-QuIC) for the detection of residual prions on surface after decontamination.
Methods:
Stainless steel wires, by mimicking the surface of surgical instruments, were proposed as a carrier model of prions for inactivation studies. To determine the sensitivity of the two amplification techniques on wires (Surf-PMCA and Surf-QuIC), steel wires were therefore contaminated with serial dilutions of brain homogenates (BH) from a 263k infected hamster and from a patient with sCJD (MM1 subtype). We then compared the different standard decontamination procedures including partially and fully efficient treatments by detecting the residual seeding activity on 263K and sCJD contaminated wires. We completed our study by the evaluation of marketed reagents endorsed for prion decontamination.
Results:
The two amplification techniques can detect minute quantities of PrPTSE adsorbed onto a single wire. 8/8 wires contaminated with a 10-6 dilution of 263k BH and 1/6 with the 10-8 dilution are positive with Surf-PMCA. Similar performances were obtained with Surf-QuIC on 263K: 10/16 wires contaminated with 10-6 dilution and 1/8 wires contaminated with 10-8 dilution are positive. Regarding the human sCJD-MM1 prion, Surf-QuIC allows us to detect 16/16 wires contaminated with 10-6 dilutions and 14/16 with 10-7 . Results obtained after decontamination treatments are very similar between 263K and sCJD prions. Efficiency of marketed treatments to remove prions is lower than expected.
Conclusions:
Surf-PMCA and Surf-QuIC are very sensitive methods for the detection of prions on wires and could be applied to prion decontamination studies for rapid evaluation of new treatments. Sodium hypochlorite is the only product to efficiently remove seeding activity of both 263K and sCJD prions.
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WA2 Oral transmission of CWD into Cynomolgus macaques: signs of atypical disease, prion conversion and infectivity in macaques and bio-assayed transgenic mice
Schatzl HM (1, 2), Hannaoui S (1, 2), Cheng Y-C (1, 2), Gilch S (1, 2), Beekes M (3), SchulzSchaeffer W (4), Stahl-Hennig C (5) and Czub S (2, 6)
(1) University of Calgary, Calgary Prion Research Unit, Calgary, Canada (2) University of Calgary, Faculty of Veterinary Medicine, Calgary, Canada, (3) Robert Koch Institute, Berlin, Germany, (4) University of Homburg/Saar, Homburg, Germany, (5) German Primate Center, Goettingen, Germany, (6) Canadian Food Inspection Agency (CFIA), Lethbridge, Canada.
To date, BSE is the only example of interspecies transmission of an animal prion disease into humans. The potential zoonotic transmission of CWD is an alarming issue and was addressed by many groups using a variety of in vitro and in vivo experimental systems. Evidence from these studies indicated a substantial, if not absolute, species barrier, aligning with the absence of epidemiological evidence suggesting transmission into humans. Studies in non-human primates were not conclusive so far, with oral transmission into new-world monkeys and no transmission into old-world monkeys. Our consortium has challenged 18 Cynomolgus macaques with characterized CWD material, focusing on oral transmission with muscle tissue. Some macaques have orally received a total of 5 kg of muscle material over a period of 2 years. After 5-7 years of incubation time some animals showed clinical symptoms indicative of prion disease, and prion neuropathology and PrPSc deposition were found in spinal cord and brain of euthanized animals. PrPSc in immunoblot was weakly detected in some spinal cord materials and various tissues tested positive in RT-QuIC, including lymph node and spleen homogenates. To prove prion infectivity in the macaque tissues, we have intracerebrally inoculated 2 lines of transgenic mice, expressing either elk or human PrP. At least 3 TgElk mice, receiving tissues from 2 different macaques, showed clinical signs of a progressive prion disease and brains were positive in immunoblot and RT-QuIC. Tissues (brain, spinal cord and spleen) from these and preclinical mice are currently tested using various read-outs and by second passage in mice. Transgenic mice expressing human PrP were so far negative for clear clinical prion disease (some mice >300 days p.i.). In parallel, the same macaque materials are inoculated into bank voles. Taken together, there is strong evidence of transmissibility of CWD orally into macaques and from macaque tissues into transgenic mouse models, although with an incomplete attack rate. The clinical and pathological presentation in macaques was mostly atypical, with a strong emphasis on spinal cord pathology. Our ongoing studies will show whether the transmission of CWD into macaques and passage in transgenic mice represents a form of non-adaptive prion amplification, and whether macaque-adapted prions have the potential to infect mice expressing human PrP. The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD.
See also poster P103
***> The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD.
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WA16 Monitoring Potential CWD Transmission to Humans
Belay ED
Centers for Disease Control and Prevention (CDC), National Center for Emerging and Zoonotic Infectious Diseases, Atlanta, GA, USA.
The spread of chronic wasting disease (CWD) in animals has raised concerns about increasing human exposure to the CWD agent via hunting and venison consumption, potentially facilitating CWD transmission to humans. Several studies have explored this possibility, including limited epidemiologic studies, in vitro experiments, and laboratory studies using various types of animal models. Most human exposures to the CWD agent in the United States would be expected to occur in association with deer and elk hunting in CWD-endemic areas. The Centers for Disease Control and Prevention (CDC) collaborated with state health departments in Colorado, Wisconsin, and Wyoming to identify persons at risk of CWD exposure and to monitor their vital status over time. Databases were established of persons who hunted in Colorado and Wyoming and those who reported consumption of venison from deer that later tested positive in Wisconsin. Information from the databases is periodically cross-checked with mortality data to determine the vital status and causes of death for deceased persons. Long-term follow-up of these hunters is needed to assess their risk of development of a prion disease linked to CWD exposure.
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P166 Characterization of CJD strain profiles in venison consumers and non-consumers from Alberta and Saskatchewan
Stephanie Booth (1,2), Lise Lamoureux (1), Debra Sorensen (1), Jennifer L. Myskiw (1,2), Megan Klassen (1,2), Michael Coulthart (3), Valerie Sim (4)
(1) Zoonotic Diseases and Special Pathogens, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg (2) Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg (3) Canadian CJD Surveillance System, Public Health Agency of Canada, Ottawa (4) Division of Neurology, Department of Medicine Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton.
Chronic wasting disease (CWD) is spreading rapidly through wild cervid populations in the Canadian provinces of Alberta and Saskatchewan. While this has implications for tourism and hunting, there is also concern over possible zoonotic transmission to humans who eat venison from infected deer. Whilst there is no evidence of any human cases of CWD to date, the Canadian CJD Surveillance System (CJDSS) in Canada is staying vigilant. When variant CJD occurred following exposure to BSE, the unique biochemical fingerprint of the pathologic PrP enabled a causal link to be confirmed. However, we cannot be sure what phenotype human CWD prions would present with, or indeed, whether this would be distinct from that see in sporadic CJD. Therefore we are undertaking a systematic analysis of the molecular diversity of CJD cases of individuals who resided in Alberta and Saskatchewan at their time of death comparing venison consumers and non-consumers, using a variety of clinical, imaging, pathological and biochemical markers. Our initial objective is to develop novel biochemical methodologies that will extend the baseline glycoform and genetic polymorphism typing that is already completed by the CJDSS. Firstly, we are reviewing MRI, EEG and pathology information from over 40 cases of CJD to select clinically affected areas for further investigation. Biochemical analysis will include assessment of the levels of protease sensitive and resistant prion protein, glycoform typing using 2D gel electrophoresis, testing seeding capabilities and kinetics of aggregation by quaking-induced conversion, and determining prion oligomer size distributions with asymmetric flow field fractionation with in-line light scattering. Progress and preliminary data will be presented. Ultimately, we intend to further define the relationship between PrP structure and disease phenotype and establish a baseline for the identification of future atypical CJD cases that may arise as a result of exposure to CWD.
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Source Prion Conference 2018 Abstracts
Volume 24, Number 8—August 2018 Research Susceptibility of Human Prion Protein to Conversion by Chronic Wasting Disease Prions
Marcelo A. BarriaComments to Author , Adriana Libori, Gordon Mitchell, and Mark W. Head Author affiliations: National CJD Research and Surveillance Unit, University of Edinburgh, Edinburgh, Scotland, UK (M.A. Barria, A. Libori, M.W. Head); National and OIE Reference Laboratory for Scrapie and CWD, Canadian Food Inspection Agency, Ottawa, Ontario, Canada (G. Mitchell)
Abstract Chronic wasting disease (CWD) is a contagious and fatal neurodegenerative disease and a serious animal health issue for deer and elk in North America. The identification of the first cases of CWD among free-ranging reindeer and moose in Europe brings back into focus the unresolved issue of whether CWD can be zoonotic like bovine spongiform encephalopathy. We used a cell-free seeded protein misfolding assay to determine whether CWD prions from elk, white-tailed deer, and reindeer in North America can convert the human prion protein to the disease-associated form. We found that prions can convert, but the efficiency of conversion is affected by polymorphic variation in the cervid and human prion protein genes. In view of the similarity of reindeer, elk, and white-tailed deer in North America to reindeer, red deer, and roe deer, respectively, in Europe, a more comprehensive and thorough assessment of the zoonotic potential of CWD might be warranted.
snip...
Discussion Characterization of the transmission properties of CWD and evaluation of their zoonotic potential are important for public health purposes. Given that CWD affects several members of the family Cervidae, it seems reasonable to consider whether the zoonotic potential of CWD prions could be affected by factors such as CWD strain, cervid species, geographic location, and Prnp–PRNP polymorphic variation. We have previously used an in vitro conversion assay (PMCA) to investigate the susceptibility of the human PrP to conversion to its disease-associated form by several animal prion diseases, including CWD (15,16,22). The sensitivity of our molecular model for the detection of zoonotic conversion depends on the combination of 1) the action of proteinase K to degrade the abundant human PrPC that constitutes the substrate while only N terminally truncating any human PrPres produced and 2) the presence of the 3F4 epitope on human but not cervid PrP. In effect, this degree of sensitivity means that any human PrPres formed during the PMCA reaction can be detected down to the limit of Western blot sensitivity. In contrast, if other antibodies that detect both cervid and human PrP are used, such as 6H4, then newly formed human PrPres must be detected as a measurable increase in PrPres over the amount remaining in the reaction product from the cervid seed. Although best known for the efficient amplification of prions in research and diagnostic contexts, the variation of the PMCA method employed in our study is optimized for the definitive detection of zoonotic reaction products of inherently inefficient conversion reactions conducted across species barriers. By using this system, we previously made and reported the novel observation that elk CWD prions could convert human PrPC from human brain and could also convert recombinant human PrPC expressed in transgenic mice and eukaryotic cell cultures (15).
A previous publication suggested that mule deer PrPSc was unable to convert humanized transgenic substrate in PMCA assays (23) and required a further step of in vitro conditioning in deer substrate PMCA before it was able to cross the deer–human molecular barrier (24). However, prions from other species, such as elk (15) and reindeer affected by CWD, appear to be compatible with the human protein in a single round of amplification (as shown in our study). These observations suggest that different deer species affected by CWD could present differing degrees of the olecular compatibility with the normal form of human PrP.
The contribution of the polymorphism at codon 129 of the human PrP gene has been extensively studied and is recognized as a risk factor for Creutzfeldt-Jakob disease (4). In cervids, the equivalent codon corresponds to the position 132 encoding methionine or leucine. This polymorphism in the elk gene has been shown to play an important role in CWD susceptibility (25,26). We have investigated the effect of this cervid Prnp polymorphism on the conversion of the humanized transgenic substrate according to the variation in the equivalent PRNP codon 129 polymorphism. Interestingly, only the homologs methionine homozygous seed–substrate reactions could readily convert the human PrP, whereas the heterozygous elk PrPSc was unable to do so, even though comparable amounts of PrPres were used to seed the reaction. In addition, we observed only low levels of human PrPres formation in the reactions seeded with the homozygous methionine (132 MM) and the heterozygous (132 ML) seeds incubated with the other 2 human polymorphic substrates (129 MV and 129 VV). The presence of the amino acid leucine at position 132 of the elk Prnp gene has been attributed to a lower degree of prion conversion compared with methionine on the basis of experiments in mice made transgenic for these polymorphic variants (26). Considering the differences observed for the amplification of the homozygous human methionine substrate by the 2 polymorphic elk seeds (MM and ML), reappraisal of the susceptibility of human PrPC by the full range of cervid polymorphic variants affected by CWD would be warranted.
In light of the recent identification of the first cases of CWD in Europe in a free-ranging reindeer (R. tarandus) in Norway (2), we also decided to evaluate the in vitro conversion potential of CWD in 2 experimentally infected reindeer (18). Formation of human PrPres was readily detectable after a single round of PMCA, and in all 3 humanized polymorphic substrates (MM, MV, and VV). This finding suggests that CWD prions from reindeer could be more compatible with human PrPC generally and might therefore present a greater risk for zoonosis than, for example, CWD prions from white-tailed deer. A more comprehensive comparison of CWD in the affected species, coupled with the polymorphic variations in the human and deer PRNP–Prnp genes, in vivo and in vitro, will be required before firm conclusions can be drawn. Analysis of the Prnp sequence of the CWD reindeer in Norway was reported to be identical to the specimens used in our study (2). This finding raises the possibility of a direct comparison of zoonotic potential between CWD acquired in the wild and that produced in a controlled laboratory setting. (Table).
The prion hypothesis proposes that direct molecular interaction between PrPSc and PrPC is necessary for conversion and prion replication. Accordingly, polymorphic variants of the PrP of host and agent might play a role in determining compatibility and potential zoonotic risk. In this study, we have examined the capacity of the human PrPC to support in vitro conversion by elk, white-tailed deer, and reindeer CWD PrPSc. Our data confirm that elk CWD prions can convert the human PrPC, at least in vitro, and show that the homologous PRNP polymorphisms at codon 129 and 132 in humans and cervids affect conversion efficiency. Other species affected by CWD, particularly caribou or reindeer, also seem able to convert the human PrP. It will be important to determine whether other polymorphic variants found in other CWD-affected Cervidae or perhaps other factors (17) exert similar effects on the ability to convert human PrP and thus affect their zoonotic potential.
Dr. Barria is a research scientist working at the National CJD Research and Surveillance Unit, University of Edinburgh. His research has focused on understanding the molecular basis of a group of fatal neurologic disorders called prion diseases.
Acknowledgments We thank Aru Balachandran for originally providing cervid brain tissues, Abigail Diack and Jean Manson for providing mouse brain tissue, and James Ironside for his critical reading of the manuscript at an early stage.
This report is independent research commissioned and funded by the United Kingdom’s Department of Health Policy Research Programme and the Government of Scotland. The views expressed in this publication are those of the authors and not necessarily those of the Department of Health or the Government of Scotland.
Author contributions: The study was conceived and designed by M.A.B. and M.W.H. The experiments were conducted by M.A.B. and A.L. Chronic wasting disease brain specimens were provided by G.M. The manuscript was written by M.A.B. and M.W.H. All authors contributed to the editing and revision of the manuscript.
Prion 2017 Conference Abstracts
First evidence of intracranial and peroral transmission of Chronic Wasting Disease (CWD) into Cynomolgus macaques: a work in progress Stefanie Czub1, Walter Schulz-Schaeffer2, Christiane Stahl-Hennig3, Michael Beekes4, Hermann Schaetzl5 and Dirk Motzkus6 1
University of Calgary Faculty of Veterinary Medicine/Canadian Food Inspection Agency; 2Universitatsklinikum des Saarlandes und Medizinische Fakultat der Universitat des Saarlandes; 3 Deutsches Primaten Zentrum/Goettingen; 4 Robert-Koch-Institut Berlin; 5 University of Calgary Faculty of Veterinary Medicine; 6 presently: Boehringer Ingelheim Veterinary Research Center; previously: Deutsches Primaten Zentrum/Goettingen
This is a progress report of a project which started in 2009.
21 cynomolgus macaques were challenged with characterized CWD material from white-tailed deer (WTD) or elk by intracerebral (ic), oral, and skin exposure routes. Additional blood transfusion experiments are supposed to assess the CWD contamination risk of human blood product. Challenge materials originated from symptomatic cervids for ic, skin scarification and partially per oral routes (WTD brain). Challenge material for feeding of muscle derived from preclinical WTD and from preclinical macaques for blood transfusion experiments. We have confirmed that the CWD challenge material contained at least two different CWD agents (brain material) as well as CWD prions in muscle-associated nerves.
Here we present first data on a group of animals either challenged ic with steel wires or per orally and sacrificed with incubation times ranging from 4.5 to 6.9 years at postmortem. Three animals displayed signs of mild clinical disease, including anxiety, apathy, ataxia and/or tremor. In four animals wasting was observed, two of those had confirmed diabetes. All animals have variable signs of prion neuropathology in spinal cords and brains and by supersensitive IHC, reaction was detected in spinal cord segments of all animals. Protein misfolding cyclic amplification (PMCA), real-time quaking-induced conversion (RT-QuiC) and PET-blot assays to further substantiate these findings are on the way, as well as bioassays in bank voles and transgenic mice.
At present, a total of 10 animals are sacrificed and read-outs are ongoing. Preclinical incubation of the remaining macaques covers a range from 6.4 to 7.10 years. Based on the species barrier and an incubation time of > 5 years for BSE in macaques and about 10 years for scrapie in macaques, we expected an onset of clinical disease beyond 6 years post inoculation.
PRION 2017 DECIPHERING NEURODEGENERATIVE DISORDERS ABSTRACTS REFERENCE
8. Even though human TSE‐exposure risk through consumption of game from European cervids can be assumed to be minor, if at all existing, no final conclusion can be drawn due to the overall lack of scientific data. In particular the US data do not clearly exclude the possibility of human (sporadic or familial) TSE development due to consumption of venison. The Working Group thus recognizes a potential risk to consumers if a TSE would be present in European cervids. It might be prudent considering appropriate measures to reduce such a risk, e.g. excluding tissues such as CNS and lymphoid tissues from the human food chain, which would greatly reduce any potential risk for consumers. However, it is stressed that currently, no data regarding a risk of TSE infections from cervid products are available.
SATURDAY, FEBRUARY 23, 2019
Chronic Wasting Disease CWD TSE Prion and THE FEAST 2003 CDC an updated review of the science 2019
TUESDAY, NOVEMBER 04, 2014
Six-year follow-up of a point-source exposure to CWD contaminated venison in an Upstate New York community: risk behaviours and health outcomes 2005–2011
Authors, though, acknowledged the study was limited in geography and sample size and so it couldn't draw a conclusion about the risk to humans. They recommended more study. Dr. Ermias Belay was the report's principal author but he said New York and Oneida County officials are following the proper course by not launching a study. "There's really nothing to monitor presently. No one's sick," Belay said, noting the disease's incubation period in deer and elk is measured in years. "
Transmission Studies
Mule deer transmissions of CWD were by intracerebral inoculation and compared with natural cases {the following was written but with a single line marked through it ''first passage (by this route)}....TSS
resulted in a more rapidly progressive clinical disease with repeated episodes of synocopy ending in coma. One control animal became affected, it is believed through contamination of inoculum (?saline). Further CWD transmissions were carried out by Dick Marsh into ferret, mink and squirrel monkey. Transmission occurred in ALL of these species with the shortest incubation period in the ferret.
snip....
Prion Infectivity in Fat of Deer with Chronic Wasting Disease▿
Brent Race#, Kimberly Meade-White#, Richard Race and Bruce Chesebro* + Author Affiliations
In mice, prion infectivity was recently detected in fat. Since ruminant fat is consumed by humans and fed to animals, we determined infectivity titers in fat from two CWD-infected deer. Deer fat devoid of muscle contained low levels of CWD infectivity and might be a risk factor for prion infection of other species.
Prions in Skeletal Muscles of Deer with Chronic Wasting Disease
Here bioassays in transgenic mice expressing cervid prion protein revealed the presence of infectious prions in skeletal muscles of CWD-infected deer, demonstrating that humans consuming or handling meat from CWD-infected deer are at risk to prion exposure.
*** now, let’s see what the authors said about this casual link, personal communications years ago, and then the latest on the zoonotic potential from CWD to humans from the TOKYO PRION 2016 CONFERENCE.
see where it is stated NO STRONG evidence. so, does this mean there IS casual evidence ???? “Our conclusion stating that we found no strong evidence of CWD transmission to humans”
From: TSS
Subject: CWD aka MAD DEER/ELK TO HUMANS ???
Date: September 30, 2002 at 7:06 am PST
From: "Belay, Ermias"
To: Cc: "Race, Richard (NIH)" ; ; "Belay, Ermias"
Sent: Monday, September 30, 2002 9:22 AM
Subject: RE: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS
Dear Sir/Madam,
In the Archives of Neurology you quoted (the abstract of which was attached to your email), we did not say CWD in humans will present like variant CJD.. That assumption would be wrong. I encourage you to read the whole article and call me if you have questions or need more clarification (phone: 404-639-3091). Also, we do not claim that "no-one has ever been infected with prion disease from eating venison." Our conclusion stating that we found no strong evidence of CWD transmission to humans in the article you quoted or in any other forum is limited to the patients we investigated.
Ermias Belay, M.D. Centers for Disease Control and Prevention
-----Original Message-----
From: Sent: Sunday, September 29, 2002 10:15 AM
Subject: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS
Sunday, November 10, 2002 6:26 PM .......snip........end..............TSS
Thursday, April 03, 2008
A prion disease of cervids: Chronic wasting disease 2008 1: Vet Res. 2008 Apr 3;39(4):41 A prion disease of cervids: Chronic wasting disease Sigurdson CJ.
snip...
*** twenty-seven CJD patients who regularly consumed venison were reported to the Surveillance Center***,
snip... full text ;
> However, to date, no CWD infections have been reported in people.
sporadic, spontaneous CJD, 85%+ of all human TSE, did not just happen. never in scientific literature has this been proven.
if one looks up the word sporadic or spontaneous at pubmed, you will get a laundry list of disease that are classified in such a way;
sporadic = 54,983 hits https://www.ncbi.nlm.nih.gov/pubmed/?term=sporadic
spontaneous = 325,650 hits https://www.ncbi.nlm.nih.gov/pubmed/?term=spontaneous
key word here is 'reported'. science has shown that CWD in humans will look like sporadic CJD. SO, how can one assume that CWD has not already transmitted to humans? they can't, and it's as simple as that. from all recorded science to date, CWD has already transmitted to humans, and it's being misdiagnosed as sporadic CJD. ...terry
*** LOOKING FOR CWD IN HUMANS AS nvCJD or as an ATYPICAL CJD, LOOKING IN ALL THE WRONG PLACES $$$ ***
> However, to date, no CWD infections have been reported in people.
key word here is ‘reported’. science has shown that CWD in humans will look like sporadic CJD. SO, how can one assume that CWD has not already transmitted to humans? they can’t, and it’s as simple as that. from all recorded science to date, CWD has already transmitted to humans, and it’s being misdiagnosed as sporadic CJD. …terry
*** LOOKING FOR CWD IN HUMANS AS nvCJD or as an ATYPICAL CJD, LOOKING IN ALL THE WRONG PLACES $$$ ***
*** These results would seem to suggest that CWD does indeed have zoonotic potential, at least as judged by the compatibility of CWD prions and their human PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests that if zoonotic CWD occurred, it would most likely effect those of the PRNP codon 129-MM genotype and that the PrPres type would be similar to that found in the most common subtype of sCJD (MM1).***
CWD TSE PRION AND ZOONOTIC, ZOONOSIS, POTENTIAL
Subject: Re: DEER SPONGIFORM ENCEPHALOPATHY SURVEY & HOUND STUDY
Date: Fri, 18 Oct 2002 23:12:22 +0100
From: Steve Dealler
Reply-To: Bovine Spongiform Encephalopathy Organization: Netscape Online member
To: BSE-L@ References: <3daf5023 .4080804="" wt.net="">
Dear Terry,
An excellent piece of review as this literature is desparately difficult to get back from Government sites.
What happened with the deer was that an association between deer meat eating and sporadic CJD was found in about 1993. The evidence was not great but did not disappear after several years of asking CJD cases what they had eaten. I think that the work into deer disease largely stopped because it was not helpful to the UK industry...and no specific cases were reported. Well, if you dont look adequately like they are in USA currenly then you wont find any!
Steve Dealler ===============
''The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).''
CREUTZFELDT JAKOB DISEASE SURVEILLANCE IN THE UNITED KINGDOM THIRD ANNUAL REPORT AUGUST 1994
Consumption of venison and veal was much less widespread among both cases and controls. For both of these meats there was evidence of a trend with increasing frequency of consumption being associated with increasing risk of CJD. (not nvCJD, but sporadic CJD...tss) These associations were largely unchanged when attention was restricted to pairs with data obtained from relatives. ...
Table 9 presents the results of an analysis of these data.
There is STRONG evidence of an association between ‘’regular’’ veal eating and risk of CJD (p = .0.01).
Individuals reported to eat veal on average at least once a year appear to be at 13 TIMES THE RISK of individuals who have never eaten veal.
There is, however, a very wide confidence interval around this estimate. There is no strong evidence that eating veal less than once per year is associated with increased risk of CJD (p = 0.51).
The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).
There is some evidence that risk of CJD INCREASES WITH INCREASING FREQUENCY OF LAMB EATING (p = 0.02).
The evidence for such an association between beef eating and CJD is weaker (p = 0.14). When only controls for whom a relative was interviewed are included, this evidence becomes a little STRONGER (p = 0.08).
snip...
It was found that when veal was included in the model with another exposure, the association between veal and CJD remained statistically significant (p = < 0.05 for all exposures), while the other exposures ceased to be statistically significant (p = > 0.05).
snip...
In conclusion, an analysis of dietary histories revealed statistical associations between various meats/animal products and INCREASED RISK OF CJD. When some account was taken of possible confounding, the association between VEAL EATING AND RISK OF CJD EMERGED AS THE STRONGEST OF THESE ASSOCIATIONS STATISTICALLY. ...
snip...
In the study in the USA, a range of foodstuffs were associated with an increased risk of CJD, including liver consumption which was associated with an apparent SIX-FOLD INCREASE IN THE RISK OF CJD. By comparing the data from 3 studies in relation to this particular dietary factor, the risk of liver consumption became non-significant with an odds ratio of 1.2 (PERSONAL COMMUNICATION, PROFESSOR A. HOFMAN. ERASMUS UNIVERSITY, ROTTERDAM). (???...TSS)
snip...see full report ;
http://web.archive.org/web/20090506050043/http://www.bseinquiry.gov.uk/files/yb/1994/08/00004001.pdf
http://web.archive.org/web/20090506050244/http://www.bseinquiry.gov.uk/files/yb/1994/07/00001001.pdf
BSE Inquiry Steve Dealler
Management In Confidence
BSE: Private Submission of Bovine Brain Dealler
snip...see full text;
MONDAY, FEBRUARY 25, 2019
***> MAD DOGS AND ENGLISHMEN BSE, SCRAPIE, CWD, CJD, TSE PRION A REVIEW 2019
***> ''The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).''
***> In conclusion, sensory symptoms and loss of reflexes in Gerstmann-Sträussler-Scheinker syndrome can be explained by neuropathological changes in the spinal cord. We conclude that the sensory symptoms and loss of lower limb reflexes in Gerstmann-Sträussler-Scheinker syndrome is due to pathology in the caudal spinal cord. <***
***> The clinical and pathological presentation in macaques was mostly atypical, with a strong emphasis on spinal cord pathology.<***
***> The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD. <***
***> All animals have variable signs of prion neuropathology in spinal cords and brains and by supersensitive IHC, reaction was detected in spinal cord segments of all animals.<***
***> In particular the US data do not clearly exclude the possibility of human (sporadic or familial) TSE development due to consumption of venison. The Working Group thus recognizes a potential risk to consumers if a TSE would be present in European cervids.'' Scientific opinion on chronic wasting disease (II) <***
TUESDAY, APRIL 20, 2021
APHIS Announces Availability of Funding to Control and Prevent Chronic Wasting Disease
***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.***
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.
https://www.nature.com/articles/srep11573
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 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
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
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
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
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 scrapie 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).
Wednesday, February 16, 2011
IN CONFIDENCE
SCRAPIE TRANSMISSION TO CHIMPANZEES
IN CONFIDENCE
reference...
RB3.20
TRANSMISSION TO CHIMPANZEES
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, ilp 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.
6. 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.
R. Bradley
23 September 1990
CVO (+Mr Wells' comments)
Dr T W A Little
Dr B J Shreeve
90/9.23/1.1.
http://web.archive.org/web/20090506041740/http://www.bseinquiry.gov.uk/files/yb/1990/09/23001001.pdf
IN CONFIDENCE CHIMPANZEES
CODE 18-77 Reference RB3.46
Some further information that may assist in decision making has been gained by discussion with Dr Rosalind Ridley.
She says that careful study of Gajdusek's work shows no increased susceptibility of chimpanzees over New World Monkeys such as Squirrel Monkeys. She does not think it would tell you anything about the susceptibility to man. Also Gajdusek did not, she believes, challenge chimpanzees with scrapie as severely as we did pigs and we know little of that source of scrapie. Comparisons would be difficult. She also would not expect the Home Office to sanction such experiments here unless there was a very clear and important objective that would be important for human health protection. She doubted such a case could be made. If this is the case she thought it would be unethical to do an experiment abroad because we could not do it in our own country.
Retrospectively she feels they should have put up more marmosets than they did. They all remain healthy. They would normally regard the transmission as negative if no disease resulted in five years.
We are not being asked for a decision but I think that before we made one we should gain as much knowledge as we can. If we decided to proceed we would have to bear any criticisms for many years if there was an adverse view by scientists ormedia. This should not be undertaken lightly. There is already some adverse comment here, I gather, on the pig experiment though that will subside.
The Gibbs' (as' distinct from Schellekers') study is somewhat different. We are merely supplying material for comparative studies in a laboratory with the greatest experience of human SEs in the world and it has been sanctioned by USDA (though we do not know for certain yet if chimpanzees specifically will be used). This would keep it at a lower profile than if we conducted such an experiment in the UK or Europe.
I consider we must have very powerful and defendable objectives to go beyond Gibbs' proposed experiments and should not initiate others just because an offer has been made.
Scientists have a responsibility to seek other methods of investigative research other than animal experimentation. At present no objective has convinced me we need to do research using Chimpanzees - a species in need of protection. Resisting such proposals would enable us to communicate that information to the scientist and the public should the need arise. A line would have been drawn.
CVO cc Dr T Dr B W A Little Dr B J Shreeve
R Bradley
26 September 1990
90/9.26/3.2
http://web.archive.org/web/20090506041605/http://www.bseinquiry.gov.uk/files/yb/1990/09/26003001.pdf
this is tse prion political theater here, i.e. what i call TSE PRION POKER...tss
3. Prof. A. Robertson gave a brief account of BSE. The US approach was to accord it a very low profile indeed. Dr. A Thiermann showed the picture in the ''Independent'' with cattle being incinerated and thought this was a fanatical incident to be avoided in the US at all costs.
snip...
PAGE 26
Transmission Studies
Mule deer transmissions of CWD were by intracerebral inoculation and compared with natural cases {the following was written but with a single line marked through it ''first passage (by this route)}....TSS
resulted in a more rapidly progressive clinical disease with repeated episodes of synocopy ending in coma. One control animal became affected, it is believed through contamination of inoculum (?saline). Further CWD transmissions were carried out by Dick Marsh into ferret, mink and squirrel monkey. Transmission occurred in ALL of these species with the shortest incubation period in the ferret.
The occurrence of CWD must be viewed against the contest of the locations in which it occurred. It was an incidental and unwelcome complication of the respective wildlife research programmes. Despite its subsequent recognition as a new disease of cervids, therefore justifying direct investigation, no specific research funding was forthcoming. The USDA veiwed it as a wildlife problem and consequently not their province! ...page 26.
snip...see;
IN CONFIDENCE
PERCEPTIONS OF UNCONVENTIONAL SLOW VIRUS DISEASE OF ANIMALS IN THE USA
GAH WELLS
REPORT OF A VISIT TO THE USA
APRIL-MAY 1989
MONDAY, DECEMBER 16, 2019
Chronic Wasting Disease CWD TSE Prion aka mad cow type disease in cervid Zoonosis Update
***> ''In particular the US data do not clearly exclude the possibility of human (sporadic or familial) TSE development due to consumption of venison. The Working Group thus recognizes a potential risk to consumers if a TSE would be present in European cervids.'' Scientific opinion on chronic wasting disease (II) <***
What if?
FRIDAY, JULY 26, 2019
Chronic Wasting Disease in Cervids: Implications for Prion Transmission to Humans and Other Animal Species
Control of Chronic Wasting Disease OMB Control Number: 0579-0189 APHIS-2021-0004 Singeltary Submission
Greetings APHIS et al, i would kindly like to comment on Control of Chronic Wasting Disease OMB Control Number: 0579-0189 APHIS-2021-0004.
Greetings APHIS et al, i would kindly like to comment on Control of Chronic Wasting Disease OMB Control Number: 0579-0189 APHIS-2021-0004.
***> 1st and foremost your biggest problem is 'VOLUNTARY'! AS with the BSE 589.2001 FEED REGULATIONS, especially since it is still voluntary with cervid, knowing full well that cwd and scrapie will transmit to pigs by oral route. VOLUNTARY DOES NOT WORK! all animal products should be banned and be made mandatory, and the herd certification program should be mandatory, or you don't move cervid. IF THE CWD HERD CERTIFICATION IS NOT MANDATORY, it will be another colossal tse prion failure from the start.
***> 2nd USA should declare a Declaration of Extraordinary Emergency due to CWD, and all exports of cervid and cervid products must be stopped internationally, and there should be a ban of interstate movement of cervid, until a live cwd test is available.
***> 3rd Captive Farmed cervid ESCAPEES should be made mandatory to report immediately, and strict regulations for those suspect cwd deer that just happen to disappear. IF a cervid escapes and is not found, that farm should be indefinitely shut down, all movement, until aid MIA cervid is found, and if not ever found, that farm shut down permanently.
***> 4th Captive Farmed Cervid, INDEMNITY, NO MORE Federal indemnity program, or what i call, ENTITLEMENT PROGRAM for game farm industry. NO MORE BAIL OUTS FROM TAX PAYERS. if the captive industry can't buy insurance to protect not only themselves, but also their customers, and especially the STATE, from Chronic Wasting Disease CWD TSE Prion or what some call mad deer disease and harm therefrom, IF they can't afford to buy that insurance that will cover all of it, then they DO NOT GET A PERMIT to have a game farm for anything. This CWD TSE Prion can/could/has caused property values to fall from some reports in some places. roll the dice, how much is a state willing to lose?
***> 5th QUARANTINE OF ALL FARMED CAPTIVE, BREEDERS, URINE, ANTLER, VELVET, SPERM, OR ANY FACILITY, AND THEIR PRODUCTS, that has been confirmed to have Chronic Wasting Disease CWD TSE Prion, the QUARANTINE should be for 21 years due to science showing what scrapie can do. 5 years is NOT near long enough. see; Infectious agent of sheep scrapie may persist in the environment for at least 16 to 21 years.
***> 6th America BSE 589.2001 FEED REGULATIONS CWD TSE Prion
***> 7TH TRUCKING TRANSPORTING CERVID CHRONIC WASTING DISEASE TSE PRION VIOLATING THE LACEY ACT
***> 8TH ALL CAPTIVE FARMING CERVID OPERATIONS MUST BE INSURED TO PAY FOR ANY CLEAN UP OF CWD AND QUARANTINE THERE FROM FOR THE STATE, NO MORE ENTITLEMENT PROGRAM FOR CERVID GAME FARMING PAY TO PLAY FOR CWD TSE PRION OFF THE TAX PAYERS BACK.
***> 9TH ANY STATE WITH DOCUMENTED CWD, INTERSTATE, NATIONAL, AND INTERNATIONAL MOVEMENT OF ALL CERVID, AND ALL CERVID PRODUCTS MUST BE HALTED!
***> 10TH BAN THE SALE OF STRAW BRED BUCKS AND ALL CERVID SEMEN AND URINE PRODUCTS
***> 11th ALL CAPTIVE FARMED CERVID AND THEIR PRODUCTS MUST BE CWD TSE PRION TESTED ANNUALLY AND BEFORE SALE FOR CWD TSE PRION
Control of Chronic Wasting Disease OMB Control Number: 0579-0189 APHIS-2021-0004 Singeltary Submission
Comment ID
APHIS-2021-0004-0002
Sunday, January 10, 2021
APHIS Concurrence With OIE Risk Designation for Bovine Spongiform Encephalopathy [Docket No. APHIS-2018-0087] Singeltary Submission June 17, 2019
APHIS Concurrence With OIE Risk Designation for Bovine Spongiform Encephalopathy [Docket No. APHIS-2018-0087] Singeltary Submission
Greetings APHIS et al,
I would kindly like to comment on APHIS Concurrence With OIE Risk Designation for Bovine Spongiform Encephalopathy [Docket No. APHIS-2018-0087], and my comments are as follows, with the latest peer review and transmission studies as references of evidence.
THE OIE/USDA BSE Minimal Risk Region MRR is nothing more than free pass to import and export the Transmissible Spongiform Encephalopathy TSE Prion disease. December 2003, when the USDA et al lost it's supposedly 'GOLD CARD' ie BSE FREE STATUS (that was based on nothing more than not looking and not finding BSE), once the USA lost it's gold card BSE Free status, the USDA OIE et al worked hard and fast to change the BSE Geographical Risk Statuses i.e. the BSE GBR's, and replaced it with the BSE MRR policy, the legal tool to trade mad cow type disease TSE Prion Globally. The USA is doing just what the UK did, when they shipped mad cow disease around the world, except with the BSE MRR policy, it's now legal.
Also, the whole concept of the BSE MRR policy is based on a false pretense, that atypical BSE is not transmissible, and that only typical c-BSE is transmissible via feed. This notion that atypical BSE TSE Prion is an old age cow disease that is not infectious is absolutely false, there is NO science to show this, and on the contrary, we now know that atypical BSE will transmit by ORAL ROUTES, but even much more concerning now, recent science has shown that Chronic Wasting Disease CWD TSE Prion in deer and elk which is rampant with no stopping is sight in the USA, and Scrapie TSE Prion in sheep and goat, will transmit to PIGS by oral routes, this is our worst nightmare, showing even more risk factors for the USA FDA PART 589 TSE PRION FEED ban.
The FDA PART 589 TSE PRION FEED ban has failed terribly bad, and is still failing, since August 1997. there is tonnage and tonnage of banned potential mad cow feed that went into commerce, and still is, with one decade, 10 YEARS, post August 1997 FDA PART 589 TSE PRION FEED ban, 2007, with 10,000,000 POUNDS, with REASON, Products manufactured from bulk feed containing blood meal that was cross contaminated with prohibited meat and bone meal and the labeling did not bear cautionary BSE statement. you can see all these feed ban warning letters and tonnage of mad cow feed in commerce, year after year, that is not accessible on the internet anymore like it use to be, you can see history of the FDA failure August 1997 FDA PART 589 TSE PRION FEED ban here, but remember this, we have a new outbreak of TSE Prion disease in a new livestock species, the camel, and this too is very worrisome.
WITH the OIE and the USDA et al weakening the global TSE prion surveillance, by not classifying the atypical Scrapie as TSE Prion disease, and the notion that they want to do the same thing with typical scrapie and atypical BSE, it's just not scientific.
WE MUST abolish the BSE MRR policy, go back to the BSE GBR risk assessments by country, and enhance them to include all strains of TSE Prion disease in all species. With Chronic Wasting CWD TSE Prion disease spreading in Europe, now including, Norway, Finland, Sweden, also in Korea, Canada and the USA, and the TSE Prion in Camels, the fact the the USA is feeding potentially CWD, Scrapie, BSE, typical and atypical, to other animals, and shipping both this feed and or live animals or even grains around the globe, potentially exposed or infected with the TSE Prion. this APHIS Concurrence With OIE Risk Designation for Bovine Spongiform Encephalopathy [Docket No. APHIS-2018-0087], under it's present definition, does NOT show the true risk of the TSE Prion in any country. as i said, it's nothing more than a legal tool to trade the TSE Prion around the globe, nothing but ink on paper.
AS long as the BSE MRR policy stays in effect, TSE Prion disease will continued to be bought and sold as food for both humans and animals around the globe, and the future ramifications from friendly fire there from, i.e. iatrogenic exposure and transmission there from from all of the above, should not be underestimated. ...
WEDNESDAY, MARCH 24, 2021
USDA Animal and Plant Health Inspection Service 2020 IMPACT REPORT BSE TSE Prion Testing and Surveillance MIA
https://animalhealthreportpriontse.blogspot.com/2021/03/usda-animal-and-plant-health-inspection.html
WEDNESDAY, DECEMBER 2, 2020
EFSA Evaluation of public and animal health risks in case of a delayed post-mortem inspection in ungulates EFSA Panel on Biological Hazards (BIOHAZ) ADOPTED: 21 October 2020
i wonder if a 7 month delay on a suspect BSE case in Texas is too long, on a 48 hour turnaround, asking for a friend???
MONDAY, NOVEMBER 30, 2020
***> REPORT OF THE MEETING OF THE OIE SCIENTIFIC COMMISSION FOR ANIMAL DISEASES Paris, 9–13 September 2019 BSE, TSE, PRION
see updated concerns with atypical BSE from feed and zoonosis...terry
WEDNESDAY, DECEMBER 23, 2020
BSE research project final report 2005 to 2008 SE1796 SID5
2.3.2. New evidence on the zoonotic potential of atypical BSE and atypical scrapie prion strains
2.3.2. New evidence on the zoonotic potential of atypical BSE and atypical scrapie prion strains
Olivier Andreoletti, INRA Research Director, Institut National de la Recherche Agronomique (INRA) – École Nationale Vétérinaire de Toulouse (ENVT), invited speaker, presented the results of two recently published scientific articles of interest, of which he is co-author: ‘Radical Change in Zoonotic Abilities of Atypical BSE Prion Strains as Evidenced by Crossing of Sheep Species Barrier in Transgenic Mice’ (MarinMoreno et al., 2020) and ‘The emergence of classical BSE from atypical/Nor98 scrapie’ (Huor et al., 2019).
In the first experimental study, H-type and L-type BSE were inoculated into transgenic mice expressing all three genotypes of the human PRNP at codon 129 and into adapted into ARQ and VRQ transgenic sheep mice. The results showed the alterations of the capacities to cross the human barrier species (mouse model) and emergence of sporadic CJD agents in Hu PrP expressing mice: type 2 sCJD in homozygous TgVal129 VRQ-passaged L-BSE, and type 1 sCJD in homozygous TgVal 129 and TgMet129 VRQ-passaged H-BSE.
Terry S. Singeltary Sr.
