Thursday, September 09, 2021

Chronic wasting disease: a cervid prion infection looming to spillover

Chronic wasting disease: a cervid prion infection looming to spillover

Alicia Otero 1 2 3, Camilo Duque Velásquez 1 2, Judd Aiken 2 4, Debbie McKenzie 5 6

Affiliations expand

PMID: 34488900 DOI: 10.1186/s13567-021-00986-y

Abstract

The spread of chronic wasting disease (CWD) during the last six decades has resulted in cervid populations of North America where CWD has become enzootic. This insidious disease has also been reported in wild and captive cervids from other continents, threatening ecosystems, livestock and public health. These CWD “hot zones” are particularly complex given the interplay between cervid PRNP genetics, the infection biology, the strain diversity of infectious prions and the long-term environmental persistence of infectivity, which hinder eradication efforts. Here, we review different aspects of CWD including transmission mechanisms, pathogenesis, epidemiology and assessment of interspecies infection. Further understanding of these aspects could help identify “control points” that could help reduce exposure for humans and livestock and decrease CWD spread between cervids.

Keywords: Chronic wasting disease, prion, prion disease, prion pathogenesis, interspecies transmission

Introduction

Chronic wasting disease (CWD) is a highly prevalent prion disease affecting various species of the Cervidae family and has been described in North America, South Korea and Scandinavia [1, 2]. Prion diseases are fatal neurodegenerative disorders affecting numerous mammalian species. In addition to CWD, prion diseases include scrapie in sheep and goats, bovine spongiform encephalopathy (BSE), transmissible mink encephalopathy (TME), and Creutzfeldt-Jakob disease (CJD) in humans. CWD is the only prion disease affecting both wild and farmed animals and stands out for being highly contagious, widespread and persistent in the environment, which facilitates the transmission of the disease and hinders its control in deer populations [3,4,5,6].

Pathogenesis of CWD, as described for other prion diseases, occurs over extended asymptomatic periods and depends on the misfolding of the cellular prion protein (PrPC), encoded by the PRNP gene, into an infectious template-directing conformation (PrPSc) [7]. Following exposure to prions, the host’s susceptibility to develop disease, the clinical presentation, and the neuropathology are regulated by the interaction between the host PrPC primary structure and the invading prion agent or strain [8,9,10].

The neuropathology of affected cervids includes spongiform degeneration, neuronal loss, gliosis, and accumulation of PrPCWD (cervid PrPSc) in the form of aggregates [3, 4, 11]. Variation in the disease presentation between cervids, including survival period, distribution of brain lesions and PrPCWD properties occur in concert with different prion strains [12,13,14,15]. Prion strains are reproducible biological information encoded in specific PrPCWD conformers that are replicated by the templated-misfolding of the host PrPC [16,17,18]. While the transmission of a prion strain between hosts sharing similar PrPC is more efficient given the compatibility of selected strain-specific PrPSc conformers, transmission between hosts species expressing different PrPC primary structures is relatively inefficient and can introduce permanent conformational modifications resulting in the emergence of strains with novel properties [14, 19,20,21]. Alternatively, a strain can be transmitted back and forth between two species expressing various PrPC amino acid differences and remain unaltered informationally [22,23,24]. Strain selection from a host co-infected with multiple strains can also occur following transmission between species expressing different PrPC molecules [12, 25]. In addition, some tissues may show differential susceptibility for some strains compared to the brain (e.g. spleen) [26].

The transmission cycle of CWD in wild and captive cervids also involves the propagation of prion strains within and between various host species expressing distinct PrPC primary structures [12, 27, 28]. As CWD outbreaks become enzootic in cervid populations, circulating CWD strains must adapt to the shifting PrPC landscape that each new host provides which might result in novel strain emergence [13, 14, 21, 29]. These shifts in the prion replication substrate (PrPC) also occur at the population level, with allele frequencies of protective PrPC polymorphisms increasing in response to CWD in deer and elk [27, 30]. Here, we review the current understanding of the CWD transmission cycle, pathogenesis, infection biology and infer from numerous bioassay studies the potential for transmission to other species, including humans.

Transmission of CWD

The progression of CWD is less understood in wild free-ranging cervids given its direct relationship with the infectious dose, the route of exposure, the prion strain and the host PRNP genotype. Under controlled conditions, the incubation period (i.e., time to onset of clinical signs) of experimentally infected, orally dosed white-tailed deer, mule deer and reindeer expressing different PrPC ranged between 1.5 and 6 years post-exposure [13, 31,32,33]. Similarly in elk, differences in incubation period were observed to range between 1.8 to 5.2 years depending on the elk PRNP genotype [34,35,36]. During the asymptomatic period, both captive and wild infected cervids contribute to the spread of CWD as they accumulate considerable amounts of prion infectivity throughout the body, which is shed through secretions and excretions into the environment [6, 37, 38].

The age range documented for cervids infected with CWD in captivity is fairly similar to that described for free-ranging animals [39, 40]. However, depending on the historical CWD prevalence and given the social nature of cervids it is possible to find pre-clinical CWD positive fawns (< 1 year-old animals) and yearlings (1–2 year old) [41]. The youngest identified clinically-positive free-ranging deer and elk were 16 and 21 months of age, respectively [4, 42]. An age range of 2.5–7.5 years has been reported for free ranging clinical deer and 1.8 to 10.5 years for elk [4]. More recently, evaluation of the prevalence of CWD infection by age as determined by detection of abnormal prion protein in 28 954 deer collected over seven years of surveillance in Wisconsin and Illinois enzootic zones reached similar conclusions as in the previous studies; the risk of CWD infection increases with age in both male and female deer (prevalence in adults 1.93%, yearlings 0.89 and 0.45% in fawns) [43]. Previous analyses of prevalence in a sample of 4510 deer culled within Wisconsin eradication zones, where CWD incidence has historically been and remains the highest, confirmed CWD infection in 3 to 3.4% of yearling deer irrespective of sex [44]. These findings suggest the higher prevalence in younger animals (yearlings and fawns) could be related to the extent to which CWD has been historically prevalent within a particular cervid population. The detection of prions in fawns could as well represent mother to offspring transmission [45].

Differences in age at which clinical CWD is observed can vary between species and are likely to depend on the source or origin of the infection. The first cases of CWD Scandinavian cervids, were described in various 9–16 year old moose, a 16 year-old red deer and 3–4 year old reindeer [2, 46, 47].

The prevalence of CWD in wild cervids also varies by sex. In CWD enzootic areas the incidence of infection is much higher in males than females [44, 48, 49]. Considering that no differences in susceptibility have been detected between captive male and female deer [3, 39, 40, 50, 51], the higher prevalence in free ranging males may be attributable to differences in behavior, particularly during the breeding season when males roam widely and interact with other males more avidly, increase the risk of contact with contaminated environments and infected animals [52, 53].

The clinical progression and signs of CWD in both captive and experimentally infected cervids vary within and between species [3, 13, 31]. A brief summary is included in Table 1. Initial clinical features are often subtle and transitory [13]. The most prominent clinical features include behavioral alterations and progressive deterioration of body condition (i.e., weight loss) that worsen over the course of weeks to months [54]. Altered postures with lowered head and ears, arching of the back and ataxia can also be displayed [13, 31, 42]. Advanced clinical disease may involve odontoprisis, polydipsia, polyuria, difficulty swallowing, regurgitation of rumen contents and excessive salivation with drooling. Following recumbency, aspiration pneumonia, dehydration, or hypothermia during the winter season (in wild affected animals) are the most likely causes of death [42]. Compared to deer, CWD-affected elk can present with nervousness and hyperesthesia and are more likely to display motor disturbances but less likely to develop polydipsia [54].

Various factors contribute to the efficiency of the CWD transmission cycle. The primary mode of transmission between cervids, early in an outbreak, is likely by direct animal to animal interactions following exposure to an infected animal or environment [53, 55]. Although experimental infection in pregnant muntjac deer (Muntiacus reevesi) and detection of PrPCWD in tissues from wild pregnant elk dams provide evidence for in utero transmission [45, 56], other studies indicate it plays a minor role in epidemiology compared to deer-to-deer transmission [57]. Given the rapid pre-clinical accumulation of PrPCWD aggregates in lymphoid tissues associated with the alimentary and the intestinal mucosa, the oral route of infection is most likely [31, 58, 59]. However, inhalation of CWD-fomites has also been proposed as a mechanism of exposure [60]. The presence of CWD infectivity in antler velvet [61] leads to the question of whether prions can persist in the calcified antler and favor male to male intradermal inoculation during the rut, or represent a risk factor in terms of oral CWD transmission, as antler gnawing is common among cervids. Antler gnawing has been suggested as a factor involved in the transmission of CWD in the reindeer population from Nordfjella, Norway [62].

The spread of CWD into “naïve” cervids also occurs through exposure to contaminated environments previously inhabited by infected animals [38, 57, 63]. This mode of transmission becomes more relevant as the prevalence of CWD in affected cervid populations increases and the disease becomes enzootic. Secretions (saliva) and excretions (urine and feces) of CWD-infected cervids contain considerable CWD infectivity. The minimum infectious dose in saliva required for a deer to become infected, assuming a single oral exposure to CWD prions, is equivalent to the infectivity contained in 100–300 ng of brain (approximate equivalent of 30 mL of CWD-positive saliva) [6]. Secretions and excretions from CWD positive animals and the decomposition of diseased carcasses contaminate the environment, in which prions can persist in a bioavailable state for years [38, 64,65,66]. The physical association of prions with certain soil microparticles enhances transmissibility [67, 68]. Environmental persistence of CWD infectivity depends on the composition of minerals and organic constituents of soil, which vary between geographical areas [69]. Minerals such as montmorillonite, can enhance the experimental transmission of prions by the oral route [67]. Deer consume a significant amount of soil, especially in adjacent areas to mineral licks, which have tested positive for infectivity in CWD endemic regions [70]. Soils, depending on their composition, represent an important reservoir of CWD infectivity in the environment. Although determination of the degree of contamination of a particular soil surface becomes more difficult with time, the soil-bound prion infectivity is not significantly altered [66].

Plants can also represent an important reservoir for CWD contamination and transmission. CWD contaminated pastures can remain infectious for at least 2 years after prion exposure [65]. Regarding the uptake of prions by plants, results are more controversial. One study, using protein misfolding cyclic amplification (PMCA), an ultrasensitive technique for the detection of prions, demonstrated that grass plants exposed to brain or excretions from CWD-infected cervids can uptake prions from the soil and transport them to the aerial parts of the plant [71]. Another study, however, showed that wheat plants do not transport CWD prions from the roots to the stems [72].

Prion neuroinvasion and body distribution of infectivity

The pathological hallmarks of CWD in deer resemble those observed in sheep with scrapie and other prion diseases acquired by ingestion of contaminated material. In orally infected deer, PrPCWD crosses the intestinal epithelial barrier and can be detected, within the first 30–42 days post-exposure, in lymphoid tissues associated with the alimentary tract such as the gut-associated lymphoid tissue (GALT), the tonsils and the retropharyngeal lymph nodes [31, 59, 73, 74]. Modified enterocytes, called M cells, participate in the uptake of the prion, incorporating it into the subepithelial lymphoid tissue. The pathological prion protein then accumulates and replicates in follicular dendritic cells and tingible body macrophages [58, 75, 76]. PrPCWD cellular targeting during early pathogenesis suggests that prions are transported by dendritic cells and/or macrophages to Peyer’s Patches and regional mesenteric lymph nodes [58, 59].

Once infection has been established in the GALT, prion colonization of the nerve endings of the Enteric Nervous System (ENS) and leakage into the lymph and blood facilitates the spread to other organs [77, 78]. Prion infection of the ENS results in the spread of infectivity through sympathetic and parasympathetic nerves [75]. The initial site of PrPCWD detection within the deer brain is the dorsal motor nucleus of the vagus nerve (DMNV), suggesting this nerve as the major route for PrPCWD traffic from the alimentary tract to the brain [73].

CWD infectivity trafficked via the lymph and the blood can reach multiple organs, including the brain. Prion neuroinvasion by this route likely occurs via the circumventricular organs [79]. Consistent with this observation, considerable prion infectivity has been demonstrated in numerous blood cell types from CWD-infected deer, suggesting that the haematogenous dissemination of infection may be important during the pathogenesis of the disease [80].

Another major route of prion neuroinvasion involving the entry via ENS is by retrograde transport of prions through the splanchnic nerve circuitry. This is consistent with the presence of prion aggregates in the intermediolateral columns of the thoracic spinal cord during early stages of prion infection [81, 82]. This route is particularly important during neuroinvasion by BSE prions in cattle, however, analysis of CWD prion accumulation following oral infection did not detect prion deposits in the coeliac ganglion of deer. This suggests that the accumulation of PrPCWD in the intermediolateral column of orally infected cervids results from the centrifugal dissemination of prions replicated within the central nervous system (CNS) [73].

The early lymphoid replication phase is particularly important for the neuroinvasion of CWD prions in deer [73, 74]. Interestingly, North American elk as well as Scandinavian moose and red deer accumulate PrPCWD in the brainstem with little to no accumulation in lymphoid tissues [46, 47, 83, 84]. This could be explained by a predominantly neural route of neuroinvasion (as in BSE pathogenesis), sporadic misfolding of PrPC or differences in the route of exposure. Differences in pathogenesis and neuropathology of sheep inoculated via different routes were not seen [85]. Similarly, no significant differences have been detected in the peripheral burden of CWD prions from deer infected through different routes [64]. Once neuroinvasion has occurred, PrPCWD accumulates producing the characteristic lesions of prion diseases, including intraneuronal vacuolation, neuropil spongiosis, gliosis and formation of amyloid plaques [86].

In addition to lymphoid and brain tissues, CWD prions have been detected in nasal mucosa, salivary glands, urinary bladder, pancreas, kidney, intestine and reproductive tract of female and male deer [15, 31, 64, 73, 87, 88]. The accumulation of PrPCWD in some of these tissues is tightly associated with shedding of infectivity through secretions and excretions [64]. Similar to scrapie in sheep [89], PRNP genotype can influence CWD pathogenesis in deer affecting PrPCWD deposition in peripheral tissues [13, 15, 31, 74, 90].

CWD in cervids

The origin of CWD remains unknown. In North America, epidemiological data suggests emergence occurred in Colorado and Wyoming [55], in the late 1960s, in captive mule deer (Odocoileus hemionus) and black-tailed deer (Odocoileus hemionus columbianus) at research facilities. These herds were captured cervids from different wild populations, including pregnant females that were released after parturition. Transfer of animals between facilities was a common practice [3]. CWD was subsequently detected in Rocky Mountain elk (Cervus elaphus nelsoni) at these facilities and, thereafter, in free-ranging populations of mule deer and elk in Wyoming and Colorado [3, 50, 91].

Cervid migration and commercial movement of preclinical animals contributed to the geographic expansion of CWD into free-ranging and captive populations of North America [42, 55]. To date, CWD occurs in at least 26 U.S. states and three Canadian provinces (Saskatchewan, Alberta and Québec). In Canada, CWD was first identified in farmed elk from Saskatchewan in 1996 [42]. In the following years, CWD was reported in farmed white-tailed deer in Alberta and in wild cervid populations from Saskatchewan and Alberta [92]. Epidemiological studies suggested that the infection was introduced into Saskatchewan farms via import of captive elk from a farm in South Dakota [42]. The origin of the CWD epidemic in wild cervids of Canada remains unknown. Transmission by contact exposure between wild deer and infected farmed elk is a possibility [92]. CWD was first detected in 2013 in wild moose from Alberta [93]. CWD has not, to date, been detected in the wild North American subspecies of caribou (Rangifer tarandus spp).

Outside of North America, CWD outbreaks in captive cervids in South Korean farms occurred following cohabitation with asymptomatic infected elk and deer imported between 1994 and 2003 from a farm in Saskatchewan (later determined to house CWD-infected animals [94]. A direct consequence was the transmission into South Korean captive red deer (Cervus elaphus), sika deer (Cervus nippon) and crosses of these two species [28]. Epidemiological studies of CWD in wild cervids from the Korean peninsula are lacking.

In 2016, CWD was identified in a free-ranging Norwegian reindeer (Rangifer tarandus tarandus), representing the first CWD case detected in Europe [2]. Since this event, thousands of cervids have been surveyed, leading to the detection of the CWD in 19 reindeer, 4 moose and one red deer in Norway, 3 moose in Sweden and one moose in Finland, suggesting that CWD has been quietly emerging in European cervids [46, 47, 95]. The origin of these cases is still unknown. Transmission of Norwegian CWD isolates into bank voles demonstrated the presence of strains different than those seen in North America, suggesting these epizootics are not epidemiologically linked [96]. In addition, importation of cervids to Norway is not allowed and, therefore, it is unlikely that these CWD infections emerged from imported positive animals as was the case for CWD in Korea [1].

The prevalence of CWD in North America has been increasing exponentially during the last 6 decades. In farmed herds the prevalence of CWD positive animals can be higher than 80% and higher than 45% in wild populations [41]. In areas where CWD has become enzootic, the CWD prevalence can be greater than 50% in adult males [97]. The latest Alberta CWD surveillance update (2019 fall hunting season) indicates that the prevalence of CWD continues to increase in all cervid species. Compared to the 2018 fall hunting season, the prevalence in the 2019 season saw an increase of 3.8% (from 7.4% in 2018 to 11.2% 2019 prevalence). Consistent with previous years, white-tailed and mule deer in Alberta and Saskatchewan show differences in prevalence between species and sexes. The prevalence rank among Alberta deer is mule deer males > mule deer females > white-tailed males > white-tailed females. The burden of CWD in Alberta wild elk has not been as extensive as in deer. In 2019, 1.3% of the tested elk resulted positive for CWD (0.8% in 2018). In addition, for the first time, CWD was detected in two hunter-harvested moose [98].

Population declines are observed in cervid herds with high CWD prevalence. CWD positive deer not only succumb to the disease but are also more prone to be killed by predators or hunters, and are more vulnerable to vehicle collisions [99]. Average declines in elk survival in Rocky Mountain National Park were attributed almost entirely to CWD [100] Mean annual survival rates of CWD-negative and CWD-positive deer were estimated as 76% and 32%, respectively, and CWD was considered a significant contributor to mule deer population decline [101]. Miller et al. also observed that the 2-year survival of infected and uninfected tagged wild mule deer was 47 and 82%, respectively [99].

Experimental CWD in cervid species

No natural cases of CWD have been described in some species of cervids, although they have proven to be susceptible to CWD following experimental exposure. These include the Asian muntjac (Muntiacus reevesi) [45] and fallow deer (Dama dama) [102]. Muntjac deer were successfully infected through oral and subcutaneous routes with CWD from white-tailed deer. Interestingly, PrPCWD was detected in fetuses from CWD-infected does, demonstrating vertical CWD transmission in this species [45]. Although fallow deer were suggested to show certain resistance to infection with CWD [103], Hamir et al. reported that this species is susceptible to the disease after intracerebral inoculation with elk and white-tailed deer prions [102]. The differences in these studies may have arisen because intracranial inoculation is more efficient to produce disease compared to environmental exposure, however, PrPC sequence and prion strain compatibility could also explain these differences [102, 103]. No natural cases of CWD have been reported in North American caribou, although these species are susceptible to experimental infection with CWD from mule deer, white-tailed deer and elk. Naive caribou can acquire the disease after oral infection [33] and environmental exposure [63]. A summary of this transmission experiments and the ones described below is included in Table 2.

Evaluating the potential transmission of CWD to non-cervid species

Most of the transmission studies of CWD into various animal species have been conducted with North American CWD isolates and have revealed different transmission patterns. The host range of European CWD isolates is still to be determined [95].

Livestock species The interactions between different animal species in captivity is a known factor favoring the emergence of new pathogens with novel zoonotic properties, as has been recently proposed as the origin of BSE in cattle by contact with sheep infected with atypical/Nor98 scrapie [104]. The distribution of CWD in North America could favor the interspecies transmission of cervid prions into cattle (i.e., overlapping of these species is common in CWD enzootic areas of North America). The transmission of a prion disease to the cattle is cause for alarm due to the potential emergence of BSE-like zoonotic capacity. CWD from different species (white-tailed deer, mule deer and elk) has been successfully transmitted to domestic cattle after intracerebral challenge with different attack rates [105,106,107,108]. The neuropathological and biochemical characteristics of bovine CWD are, however, clearly distinct from BSE [105]. In addition, oral infections in cattle with mule deer prions have been unsuccessful, and no positive transmission has been detected in this species after 10 years of environmental exposure to mule deer and elk CWD [109]. This demonstrates that an important species barrier limits the oral transmission of CWD to cattle.

In 2006, Hamir et al. reported the transmission of mule deer CWD into sheep via the intracranial route [110]. Only 2 of 8 inoculated lambs developed lesions compatible with a prion disease, and they expressed different PRNP genotypes at codons 136, 154 and 171, which are known to determine sheep susceptibility to scrapie [111,112,113]. One animal expressed ARQ/ARQ (subclinical) and one ARQ/VRQ (clinical) sheep. ARQ/ARR sheep were completely resistant to CWD inoculation, suggesting that the transmission of CWD to small ruminants is strongly determined by the host genotype, as seen with scrapie [110]. Clinical disease was described, however, in ARQ/ARQ sheep inoculated with elk CWD prions, which suggests a different strain in the elk isolate. Transgenic mice overexpressing the ovine VRQ PrP allele (tg338 mice) do not accumulate prions in the brain after experimental infection with a number of different CWD isolates [26, 114, 115]. These tg mice, however, efficiently replicate CWD prions in the spleen, suggesting that the lymphoid tissue is more permissive than the brain for interspecies transmission [26].

The susceptibility of pigs to CWD has also been investigated. Moore et al. found that white-tailed deer CWD prions can be detected by real-time quaking-induced conversion (RT-QuIC) in some orally and intracranially inoculated pigs when euthanized at market weight (8 months age, 6 months after inoculation). One aged pig showed clinical signs and, in these aged animals, PrPCWD was detectable by immunohistochemistry and Western blotting in 4/10 intracranially inoculated and in 1/10 orally inoculated pigs. Passages in transgenic mice expressing the porcine PrP showed reduced attack rates. Therefore, they concluded that pigs could support a low-level propagation of CWD prions, albeit with a high species barrier. These results are not necessarily encouraging since it is possible that feral pigs, whose ranges are shared with CWD affected cervids, could act as a reservoir of CWD [116].

Other wildlife species

Comparison of the PRNP sequences of different species of ungulates that inhabit CWD endemic areas showed high sequence identity between bighorn sheep (Ovis canadensis), mountain goats (Oreamnos americanus) and domestic sheep suggesting that these species are potentially susceptible to CWD [117]. No experimental challenges of these wildlife species, sympatric to deer in CWD-endemic areas have been performed yet.

Rodents

Several different rodent species sympatric with deer in CWD endemic areas including meadow voles (Microtus pennsylvanicus), red-backed voles (Myodes gapperi), white-footed mice (Peromyscus leucopus) and deer mice (P. maniculatus) have proven to be susceptible to CWD after experimental inoculation [118]. Among these species, meadow voles showed to be the most susceptible, but incubation periods were shortened in all the rodent species upon second passage, indicating CWD adaptation to these hosts. House mice (Mus musculus) live in close proximity to humans, and their susceptibility to particular CWD strains has been demonstrated [29]. It is possible that wild rodents represent a reservoir for CWD in ecosystems considering that these animals are scavengers, and one of the main sources of food for predators. In addition, they can be accidentally consumed by deer or livestock since rodent carcasses contaminate pastures and forage [118].

CWD is also transmissible to other rodent species that do not cohabitate with deer in CWD-affected regions. These include Syrian golden hamsters (Mesocricetus auratus) [119] and European bank voles (Myodes glareolus) [120]. Curiously, the adaptation of CWD to the European bank vole resulted in the identification of a prion strain (CWD-vole strain) with the shortest incubation period observed to date [120].

Carnivores

Ferrets (Mustela putorius) are a valuable model for the study of prions, including CWD [121,122,123]. Mink (Mustela vison) can also be infected with CWD, but only by intracerebral inoculation. The disease characteristics differed from those of TME-affected mink, demonstrating different strains cause CWD and TME, and suggest that mink are unlikely involved in natural CWD transmission [124].

Oral and intracerebral inoculation of mule deer prions into domestic cats (Felis catus) resulted in no clinical disease or low attack rates, respectively, on first passage. A second passage of the prions from the intracerebrally inoculated cats resulted in 100% of the recipient cats presenting with clinical disease while the second oral passage resulted in a 50% attack rate demonstrating the adaptability of CWD prions to felines [125]. The PrPC sequence similarity between cats and mountain lions (Puma concolor) suggests that these wild carnivores would be susceptible to CWD infection [126]. As mountain lions selectively prey CWD-infected cervids, it would be of interest to test dead animals for CWD to evaluate for prion spillover [127].

CWD prions from white-tailed deer and elk transmitted with low attack rates (25%) following intracerebral challenge in raccoons (Procyon lotor) [128]. Accumulation of protease resistant prions in the cerebrum and obex differed depending on the inoculum. Interestingly, prions from mule deer did not transmit to raccoons after 6 years following intracerebral challenge [129, 130]. This further suggests strain differences in CWD prions from the various cervid species affected.

Among all mammals, canids are probably the most resistant to prion diseases, with the amino acid residue 163 of canine PrPC conferring protection [131,132,133]. Oral exposure of captive coyotes (Canis latrans) to elk prions demonstrated the presence of prions in the coyote fecal material during the first days after consumption [134]. However, even after a large volume of infectious brain homogenate was inoculated, only 50% of exposed coyotes had detectable infectivity in feces between 1- and 4-days post-exposure (dpe) as evaluated by bioassay in tg12 mice (expressing elk PrPC), while the other half lacked detectable prions or were only recovered in feces after 1 day. No evidence of CWD accumulation in the coyote lymph tissue was detected [134]. These results suggest that coyotes were capable of degrading the CWD infectivity. Consistent with this interpretation, the attack rates were incomplete in tg12 mice inoculated with feces collected at various times following exposure. When inoculated with brain homogenates from CWD-infected elk, this transgenic mouse line develops prion disease with full attack rates after incubation periods of < 150 days post-infection [135]. In addition, in the wild, coyotes will likely consume a smaller infective dose as CWD infectivity in muscle and fat is lower than in the brain [51, 136]. The role of canine predators in the control of CWD has been discussed previously, suggesting that the selective predation exerted by wolves (Canis lupus), which hunt weak and vulnerable cervids, could represent an important natural tool to limit CWD contamination of the environment [137]. The reintroduction and protection of wolves in CWD-affected areas, although controversial, could be very efficient for the natural control of the disease.

Humans

To date, there is no clear evidence that CWD can cross the transmission barrier and infect humans, as other animal prions such as BSE [138]. Several epidemiological studies have been developed to assess whether, statistically, there are more cases of prion diseases in population groups living in endemic areas for CWD. These studies mainly consider people exposed to CWD-infected cervids, such as consumers of deer meat and hunters. None of these studies have found a clear correlation between CWD exposure and an increase in human prion disease frequency [90, 139,140,141]. Evaluating the risk of humans to CWD through this type of studies is difficult due to the variety of strains present in the environment, the transport of hunted animals between long distances and the long incubation period of prion diseases in humans (even decades).The identification of the zoonotic ability of an agent requires an abnormally high number of human cases within a particular geographical location or period of time, which necessitates a large number of human exposures to the disease. Prevalence of CWD in several areas has increased exponentially in the last decade, therefore, there may not historically have been a sufficient level of exposure to the disease to detect a zoonotic transmission of CWD.

There are tools, however, to evaluate the susceptibility of humans to CWD. These include bioassays in non-human primates and transgenic mice expressing human PrPC and in vitro studies of the human transmission barrier to CWD.

Squirrel monkeys (Saimiri sciureus) are susceptible to CWD prions from mule deer, elk and white-tailed deer after oral and intracerebral challenge [142, 143]. Race et al. did not observe evidence for CWD transmission to macaques (Macaca fascicularis) at 13 years post-inoculation and using ultra-sensitive techniques for the detection of prions [144]. In an ongoing study, macaques were exposed to different sources of CWD through various routes. Analysis of the tissues identified PrP deposition in the dorsal horns of the spinal cord in a subset of the macaques [145]. Similar PrP immunopositive staining affecting the spinal cord was also reported by Race et al.; these deposits were found in both CWD-challenged and uninoculated, aged macaques, suggesting that this staining was likely due to cellular PrP [144]. Evaluating the zoonotic potential to humans through bioassays in non-human primates has, however, several drawbacks. The degree of sequence similarity between human PrP and the PrP from non-human primates varies between 92.2 and 99.7% [146]. Even species with high sequence homology, such as chimpanzees, express amino acid substitutions in key structural motifs of PrP that could alter the transmission barrier of prions [146, 147]. Although chimpanzees are more closely related to humans, the presence of 2 amino acid polymorphisms adjacent and within the α2-β2 loop, an important structural motif modulating interspecies transmission of some prion strains [148], undermines their utility in testing the species barrier. In particular, the residue E168 in humans (Q168 in chimpanzees) appears to be fundamental for human reduced susceptibility to CWD and other prion strains from ruminants [149].

Transgenic mice expressing different variants of human PrPC (MM129, MV129 and VV129) at 1–16-fold the levels expressed in the human brain were challenged with US and Canadian CWD isolates in seven different studies. Elegantly reviewed by Waddell et al., none of these studies found evidence of transmission to any of the transgenic mice (reviewed by [141]). Studies in chimeric mice suggested that the α2–β2 loop of the prion protein is the key to the transmission barrier of humans to CWD [148]. However, a recent study found low levels of RT-QuIC seeding activity in four mice overexpressing human prion protein (MM129) inoculated with elk and white-tailed deer isolates (2 mice per inoculation group). These results need to be interpreted with caution, as these reactions were inconsistently positive perhaps representing poorly adapted CWD prions into human PrP or alternatively, persistence of the inoculum in the brain of these mice since human prions can physically persist even in knock-out mice for extended periods post-inoculation [149]. In addition, these RT-QuIC positive mice (tg66) express the highest levels of human PrP tested in CWD transmission studies (8–16 × compared to human brain), which could facilitate the replication of CWD in human PrP [150]. In contrast, the same CWD isolates when inoculated into the tgRM (2–4×) resulted in less clinical suspects and no positive detection by RT-QuIC [150].

Finally, the transmission barrier of humans for CWD has been studied using ultra-sensitive in vitro techniques. The first in vitro study suggested a substantial molecular barrier limiting susceptibility of humans to CWD [151]. Davenport et al. demonstrated positive seeding activity when human recombinant PrP was seeded with CWD, but not when using BSE, contradicting results observed in vivo [152]. Successful conversion of human PrP using different CWD seeds in PMCA has been reported by Barria et al. Their studies suggest that CWD from MM132 elk and CWD from reindeer have the highest potential to convert human PrP, followed by white-tailed deer prions and, finally, mule deer CWD isolates, which require an intermediate step of in vitro conditioning to deer substrate [153,154,155]. This positive conversion was achieved, however, in PMCA reactions using a large CWD prions-to- human substrate ratio [154].

Conclusions

The prevalence and geographic spread of CWD continues to rise, expanding the likelihood of transmission to other species. Particularly of concern in North America is the risk to caribou, an endangered species. Although canids appear to have resistance to infection by CWD prions, other carnivores, i.e., the big felids, are predicted to be susceptible to infection. The zoonotic potential is still unclear but the increased prevalence of CWD in cervids will result in greater likelihood of human exposure.

Abbreviations...snip...end



TUESDAY, SEPTEMBER 7, 2021 

Classical BSE prions emerge from asymptomatic pigs challenged with atypical/Nor98 scrapie


TUESDAY, SEPTEMBER 07, 2021 

Atypical Bovine Spongiform Encephalopathy BSE OIE, FDA 589.2001 FEED REGULATIONS, and Ingestion Therefrom


Fri, Sep 3, 2021 5:02 pm

comments comments@tahc.texas.govHide

To Terry Singeltary flounder9@verizon.net

Cc comments comments@tahc.texas.gov

Mr. Singeltary,

This email is to acknowledge receipt of your proposed rule comments. Thank you for your interest and participation in the Texas Animal Health Commission’s rulemaking process.

Sincerely,

Amanda 

Amanda Bernhard

Assistant to the Executive Director

Texas Animal Health Commission

512-719-0704

www.tahc.texas.gov 

***> 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

SEE FULL SCIENCE REFERENCES AND REASONINGS ;

Control of Chronic Wasting Disease OMB Control Number: 0579-0189 APHIS-2021-0004 Singeltary Submission



Docket No. APHIS-2018-0011 Chronic Wasting Disease Herd Certification



5 or 6 years quarantine is NOT LONG ENOUGH FOR CWD TSE PRION !!!

QUARANTINE NEEDS TO BE 21 YEARS FOR CWD TSE PRION !

FRIDAY, APRIL 30, 2021 

Should Property Evaluations Contain Scrapie, CWD, TSE PRION Environmental Contamination of the land?

***> Confidential!!!!

***> As early as 1992-3 there had been long studies conducted on small pastures containing scrapie infected sheep at the sheep research station associated with the Neuropathogenesis Unit in Edinburgh, Scotland. Whether these are documented...I don't know. But personal recounts both heard and recorded in a daily journal indicate that leaving the pastures free and replacing the topsoil completely at least 2 feet of thickness each year for SEVEN years....and then when very clean (proven scrapie free) sheep were placed on these small pastures.... the new sheep also broke out with scrapie and passed it to offspring. I am not sure that TSE contaminated ground could ever be free of the agent!! A very frightening revelation!!!

---end personal email---end...tss


WEDNESDAY, AUGUST 11, 2021 
 
TAHC Chapter 40, Chronic Wasting Disease Terry Singeltary Comment Submission
 

FRIDAY, SEPTEMBER 03, 2021 

Wisconsin Outagamie County Deer Farm Tests Positive for CWD


WEDNESDAY, SEPTEMBER 01, 2021 

Wisconsin Langlade County Deer Farm Tests Positive for CWD


WEDNESDAY, SEPTEMBER 01, 2021 

Michigan CWD TSE Prion 211 Cases To Date


TUESDAY, AUGUST 31, 2021 

TENNESSEE CWD TSE PRION CONFIRMED TO DATE 1300 POSITIVES IN 3 YEARS

''TURNS OUT WE HAVE A LOT OF IT, OVER A PRETTY BROAD AREA''


WEDNESDAY, AUGUST 25, 2021 

Arkansas CWD TSE Prion 1113 CONFIRMED TO DATE JUST TIP OF ICEBERG 

Public Meeting Mississippi, AR VIDEO 


TUESDAY, AUGUST 17, 2021 

Pennsylvania HUNTERS SHOULD BE AWARE OF ENHANCED CWD PROTECTIONS 08/17/2021

To date, CWD has been found in 727 deer. 


MONDAY, APRIL 26, 2021 

Missouri MDC REPORTS FINAL CWD RESULTS FOR 2020-2021 44 POSITIVE WITH TOTAL TO DATE 206 CONFIRMED


WEDNESDAY, AUGUST 18, 2021 

Mississippi CWD TSE Prion Confirmed 82 Positives (Since February 2018) With Suspect Positive 1


MONDAY, AUGUST 30, 2021 

MONTANA CWD TSE PRION UPDATE What's new for chronic wasting disease (CWD) management for 2021


MONDAY, AUGUST 30, 2021 

North Dakota CWD Big Game Transport Rules, Hunting Big Game Over Bait, 26 deer have tested positive to date


SUNDAY, AUGUST 15, 2021 

New Mexico CWD TEST RESULTS 1/19/2021 update


FRIDAY, AUGUST 13, 2021 

Ohio Annual Deer Program Summary Spring 2021 CWD TSE Prion Update


FRIDAY, AUGUST 13, 2021 

West Virginia DNR CWD TSE Prion CWD has been found in 451 white-tailed deer to date 


WEDNESDAY, AUGUST 18, 2021 

Utah 131 mule deer and three elk have tested positive for CWD in Utah, to date


Sent: Fri, Aug 27, 2021 11:08 am

Subject: Chronic Wasting Disease from pigs is infectious in transgenic mice expressing human PRNP

FRIDAY, AUGUST 27, 2021 

Chronic Wasting Disease from pigs is infectious in transgenic mice expressing human PRNP



FRIDAY, AUGUST 27, 2021 

Cattle are highly susceptible to white-tailed deer CWD and mule deer CWD in experimental conditions


SUNDAY, DECEMBER 20, 2020 

Second passage of chronic wasting disease of mule deer in sheep compared to classical scrapie after intracranial inoculation


THURSDAY, DECEMBER 19, 2019 

TSE surveillance statistics exotic species and domestic cats Update December 2019


we now know that cwd and scrapie, both tse prion disease, transmit to pigs by oral routes, so then we feed pigs back to other livestock animals. wonder where the new camel Prion disease outbreak came from?...terry

Open Access

Published: 31 August 2021

Classical BSE prions emerge from asymptomatic pigs challenged with atypical/Nor98 scrapie

Belén Marín, Alicia Otero, Séverine Lugan, Juan Carlos Espinosa, Alba Marín-Moreno, Enric Vidal, Carlos Hedman, Antonio Romero, Martí Pumarola, Juan J. Badiola, Juan María Torres, Olivier Andréoletti & Rosa Bolea 

Scientific Reports volume 11, Article number: 17428 (2021) Cite this article

108 Accesses

10 Altmetric

Metricsdetails

Abstract

Pigs are susceptible to infection with the classical bovine spongiform encephalopathy (C-BSE) agent following experimental inoculation, and PrPSc accumulation was detected in porcine tissues after the inoculation of certain scrapie and chronic wasting disease isolates. However, a robust transmission barrier has been described in this species and, although they were exposed to C-BSE agent in many European countries, no cases of natural transmissible spongiform encephalopathies (TSE) infections have been reported in pigs. Transmission of atypical scrapie to bovinized mice resulted in the emergence of C-BSE prions. Here, we conducted a study to determine if pigs are susceptible to atypical scrapie. To this end, 12, 8–9-month-old minipigs were intracerebrally inoculated with two atypical scrapie sources. Animals were euthanized between 22- and 72-months post inoculation without clinical signs of TSE. All pigs tested negative for PrPSc accumulation by enzyme immunoassay, immunohistochemistry, western blotting and bioassay in porcine PrP mice. Surprisingly, in vitro protein misfolding cyclic amplification demonstrated the presence of C-BSE prions in different brain areas from seven pigs inoculated with both atypical scrapie isolates. Our results suggest that pigs exposed to atypical scrapie prions could become a reservoir for C-BSE and corroborate that C-BSE prions emerge during interspecies passage of atypical scrapie.

snip...

In conclusion, our findings suggest that, although pigs present a strong transmission barrier against the propagation of atypical scrapie, they can propagate low levels of C-BSE prions. The prevalence of atypical scrapie and the presence of infectivity in tissues from atypical scrapie infected sheep are underestimated24,25. Given that pigs have demonstrated being susceptible to other prion diseases, and to propagate prions without showing signs of disease, the measures implemented to ban the inclusion of ruminant proteins in livestock feed must not be interrupted.


Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies Location: Virus and Prion Research

Title: Experimental transmission of the chronic wasting disease agent to swine after oral or intracranial inoculation

Author item MOORE, SARAH - Orise Fellow item WEST GREENLEE, M - Iowa State University item KONDRU, NAVEEN - Iowa State University item MANNE, SIREESHA - Iowa State University item Smith, Jodi item Kunkle, Robert item KANTHASAMY, ANUMANTHA - Iowa State University item Greenlee, Justin Submitted to: Journal of Virology Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/6/2017 Publication Date: 9/12/2017

Citation: Moore, S.J., West Greenlee, M.H., Kondru, N., Manne, S., Smith, J.D., Kunkle, R.A., Kanthasamy, A., Greenlee, J.J. 2017. Experimental transmission of the chronic wasting disease agent to swine after oral or intracranial inoculation. Journal of Virology. 91(19):e00926-17. https://doi.org/10.1128/JVI.00926-17.

Interpretive Summary: Chronic wasting disease (CWD) is a fatal disease of wild and captive deer and elk that causes damaging changes in the brain. The infectious agent is an abnormal protein called a prion that has misfolded from its normal state. Whether CWD can transmit to swine is unknown. This study evaluated the potential of pigs to develop CWD after either intracranial or oral inoculation. Our data indicates that swine do accumulate the abnormal prion protein associated with CWD after intracranial or oral inoculation. Further, there was evidence of abnormal prion protein accumulation in lymph nodes. Currently, swine rations in the U.S. could contain animal derived components including materials from deer or elk. In addition, feral swine could be exposed to infected carcasses in areas where CWD is present in wildlife populations. This information is useful to wildlife managers and individuals in the swine and captive cervid industries. These findings could impact future regulations for the disposal of offal from deer and elk slaughtered in commercial operations. U.S. regulators should carefully consider the new information from this study before relaxing feed ban standards designed to control potentially feed borne prion diseases.

Technical Abstract: Chronic wasting disease (CWD) is a naturally occurring, fatal neurodegenerative disease of cervids. The potential for swine to serve as a host for the agent of chronic wasting disease is unknown. The purpose of this study was to investigate the susceptibility of swine to the CWD agent following oral or intracranial experimental inoculation. Crossbred piglets were assigned to one of three groups: intracranially inoculated (n=20), orally inoculated (n=19), or non-inoculated (n=9). At approximately the age at which commercial pigs reach market weight, half of the pigs in each group were culled ('market weight' groups). The remaining pigs ('aged' groups) were allowed to incubate for up to 73 months post inoculation (MPI). Tissues collected at necropsy were examined for disease-associated prion protein (PrPSc) by western blotting (WB), antigen-capture immunoassay (EIA), immunohistochemistry (IHC) and in vitro real-time quaking induced conversion (RT-QuIC). Brain samples from selected pigs were also bioassayed in mice expressing porcine prion protein. Four intracranially inoculated aged pigs and one orally inoculated aged pig were positive by EIA, IHC and/or WB. Using RT-QuIC, PrPSc was detected in lymphoid and/or brain tissue from pigs in all inoculated groups. Bioassay was positive in 4 out of 5 pigs assayed. This study demonstrates that pigs can serve as hosts for CWD, though with scant PrPSc accumulation requiring sensitive detection methods. Detection of infectivity in orally inoculated pigs using mouse bioassay raises the possibility that naturally exposed pigs could act as a reservoir of CWD infectivity.


12 September 2017

Experimental Transmission of the Chronic Wasting Disease Agent to Swine after Oral or Intracranial Inoculation

Authors: S. Jo Moore, M. Heather West Greenlee, Naveen Kondru, Sireesha Manne, Jodi D. Smith, Robert A. Kunkle, Anumantha Kanthasamy, and Justin J. Greenlee 


AUTHORS INFO & AFFILIATIONS


Volume 91, Number 19

1 October 2017

ABSTRACT

Chronic wasting disease (CWD) is a naturally occurring, fatal neurodegenerative disease of cervids. The potential for swine to serve as hosts for the agent of CWD is unknown. The purpose of this study was to investigate the susceptibility of swine to the CWD agent following experimental oral or intracranial inoculation. Crossbred piglets were assigned to three groups, intracranially inoculated (n = 20), orally inoculated (n = 19), and noninoculated (n = 9). At approximately the age at which commercial pigs reach market weight, half of the pigs in each group were culled (“market weight” groups). The remaining pigs (“aged” groups) were allowed to incubate for up to 73 months post inoculation (mpi). Tissues collected at necropsy were examined for disease-associated prion protein (PrPSc) by Western blotting (WB), antigen capture enzyme immunoassay (EIA), immunohistochemistry (IHC), and in vitro real-time quaking-induced conversion (RT-QuIC). Brain samples from selected pigs were also bioassayed in mice expressing porcine prion protein. Four intracranially inoculated aged pigs and one orally inoculated aged pig were positive by EIA, IHC, and/or WB. By RT-QuIC, PrPSc was detected in lymphoid and/or brain tissue from one or more pigs in each inoculated group. The bioassay was positive in four out of five pigs assayed. This study demonstrates that pigs can support low-level amplification of CWD prions, although the species barrier to CWD infection is relatively high. However, detection of infectivity in orally inoculated pigs with a mouse bioassay raises the possibility that naturally exposed pigs could act as a reservoir of CWD infectivity. IMPORTANCE We challenged domestic swine with the chronic wasting disease agent by inoculation directly into the brain (intracranially) or by oral gavage (orally). Disease-associated prion protein (PrPSc) was detected in brain and lymphoid tissues from intracranially and orally inoculated pigs as early as 8 months of age (6 months post inoculation). Only one pig developed clinical neurologic signs suggestive of prion disease. The amount of PrPSc in the brains and lymphoid tissues of positive pigs was small, especially in orally inoculated pigs. Regardless, positive results obtained with orally inoculated pigs suggest that it may be possible for swine to serve as a reservoir for prion disease under natural conditions.


Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES Location: Virus and Prion Research

Title: Disease-associated prion protein detected in lymphoid tissues from pigs challenged with the agent of chronic wasting disease 

Conclusions: This study demonstrates that PrPSc accumulates in lymphoid tissues from pigs challenged intracranially or orally with the CWD agent, and can be detected as early as 4 months after challenge. CWD-infected pigs rarely develop clinical disease and if they do, they do so after a long incubation period. This raises the possibility that CWD-infected pigs could shed prions into their environment long before they develop clinical disease. Furthermore, lymphoid tissues from CWD-infected pigs could present a potential source of CWD infectivity in the animal and human food chains.



Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies Location: Virus and Prion Research

Title: The agent of chronic wasting disease from pigs is infectious in transgenic mice expressing human PRNP 

Author item MOORE, S - Orise Fellow item Kokemuller, Robyn item WEST-GREENLEE, M - Iowa State University item BALKEMA-BUSCHMANN, ANNE - Friedrich-Loeffler-institut item GROSCHUP, MARTIN - Friedrich-Loeffler-institut item Greenlee, Justin Submitted to: Prion Publication Type: Abstract Only Publication Acceptance Date: 5/10/2018 Publication Date: 5/22/2018 Citation: Moore, S.J., Kokemuller, R.D., West-Greenlee, M.H., Balkema-Buschmann, A., Groschup, M.H., Greenlee, J.J. 2018. The agent of chronic wasting disease from pigs is infectious in transgenic mice expressing human PRNP. Prion 2018, Santiago de Compostela, Spain, May 22-25, 2018. Paper No. WA15, page 44.

Interpretive Summary:

 The successful transmission of pig-passaged CWD to Tg40 mice reported here suggests that passage of the CWD agent through pigs results in a change of the transmission characteristics which reduces the transmission barrier of Tg40 mice to the CWD agent. If this biological behavior is recapitulated in the original host species, passage of the CWD agent through pigs could potentially lead to increased pathogenicity of the CWD agent in humans.


cwd scrapie pigs oral routes 

***> However, at 51 months of incubation or greater, 5 animals were positive by one or more diagnostic methods. Furthermore, positive bioassay results were obtained from all inoculated groups (oral and intracranial; market weight and end of study) suggesting that swine are potential hosts for the agent of scrapie. <*** 

>*** Although the current U.S. feed ban is based on keeping tissues from TSE infected cattle from contaminating animal feed, swine rations in the U.S. could contain animal derived components including materials from scrapie infected sheep and goats. These results indicating the susceptibility of pigs to sheep scrapie, coupled with the limitations of the current feed ban, indicates that a revision of the feed ban may be necessary to protect swine production and potentially human health. <*** 

***> Results: PrPSc was not detected by EIA and IHC in any RPLNs. All tonsils and MLNs were negative by IHC, though the MLN from one pig in the oral <6 month group was positive by EIA. PrPSc was detected by QuIC in at least one of the lymphoid tissues examined in 5/6 pigs in the intracranial <6 months group, 6/7 intracranial >6 months group, 5/6 pigs in the oral <6 months group, and 4/6 oral >6 months group. Overall, the MLN was positive in 14/19 (74%) of samples examined, the RPLN in 8/18 (44%), and the tonsil in 10/25 (40%). 

***> Conclusions: This study demonstrates that PrPSc accumulates in lymphoid tissues from pigs challenged intracranially or orally with the CWD agent, and can be detected as early as 4 months after challenge. CWD-infected pigs rarely develop clinical disease and if they do, they do so after a long incubation period. This raises the possibility that CWD-infected pigs could shed prions into their environment long before they develop clinical disease. Furthermore, lymphoid tissues from CWD-infected pigs could present a potential source of CWD infectivity in the animal and human food chains. 




Conclusions: This study demonstrates that PrPSc accumulates in lymphoid tissues from pigs challenged intracranially or orally with the CWD agent, and can be detected as early as 4 months after challenge. CWD-infected pigs rarely develop clinical disease and if they do, they do so after a long incubation period. This raises the possibility that CWD-infected pigs could shed prions into their environment long before they develop clinical disease. Furthermore, lymphoid tissues from CWD-infected pigs could present a potential source of CWD infectivity in the animal and human food chains.


CONFIDENTIAL

EXPERIMENTAL PORCINE SPONGIFORM ENCEPHALOPATHY

LINE TO TAKE

3. If questions on pharmaceuticals are raised at the Press conference, the suggested line to take is as follows:- 

 "There are no medicinal products licensed for use on the market which make use of UK-derived porcine tissues with which any hypothetical “high risk" ‘might be associated. The results of the recent experimental work at the CSM will be carefully examined by the CSM‘s Working Group on spongiform encephalopathy at its next meeting.

DO Hagger RM 1533 MT Ext 3201


While this clearly is a cause for concern we should not jump to the conclusion that this means that pigs will necessarily be infected by bone and meat meal fed by the oral route as is the case with cattle. ...


we cannot rule out the possibility that unrecognised subclinical spongiform encephalopathy could be present in British pigs though there is no evidence for this: only with parenteral/implantable pharmaceuticals/devices is the theoretical risk to humans of sufficient concern to consider any action.


May I, at the outset, reiterate that we should avoid dissemination of papers relating to this experimental finding to prevent premature release of the information. ...


3. It is particularly important that this information is not passed outside the Department, until Ministers have decided how they wish it to be handled. ...


But it would be easier for us if pharmaceuticals/devices are not directly mentioned at all. ...


Our records show that while some use is made of porcine materials in medicinal products, the only products which would appear to be in a hypothetically ''higher risk'' area are the adrenocorticotrophic hormone for which the source material comes from outside the United Kingdom, namely America China Sweden France and Germany. The products are manufactured by Ferring and Armour. A further product, ''Zenoderm Corium implant'' manufactured by Ethicon, makes use of porcine skin - which is not considered to be a ''high risk'' tissue, but one of its uses is described in the data sheet as ''in dural replacement''. This product is sourced from the United Kingdom.....


***> CHRONIC WASTING DISEASE TSE PRP HUMANS ZOONOSIS ZOONOTIC <***

WHAT WE HAVE HERE, IS A LACK OF COMMUNICATION!

seems to me we might have another zoonotic tse prion disease, OR multiple new tse prion zoonotic diseases, that no one wants to talk about, and that's bad...terry

i thought i might share some news about cwd zoonosis that i got, that i cannot share or post to the public yet, i promised for various reasons, one that it will cause a shit storm for sure, but it was something i really already knew from previous studies, but, i was told that ;

==================

''As you can imagine, 2 and 5 (especially 5) may raise alarms.  The evidence we have for 4 are not as strong or tight as I would like to have.   At this point, please do not post any of the points publicly yet, but you can refer to points 1-3 in private discussions and all 5 points when discussing with relevant public officials to highlight the long-term risks of CWD zoonosis.''

====================

so, i figure your as about as official as it gets, and i think this science is extremely important for you to know and to converse about with your officials. it's about to burn a whole in my pocket. this is about as close as it will ever get for cwd zoonosis to be proven in my time, this and what Canada Czub et al found with the Macaques, plus an old study from cjd surveillance unit back that showed cjd and a 9% increase in risk from folks that eat venison, i will post all this below for your files Sir. i remember back in the BSE nvCJD days, from when the first BSE case in bovine was confirmed around 1984 maybe 83, i forget the good vets named that screwed it up first, Carol something, but from 83ish to 95 96 when nvCJD was linked to humans from BSE in cattle, so that took 10 to 15 years. hell, at that rate, especially with Texas and cwd zoonsis, hell, i'll be dead before it's official, if ever, so here ya go Sir. there was a grant study on cwd zoonosis that had been going on for some time, i followed it over the years, then the grant date for said study had expired, so, i thought i would write the good Professor about said study i.e. Professor Kong, CWRU et al. i will post the grant study abstract first, and then after that, what reply i got back, about said study that i was told not to post/publish...

CWD ZOONOSIS GRANT FIRST;

===============

Cervid to human prion transmission

Kong, Qingzhong 

Case Western Reserve University, Cleveland, OH, United States

 Abstract 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.

 Funding Agency Agency National Institute of Health (NIH) Institute National Institute of Neurological Disorders and Stroke (NINDS) Type Research Project (R01) Project # 1R01NS088604-01A1 Application # 9037884 Study Section Cellular and Molecular Biology of Neurodegeneration Study Section (CMND) Program Officer Wong, May Project Start 2015-09-30 Project End 2019-07-31 Budget Start 2015-09-30 Budget End 2016-07-31 Support Year 1 Fiscal Year 2015 Total Cost $337,507 Indirect Cost $118,756

snip... 


Professor Kongs reply to me just this month about above grant study that has NOT been published in peer reveiw yet...

=================================

Here is a brief summary of our findings:

snip...can't post, made a promise...tss

On Sat, Apr 3, 2021 at 12:19 PM Terry Singeltary <flounder9@verizon.net> wrote:

snip...

end...tss

==============

CWD ZOONOSIS THE FULL MONTY TO DATE

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.






SUNDAY, JULY 25, 2021 

North American and Norwegian Chronic Wasting Disease prions exhibit different potential for interspecies transmission and zoonotic risk 

''Our data suggest that reindeer and red deer from Norway could be the most transmissible CWD prions to other mammals, whereas North American CWD prions were more prone to generate human prions in vitro.''


MONDAY, JULY 19, 2021 

***> U Calgary researchers at work on a vaccine against a fatal infectious disease affecting deer and potentially people


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.

=====

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.

=====

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.

=====

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:


=====

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.

=====

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.

=====

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.

=====

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.

=====

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;



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 ;




Stephen Dealler is a consultant medical microbiologist  deal@airtime.co.uk 

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) <***


North American and Norwegian Chronic Wasting Disease prions exhibit different potential for interspecies transmission and zoonotic risk

Sandra Pritzkow1,*, Damian Gorski1,*, Frank Ramirez1 , Glenn C. Telling2 , Sylvie L. Benestad3 and Claudio Soto1,#

1 Mitchell Center for Alzheimer's disease and related Brain disorders, Department of Neurology, University of Texas McGovern Medical School at Houston, Texas, USA 2 Prion Research Center, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA 3 Norwegian Veterinary Institute, OIE Reference Laboratory for CWD, Oslo, Norway.

Summary: We investigated the in vitro spillover and zoonotic potential of CWD from various cervid species. Our results suggest that Norway CWD prions have a higher potential to infect other animals, but NorthAmerican CWD appear more prone to generate human prions.

The current evidence for CWD transmission to humans is controversial; indeed, while transgenic mice expressing human PrP did not develop disease when challenged with CWD prions in various laboratories [6-8, 41], experimental inoculation of CWD into squirrel monkeys produced disease [9, 10]. Studies in macaques, which are phylogenetically closer to humans than squirrel monkeys [45] have shown mixed results. A study from Czub and colleagues found that CWD prions can induce disease and pathologic abnormalities typical of prion disease in macaques exposed to CWD prions, even by oral inoculation of muscle tissue from cervids affected by CWD [46]. However, a different study found no evidence for prion disease in macaques inoculated with CWD [47]. To assess the cervid/human species barrier, we previously used PMCA to determine prion replication in vitro. We found that, after stabilization by successive passages in deer PrPC, PrPSc from CWD infected deer can convert human PrPC into a novel form of PrPSc [13]. Our current study to evaluate in vitro zoonotic potential of various CWD prions showed that although the cervid/human barrier is large, we were able to observe generation of human PrPSc with some specific CWD strains in a second round of PMCA (Fig. 5). The three North American CWD isolates were capable to sustain generation of human PrPSc, with white-tailed deer showing the highest efficiency. Conversely, none of the three Norway CWD isolates generated any detectable PrPSc signal up to the second round of PMCA. This data suggest that North American CWD prions might be of a greater risk to humans than the infected animals in Northern Europe. We speculate that these differences might be due to Norwegian CWD being less stable prion strains as compared to North American CWD, which have had longer time to replicate in cervids and become stabilized through many rounds of natural infection. Our findings may provide important information to understand the diversity of natural CWD prion strains in different animals across distinct geographical areas and their consequences for the spillover into other animal species, including humans.


MONDAY, JULY 19, 2021 

U Calgary researchers at work on a vaccine against a fatal infectious disease affecting deer and potentially people


TUESDAY, JULY 13, 2021

Chronic Wasting Disease and the Canadian Agriculture and Agri-food Sectors Current Knowledge Risks and Policy Options

''The science is progressing on the possibility of transmission of CWD to humans through oral transmission, but the complete assessment of this possibility remains to be done.''


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?


TUESDAY, MAY 11, 2021 
 
A Unique Presentation of Creutzfeldt-Jakob Disease in a Patient Consuming Deer Antler Velvet

Conclusion

We believe that our patient’s case of CJD is highly suspicious for cervid etiology given the circumstances of the case as well as the strong evidence of plausibility reported in published literature. This is the first known case of CJD in a patient who had consumed deer antler velvet. Despite the confirmed diagnosis of CJD, a causal relationship between the patient’s disease and his consumption of deer antler velvet cannot be definitively concluded.

Supplemental data including molecular tissue sample analysis and autopsy findings could yield further supporting evidence. Given this patient’s clinical resemblance to CBD and the known histological similarities of CBD with CJD, clinicians should consider both diseases in the differential diagnosis of patients with a similarly esoteric presentation. Regardless of the origin of this patient’s disease, it is clear that the potential for prion transmission from cervids to humans should be further investigated by the academic community with considerable urgency. 


''We believe that our patient’s case of CJD is highly suspicious for cervid etiology given the circumstances of the case as well as the strong evidence of plausibility reported in published literature. This is the first known case of CJD in a patient who had consumed deer antler velvet. Despite the confirmed diagnosis of CJD, a causal relationship between the patient’s disease and his consumption of deer antler velvet cannot be definitively concluded.''
 
https://creutzfeldt-jakob-disease.blogspot.com/2021/05/a-unique-presentation-of-creutzfeldt.html

ABOUT that deer antler spray and CWD TSE PRION...
 
I have been screaming this since my neighbors mom died from cjd, and she had been taking a supplement that contained bovine brain, bovine eyeball, and other SRMs specified risk materials, the most high risk for mad cow disease.
just saying...
 
I made a submission to the BSE Inquiry long ago during the BSE Inquiry days, and they seemed pretty interested.
 
Sender: "Patricia Cantos"
 
To: "Terry S Singeltary Sr. (E-mail)"
 
Subject: Your submission to the Inquiry
 
Date: Fri, 3 Jul 1998 10:10:05 +0100
 
3 July 1998
 
Mr Terry S Singeltary Sr.
 
E-Mail: Flounder at wt.net
 
Ref: E2979
 
Dear Mr Singeltary,
 
Thank you for your E-mail message of the 30th of June 1998 providing the Inquiry with your further comments.
 
Thank you for offering to provide the Inquiry with any test results on the nutritional supplements your mother was taking before she died.
 
As requested I am sending you our general Information Pack and a copy of the Chairman's letter. Please contact me if your system cannot read the attachments.
 
Regarding your question, the Inquiry is looking into many aspects of the scientific evidence on BSE and nvCJD. I would refer you to the transcripts of evidence we have already heard which are found on our internet site at ;
 
 
Could you please provide the Inquiry with a copy of the press article you refer to in your e-mail? If not an approximate date for the article so that we can locate it?
 
In the meantime, thank you for you comments. Please do not hesitate to contact me on...
 
snip...end...tss
 
everyone I tell this too gets it screwed up...MY MOTHER WAS NOT TAKING THOSE SUPPLEMENTS IPLEX (that I ever knew of). this was my neighbors mother that died exactly one year _previously_ and to the day of sporadic CJD that was diagnosed as Alzheimer’s at first. my mother died exactly a year later from the Heidenhain Variant of Creutzfeldt Jakob Disease hvCJD, and exceedingly rare strains of the ever growing sporadic CJD’s. _both_ cases confirmed. ...kind regards, terry
 
TSEs i.e. mad cow disease's BSE/BASE and NUTRITIONAL SUPPLEMENTS
 
IPLEX, mad by standard process;
 
vacuum dried bovine BRAIN, bone meal, bovine EYE, veal Bone, bovine liver powder, bovine adrenal, vacuum dried bovine kidney, and vacuum dried porcine stomach.
 
also;
 
what about potential mad cow candy bars ?
 
see their potential mad cow candy bar list too...
 
THESE are just a few of MANY of just this ONE COMPANY...TSS
 
DEPARTMENT OF HEALTH AND HUMAN SERVICES
 
FOOD AND DRUG ADMINISTRATION CENTER FOR BIOLOGICS EVALUATION AND RESEARCH
 
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES ADVISORY COMMITTEE
 
Friday, January 19, 2001 snip...
 
17 But I think that we could exhibit some quite
 
18 reasonable concern about blood donors who are taking dietary
 
19 supplements that contain a certain amount of unspecified-
 
20 origin brain, brain-related, brain and pituitary material.
 
21 If they have done this for more than a sniff or something
 
22 like that, then, perhaps, they should be deferred as blood
 
23 donors.
 
24 That is probably worse than spending six months in
 
25 the U.K.
 
1/19/01
 
3681t2.rtf(845) page 501
 
 
 
 
see full text ;
 

Saturday, May 1, 2021 

Clinical Use of Improved Diagnostic Testing for Detection of Prion Disease

https://prionprp.blogspot.com/2021/05/clinical-use-of-improved-diagnostic.html
TUESDAY, MAY 11, 2021 
 
A Unique Presentation of Creutzfeldt-Jakob Disease in a Patient Consuming Deer Antler Velvet
 

Thursday, July 29, 2021 

TSE PRION OCCUPATIONAL EXPOSURE VIA ANIMAL OR HUMAN, iatrogenic transmission, nvCJD or sCJD, what if? 


Wednesday, July 28, 2021 

France issues moratorium on prion research after fatal brain disease strikes two lab workers


TUESDAY, AUGUST 03, 2021 

USA Tables of Cases Examined National Prion Disease Pathology Surveillance Center Cases Examined July 9th, 2021


JOHN CORNYN TEXAS UNITED STATES SENATE WASHINGTON, DC 20510-4305 April 26,2005
Mr. Terry Singeltary

P.O. Box 

Bacliff, Texas 77518

Dear Mr. Singeltary:

In response to your recent request for my assistance, I have contacted the National Institutes of Health. I will write you again as soon as I receive a reply. I appreciate having the opportunity to represent you in the United States Senate and to be of service in this matter.

Sincerely,

JOHN CORNYN United States Senator JC:djl 

=============== 

JOHN CORNYN TEXAS UNITED STATES SENATE WASHINGTON, DC 20510-4305

May 18,2005

Mr. Terry Singeltary

P.O. Box 

Bacliff, Texas 77518

Dear Mr. Singeltary:

Enclosed is the reply I received from the Department of Health and Human Services in response to my earlier inquiry on your behalf. I hope this will be useful to you. I appreciate having the opportunity to represent you in the United States Senate. Thank you for taking time to contact me. Sincerely,

JOHN CORNYN United States Senate JC:djl Enclosure

DEPARTMENT OF HEALTH & HUMAN SERVICES National Institutes of Health National Institute of Neurological Disorders and Stroke NINDS Building 31, Room 8A52 31 Center Dr., MSC 2540 Bethesda, Maryland 20892-2540 Phone: 301-496-9746 Fax: 301-496-0296 Email: [log in to unmask]

May 10, 2005

The Honorable John Cornyn United States Senator Occidental Tower5005 LBJ Freeway, Suite 1150Dallas, Texas 75244-6199

Dear Senator Cornyn:

Your letter to the National Institutes of Health (NIH) forwarding correspondence from Mr. Terry S. Singeltary, Sr., has been forwarded to me for reply. Mr. Singeltary is concerned about the preservation of Creutzfeldt-Jakob disease (CJD) brain samples that have been maintained by the National Institute of Neurological Disorders and Stroke (NINDS) Intramural Research program for many years. I am sorry to learn that Mr. Singeltary's mother died of CJD and can certainly understand his desire that any tissues that could help investigators unravel the puzzle of this deadly disease are preserved. I hope he will be pleased to learn that all the brains and other tissues with potential to help scientists learn about CJD are, and will continue to be, conserved. (The tissues that are discarded are those that have either decayed to an extent that renders them no longer appropriate for research or those for which we do not have sufficient identification.) The purpose of gathering these brains and tissues is to help scientists learn about CJD. To that end, some of the NINDS-held samples are distributed to investigators who can demonstrate that they have a compelling research or public health need for such materials. For example, samples have been transferred to NIH grantee Dr. Pierluigi Gambetti, who heads the National Prion Diseases Pathology Surveillance Center at Case Western Reserve University in Ohio and works with the Centers for Disease Control and Prevention to monitor all cases of CJD in the United States. Dr. Gambetti studies the tissues to learn about the formation, physical and chemical properties, and pathogenic mechanisms of prion proteins, which are believed to be involved inthe cause of CJD. Samples have also been transferred to Dr. David Asher, at the U.S. Food and Drug Administration, for use in assessing a potential diagnostic test for CJD.

Page 2 - The Honorable John Cornyn

in closing, we know that donating organs and tissue from loved ones is a very difficult and personal choice that must often be made at the most stressful of times. We at the NINDS are grateful to those stalwart family members who make this choice in the selfless hope that it will help others afflicted with CJD. We also know the invaluable contribution such donations make to the advancement of medical science, and we are dedicated to the preservation of all of the tissue samples that can help in our efforts to overcome CJD.

I hope this information is helpful to you in responding to Mr. Singeltary. Sincerely,

Story C. Landis, Ph.D. Director, National Institute of Neurological Disorders and Stroke

snip...see full text;



Diagnosis and Reporting of Creutzfeldt-Jakob Disease Singeltary, Sr et al. 

JAMA.2001; 285: 733-734. Vol. 285 No. 6, February 14, 2001 JAMA 

Diagnosis and Reporting of Creutzfeldt-Jakob Disease 

To the Editor: In their Research Letter, Dr Gibbons and colleagues1 reported that the annual US death rate due to Creutzfeldt-Jakob disease (CJD) has been stable since 1985. These estimates, however, are based only on reported cases, and do not include misdiagnosed or preclinical cases. It seems to me that misdiagnosis alone would drastically change these figures. An unknown number of persons with a diagnosis of Alzheimer disease in fact may have CJD, although only a small number of these patients receive the postmortem examination necessary to make this diagnosis. Furthermore, only a few states have made CJD reportable. Human and animal transmissible spongiform encephalopathies should be reportable nationwide and internationally.. 

Terry S. Singeltary, Sr Bacliff, Tex 1. Gibbons RV, Holman RC, Belay ED, Schonberger LB. Creutzfeldt-Jakob disease in the United States: 1979-1998. JAMA. 2000;284:2322-2323. 


doi:10.1016/S1473-3099(03)00715-1 Copyright © 2003 Published by Elsevier Ltd. Newsdesk

Tracking spongiform encephalopathies in North America

Xavier Bosch

Available online 29 July 2003. 

Volume 3, Issue 8, August 2003, Page 463 

“My name is Terry S Singeltary Sr, and I live in Bacliff, Texas. I lost my mom to hvCJD (Heidenhain variant CJD) and have been searching for answers ever since. What I have found is that we have not been told the truth. CWD in deer and elk is a small portion of a much bigger problem..” 



January 28, 2003; 60 (2) VIEWS & REVIEWS

RE-Monitoring the occurrence of emerging forms of Creutzfeldt-Jakob disease in the United States Terry S. Singeltary, retired (medically) 

Published March 26, 2003

26 March 2003

Terry S. Singeltary, retired (medically) CJD WATCH

I lost my mother to hvCJD (Heidenhain Variant CJD). I would like to comment on the CDC's attempts to monitor the occurrence of emerging forms of CJD. Asante, Collinge et al [1] have reported that BSE transmission to the 129-methionine genotype can lead to an alternate phenotype that is indistinguishable from type 2 PrPSc, the commonest sporadic CJD. However, CJD and all human TSEs are not reportable nationally. CJD and all human TSEs must be made reportable in every state and internationally. I hope that the CDC does not continue to expect us to still believe that the 85%+ of all CJD cases which are sporadic are all spontaneous, without route/source. We have many TSEs in the USA in both animal and man. CWD in deer/elk is spreading rapidly and CWD does transmit to mink, ferret, cattle, and squirrel monkey by intracerebral inoculation. With the known incubation periods in other TSEs, oral transmission studies of CWD may take much longer. Every victim/family of CJD/TSEs should be asked about route and source of this agent. To prolong this will only spread the agent and needlessly expose others. In light of the findings of Asante and Collinge et al, there should be drastic measures to safeguard the medical and surgical arena from sporadic CJDs and all human TSEs. I only ponder how many sporadic CJDs in the USA are type 2 PrPSc?


SPORADIC CJD LAYING ODDS


In brief

BMJ 2000; 320 doi: https://doi.org/10.1136/bmj.320.7226.8/b (Published 01 January 2000)

Cite this as: BMJ 2000;320:8

Rapid Response:

02 January 2000

Terry S Singeltary

retired

U.S. Scientist should be concerned with a CJD epidemic in the U.S., as well... In reading your short article about 'Scientist warn of CJD epidemic' news in brief Jan. 1, 2000. I find the findings in the PNAS old news, made famous again. Why is the U.S. still sitting on their butts, ignoring the facts? We have the beginning of a CJD epidemic in the U.S., and the U.S. Gov. is doing everything in it's power to conceal it.

The exact same recipe for B.S.E. existed in the U.S. for years and years. In reading over the Qualitative Analysis of BSE Risk Factors-1, this is a 25 page report by the USDA:APHIS:VS. It could have been done in one page. The first page, fourth paragraph says it all;

"Similarities exist in the two countries usage of continuous rendering technology and the lack of usage of solvents, however, large differences still remain with other risk factors which greatly reduce the potential risk at the national level."

Then, the next 24 pages tries to down-play the high risks of B.S.E. in the U.S., with nothing more than the cattle to sheep ratio count, and the geographical locations of herds and flocks. That's all the evidence they can come up with, in the next 24 pages.

Something else I find odd, page 16;

"In the United Kingdom there is much concern for a specific continuous rendering technology which uses lower temperatures and accounts for 25 percent of total output. This technology was _originally_ designed and imported from the United States. However, the specific application in the production process is _believed_ to be different in the two countries."

A few more factors to consider, page 15;

"Figure 26 compares animal protein production for the two countries. The calculations are based on slaughter numbers, fallen stock estimates, and product yield coefficients. This approach is used due to variation of up to 80 percent from different reported sources. At 3.6 million tons, the United States produces 8 times more animal rendered product than the United Kingdom."

"The risk of introducing the BSE agent through sheep meat and bone meal is more acute in both relative and absolute terms in the United Kingdom (Figures 27 and 28). Note that sheep meat and bone meal accounts for 14 percent, or 61 thousand tons, in the United Kingdom versus 0.6 percent or 22 thousand tons in the United States. For sheep greater than 1 year, this is less than one-tenth of one percent of the United States supply."

"The potential risk of amplification of the BSE agent through cattle meat and bone meal is much greater in the United States where it accounts for 59 percent of total product or almost 5 times more than the total amount of rendered product in the United Kingdom."

Considering, it would only take _one_ scrapie infected sheep to contaminate the feed. Considering Scrapie has run rampant in the U.S. for years, as of Aug. 1999, 950 scrapie infected flocks. Also, Considering only one quarter spoonful of scrapie infected material is lethal to a cow.

Considering all this, the sheep to cow ration is meaningless. As I said, it's 24 pages of B.S.e.

To be continued...

Terry S. Singeltary Sr.

Bacliff, Texas USA

Competing interests: No competing interests


Rapid response to:

US scientists develop a possible test for BSE

15 November 1999

Terry S Singeltary

NA

BMJ 1999; 319 doi: https://doi.org/10.1136/bmj.319.7220.1312b (Published 13 November 1999)

Cite this as: BMJ 1999;319:1312

Article Related content Article metrics 

Rapid responses 

Response Rapid Response: Re: vCJD in the USA * BSE in U.S. In reading the recent article in the BMJ about the potential BSE tests being developed in the U.S. and Bart Van Everbroeck reply. It does not surprize me, that the U.S. has been concealing vCJD. There have been people dying from CJD, with all the symptoms and pathological findings that resemble U.K. vCJD for some time. It just seems that when there is one found, they seem to change the clarical classification of the disease, to fit their agenda. I have several autopsies, stating kuru type amyloid plaques, one of the victims was 41 years of age. Also, my Mom died a most hideous death, Heidenhain Variant Creutzfeldt Jakob disease. Her symptoms resemble that of all the U.K. vCJD victims. She would jerk so bad at times, it would take 3 of us to hold her down, while she screamed "God, what's wrong with me, why can't I stop this." 1st of symptoms to death, 10 weeks, she went blind in the first few weeks. But, then they told me that this was just another strain of sporadic CJD. They can call it what ever they want, but I know what I saw, and what she went through. Sporadic, simply means, they do not know. My neighbors Mom also died from CJD. She had been taking a nutritional supplement which contained the following; vacuum dried bovine BRAIN, bone meal, bovine EYE, veal bone, bovine liver powder, bovine adrenal, vacuum dried bovine kidney, and vacuum dried porcine stomach. As I said, this woman taking these nutritional supplements, died from CJD. The particular batch of pills that was located, in which she was taking, was tested. From what I have heard, they came up negative, for the prion protein. But, in the same breath, they said their testing, may not have been strong enough to pick up the infectivity. Plus, she had been taking these type pills for years, so, could it have come from another batch?

CWD is just a small piece of a very big puzzle. I have seen while deer hunting, deer, squirrels and birds, eating from cattle feed troughs where they feed cattle, the high protein cattle by products, at least up until Aug. 4, 1997.

So why would it be so hard to believe that this is how they might become infected with a TSE. Or, even by potentially infected land. It's been well documented that it could be possible, from scrapie. Cats becoming infected with a TSE. Have you ever read the ingredients on the labels of cat and dog food? But, they do not put these tissues from these animals in pharmaceuticals, cosmetics, nutritional supplements, hGH, hPG, blood products, heart valves, and the many more products that come from bovine, ovine, or porcine tissues and organs. So, as I said, this CWD would be a small piece of a very big puzzle. But, it is here, and it most likely has killed. You see, greed is what caused this catastrophe, rendering and feeding practices. But, once Pandora's box was opened, the potential routes of infection became endless.

No BSE in the U.S.A.? I would not be so sure of that considering that since 1990;

Since 1990 the U.S. has raised 1,250,880,700 cattle;

Since 1990 the U.S. has ONLY checked 8,881 cattle brains for BSE, as of Oct. 4, 1999;

There are apprx. 100,000 DOWNER cattle annually in the U.S., that up until Aug. 4, 1997 went to the renders for feed;

Scrapie running rampant for years in the U.S., 950 infected FLOCKS, as of Aug. 1999;

Our feeding and rendering practices have mirrored that of the U.K. for years, some say it was worse. Everything from the downer cattle, to those scrapie infected sheep, to any roadkill, including the city police horse and the circus elephant went to the renders for feed and other products for consumption. Then they only implemented a partial feed ban on Aug. 4, 1997, but pigs, chickens, dogs, and cats, and humans were exempt from that ban. So they can still feed pigs and chickens those potentially TSE tainted by-products, and then they can still feed those by-products back to the cows. I believe it was Dr. Joe Gibbs, that said, the prion protein, can survive the digestinal track. So you have stopped nothing. It was proven in Oprah Winfrey's trial, that Cactus Cattle feeders, sent neurologically ill cattle, some with encephalopathy stamped on the dead slips, were picked up and sent to the renders, along with sheep carcasses. Speaking of autopsies, I have a stack of them, from CJD victims. You would be surprised of the number of them, who ate cow brains, elk brains, deer brains, or hog brains.

I believe all these TSE's are going to be related, and originally caused by the same greedy Industries, and they will be many. Not just the Renders, but you now see, that they are re-using medical devices that were meant for disposal. Some medical institutions do not follow proper auto- claving procedures (even Olympus has put out a medical warning on their endescopes about CJD, and the fact you cannot properly clean these instruments from TSE's), and this is just one product. Another route of infection.

Regardless what the Federal Government in the U.S. says. It's here, I have seen it, and the longer they keep sweeping it under the rug and denying the fact that we have a serious problem, one that could surpass aids (not now, but in the years to come, due to the incubation period), they will be responsible for the continued spreading of this deadly disease.

It's their move, it's CHECK, but once CHECKMATE has been called, how many thousands or millions, will be at risk or infected or even dead. You can't play around with these TSE's. I cannot stress that enough. They are only looking at body bags, and the fact the count is so low. But, then you have to look at the fact it is not a reportable disease in most states, mis-diagnosis, no autopsies performed. The fact that their one-in-a- million theory is a crude survey done about 5 years ago, that's a joke, under the above circumstances. A bad joke indeed........

The truth will come, but how many more have to die such a hideous death. It's the Government's call, and they need to make a serious move, soon. This problem, potential epidemic, is not going away, by itself.

Terry S. Singeltary Sr.

Bacliff, Texas 77518 USA


Competing interests: No competing interests


Terry S. Singeltary Sr.

posted by Terry S. Singeltary Sr. at 11:14 AM

0 Comments:

Post a Comment

Subscribe to Post Comments [Atom]

<< Home