scholarly journals Demographic risk factors for classical and atypical scrapie in Great Britain

2007 ◽  
Vol 88 (12) ◽  
pp. 3486-3492 ◽  
Author(s):  
Darren M. Green ◽  
Victor J. del Rio Vilas ◽  
Colin P. D. Birch ◽  
Jethro Johnson ◽  
Istvan Z. Kiss ◽  
...  
Keyword(s):  
European Union ◽  
Great Britain ◽  
Classical Scrapie ◽  
Transmissible Spongiform Encephalopathies ◽  
Spongiform Encephalopathy ◽  
Atypical Scrapie ◽  
The European Union ◽  
Spongiform Encephalopathies ◽  
Breeding Programmes ◽  
Trading Network

Following the bovine spongiform encephalopathy (BSE) crisis, the European Union has introduced policies for eradicating transmissible spongiform encephalopathies (TSEs), including scrapie, from large ruminants. However, recent European Union surveillance has identified a novel prion disease, ‘atypical’ scrapie, substantially different from classical scrapie. It is unknown whether atypical scrapie is naturally transmissible or zoonotic, like BSE. Furthermore, cases have occurred in scrapie-resistant genotypes that are targets for selection in legislated selective breeding programmes. Here, the first epidemiological study of British cases of atypical scrapie is described, focusing on the demographics and trading patterns of farms and using databases of recorded livestock movements. Triplet comparisons found that farms with atypical scrapie stock more sheep than those of the general, non-affected population. They also move larger numbers of animals than control farms, but similar numbers to farms reporting classical scrapie. Whilst there is weak evidence of association through sheep trading of farms reporting classical scrapie, atypical scrapie shows no such evidence, being well-distributed across regions of Great Britain and through the sheep-trading network. Thus, although cases are few in number so far, our study suggests that, should natural transmission of atypical scrapie be occurring at all, it is doing so slowly.

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

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Belén Marín ◽  
Alicia Otero ◽  
Séverine Lugan ◽  
Juan Carlos Espinosa ◽  
Alba Marín-Moreno ◽  
...  
Keyword(s):  
Protein Misfolding ◽  
Clinical Signs ◽  
Transmissible Spongiform Encephalopathies ◽  
Spongiform Encephalopathy ◽  
Post Inoculation ◽  
Atypical Scrapie ◽  
Wasting Disease ◽  
Spongiform Encephalopathies ◽  
Robust Transmission

AbstractPigs 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.

scholarly journals Analysis of the PRNP gene polymorphisms in healthy Greek sheep during 2012 – 2016

2018 ◽  
Vol 69 (1) ◽  
pp. 839
Author(s):  
E. BOUKOUVALA ◽  
E. KATHAROPOULOS ◽  
S. CHRISTOFORIDOU ◽  
M. BABETSA ◽  
L. V. EKATERINIADOU
Keyword(s):  
Genetic Resistance ◽  
Prnp Gene ◽  
Classical Scrapie ◽  
Transmissible Spongiform Encephalopathies ◽  
Spongiform Encephalopathy ◽  
Breeding Programs ◽  
Spongiform Encephalopathies ◽  
Blood Samples ◽  
Taqman Probes ◽  
The Central Nervous System

Scrapie is a slowly progressive infectious disease of sheep and goats that causes degeneration of the central nervous system. Scrapie is one of several transmissible spongiform encephalopathies (TSEs), like the bovine spongiform encephalopathy (BSE). In sheep, polymorphisms at codons 136, 154 and 171 of the host gene PRPN that encodes the PrP protein, are known to be closely linked to susceptibility or resistance to natural and experimental classical scrapie. In many countries, but not in Greece, breeding programs have been implemented to increase genetic resistance. This study was supported mainly by the private initiatives of farmers willing to improve their flocks by increasing the resistance to scrapie. Thus, the PrP genotypes (of the three mentioned codons) from 5815 blood samples of clinically healthy rams from 160 healthy flocks during the period 2012 – 2016 were determined. Additionally, 1399 blood samples were genotyped only for the 171 codon. Samples were analyzed by Real Time PCR (TaqMan probes) with specific labeled probes. Our results showed an increased percentage of the two genotypes, ARR/ARR and ARR/ARQ linked with resistance to the disease (27.29% and 34.6%, respectively) and relatively reduced percentage of the genotype ARQ/ARQ (24.23%) which is associated with susceptibility to disease and is the most common genotype in the Greek flocks. This joined effort has resulted in the establishment of an important number of farms with an increased population of genetically resistant rams to classical scrapie.

scholarly journals Creutzfeldt-Jakob disease: results of an inquiry in the fifteen Member States of the European Union

1996 ◽  
Vol 1 (6) ◽  
pp. 42-45 ◽  
Author(s):  
B. C. Merkel ◽  
P. W.J Peters ◽  
L Chambaud
Keyword(s):  
European Union ◽  
Rare Disease ◽  
Transmissible Spongiform Encephalopathies ◽  
The European Union ◽  
Member States ◽  
Spongiform Encephalopathies ◽  
Jakob Disease

Creutzfeldt-Jakob Disease (CJD) was first described in 1920-1921. CJD is a rare disease with a reported incidence of 0.5 to 1 case per million people in Europe. This fatal dementia belongs to the category of Transmissible Spongiform Encephalopathies (TSE)

Bovine Spongiform Encephalopathy: Hypothetical Risk of Emergence as a Zoonotic Foodborne Epidemic

1996 ◽  
Vol 59 (10) ◽  
pp. 1106-1111 ◽  
Author(s):  
HARLEY W. MOON
Keyword(s):  
Great Britain ◽  
Bovine Spongiform Encephalopathy ◽  
Prion Diseases ◽  
Oral Route ◽  
Transmissible Spongiform Encephalopathies ◽  
Spongiform Encephalopathy ◽  
Infected Cattle ◽  
Spongiform Encephalopathies ◽  
Clinically Normal ◽  
Zoological Parks

Bovine spongiform encephalopathy (BSE) is a fatal neurological disease of cattle, recognized in Great Britain in 1986. Cases in other countries have been attributed to imports from Great Britain. The disease has not occurred in the U.S. BSE is one of a group of diseases (other examples are scrapie of sheep and Creutzfeld-Jacob disease of humans) referred to as prion diseases or transmissible spongiform encephalopathies. Under some circumstances prion diseases can be transmitted by injection or by feeding infected (abnormal prion protein-containing) tissue to susceptible hosts. BSE was disseminated by feeding meat and bone meal containing BSE agent which was not completely inactivated by rendering. BSE is hypothesized to have emerged from scrapie via recycling of rendered by-products in cattle. There is also evidence of spontaneous feed-borne transmission of BSE to wild ruminants in zoological parks and to domestic cats. It has been hypothesized that foodborne transmission of BSE to humans has occurred or could occur. This hypothesis can neither be definitively refuted nor supported. However, it seems unlikely. In spite of hundreds of years of human exposure to scrapie, there is no evidence of transmission of scrapie to humans. Even if BSE is ultimately found to be somehow transmissible to humans, the risk of foodborne transmission appears to be low for several reasons: (i) The oral route is several orders of magnitude less sensitive than the parenteral route for transmission of prion diseases; (ii) the BSE agent is only detectable in brain, spinal cord, and intestine of infected cattle, tissues infrequently used for human food; and (iii) Great Britain (where the disease occurs) destroys and bans the use of all tissues from BSE-infected cattle as well as the brains, spinal cords, and intestinal tracts from clinically normal cattle.

scholarly journals Prion Protein Alleles Showing a Protective Effect on the Susceptibility of Sheep to Scrapie and Bovine Spongiform Encephalopathy

2007 ◽  
Vol 81 (13) ◽  
pp. 7306-7309 ◽  
Author(s):  
Gabriele Vaccari ◽  
Claudia D'Agostino ◽  
Romolo Nonno ◽  
Francesca Rosone ◽  
Michela Conte ◽  
...  
Keyword(s):  
Amino Acid ◽  
Protective Effect ◽  
Bovine Spongiform Encephalopathy ◽  
Prion Protein ◽  
Amino Acid Substitution ◽  
Classical Scrapie ◽  
Transmissible Spongiform Encephalopathies ◽  
Spongiform Encephalopathy ◽  
Spongiform Encephalopathies ◽  
Disease Eradication

ABSTRACT The susceptibility of sheep to classical scrapie and bovine spongiform encephalopathy (BSE) is mainly influenced by prion protein (PrP) polymorphisms A136V, R154H, and Q171R, with the ARR allele associated with significantly decreased susceptibility. Here we report the protective effect of the amino acid substitution M137T, I142K, or N176K on the ARQ allele in sheep experimentally challenged with either scrapie or BSE. Such observations suggest the existence of additional PrP alleles that significantly decrease the susceptibility of sheep to transmissible spongiform encephalopathies, which may have important implications for disease eradication strategies.

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