France Sporadic CJD Rising, Typical and Atypical, BSE, Scrapie, and CWD, Zoonosis, what if?
France Sporadic CJD Rising, Typical and Atypical, BSE, Scrapie, and CWD, Zoonosis, what if?
France CJD cases continue to rise, what about zoonotic TSE to humans?
France is having a serious problem with continued spontaneous atypical BSE cases?
France Chronic Wasting Disease CWD TSE Prion in cervid?
France, what about their typical and atypical Scrapie cases?
France, what about TSE Prion tainted feed for livestock?
France, sCJD, Iatrogenic CJD cases, misdiagnosis, what if?
Seems to me, if atypical BSE was as spontaneous and sporadic as they claim it to be, it would be the same across the board, however, this hypothesis is crumbling, imo.
The European Union summary report on surveillance for the presence of transmissible spongiform encephalopathies (TSE) in 2022
European Food Safety Authority (EFSA)
First published: 28 November 2023
Approved: 19 October 2023 Abstract
with one case of H-BSE in France.
Annual Report of the Scientific Network on BSE-TSE 2022 European Food Safety Authority (EFSA) First published: 10 November 2022
with two cases of H-BSE in France and Spain, and four L-BSE in France (2), Germany and Spain
The European Union summary report on surveillance for the presence of transmissible spongiform encephalopathies (TSE) in 2020
Published: 30 November 2021
Approved: 25 October 2021
with three cases of H‐BSE in France, Ireland and Spain, and two L‐BSE in France and Switzerland.
The European Union summary report on surveillance for the presence of transmissible spongiform encephalopathies (TSE) in 2019
Published: 17 November 2020
Approved: 16 October 2020
Six cases of H‐BSE were reported by France (4) and Spain (2), and 1 L‐BSE by Poland.
The European Union summary report on surveillance for the presence of transmissible spongiform encephalopathies (TSE) in 2018
Published: 3 December 2019
Approved: 15 November 2019
Three atypical BSE cases (2 L‐type/1 H‐type) were reported by France.
The European Union summary report on surveillance for the presence of transmissible spongiform encephalopathies (TSEs) in 2017
Published: 29 November 2018
Approved: 6 November 2018
Six atypical BSE cases were reported by three different MSs: Spain 1 H‐BSE/2 L‐BSE; France 1 H‐BSE/1 L‐BSE; and Ireland 1 L‐BSE.
The European Union summary report on surveillance for the presence of transmissible spongiform encephalopathies (TSE) in 2016
Published: 30 November 2017
Approved: 30 October 2017
For the first time, the United Kingdom did not report any case of bovine spongiform encephalopathy (BSE), whereas France reported one classical and three atypical cases (H), and Spain one atypical case (H).
H-BSE was first reported in France7, and has been subsequently detected in several European countries and North America5,6.
Atypical Bovine Spongiform Encephalopathies, France, 2001–2007
Abstract
In France, through exhaustive active surveillance, ≈17.1 million adult cattle were tested for bovine spongiform encephalopathy from July 2001 through July 2007; ≈3.6 million were >8 years of age.
Our retrospective Western blot study of all 645 confirmed cases found that 7 were H-type and 6 were L-type.
Thursday, March 24, 2016
FRANCE CONFIRMS BOVINE SPONGIFORM ENCEPHALOPATHY BSE MAD COW (ESB) chez une vache dans les Ardennes
***atypical spontaneous BSE in France LOL***
FRANCE STOPS TESTING FOR MAD COW DISEASE BSE, and here’s why, to many spontaneous events of mad cow disease $$$
If you Compare France to other Countries with atypical BSE, in my opinion, you cannot explain this with ‘spontaneous’.
Table 1: Number of Atypical BSE cases reported by EU Member States in the period 2001–2014 by country and by type (L- and H-BSE) (extracted from EU BSE databases on 1 July 2014). By 2015, these data might be more comprehensive following a request from the European Commission to Member States for re-testing and retrospective classification of all positive bovine isolates in the EU in the years 2003–2009
BSE type
Country 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013(a) 2014(a) Total
H-BSE Austria 1 1
***> France(b) 1 2 3 1 2 2 2 2 15
Germany 1 1 2
Ireland 1 1 2 1 5
The Netherlands 1 1
Poland 1 1 2
Portugal 1 1
Spain 1 1 2
Sweden 1 1
United Kingdom 1 1 1 1 1 5
Total 2 3 3 1 1 2 2 2 4 4 5 1 4 1 35
L-BSE Austria 1 1 2
Denmark 1 1
France(b) 1 1 1 1 2 1 3 2 1 1 14
Germany 1 1 2
Italy 1 1 1 1 1 5
The Netherlands 1 1 1 3
Poland 1 2 2 1 2 1 2 1 12
Spain 2 2
United Kingdom 1 1 1 1 4
Total 0 5 3 4 3 3 6 3 3 4 3 6 1 1 45
Total Atypical cases (H + L)
2 8 6 5 4 5 8 5 7 8 8 7 5 2 80
(a): Data for 2013-2014 are incomplete and may not include all cases/countries reported.
(b): France has performed extensive retrospective testing to classify BSE cases, which is probably the explanation for the higher number of Atypical BSE cases reported in this country.
The number of Atypical BSE cases detected in countries that have already identified them seems to be similar from year to year. In France, a retrospective study of all TSE-positive cattle identified through the compulsory EU surveillance between 2001 and 2007 indicated that the prevalence of H-BSE and L-BSE was 0.35 and 0.41 cases per million adult cattle tested, respectively, which increased to 1.9 and 1.7 cases per million, respectively, in tested animals over eight years old (Biacabe et al., 2008). No comprehensive study on the prevalence of Atypical BSE cases has yet been carried out in other EU Member States. All cases of Atypical BSE reported in the EU BSE databases have been identified by active surveillance testing (59 % in fallen stock, 38 % in healthy slaughtered cattle and 4 % in emergency slaughtered cattle). Cases were reported in animals over eight years of age, with the exception of two cases (one H-BSE and one L-BSE) detected in Spain in 2011/2012. One additional case of H-BSE was detected in Switzerland in 2012 in a cow born in Germany in 2005 (Guldimann et al., 2012).
SUNDAY, OCTOBER 5, 2014
France stops BSE testing for Mad Cow Disease France stops BSE testing 0 79 Process Management
The France government has decided to stop testing cattle on mad cow disease (BSE). The measure applies to all animals born after 2002. This is what the French Minister of Agriculture: Stéphane Le Foll communicated during the Sommet de 'Elevage in Cournon, near Clermont-Ferrand.
Research indicates that the first probable infections of BSE in cows occurred during the 1970's with two cases of BSE being identified in 1986. BSE possibly originated as a result of feeding cattle meat-and-bone meal that contained BSE-infected products from a spontaneously occurring case of BSE or scrapie-infected sheep products. The major epidemic in the UK in the early 90s led to the decision to introduce compulsory BSE testing of cattle in 2001.
The remaining tests cost € 40 million annually, but show little or no more positive results for BSE. Moreover, the organs that can be infected with BSE are already standardly removed. 'Consumption of beef is therefore without any risk,' said the minister.
by Ruud Peijs 2 Oct 2014
Posted May 2, 2016
A cow in northern France has been confirmed to have bovine spongiform encephalopathy, according to the World Organisation for Animal Health (OIE).
The cow had developed partial paralysis and was euthanized March 1, a March 25 OIE report states.
BSE is a fatal neurologic prion disease with a typical incubation period of four to five years. The cow in France was almost 5 years old.
The affected cow had the classic form of BSE, which is most often associated with feed containing neurologic tissue from infected animals. It is distinct from atypical BSE, which may develop spontaneously, according to information from the U.S. Centers for Disease Control and Prevention.
Investigators were trying to identify the source of infection and other animals at risk for BSE at the time the report was published.
The affected bovine, a Salers female born on April, 8th 2011, showed paresis and was euthanized on March, 1st 2016. Samples made on March, 4th 2016 during rendering were analyzed at the Department Laboratory of La Somme. The rapid test proved positive on March, 8th 2016 and the samples were then sent for further analysis to the National Reference Laboratory, ANSES, which confirmed a case of classical BSE on March, 21st 2016. The European Union Reference Laboratory confirmed those results on the basis of documentation on March, 23rd 2016.
Number of reported cases of bovine spongiform encephalopathy (BSE) in farmed cattle worldwide*(excluding the United Kingdom) Country/Year
1989 - 2012
France 0 0 5 0 1 4 3 12 6 18 31a 162d 274e 239f 137g 54h 31 8 9 8 10 5 3
* Cases are shown by year of confirmation. ... Not available
a
Canada: 1 case diagnosed in Canada in May 2003 + 1 case diagnosed in the United States of America in December 2003 and confirmed as having been imported from Canada.
Finland: date of confirmation of the case: 7 December 2001.
France: includes 1 imported case (confirmed on 13 August 1999).
Ireland: includes imported cases: 5 in 1989, 1 in 1990, 2 in 1991 and 1992, 1 in 1994 and 1995.
Italy: includes 2 imported cases.
Liechtenstein : date of the last confirmation of a case: 30 September 1998.
Portugal: includes 1 imported case.
Slovenia: includes 1 imported case.
b
Imported case(s).
c
Czech Republic - Data as of 30 June 2012. Ireland - Data as of 30 June 2012. Liechtenstein - Data as of 30 June 2012. Luxembourg - Data as of 30 September 2012. Poland - Includes 1 atypical BSE case (L-type). Data as of 6 August 2012. Slovenia - Data as of 30 June 2012. Sweden - Data as of 30 June 2012. Switzerland - Atypical imported BSE case. Data as of 12 March 2012. United States of America - Atypical BSE case. Data as of 26 April 2012.
d
France year 2000 - Clinical cases = 102. Cases detected within the framework of the research programme launched on 8 June 2000 = 60. Ireland year 2000 - Clinical cases = 138. Cases identified by active surveillance of at risk cattle populations = 7. Cases identified by examination of depopulated BSE positive herds, birth cohorts and progeny animals = 4. Switzerland year 2000 - Clinical cases = 17. Cases detected within the framework of the investigation programme = 16.
e
France year 2001 - Clinical cases = 91. Cases detected at rendering (bovines at risk) = 100 (out of 139,500 bovines tested). Cases detected as result of routine screening at the abattoir = 83 (out of 2,373,000 bovines tested). Ireland year 2001 - Clinical cases = 123. Cases identified by systematic active surveillance of all adult bovines = 119. Cases identified by examination of depopulated BSE positive herds, birth cohorts and progeny animals = 4. Japan year 2001 - Clinical cases = 1. Cases detected as result of screening at the abattoir = 2.
f
France year 2002 - Clinical cases = 41. Cases detected at rendering (bovines at risk) = 124 (out of 274,143 bovines tested). Cases detected as result of systematic screening at the abattoir = 74 (out of 2,915,103 bovines tested). The active BSE surveillance programmes implemented in France in 2002 led to routine examination of cattle aged over 24 months, which were slaughtered for consumption purposes, were euthanised or died due to other reasons. Ireland year 2002 - Clinical cases = 108. Cases detected by the active surveillance programme = 221. Cases identified by examination of depopulated BSE positive herds, birth cohorts and progeny animals = 4. Poland year 2002 - Clinical cases = 1. Cases detected as result of routine screening at the abattoir (cattle over 30 months) = 3.
g
France year 2003 - Clinical cases = 13. Cases detected at rendering (bovines at risk) = 87. Cases detected as result of systematic screening at the abattoir = 37. Japan year 2003 - The 9th case was a bullock aged 21 months. Ireland year 2003 - Clinical cases = 41. Cases detected by the active surveillance programme = 140. Switzerland year 2003 - Clinical cases: 8. Cases detected within the framework of the official surveillance programme: 11. Cases detected through voluntary testing following routine slaughter: 2.
h
France year 2004 - Clinical cases = 8. Cases detected at rendering (bovines at risk) = 29. Cases detected as result of systematic screening at the abattoir = 17. Ireland year 2004 - Clinical cases = 31. Cases detected by the active surveillance programme = 94. Cases identified by examination of depopulated BSE positive herds, birth cohorts and progeny animals = 1.
i
Ireland year 2005 - Cases detected by the passive surveillance programme = 13. Cases detected by the active surveillance programme = 56. Switzerland year 2005 - Cases detected by the passive surveillance programme = 1. Cases detected within the framework of the official surveillance programme: 1. Cases detected through voluntary testing following routine slaughter = 1.
j
Ireland year 2006 - Cases detected by the passive surveillance programme = 5. Cases detected by the active surveillance programme = 36.
k
Ireland year 2007 - Cases detected by the passive surveillance programme = 5. Cases detected by the active surveillance programme = 20.
l
Ireland year 2008 - Cases detected by the passive surveillance programme = 3. Cases detected by the active surveillance programme = 20.
m
Netherlands - Atypical BSE case (L-type) Switzerland - Atypical BSE cases
Emerg Infect Dis. 2005 Aug; 11(8): 1274–1279. doi: 10.3201/eid1108.041223
PMCID: PMC3320489PMID: 16102318
Sheep Feed and Scrapie, France
Sandrine Philippe,* Christian Ducrot,† Pascal Roy,‡ Laurent Remontet,‡ Nathalie Jarrige,* and Didier Calavas corresponding author*
Proprietary concentrates and milk replacers were linked to risk for scrapie.
Keywords: Scrapie, Sheep, Transmission, Epidemiology, Case-Control studies, Risk Factors, France, Transmissible Spongiform Encephalopathy Go to:
Abstract
Scrapie is a small ruminant, transmissible spongiform encephalopathy (TSE). Although in the past scrapie has not been considered a zoonosis, the emergence of bovine spongiform encephalopathy, transmissible to humans and experimentally to sheep, indicates that risk exists for small ruminant TSEs in humans. To identify the risk factors for introducing scrapie into sheep flocks, a case-control study was conducted in France from 1999 to 2000. Ninety-four case and 350 control flocks were matched by location and main breed. Three main hypotheses were tested: direct contact between flocks, indirect environmental contact, and foodborne risk. Statistical analysis was performed by using adjusted generalized linear models with the complementary log-log link function, considering flock size as an offset. A notable effect of using proprietary concentrates and milk replacers was observed. The risk was heterogeneous among feed factories. Contacts between flocks were not shown to be a risk factor.
Keywords: Scrapie, Sheep, Transmission, Epidemiology, Case-Control studies, Risk Factors, France, Transmissible Spongiform Encephalopathy
Scrapie is a transmissible spongiform encephalopathy (TSE) affecting sheep and goats (1), as is Creutzfeldt-Jakob disease (CJD) in humans or bovine spongiform encephalopathy (BSE) in cattle. Moreover, scrapie is contagious in natural conditions (2). Though genetic determinism is a major feature of scrapie, the infectious agent is nonetheless needed for the disease to develop (3,4).
Known to exist for centuries, scrapie was thought to be a possible origin of BSE, although this hypothesis has not yet been verified. Sheep and goats can be experimentally infected with BSE, resulting in a disease that is impossible to distinguish from natural scrapie (5). Since BSE is implicated in the emergence of variant CJD (6,7), the existence of BSE in small ruminants poses a further risk for human health. Scrapie has become a public health challenge, and its propagation must be stopped; therefore, the risk factors for the introduction of scrapie in sheep must be understood.
In sheep infected with scrapie, the infectious agent is widely distributed in the organism. In particular, the gut-associated lymphoid tissues and the placenta are considered highly important in spreading the disease (8) and can contaminate the environment (9). Because feed is considered to be the main, if not the only, contamination source of BSE in cattle (10,11), it can also be presumed to be a potential risk factor for scrapie in sheep.
A case-control study of infected and scrapie-free flocks was conducted to identify risk factors for introducing scrapie into sheep flocks in France. Various risk factors hypotheses were tested from the most plausible to the weakest.
Study Design
A case-control study of infected and scrapie–free flocks was designed (Appendix). A flock was defined as having at least 20 adult ewes. To consider the heterogeneity of exposure to scrapie risk, cases and controls were matched according to main sheep breed and location. A "case" was any flock having ≥1 animal that had been shown as scrapie-positive by the French surveillance network from January 1996 to July 2000 (12). Four frequency-matched control flocks were randomly selected from the sheep flocks in which scrapie had never been reported. Flocks that did not meet this criterion were excluded.
The suspected risk factors were grouped into 3 categories corresponding to the main working hypotheses of scrapie dissemination. The first category covered risks for transmission by direct contact between flocks and indirectly through the environment. The second category covered foodborne risks. The third category covered other environmental dissemination risks such as equipment sharing between farms or transmission through hay mites. Table 1describes the 22 potential risk factors studied.
Data Collection
Information was collected by using a preestablished questionnaire to interview farmers and analyzing farm records. Questions related to potential risk factors covered the 4-year period preceding detection of the first clinical case of scrapie in case flocks and the 4-year period preceding the interview for controls. Additionally, information regarding potential confounding factors including flock size, production type (dairy, meat, or mixed), and intensification level of the flock production was recorded (Table 2). Interviews were conducted from May 1999 to July 2000 with 453 flock owners (98 cases and 355 controls). Nine flocks were excluded because they did not meet the inclusion criteria. A total of 444 flocks (94 cases and 350 controls) were included in the study. Data were encoded and then stored in an Access database (Microsoft Access 97 SR-2, Microsoft Corporation, Redmond, WA, USA).
Study Sample
The flocks were mainly located in 2 departments (Pyrénées Atlantiques, n = 267/444, Aveyron n = 51/444). The others were widely distributed throughout metropolitan France. Ten mixed breeds and 23 pure breeds were included in the study. The flocks were mainly specialized in 1 type of production (66% in dairy production, 32% in meat production) (Table 2). The flock size ranged from 21 to 1,787 ewes (mean 274, SD 198).
Analysis
Data analysis was conducted in 2 steps by using statistical models adjusted for the 2 matching factors through the corresponding cross-variable "strata" (main breed and location) treated as a stratification variable (13). First, to identify the confounding factors to be further analyzed (14), a log-linear model considered 5 factors, including flock size (number of ewes), production type, intensification level of the flock production as potential confounding factors, flock status, and strata. The model introduced the main effect of these 5 factors with all second interaction terms. Flock size was the only potential confounding factor notably associated with the flock status (Table 2). Second, to assess associations between flock status and risk factors, a generalized linear model for binary outcome was set up with the complementary log-log link function (Clog-log model) (14) (Appendix). This model considered the flock size by using the logarithm of the flock size as an offset (15,16). All exposures were considered as binary, and the absence of exposition was the reference modality for each risk factor. Factors notably associated with the flock status at 20% level through univariate analysis (Table 1) were selected for subsequent multivariate analyses. The univariate analysis consisted of the construction of a Clog-log model for each risk factor; strata were systematically introduced as covariate. Furthermore, 2 distinct multivariate models were applied to consider colinearity between feed type and feed factories in the foodborne risk study. The first model (multivariate Clog-log 1) analyzed feed types without regard to factories, whereas the second one (multivariate Clog-log 2) evaluated the risk according to the feed factories that produced milk replacers and proprietary concentrates. Regarding the proprietary feed factories, only the purchase of milk replacers and proprietary concentrates at factory 1 and the purchase of proprietary concentrates at factory 2 occurred frequently enough to be studied separately. Statistical software Splus (S-Plus 2000 Professional Release 2, Mathsoft, Inc., Seattle, WA, USA) was used to analyze the data.
Results
According to the univariate analysis, 8 potential risk factors were selected (Table 1). Six risk factors were related to foodborne risk; the other 2 were related to purchasing ewes, and cesarean sections performed by the veterinarian. The subsequent multivariate model (multivariate Clog-log 1) (Table 3) showed a significant association between the flock status and using milk replacers. In addition, using the multivariate Clog-log 2 model milk replacers and proprietary concentrates from factory 1 were significantly associated with the flock status (Table 3).
Discussion
The main finding of the study was the role of feed as a risk factor for scrapie. This is consistent with what has been shown for BSE in cattle. The use of proprietary concentrates, and more precisely the use of feeds containing meat and bone meal (MBM), was shown to have a major role in BSE infection of cattle (11). The agent of BSE is not inactivated by MBM processing methods, which were put into place by the industry in the late 1970s (17).
In France, MBM was authorized for small ruminants until July 1994. Moreover, the MBM ban proved to be <100% efficient; hundreds of BSE cases were observed in cattle in France born after the MBM ban of feeds for cattle. The exposure period that was investigated in the current study was from 1991 to June 2000, depending on the case. It occurred before the French MBM ban in feeds for all farmed animals in November 2000; furthermore, the period investigated was before the MBM ban for small ruminants in France for more than half of the cases. It is, therefore, plausible that sheep may have been contaminated by MBM in feeds throughout the 1990s, despite control measures. The results showed that 1 feed company was at risk for proprietary concentrates when others were not. This finding is in agreement with the fact that risk might depend on the type of raw materials used in the factory, as well as the way they were processed and used.
The risk attributable to milk replacers is the first evidence of such a TSE risk in animals. Milk replacers for all farmed species are made of skimmed cow milk enriched with vegetable or animal fats. Milk has not been shown to be at risk for scrapie transmission (18–20). Even if animal fat is not infectious, the animal fats that were incorporated in milk replacers may have been contaminated. Contamination could have occurred during collection at the slaughterhouse by contact with infectious material such as central nervous system or paravertebral ganglia. In France, these fats were prohibited for use in farm animal feeds in November 2000.
The same factory was identified as selling both the milk replacers and the proprietary concentrates at risk for scrapie. Most farmers buy both their feeds concentrates and milk replacers from the same wholesaler (which, in turn, buys from the same factory). Even if the effect of the 2 factors remained in the multivariate analysis, a confounding effect between these 2 factors cannot be excluded.
The main concern raised by this study is the nature of the infectious agent that was transmitted to sheep by means of feeds. It might be scrapie, but it could be also BSE, since cattle were infected by feeds during the same period in France. In 2005, BSE in a goat was first reported in France (21); in the United Kingdom, a goat that was thought to have scrapie in 1990 is being reexamined because it is now suspected to have had BSE (http://www.defra.gov.uk/news/2005/050208a.htm). In France, every index case animal from infected small ruminant flocks that has been reported since the surveillance began in 1990 has been biochemically tested to distinguish natural scrapie isolates from isolates sharing common biochemical features with experimental ovine BSE (validated by the TSEs Community Reference Laboratory of Weybridge, UK [unpub. data]). Among >400 small ruminant field isolates tested in France, only 1 isolate from a goat was indistinguishable from BSE. These arguments suggest that the agent transmitted to sheep by food was scrapie rather than BSE. Moreover, BSE is thought to have been transmitted and amplified by recycling contaminated carcasses into MBM on a regional basis (22). It follows that if the sheep identified as having scrapie did in fact have BSE, this misconception would have occurred in the same regions as BSE in cattle. That the areas of France most at risk for BSE in cattle (23) were different from those where scrapie occurred during the study does not suggest that the infectious agent for sheep was BSE.
Unexpectedly, the other hypotheses concerning the contamination of flocks with scrapie were not confirmed by the present study. In Norway, a matched case-control study showed 3 risk factors, though at a 10% a level: purchasing females, sharing rams, and sharing pastures between flocks (24). However, in a recent Irish study, purchasing breeding sheep through markets was not a risk factor for scrapie at a 5% a level (25). In the Norwegian study, feed did not appear to be a risk factor, whereas in the Irish study, feeding proprietary concentrates to lambs appeared to be protective. In the present study, purchasing ewes may not have emerged as a risk factor merely because of the lack of power of the study. The link between cesarean sections and scrapie occurrence that was observed in the univariate analysis was likely due to a confounding effect with the real risk factors and so became nonsignificant in the multivariate analyses.
Beyond the limits of the study, our results clearly show that in France, and more precisely in southwest France where most of the studied farms were located, the major risk for the introduction of scrapie in a flock during the 1990s was feeding certain proprietary concentrates and, possibly, milk replacers to sheep. Exposing sheep to TSE risk by feeding has certainly decreased since that time because of the complementary control measures taken in 1996 (ban on specified risk materials and cadavers in the processing of MBM) and 2000 (complete ban of MBM and certain animal fats for all farmed animals). However, it is essential to monitor these risk factors over time in France and to extend this kind of study to other countries in which the disease occurs.
The study results show strong evidence that TSEs can spread to sheep through feeding in field conditions, as is the case for cattle. Given the potential risk for humans, the possibility of BSE spreading to sheep must be taken seriously, even though the horizontal transmission of BSE in sheep would occur and stay at a low level (26), should such contamination occur (27). In any case, such findings support the need for a more comprehensive surveillance of TSEs in sheep, as well as the need to systematically examine all scrapie cases for their resemblance to BSE.
Appendix
Description of the Clog-log model
This appendix provides a description of the statistic model, a generalized linear model for binary outcome with the complementary log-log link function, used to assess the associations between flock status and risk factors. The construction is based on the probability (P) for a sheep flock to be qualified as an "infected scrapie flock," assuming independence and equiprobability for animals of a same flock to be infected by scrapie. This probability is equal to
An external file that holds a picture, illustration, etc.
Object name is 04-1223-M1.jpg where k is the flock size and p the probability for an animal of the flock to be diagnosed infected by scrapie. Then, applying the complementary log-log function (Clog-log) on P, the quantity below was obtained.
An external file that holds a picture, illustration, etc. Object name is 04-1223-M2.jpg Therefore, the use of Clog-log as the link function (28) leads to model the probability to be infected at the animal level instead of at the flock level. In this model, flock size is introduced through the offset "Log(k)".
An external file that holds a picture, illustration, etc. Object name is 04-1223-M3.jpg where Xj, j∈{1, …, q} is the vector of covariates. Moreover, if X1 and X2 are two exposure variables, then
An external file that holds a picture, illustration, etc. Object name is 04-1223-M4.jpg For values of p smaller than 10%, An external file that holds a picture, illustration, etc. Object name is 04-1223-M5.jpg and An external file that holds a picture, illustration, etc. Object name is 04-1223-M6.jpg are very close. Hence, for small values of p,
An external file that holds a picture, illustration, etc. Object name is 04-1223-M7.jpg. The parameters estimated from the complementary log-log model can be interpreted as those from a logistic model. The appropriate coding of exposure (X = 1) and nonexposure (X = 0) provides an easy interpretation of the parameters with OR = exp(β) and IC95% = [exp(β) +/- zα/2 s.e.(β)], zα/2 being issued from the cumulative distribution function of the standard normal distribution, and s.e. (β) being the standard error of parameter β (29,30).
Acknowledgments
snip...
2023 ORAL TRANSMISSION OF TYPICAL BSE AND ATYPICAL BSE L-TYPE AND H-TYPE TO CATTLE
''Results: After 6 years of incubation, 3/4 animals (2/2 steers IC challenged with brain from P1 L-BSE oral challenge and 1/2 steer IC challenged with brain from P1 H-BSE oral challenge) developed clinical disease.''
Abstract for Prion 2023
Title: Transmission of atypical BSE: a possible origin of Classical BSE in cattle
Authors: Sandor Dudas1, Samuel James Sharpe1, Kristina Santiago-Mateo1, Stefanie Czub1, Waqas Tahir1,2, *
Affiliation: 1National and WOAH reference Laboratory for Bovine Spongiform Encephalopathy, Canadian Food inspection Agency, Lethbridge Laboratory, Lethbridge, Canada. 2Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada.
*Corresponding and Presenting Author: waqas.tahir@inspection.gc.ca
Background: Bovine spongiform encephalopathy (BSE) is a fatal neurodegenerative disease of cattle and is categorized into classical and atypical forms. Classical BSE (CBSE) is linked to the consumption of BSE contaminated feed whereas atypical BSE is considered to be spontaneous in origin. The potential for oral transmission of atypical BSE is yet to be clearly defined.
Aims: To assess the oral transmissibility of atypical BSE (H and L type) in cattle. Should transmission be successful, determine the biochemical characteristics and distribution of PrPSc in the challenge cattle.
Material and Methods: For oral transmission, calves were fed with 100 g of either H (n=3) or L BSE (n=3) positive brain material. Two years post challenge, 1 calf from each of the H and L BSE challenge groups exhibited behavioural signs and were euthanized. Various brain regions of both animals were tested by traditional and novel prion detection methods with inconclusive results. To detect infectivity, brain homogenates from these oral challenge animals (P1) were injected intra-cranially (IC) into steer calves. Upon clinical signs of BSE, 3/4 of IC challenged steer calves were euthanized and tested for PrPSc with ELISA, immunohistochemistry and immunoblot.
Results: After 6 years of incubation, 3/4 animals (2/2 steers IC challenged with brain from P1 L-BSE oral challenge and 1/2 steer IC challenged with brain from P1 H-BSE oral challenge) developed clinical disease. Analysis of these animals revealed high levels of PrPSc in their brains, having biochemical properties similar to that of PrPSc in C-BSE.
Conclusion: These results demonstrate the oral transmission potential of atypical BSE in cattle. Surprisingly, regardless of which atypical type of BSE was used for P1 oral challenge, PrPSc in the P2 animals acquired biochemical characteristics similar to that of PrPSc in C-BSE, suggesting atypical BSE as a possible origin of C-BSE in UK.
Presentation Type: Oral Presentation
Funded by: CFIA, Health Canada, Alberta Livestock and Meat Agency, Alberta Prion Research Institute
Grant Number: ALMA/APRI: 201400006, HC 414250
2023 ORAL TRANSMISSION OF CWD TO CATTLE
Transmission of the Chronic Wastng Disease agent from elk to cattle after oronasal exposure
Justin Greenlee, Jifeng Bian, Zoe Lambert, Alexis Frese, and Eric Cassmann
Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, IA, USA
Aims: The purpose of this study was to determine the susceptibility of cattle to chronic wasting disease agent from elk.
Materials and Methods: Initial studies were conducted in bovinized mice using inoculum derived from elk with various genotypes at codon 132 (MM, LM, LL). Based upon attack rates, inoculum (10% w/v brain homogenate) from an LM132 elk was selected for transmission studies in cattle. At approximately 2 weeks of age, one wild type steer (EE211) and one steer with the E211K polymorphism (EK211) were fed 1 mL of brain homogenate in a quart of milk replacer while another 1 mL was instilled intranasally. The cattle were examined daily for clinical signs for the duration of the experiment. One steer is still under observation at 71 months post-inoculation (mpi).
Results: Inoculum derived from MM132 elk resulted in similar attack rates and incubation periods in mice expressing wild type or K211 bovine PRNP, 35% at 531 days post inoculation (dpi) and 27% at 448 dpi, respectively. Inoculum from LM132 elk had a slightly higher attack ratesin mice: 45% (693 dpi) in wild type cattle PRNP and 33% (468) in K211 mice. Inoculum from LL132 elk resulted in the highest attack rate in wild type bovinized mice (53% at 625 dpi), but no K211 mice were affected at >700 days. At approximately 70 mpi, the EK211 genotype steer developed clinical signs suggestive of prion disease, depression, low head carriage, hypersalivation, and ataxia, and was necropsied. Enzyme immunoassay (IDEXX) was positive in brainstem (OD=4.00, but non-detect in retropharyngeal lymph nodes and palatine tonsil. Immunoreactivity was largely limited to the brainstem, midbrain, and cervical spinal cord with a pattern that was primarily glia-associated.
Conclusions: Cattle with the E211K polymorphism are susceptible to the CWD agent after oronasal exposure of 0.2 g of infectious material.
Funded by: This research was funded in its entirety by congressionally appropriated funds to the United States Department of Agriculture, Agricultural Research Service. The funders of the work did not influence study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Grant number: NA
Acknowledgement: The authors wish to thank Quazetta Brown, Ami Frank, and Kevin Hassall for their technical contributions.
Strain characterization of chronic wasting disease in bovine-PrP transgenic mice
Nuria Jerez-Garrido1, Sara Canoyra1, Natalia Fernández-Borges1, Alba Marín Moreno1, Sylvie L. Benestad2, Olivier Andreoletti3, Gordon Mitchell4, Aru Balachandran4, Juan María Torres1 and Juan Carlos Espinosa1.
1 Centro de Investigación en Sanidad Animal, CISA-INIA-CSIC, Madrid, Spain.
2 Norwegian Veterinary Institute, Ås, Norway.
3 UMR Institut National de la Recherche Agronomique (INRA)/École Nationale Vétérinaire de Toulouse (ENVT), Interactions Hôtes Agents Pathogènes, Toulouse, France.
4 Canadian Food Inspection Agency, Ottawa, Canada.
Aims: Chronic wasting disease (CWD) is an infectious prion disease that affects cervids. Various CWD prion strains have been identified in different cervid species from North America and Europe. The properties of the infectious prion strains are influenced by amino acid changes and polymorphisms in the PrP sequences of different cervid species. This study, aimed to assess the ability of a panel of CWD prion isolates from diverse cervid species from North America and Europe to infect bovine species, as well as to investigate the properties of the prion strains following the adaptation to the bovine-PrP context.
Materials and Methods: BoPrP-Tg110 mice overexpressing the bovine-PrP sequence were inoculated by intracranial route with a panel of CWD prion isolates from both North America (two white-tailed deer and two elk) and Europe (one reindeer, one moose and one red deer).
Results: Our results show distinct behaviours in the transmission of the CWD isolates to the BoPrP-Tg110 mouse model. Some of these isolates did not transmit even after the second passage. Those able to transmit displayed differences in terms of attack rate, survival times, biochemical properties of brain PrPres, and histopathology.
Conclusions: Altogether, these results exhibit the diversity of CWD strains present in the panel of CWD isolates and the ability of at least some CWD isolates to infect bovine species.
Cattle being one of the most important farming species, this ability represents a potential threat to both animal and human health, and consequently deserves further study.
Funded by: MCIN/AEI /10.13039/501100011033 and by European Union Next Generation EU/PRTR
Grant number: PCI2020-120680-2 ICRAD
2023 ATYPICAL SCRAPIE TRANSMIT TO CATTLE
Detection of classical BSE prions in asymptomatic cows after inoculation with atypical/Nor98 scrapie
Marina Betancor1, Belén Marín1, Alicia Otero1#, Carlos Hedman1, Antonio Romero2, Tomás Barrio3, Eloisa Sevilla1, Jean Yves Douet3, Alvina Huor3, Juan José Badiola1, Olivier Andréoletti3, Rosa Bolea1.
1Centro de Encefalopatías y Enfermedades Transmisibles Emergentes, Facultad de Veterinaria, Universidad de Zaragoza, Instituto Agroalimentario de Aragón - IA2, 50013, Zaragoza, Spain.
2 Servicio de Cirugía y Medicina Equina, Hospital Veterinario, Universidad de Zaragoza, 50013, Zaragoza, Spain
3 UMR École Nationale Vétérinaire de Toulouse (ENVT) - Institut National pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) - 1225 Interactions Hôtes Agents Pathogènes (IHAP), 31300 Toulouse, France.
Aims: The emergence of bovine spongiform encephalopathy (BSE) prions from atypical scrapie has been recently proved in rodent and swine models. This study aimed to assess whether the inoculation of atypical scrapie could induce BSE-like disease in cattle.
Materials and Methods: Four calves were intracerebrally challenged with atypical scrapie. Animals were euthanized without clinical signs of prion disease between 7.2 and 11.3 years post-inoculation and tested for the accumulation of prions by conventional techniques and protein misfolding cyclic amplification (PMCA).
Results: None of the bovines showed signs compatible with prion disease. In addition, all tested negative for PrPSc accumulation by immunohistochemistry and western blotting. However, an emergence of BSE-like prions was detected during in vitro propagation of brain samples from the inoculated animals.
Conclusions: These findings suggest that atypical scrapie may represent a potential source of BSE infection in cattle.
Funded by: This work was supported financially by the following Spanish and European Interreg grants: Ministerio de Ciencia, Innovación y Universidades (Spanish Government), cofunded by Agencia Estatal de Investigación and the European Union and POCTEFA, which was 65% co-financed by the European Regional Development Fund (ERDF) through the Interreg V-A Spain-France-Andorra program (POCTEFA 2014– 2020).
Grant number: n° PID2021-125398OB-I00, EFA148/16 REDPRION
Acknowledgement: The authors would like to thank Sandra Felices and Daniel Romanos for their excellent technical assistance. Authors would also like to acknowledge the use of Servicio General de Apoyo a la Investigación-SAI, Universidad de Zaragoza
Emerg Infect Dis. 2011 May; 17(5): 848–854.
doi: 10.3201/eid1705.101654
Experimental Oral Transmission of Atypical Scrapie to Sheep
Marion M. Simmons, corresponding author S. Jo Moore,1 Timm Konold, Lisa Thurston, Linda A. Terry, Leigh Thorne, Richard Lockey, Chris Vickery, Stephen A.C. Hawkins, Melanie J. Chaplin, and John Spiropoulos
Abstract
To investigate the possibility of oral transmission of atypical scrapie in sheep and determine the distribution of infectivity in the animals’ peripheral tissues, we challenged neonatal lambs orally with atypical scrapie; they were then killed at 12 or 24 months. Screening test results were negative for disease-specific prion protein in all but 2 recipients; they had positive results for examination of brain, but negative for peripheral tissues. Infectivity of brain, distal ileum, and spleen from all animals was assessed in mouse bioassays; positive results were obtained from tissues that had negative results on screening. These findings demonstrate that atypical scrapie can be transmitted orally and indicate that it has the potential for natural transmission and iatrogenic spread through animal feed. Detection of infectivity in tissues negative by current surveillance methods indicates that diagnostic sensitivity is suboptimal for atypical scrapie, and potentially infectious material may be able to pass into the human food chain.
SNIP...
Although we do not have epidemiologic evidence that supports the efficient spread of disease in the field, these data imply that disease is potentially transmissible under field situations and that spread through animal feed may be possible if the current feed restrictions were to be relaxed. Additionally, almost no data are available on the potential for atypical scrapie to transmit to other food animal species, certainly by the oral route. However, work with transgenic mice has demonstrated the potential susceptibility of pigs, with the disturbing finding that the biochemical properties of the resulting PrPSc have changed on transmission (40). The implications of this observation for subsequent transmission and host target range are currently unknown.
CWD, SCRAPIE, ORAL TRANSMISSION TO PIGS, OH MY!
Experimental transmission of the chronic wasting disease agent to swine after oral or intracranial inoculation
Running Title: The chronic wasting disease agent transmits to swine
S. Jo Moore1,2 , M. Heather West Greenlee3 , Naveen Kondru3 , Sireesha Manne3 , Jodi D. Smith1,# , Robert A. Kunkle1 , Anumantha Kanthasamy3 , Justin J. Greenlee1*
Virus and Prion Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, Ames, Iowa, United States of America
Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee, United States of America
Department of Biomedical Sciences, Iowa State University College of Veterinary Medicine, Ames, Iowa, United States of America
Current Address: Department of Veterinary Pathology, Iowa State University College of Veterinary Medicine, Ames, Iowa, United States of America * Corresponding author Email: justin.greenlee@ars.usda.gov
JVI Accepted Manuscript Posted Online 12 July 2017 J. Virol. doi:10.1128/JVI.00926-17
This is a work of the U.S. Government and is not subject to copyright protection in the United States. Foreign copyrights may apply.
on July 27, 2017 by guest http://jvi.asm.org/ Downloaded from
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 experimental oral or intracranial 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 one or more pigs in each inoculated group. Bioassay was positive in 4 out of 5 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 using mouse bioassay raises the possibility that naturally exposed pigs could act as a reservoir of CWD infectivity.
Discussion
snip...
In the case of feral pigs, exposure to the agent of CWD through scavenging of CWD-affected cervid carcasses or through consumption of prion contaminated plants or soil could allow feral pigs to serve as reservoirs of CWD infectivity. The range and numbers of feral pigs is predicted to continue to increase due to the ability of pigs to adapt to many climates, reproduce year-round, and survive on a varied diet (55 ). The range of CWD-affected cervids also continues to spread, increasing the likelihood of overlap of ranges of feral pigs and CWD -affected environments.
We demonstrate here that PrPSc accumulates in lymphoid tissues from pigs inoculated intracranially or orally with the CWD agent, and can be detected as early as 6 months after inoculation. Clinical disease suggestive of prion disease developed only in a single pig after a long (64 months) incubation period. This raises the possibility that CWD-infected pigs could shed prions into their environment long before they develop clinical disease. However, the low amounts of PrPSc detected in the study pigs combined with the low attack rates in Tg002 mice suggest that there is a relatively strong species barrier to CWD prions in pigs.
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.....
***> Singeltary Hacks in to USDA 50 State Emergency BSE Conference Call <***
BSE--U.S. 50 STATE CONFERENCE CALL Jan. 9, 2001
Date: Tue, 9 Jan 2001 16:49:00 -0800
From: "Terry S. Singeltary Sr."
Reply-To: Bovine Spongiform Encephalopathy
To: BSE-L@uni-karlsruhe.de
CWD ORAL TRANSMISSION TO WTD
Experimental Oronasal Inoculation of the Chronic Wasting Disease Agent into White Tailed Deer
Author list: Sarah Zurbuchena,b , S. Jo Moorea,b , Jifeng Biana , Eric D. Cassmanna , and Justin J. Greenleea .
a. Virus and Prion Research Unit, National Animal Disease Center, ARS, United States Department of Agriculture, Ames, IA, US
b. Oak Ridge Institute for Science and Education (ORISE), U.S. Department of Energy, Oak Ridge, TN, United States
Aims: The purpose of this experiment was to determine whether white-tailed deer (WTD) are susceptible to inoculation of chronic wasting disease (CWD) via oronasal exposure.
Materials and methods: Six male, neutered WTD were oronasally inoculated with brainstem material (10% w/v) from a CWD-positive wild-type WTD. The genotypes of five inoculated deer were Q95/G96 (wild-type). One inoculated deer was homozygous S at codon 96 (96SS). Cervidized (Tg12; M132 elk PrP) mice were inoculated with 1% w/v brainstem homogenate from either a 96GG WTD (n=10) or the 96SS WTD (n=10).
Results: All deer developed characteristic clinical signs of CWD including weight loss, regurgitation, and ataxia. The 96SS individual had a prolonged disease course and incubation period compared to the other deer. Western blots of the brainstem on all deer yielded similar molecular profiles. All deer had widespread lymphoid distribution of PrPCWD and neuropathologic lesions associated with transmissible spongiform encephalopathies. Both groups of mice had a 100% attack rate and developed clinical signs, including loss of body condition, ataxia, and loss of righting reflex. Mice inoculated with material from the 96SS deer had a significantly shorter incubation period than mice inoculated with material from 96GG deer (Welch two sample T-test, P<0.05). Serial dilutions of each inocula suggests that differences in incubation period were not due to a greater concentration of PrPCWD in the 96SS inoculum. Molecular profiles from western blot of brain homogenates from mice appeared similar regardless of inoculum and appear similar to those of deer used for inoculum.
Conclusions: This study characterizes the lesions and clinical course of CWD in WTD inoculated in a similar manner to natural conditions. It supports previous findings that 96SS deer have a prolonged disease course. Further, it describes a first pass of inoculum from a 96SS deer in cervidized mice which shortened the incubation period.
Funded by: This research was funded in its entirety by congressionally appropriated funds to the United States Department of Agriculture, Agricultural Research Service. The funders of the work did not influence study design, data collection, analysis, decision to publish, or preparation of the manuscript.
Acknowledgement: We thank Ami Frank and Kevin Hassall for their technical contributions to this project.
The detection and decontamination of chronic wasting disease prions during venison processing
Marissa S. Milstein1,2, Marc D. Schwabenlander1,2, Sarah C. Gresch1,2, Manci Li1,2, Stuart Lichtenberg1,2, Rachel Shoemaker1,2, Gage R. Rowden1,2, Jason C. Bartz2,3 , Tiffany M. Wolf2,4, Peter A. Larsen1,2
Presenting author: Tiffany M. Wolf 1 Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, USA 2 Minnesota Center for Prion Research and Outreach, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, USA 3 Department of Medical Microbiology and Immunology, School of Medicine, Creighton University, Omaha, Nebraska, USA 4 Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, USA
Aims: There is a growing concern that chronic wasting disease (CWD) prions in venison pose a risk to human health. CWD prions accumulate in infected deer tissues that commonly enter the human food chain through meat processing and consumption. The United States (US) Food and Drug Administration and US Department of Agriculture now formally consider CWD-positive venison unfit for human and animal consumption. Yet, the degree to which prion contamination occurs during routine venison processing is unknown. Here, we use environmental surface swab methods to: a) experimentally test meat processing equipment (i.e., stainless steel knives and polyethylene cutting boards) before and after processing CWD-positive venison and b) test the efficacy of five different disinfectant types (i.e., Dawn dish soap, Virkon-S, Briotech, 10% bleach, and 40% bleach) to determine prion decontamination efficacy.
Materials and Methods: We used a real-time quaking-induced conversion (RT-QuIC) assay to determine CWD infection status of venison and to detect CWD prions in the swabs. We collected three swabs per surface and ran eight technical replicates on RT-QuIC.
Results: CWD prions were detected on all cutting boards (n= 3; replicates= 8/8, 8/8, 8/8 and knives (n= 3; replicates= 8/8, 8/8, 8/8) used in processing CWD-positive venison, but not on those used for CWD-negative venison. After processing CWD-positive venison, allowing the surfaces to dry, and washing the cutting board with Dawn dish soap, we detected CWD prions on the cutting board surface (n= 3; replicates= 8/8, 8/8, 8/8) but not on the knife (n= 3, replicates = 0/8, 0/8, 0/8). Similar patterns were observed with Briotech (cutting board: n= 3; replicates= 7/8, 1/8, 0/8; knife: n= 3; replicates = 0/8, 0/8, 0/8). We did not detect CWD prions on the knives or cutting boards after disinfecting with Virkon-S, 10% bleach, and 40% bleach.
Conclusions: These preliminary results suggest that Dawn dish soap and Briotech do not reliably decontaminate CWD prions from these surfaces. Our data suggest that Virkon-S and various bleach concentrations are more effective in reducing prion contamination of meat processing surfaces; however, surface type may also influence the ability of prions to adsorb to surfaces, preventing complete decontamination. Our results will directly inform best practices to prevent the introduction of CWD prions into the human food chain during venison processing.
Acknowledgement: Funding was provided by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources (LCCMR), the Rapid Agriculture Response Fund (#95385/RR257), and the Michigan Department of Natural Resources.
Theme: Animal prion diseases
=====end
Prion 2023 Abstracts
17 DETECTION OF CHRONIC WASTING DISEASE PRIONS IN PROCESSED MEATS.
Rebeca Benavente1, Francisca Bravo1,2, Paulina Soto1,2, J. Hunter Reed3, Mitch Lockwood3, Rodrigo Morales1,2
1Department of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, USA. 2Universidad Bernardo O’Higgins, Santiago, Chile. 3Texas Parks and Wildlife, Austin, USA
Abstract
The zoonotic potential of chronic wasting disease (CWD) remains unknown. Currently, there are no known natural cases of CWD transmission to humans but increasing evidence suggests that the host range of CWD is not confined only to cervid species. Alarmingly, recent experimental evidence suggests that certain CWD isolates can induce disease in non-human primates. While the CDC strongly recommends determining CWD status in animals prior to consumption, this practice is voluntary. Consequently, it is plausible that a proportion of the cervid meat entering the human food chain may be contaminated with CWD. Of additional concern is that traditional diagnostic techniques used to detect CWD have relatively low sensitivity and are only approved for use in tissues other than those typically ingested by humans. In this study, we analyzed different processed meats derived from a pre-clinical, CWD-positive free-ranging elk. Products tested included filets, sausages, boneless steaks, burgers, ham steaks, seasoned chili meats, and spiced meats. CWD-prion presence in these products were assessed by PMCA using deer and elk substrates. Our results show positive prion detection in all products. To confirm the resilience of CWD-prions to traditional cooking methods, we grilled and boiled the meat products and evaluated them for any remnant PMCA seeding activity. Results confirmed the presence of CWD-prions in these meat products suggesting that infectious particles may still be available to people even after cooking. Our results strongly suggest ongoing human exposure to CWD-prions and raise significant concerns of zoonotic transmission through ingestion of CWD contaminated meat products.
***> Products tested included filets, sausages, boneless steaks, burgers, ham steaks, seasoned chili meats, and spiced meats.
***> CWD-prion presence in these products were assessed by PMCA using deer and elk substrates.
***> Our results show positive prion detection in all products.
***> Results confirmed the presence of CWD-prions in these meat products suggesting that infectious particles may still be available to people even after cooking.
***> Our results strongly suggest ongoing human exposure to CWD-prions and raise significant concerns of zoonotic transmission through ingestion of CWD contaminated meat products.
=====
9 Carrot plants as potential vectors for CWD transmission.
Paulina Soto1,2, Francisca Bravo-Risi1,2, Claudio Soto1, Rodrigo Morales1,2
1Department of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, USA. 2Universidad Bernardo O’Higgins, Santiago, Chile
***> We show that edible plant components can absorb prions from CWD-contaminated soils and transport them to their aerial parts.
***> Our results indicate that edible plants could participate as vectors of CWD transmission.
=====
Transmission of prion infectivity from CWD-infected macaque tissues to rodent models demonstrates the zoonotic potential of chronic wasting disease.
Samia Hannaoui1,2, Ginny Cheng1,2, Wiebke Wemheuer3, Walter Schulz-Schaeffer3, Sabine Gilch1,2, Hermann Schatzl1,2 1University of Calgary, Calgary, Canada. 2Calgary Prion Research Unit, Calgary, Canada. 3Institute of Neuropathology, Medical Faculty, Saarland University, Homburg/Saar, Germany
***> Further passage to cervidized mice revealed transmission with a 100% attack rate.
***> Our findings demonstrate that macaques, considered the best model for the zoonotic potential of prions, were infected upon CWD challenge, including the oral one.
****> The disease manifested as atypical in macaques and initial transgenic mouse transmissions, but with infectivity present at all times, as unveiled in the bank vole model with an unusual tissue tropism.
***> Epidemiologic surveillance of prion disease among cervid hunters and people likely to have consumed venison contaminated with chronic wasting disease
=====
Transmission of Cervid Prions to Humanized Mice Demonstrates the Zoonotic Potential of CWD
Samia Hannaouia, Irina Zemlyankinaa, Sheng Chun Changa, Maria Immaculata Arifina, Vincent Béringueb, Debbie McKenziec, Hermann M. Schatzla, and Sabine Gilcha
Results: Here, we provide the strongest evidence supporting the zoonotic potential of CWD prions, and their possible phenotype in humans. Inoculation of mice expressing human PrPCwith deer CWD isolates (strains Wisc-1 and 116AG) resulted in atypical clinical manifestations in > 75% of the mice, with myoclonus as leading clinical sign. Most of tg650brain homogenates were positive for seeding activity in RT-QuIC. Clinical disease and presentation was transmissible to tg650 mice and bank voles. Intriguingly, protease-resistant PrP in the brain of tg650 mice resembled that found in a familial human prion disease and was transmissible upon passage. Abnormal PrP aggregates upon infection with Wisc-1 were detectable in thalamus, hypothalamus, and midbrain/pons regions.
Unprecedented in human prion disease, feces of CWD-inoculated tg650 mice harbored prion seeding activity and infectious prions, as shown by inoculation of bank voles and tg650 with fecal homogenates.
Conclusions: This is the first evidence that CWD can infect humans and cause disease with a distinctive clinical presentation, signature, and tropism, which might be transmissible between humans while current diagnostic assays might fail to detect it. These findings have major implications for public health and CWD-management.
The finding that infectious PrPSc was shed in fecal material of CWD-infected humanized mice and induced clinical disease, different tropism, and typical three banding pattern-PrPres in bank voles that is transmissible upon second passage is highly concerning for public health. The fact that this biochemical signature in bank voles resembles that of the Wisc-1 original deer isolate and is different from that of bvWisc-1, in the migration profile and the glyco-form-ratio, is valid evidence that these results are not a product of contamination in our study. If CWD in humans is found to be contagious and transmissible among humans, as it is in cervids [57], the spread of the disease within humans might become endemic.
Transmission of cervid prions to humanized mice demonstrates the zoonotic potential of CWD
Acta Neuropathol 144, 767–784 (2022). https://doi.org/10.1007/s00401-022-02482-9
Published
22 August 2022
Transmission of cervid prions to humanized mice demonstrates the zoonotic potential of CWD
Samia Hannaoui1 · Irina Zemlyankina1 · Sheng Chun Chang1 · Maria Immaculata Arifn1 · Vincent Béringue2 · Debbie McKenzie3 · Hermann M. Schatzl1 · Sabine Gilch1
Received: 24 May 2022 / Revised: 5 August 2022 / Accepted: 7 August 2022
© The Author(s) 2022
Abstract
Prions cause infectious and fatal neurodegenerative diseases in mammals. Chronic wasting disease (CWD), a prion disease of cervids, spreads efficiently among wild and farmed animals. Potential transmission to humans of CWD is a growing concern due to its increasing prevalence. Here, we provide evidence for a zoonotic potential of CWD prions, and its probable signature using mice expressing human prion protein (PrP) as an infection model. Inoculation of these mice with deer CWD isolates resulted in atypical clinical manifestation with prion seeding activity and efficient transmissible infectivity in the brain and, remarkably, in feces, but without classical neuropathological or Western blot appearances of prion diseases. Intriguingly, the protease-resistant PrP in the brain resembled that found in a familial human prion disease and was transmissible upon second passage. Our results suggest that CWD might infect humans, although the transmission barrier is likely higher compared to zoonotic transmission of cattle prions. Notably, our data suggest a different clinical presentation, prion signature, and tissue tropism, which causes challenges for detection by current diagnostic assays. Furthermore, the presence of infectious prions in feces is concerning because if this occurs in humans, it is a source for human-to-human transmission. These findings have strong implications for public health and CWD management.
Keywords Chronic wasting disease · CWD · Zoonotic potential · Prion strains · Zoonotic prions
HIGHLIGHTS OF THIS STUDY
================================
Our results suggest that CWD might infect humans, although the transmission barrier is likely higher compared to zoonotic transmission of cattle prions. Notably, our data suggest a different clinical presentation, prion signature, and tissue tropism, which causes challenges for detection by current diagnostic assays. Furthermore, the presence of infectious prions in feces is concerning because if this occurs in humans, it is a source for human-to-human transmission. These findings have strong implications for public health and CWD management.
In this study, we evaluated the zoonotic potential of CWD using a transgenic mouse model overexpressing human M129-PrPC (tg650 [12]). We inoculated tg650 mice intracerebrally with two deer CWD isolates, Wisc-1 and 116AG [22, 23, 27, 29]. We demonstrate that this transgenic line was susceptible to infection with CWD prions and displayed a distinct leading clinical sign, an atypical PrPSc signature and unusual fecal shedding of infectious prions. Importantly, these prions generated by the human PrP transgenic mice were transmissible upon passage. Our results are the first evidence of a zoonotic risk of CWD when using one of the most common CWD strains, Wisc-1/CWD1 for infection. We demonstrated in a human transgenic mouse model that the species barrier for transmission of CWD to humans is not absolute. The fact that its signature was not typical raises the questions whether CWD would manifest in humans as a subclinical infection, whether it would arise through direct or indirect transmission including an intermediate host, or a silent to uncovered human-to-human transmission, and whether current detection techniques will be suffcient to unveil its presence.
Our findings strongly suggest that CWD should be regarded as an actual public health risk. Here, we use humanized mice to show that CWD prions can cross the species barrier to humans, and remarkably, infectious prions can be excreted in feces.
Our results indicate that if CWD crosses the species-barrier to humans, it is unlikely to resemble the most common forms of human prion diseases with respect to clinical signs, tissue tropism and PrPSc signature. For instance, PrPSc in variable protease-sensitive prionopathy (VPSPr), a sporadic form of human prion disease, and in the genetic form Gerstmann-Sträussler-Scheinker syndrome (GSS) is defined by an atypical PK-resistant PrPSc fragment that is non-glycosylated and truncated at both C- and N-termini, with a molecular weight between 6 and 8 kDa [24, 44–46]. These biochemical features are unique and distinctive from PrPSc (PrP27-30) found in most other human or animal prion disease. The atypical PrPSc signature detected in brain homogenate of tg650 mice #321 (1st passage) and #3063 (2nd passage), and the 7–8 kDa fragment (Figs. 2, 4) are very similar to that of GSS, both in terms of migration profile and the N-terminal cleavage site.
CWD in humans might remain subclinical but with PrPSc deposits in the brain with an unusual morphology that does not resemble the patterns usually seen in different prion diseases (e.g., mouse #328; Fig. 3), clinical with untraceable abnormal PrP (e.g., mouse #327) but still transmissible and uncovered upon subsequent passage (e.g., mouse #3063; Fig. 4), or prions have other reservoirs than the usual ones, hence the presence of infectivity in feces (e.g., mouse #327) suggesting a potential for human-to-human transmission and a real iatrogenic risk that might be unrecognizable.
suggesting a potential for human-to-human transmission and a real iatrogenic risk that might be unrecognizable.
=================================
Supplementary Information The online version contains supplementary material available at
snip...see full text;
CWD transmits to cervid by oral routes with as little as 300NG!
PLoS One. 2020; 15(8): e0237410.
Published online 2020 Aug 20. doi: 10.1371/journal.pone.0237410
PMCID: PMC7446902
PMID: 32817706
Very low oral exposure to prions of brain or saliva origin can transmit chronic wasting disease
We orally inoculated white-tailed deer with either single or multiple divided doses of prions of brain or saliva origin and monitored infection by serial longitudinal tissue biopsies spanning over two years. We report that oral exposure to as little as 300 nanograms (ng) of CWD-positive brain or to saliva containing seeding activity equivalent to 300 ng of CWD-positive brain, were sufficient to transmit CWD disease.
snip...
These studies suggest that the CWD minimum infectious dose approximates 100 to 300 ng CWD-positive brain (or saliva equivalent), and that CWD infection appears to conform more with a threshold than a cumulative dose dynamic.
Food and Drug Administration's BSE Feed Regulation (21 CFR 589.2000) Singeltary Another Request for Update 2023
The infamous 1997 mad cow feed ban i.e. Food and Drug Administration's BSE Feed Regulation (21 CFR 589.2000) most material (exceptions include milk, tallow, and gelatin) from deer and elk is prohibited for use in feed for ruminant animals. With regards to feed for non-ruminant animals, under FDA law, CWD positive deer may not be used for any animal feed or feed ingredients. For elk and deer considered at high risk for CWD, the FDA recommends that these animals do not enter the animal feed system. However, this recommendation is guidance and not a requirement by law.
***>However, this recommendation is guidance and not a requirement by law.
WITH GREAT URGENCY, THE Food and Drug Administration's BSE Feed Regulation (21 CFR 589.2000) MUST BE ENHANCED AND UPDATED TO INCLUDE CERVID, PIGS, AND SHEEP, SINCE RECENT SCIENCE AND TRANSMISSION STUDIES ALL, INCLUDING CATTLE, HAVE SHOWN ORAL TSE PrP TRANSMISSIONS BETWEEN THE SPECIES, AND THIS SHOULD BE DONE WITH THE UTMOST URGENCY, REASONS AS FOLLOW.
First off I will start with a single BSE feed breach 10 years after 1997 partial ban. If you got to the archived link, all the way down to bottom…THE NEXT YEAR I RECALL ONE WITH 10,000,000+ banned products recall…see this records at the bottom…terry
REASON The feed was manufactured from materials that may have been contaminated with mammalian protein.
VOLUME OF PRODUCT IN COMMERCE 27,694,240 lbs DISTRIBUTION MI
snip..... end
***>However, this recommendation is guidance and not a requirement by law.
THIS MUST CHANGE ASAP!
“For elk and deer considered at high risk for CWD, the FDA recommends that these animals do not enter the animal feed system. However, this recommendation is guidance and not a requirement by law.”…
Snip…please see my full submission with reference materials…
Monday, November 13, 2023
Food and Drug Administration's BSE Feed Regulation (21 CFR 589.2000) Singeltary Another Request for Update 2023
FRIDAY, JULY 07, 2023
***> TME, 589.2000 (21 C.F.R. 589.2000), atypical L-BSE, who’s testing MINK for TSE?
EFSA Panel on Biological Hazards (BIOHAZ) Antonia Ricci Ana Allende Declan Bolton Marianne Chemaly Robert Davies Pablo Salvador Fernández Escámez ... See all authors
First published: 17 January 2018 https://doi.org/10.2903/j.efsa.2018.5132
also, see;
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.
OIE Conclusions on transmissibility of atypical BSE among cattle
Given that cattle have been successfully infected by the oral route, at least for L-BSE, it is reasonable to conclude that atypical BSE is potentially capable of being recycled in a cattle population if cattle are exposed to contaminated feed. In addition, based on reports of atypical BSE from several countries that have not had C-BSE, it appears likely that atypical BSE would arise as a spontaneous disease in any country, albeit at a very low incidence in old cattle. In the presence of livestock industry practices that would allow it to be recycled in the cattle feed chain, it is likely that some level of exposure and transmission may occur. As a result, since atypical BSE can be reasonably considered to pose a potential background level of risk for any country with cattle, the recycling of both classical and atypical strains in the cattle and broader ruminant populations should be avoided.
Annex 7 (contd) AHG on BSE risk assessment and surveillance/March 2019
34 Scientific Commission/September 2019
3. Atypical BSE
The Group discussed and endorsed with minor revisions an overview of relevant literature on the risk of atypical BSE being recycled in a cattle population and its zoonotic potential that had been prepared ahead of the meeting by one expert from the Group. This overview is provided as Appendix IV and its main conclusions are outlined below. With regard to the risk of recycling of atypical BSE, recently published research confirmed that the L-type BSE prion (a type of atypical BSE prion) may be orally transmitted to calves1 . In light of this evidence, and the likelihood that atypical BSE could arise as a spontaneous disease in any country, albeit at a very low incidence, the Group was of the opinion that it would be reasonable to conclude that atypical BSE is potentially capable of being recycled in a cattle population if cattle were to be exposed to contaminated feed. Therefore, the recycling of atypical strains in cattle and broader ruminant populations should be avoided.
4. Definitions of meat-and-bone meal (MBM) and greaves
Oral Transmission of L-type Bovine Spongiform Encephalopathy in Primate Model
Nadine Mestre-Francés, Simon Nicot, Sylvie Rouland, Anne-Gaëlle Biacabe, Isabelle Quadrio, Armand Perret-Liaudet, Thierry Baron, and Jean-Michel Verdier
We report transmission of atypical L-type bovine spongiform encephalopathy to mouse lemurs after oral or intracerebral inoculation with infected bovine brain tissue. After neurologic symptoms appeared, transmissibility of the disease by both inoculation routes was con firmed by detection of disease-associated prion protein in samples of brain tissue.
SNIP...
Our study clearly con firms, experimentally, the potential risk for interspecies oral transmission of the agent of L-BSE. In our model, this risk appears higher than that for the agent of classical BSE, which could only be transmitted to mouse lemurs after a first passage in macaques (14). We report oral transmission of the L-BSE agent in young and adult primates. Transmission by the IC route has also been reported in young macaques ( 6,7). A previous study of L-BSE in transgenic mice expressing human PrP suggested an absence of any transmission barrier between cattle and humans for this particular strain of the agent of BSE, in contrast to findings for the agent of classical BSE (9). Thus, it is imperative to maintain measures that prevent the entry of tissues from cattle possibly infected with the agent of L-BSE into the food chain.
Title: Transmission of atypical BSE: a possible origin of Classical BSE in cattle
Authors: Sandor Dudas1, Samuel James Sharpe1, Kristina Santiago-Mateo1, Stefanie Czub1, Waqas Tahir1,2, *
Affiliation: 1National and WOAH reference Laboratory for Bovine Spongiform Encephalopathy, Canadian Food inspection Agency, Lethbridge Laboratory, Lethbridge, Canada. 2Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada.
*Corresponding and Presenting Author: waqas.tahir@inspection.gc.ca
Background: Bovine spongiform encephalopathy (BSE) is a fatal neurodegenerative disease of cattle and is categorized into classical and atypical forms. Classical BSE (CBSE) is linked to the consumption of BSE contaminated feed whereas atypical BSE is considered to be spontaneous in origin. The potential for oral transmission of atypical BSE is yet to be clearly defined.
Aims: To assess the oral transmissibility of atypical BSE (H and L type) in cattle. Should transmission be successful, determine the biochemical characteristics and distribution of PrPSc in the challenge cattle.
Material and Methods: For oral transmission, calves were fed with 100 g of either H (n=3) or L BSE (n=3) positive brain material. Two years post challenge, 1 calf from each of the H and L BSE challenge groups exhibited behavioural signs and were euthanized. Various brain regions of both animals were tested by traditional and novel prion detection methods with inconclusive results. To detect infectivity, brain homogenates from these oral challenge animals (P1) were injected intra-cranially (IC) into steer calves. Upon clinical signs of BSE, 3/4 of IC challenged steer calves were euthanized and tested for PrPSc with ELISA, immunohistochemistry and immunoblot.
Results: After 6 years of incubation, 3/4 animals (2/2 steers IC challenged with brain from P1 L-BSE oral challenge and 1/2 steer IC challenged with brain from P1 H-BSE oral challenge) developed clinical disease. Analysis of these animals revealed high levels of PrPSc in their brains, having biochemical properties similar to that of PrPSc in C-BSE.
Conclusion: These results demonstrate the oral transmission potential of atypical BSE in cattle. Surprisingly, regardless of which atypical type of BSE was used for P1 oral challenge, PrPSc in the P2 animals acquired biochemical characteristics similar to that of PrPSc in C-BSE, suggesting atypical BSE as a possible origin of C-BSE in UK.
Presentation Type: Oral Presentation
Funded by: CFIA, Health Canada, Alberta Livestock and Meat Agency, Alberta Prion Research Institute
Grant Number: ALMA/APRI: 201400006, HC 414250
Title: Transmission of atypical BSE: a possible origin of Classical BSE in cattle
Authors: Sandor Dudas1, Samuel James Sharpe1, Kristina Santiago-Mateo1, Stefanie Czub1, Waqas Tahir1,2, * Affiliation: 1National and WOAH reference Laboratory for Bovine Spongiform Encephalopathy, Canadian Food inspection Agency, Lethbridge Laboratory, Lethbridge, Canada. 2Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada. *Corresponding and Presenting Author: waqas.tahir@inspection.gc.ca
Background: Bovine spongiform encephalopathy (BSE) is a fatal neurodegenerative disease of cattle and is categorized into classical and atypical forms. Classical BSE (CBSE) is linked to the consumption of BSE contaminated feed whereas atypical BSE is considered to be spontaneous in origin. The potential for oral transmission of atypical BSE is yet to be clearly defined.
Aims: To assess the oral transmissibility of atypical BSE (H and L type) in cattle. Should transmission be successful, determine the biochemical characteristics and distribution of PrPSc in the challenge cattle.
Material and Methods: For oral transmission, calves were fed with 100 g of either H (n=3) or L BSE (n=3) positive brain material. Two years post challenge, 1 calf from each of the H and L BSE challenge groups exhibited behavioural signs and were euthanized. Various brain regions of both animals were tested by traditional and novel prion detection methods with inconclusive results. To detect infectivity, brain homogenates from these oral challenge animals (P1) were injected intra-cranially (IC) into steer calves. Upon clinical signs of BSE, 3/4 of IC challenged steer calves were euthanized and tested for PrPSc with ELISA, immunohistochemistry and immunoblot.
Results: After 6 years of incubation, 3/4 animals (2/2 steers IC challenged with brain from P1 L-BSE oral challenge and 1/2 steer IC challenged with brain from P1 H-BSE oral challenge) developed clinical disease. Analysis of these animals revealed high levels of PrPSc in their brains, having biochemical properties similar to that of PrPSc in C-BSE.
Conclusion: These results demonstrate the oral transmission potential of atypical BSE in cattle. Surprisingly, regardless of which atypical type of BSE was used for P1 oral challenge, PrPSc in the P2 animals acquired biochemical characteristics similar to that of PrPSc in C-BSE, suggesting atypical BSE as a possible origin of C-BSE in UK.
Presentation Type: Oral Presentation Funded by: CFIA, Health Canada, Alberta Livestock and Meat Agency, Alberta Prion Research Institute
Grant Number: ALMA/APRI: 201400006, HC 414250
Acknowledgement: TSE unit NCAD, Lethbridge (Jianmin Yang, Sarah Bogart, Rachana Muley, Yuanmu Fang, Keri Colwell, Renee Anderson, John Gray, Rakhi Katoch) (CFIA, Canada), Dr. Catherine Graham (NSDA, Canada), Dr. Michel Levy (UCVM, Canada), Dr. Martin Groschup (FLI, Germany), Dr. Christine Fast (FLI, Germany), Dr. Bob Hills (Health Canada, Canada) Theme: Animal prion diseases
"After 6 years of incubation, 3/4 animals (2/2 steers IC challenged with brain from P1 L-BSE oral challenge and 1/2 steer IC challenged with brain from P1 H-BSE oral challenge) developed clinical disease. Analysis of these animals revealed high levels of PrPSc in their brains, having biochemical properties similar to that of PrPSc in C-BSE. "
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PRION 2023 CONTINUED;
Molecular phenotype shift after passage of low-type bovine spongiform encephalopathy (L-BSE).
Zoe J. Lambert, M. Heather West Greenlee, Jifeng Bian, Justin J. Greenlee Ames, USA
Aims: The purpose of this study is to compare the molecular phenotypes of L-BSE in wild type cattle and cattle with the E211K polymorphism to samples of other cattle TSEs, such as classical BSE (C-BSE), hightype BSE (H-BSE), and transmissible mink encephalopathy (TME).
Materials and Methods: Two wild type cattle (EE211 PRNP) and one steer with the E211K polymorphism (EK211) were intracranially inoculated with 1 mL of brain homogenate that originated from a 2005 French L-BSE case. Multiple assays were used to compare and differentiate tissues, including enzyme immunoassay, western blot (Sha31, 12B2, SAF84), stability (Sha31), and immunohistochemistry (F99/97).
Results: Approximately 16.6 months post-inoculation, Steer 6 (EK211 L-BSE) developed neurologic signs, including agitation, difficulty eating accompanied by weight loss, head tremor, ataxia, and fasciculations in the forelimbs, and was necropsied. Enzyme immunoassays demonstrated misfolded prion protein in the brainstem (4.0 O.D) but not in peripheral tissues, such as the retropharyngeal lymph node and palatine tonsil. When compared by western blot, the molecular phenotype of the brainstem of Steer 6 (EK211 L-BSE) is higher than that of wildtype cattle inoculated with L-BSE, requiring careful differentiation from C-BSE. Ongoing mouse studies in bovinized mice (K211 and TgBov) will provide data to compare to all other BSE strains available, including L-BSE, C-BSE, H-BSE, E211K H-BSE, and TME.
Conclusions: Further study of L-BSE in EK211 cattle with a higher molecular phenotype in the brainstem may give more insight into the origin of C-BSE.
Funded by: This research was funded in its entirety by congressionally appropriated funds to the United States Department of Agriculture, Agricultural Research Service. The funders of the work did not influence study design, data collection and analysis, decision to publish, or preparation of the manuscript. This research was supported in part by an appointment to the Agricultural Research Service (ARS) Research Participation Program administered by the Oak Ridge Institute for Science and Education (ORISE) through an interagency agreement between the U.S. Department of Energy (DOE) and the U.S. Department of Agriculture (USDA). ORISE is managed by ORAU under DOE contract number DE-SC0014664. All opinions expressed in this paper are the author’s and do not necessarily reflect the policies and views of USDA, ARS, DOE, or ORAU/ORISE.
Grant number: DOE contract number DE-SC0014664 Acknowledgements: NA Theme: Animal prion diseases
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PRION 2023 CONTINUED;
Transmission of scrapie prions to primate after an extended silent incubation period
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
***Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
***Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
***Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.***
Even if the prevailing view is that sporadic CJD is due to the spontaneous formation of CJD prions, it remains possible that its apparent sporadic nature may, at least in part, result from our limited capacity to identify an environmental origin.
O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations
*** We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period,
***with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold long incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014),
***is the third potentially zoonotic PD (with BSE and L-type BSE),
***thus questioning the origin of human sporadic cases.
==============
PRION 2015 CONFERENCE
PRION 2016 TOKYO
Saturday, April 23, 2016
SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016
Prion. 10:S15-S21. 2016 ISSN: 1933-6896 1933-690X
WS-01: Prion diseases in animals and zoonotic potential
Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
Tuesday, December 16, 2014
Evidence for zoonotic potential of ovine scrapie prions
Hervé Cassard,1, n1 Juan-Maria Torres,2, n1 Caroline Lacroux,1, Jean-Yves Douet,1, Sylvie L. Benestad,3, Frédéric Lantier,4, Séverine Lugan,1, Isabelle Lantier,4, Pierrette Costes,1, Naima Aron,1, Fabienne Reine,5, Laetitia Herzog,5, Juan-Carlos Espinosa,2, Vincent Beringue5, & Olivier Andréoletti1, Affiliations Contributions Corresponding author Journal name: Nature Communications
Volume: 5, Article number: 5821 DOI: doi:10.1038/ncomms6821 Received 07 August 2014 Accepted 10 November 2014 Published 16 December 2014
Abstract
Although Bovine Spongiform Encephalopathy (BSE) is the cause of variant Creutzfeldt Jakob disease (vCJD) in humans, the zoonotic potential of scrapie prions remains unknown. Mice genetically engineered to overexpress the humanprion protein (tgHu) have emerged as highly relevant models for gauging the capacity of prions to transmit to humans. These models can propagate human prions without any apparent transmission barrier and have been used used to confirm the zoonotic ability of BSE. Here we show that a panel of sheep scrapie prions transmit to several tgHu mice models with an efficiency comparable to that of cattle BSE.
***The serial transmission of different scrapie isolates in these mice led to the propagation of prions that are phenotypically identical to those causing sporadic CJD (sCJD) in humans.
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
Subject terms: Biological sciences• Medical research At a glance
why do we not want to do TSE transmission studies on chimpanzees $ 5. A positive result from a chimpanzee challenged severly would likely create alarm in some circles even if the result could not be interpreted for man. I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough. Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.
snip... R. BRADLEY
1: J Infect Dis 1980 Aug;142(2):205-8
Oral transmission of kuru, Creutzfeldt-Jakob disease, and scrapie to nonhuman primates
Gibbs CJ Jr, Amyx HL, Bacote A, Masters CL, Gajdusek DC.
Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of sheep and goats were transmitted to squirrel monkeys (Saimiri sciureus) that were exposed to the infectious agents only by their nonforced consumption of known infectious tissues. The asymptomatic incubation period in the one monkey exposed to the virus of kuru was 36 months; that in the two monkeys exposed to the virus of Creutzfeldt-Jakob disease was 23 and 27 months, respectively; and that in the two monkeys exposed to the virus of scrapie was 25 and 32 months, respectively. Careful physical examination of the buccal cavities of all of the monkeys failed to reveal signs or oral lesions. One additional monkey similarly exposed to kuru has remained asymptomatic during the 39 months that it has been under observation.
snip...
The successful transmission of kuru, Creutzfeldt-Jakob disease, and scrapie by natural feeding to squirrel monkeys that we have reported provides further grounds for concern that scrapie-infected meat may occasionally give rise in humans to Creutzfeldt-Jakob disease. PMID: 6997404
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6997404&dopt=Abstract
Recently the question has again been brought up as to whether scrapie is transmissible to man. This has followed reports that the disease has been transmitted to primates. One particularly lurid speculation (Gajdusek 1977) conjectures that the agents of scrapie, kuru, Creutzfeldt-Jakob disease and transmissible encephalopathy of mink are varieties of a single "virus". The U.S. Department of Agriculture concluded that it could "no longer justify or permit scrapie-blood line and scrapie-exposed sheep and goats to be processed for human or animal food at slaughter or rendering plants" (ARC 84/77)" The problem is emphasised by the finding that some strains of scrapie produce lesions identical to the once which characterise the human dementias" Whether true or not. the hypothesis that these agents might be transmissible to man raises two considerations. First, the safety of laboratory personnel requires prompt attention. Second, action such as the "scorched meat" policy of USDA makes the solution of the acrapie problem urgent if the sheep industry is not to suffer grievously. snip... 76/10.12/4.6
Nature. 1972 Mar 10;236(5341):73-4.
Transmission of scrapie to the cynomolgus monkey (Macaca fascicularis)
Gibbs CJ Jr, Gajdusek DC. Nature 236, 73 - 74 (10 March 1972); doi:10.1038/236073a0
Transmission of Scrapie to the Cynomolgus Monkey (Macaca fascicularis)
C. J. GIBBS jun. & D. C. GAJDUSEK National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland
SCRAPIE has been transmitted to the cynomolgus, or crab-eating, monkey (Macaca fascicularis) with an incubation period of more than 5 yr from the time of intracerebral inoculation of scrapie-infected mouse brain. The animal developed a chronic central nervous system degeneration, with ataxia, tremor and myoclonus with associated severe scrapie-like pathology of intensive astroglial hypertrophy and proliferation, neuronal vacuolation and status spongiosus of grey matter. The strain of scrapie virus used was the eighth passage in Swiss mice (NIH) of a Compton strain of scrapie obtained as ninth intracerebral passage of the agent in goat brain, from Dr R. L. Chandler (ARC, Compton, Berkshire).
spontaneous/sporadic CJD in 85%+ of all human TSE, or spontaneous BSE in cattle, is a pipe dream, dreamed up by USDA/OIE et al, that has never been proven. let me repeat, NEVER BEEN PROVEN FOR ALL HUMAN OR ANIMAL TSE I.E. ATYPICAL BSE OR SPORADIC CJD! please see;
***Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.***
Even if the prevailing view is that sporadic CJD is due to the spontaneous formation of CJD prions, it remains possible that its apparent sporadic nature may, at least in part, result from our limited capacity to identify an environmental origin.
The L-type BSE prion is much more virulent in primates and in humanized mice than is the classical BSE prion, which suggests the possibility of zoonotic risk associated with the L-type BSE prion
Consumption of L-BSE–contaminated feed may pose a risk for oral transmission of the disease agent to cattle.
Thus, it is imperative to maintain measures that prevent the entry of tissues from cattle possibly infected with the agent of L-BSE into the food chain.
Atypical L-type bovine spongiform encephalopathy (L-BSE) transmission to cynomolgus macaques, a non-human primate
Fumiko Ono 1, Naomi Tase, Asuka Kurosawa, Akio Hiyaoka, Atsushi Ohyama, Yukio Tezuka, Naomi Wada, Yuko Sato, Minoru Tobiume, Ken'ichi Hagiwara, Yoshio Yamakawa, Keiji Terao, Tetsutaro Sata
Affiliations expand
PMID: 21266763
Abstract
A low molecular weight type of atypical bovine spongiform encephalopathy (L-BSE) was transmitted to two cynomolgus macaques by intracerebral inoculation of a brain homogenate of cattle with atypical BSE detected in Japan. They developed neurological signs and symptoms at 19 or 20 months post-inoculation and were euthanized 6 months after the onset of total paralysis. Both the incubation period and duration of the disease were shorter than those for experimental transmission of classical BSE (C-BSE) into macaques. Although the clinical manifestations, such as tremor, myoclonic jerking, and paralysis, were similar to those induced upon C-BSE transmission, no premonitory symptoms, such as hyperekplexia and depression, were evident. Most of the abnormal prion protein (PrP(Sc)) was confined to the tissues of the central nervous system, as determined by immunohistochemistry and Western blotting. The PrP(Sc) glycoform that accumulated in the monkey brain showed a similar profile to that of L-BSE and consistent with that in the cattle brain used as the inoculant. PrP(Sc) staining in the cerebral cortex showed a diffuse synaptic pattern by immunohistochemistry, whereas it accumulated as fine and coarse granules and/or small plaques in the cerebellar cortex and brain stem. Severe spongiosis spread widely in the cerebral cortex, whereas florid plaques, a hallmark of variant Creutzfeldt-Jakob disease in humans, were observed in macaques inoculated with C-BSE but not in those inoculated with L-BSE.
see full text;
''H-TYPE BSE AGENT IS TRANSMISSIBLE BY THE ORONASAL ROUTE''
This study demonstrates that the H-type BSE agent is transmissible by the oronasal route. These results reinforce the need for ongoing surveillance for classical and atypical BSE to minimize the risk of potentially infectious tissues entering the animal or human food chains.
2023 PRION CONFERENCE
Comparing the Distribution of Ovine Classical Scrapie and Sporadic Creutzfeldt-Jakob Disease in Italy: Spatial and Temporal Associations (2002-2014)
Aim: This study aims to investigate potential spatial and temporal associations between Creutzfeldt-Jakob disease (CJD) in humans (2010-2014) and ovine classical scrapie (CS) (2002- 2006) in Italy, serving as a proxy for exposure.
Results: The analysis of data at the district level revealed no significant association. However, when considering aggregated regional data, all four models consistently indicated a statistically significant positive association, suggesting a higher incidence of the disease in humans as the regional incidence of sheep scrapie increased.
Conclusions: While the results are intriguing, it is important to acknowledge the inherent limitations of ecological studies. Nevertheless, these findings provide valuable evidence to formulate a hypothesis regarding the zoonotic potential of classical scrapie. Further investigations are necessary, employing specific designs such as analytical epidemiology studies, to test this hypothesis effectively.
Prospective 25-year surveillance of prion diseases in France, 1992 to 2016: a slow waning of epidemics and an increase in observed sporadic forms separator commenting unavailable
Angéline Denouel1 , Jean-Philippe Brandel1,2 , Laurène Peckeu-Abboud3 , Danielle Seilhean1 , Elodie Bouaziz-Amar4,5 , Isabelle Quadrio6,7 , Jean-Baptiste Oudart8,9,10 , Sylvain Lehmann11 , Pantxika Bellecave12 , Jean-Louis Laplanche4,5 , Stéphane Haik1,2
Background
Prion diseases are rare, fatal disorders that have repeatedly raised public health concerns since the early 1990s. An active prion disease surveillance network providing national level data was implemented in France in 1992.AimWe aimed to describe the epidemiology of sporadic, genetic and infectious forms of prion diseases in France since surveillance implementation.
Methods
We included all suspected cases notified from January 1992 to December 2016, and cases who died during the period with a definite or probable prion disease diagnosis according to EuroCJD criteria. Demographic, clinical, genetic, neuropathological and biochemical data were collected.
Results
In total, 25,676 suspected cases were notified and 2,907 were diagnosed as prion diseases, including 2,510 (86%) with sporadic Creutzfeldt-Jakob disease (sCJD), 240 (8%) genetic and 157 (6%) with infectious prion disease. Suspected cases and sCJD cases increased over time. Younger sCJD patients (≤ 50 years) showed phenotypes related to a distinct molecular subtype distribution vs those above 50 years. Compared to other European countries, France has had a higher number of cases with iatrogenic CJD after growth hormone treatment and variant CJD (vCJD) linked to bovine spongiform encephalopathy (second after the United Kingdom), but numbers slowly decreased over time.
Conclusion
We observed a decrease of CJD infectious forms, demonstrating the effectiveness of measures to limit human exposure to exogenous prions. However, active surveillance is needed regarding uncertainties about future occurrences of vCJD, possible zoonotic potential of chronic wasting diseases in cervids and increasing trends of sCJD observed in France and other countries.
Keywords: Creutzfeldt-Jakob diseases; diagnosis; prion diseases; surveillance system.
Key public health message
What did you want to address in this study?
Prion diseases are rare, devastating brain diseases that are transmissible and always fatal. They include genetic, sporadic and infectious forms, e.g. from consumption of contaminated beef (i.e. mad cow disease) or treatment using human-derived medical products. Using the French prion surveillance data, we analysed the data collected since 1992 to understand the appearance of different forms of prion diseases over time within the general population.
What have we learnt from this study?
Infectious forms, and notably cases after treatment with growth hormone of human origin or from consumption of contaminated beef, decreased over time. On the contrary, the number of sporadic cases, for which the cause remains unknown, tended to increase without clear explanation.
What are the implications of your findings for public health?
The decreasing trend of infectious forms we observed in France demonstrates the effectiveness of measures taken to limit prion diseases in the general population. The tendency toward an increase of sporadic forms, also noted in other countries, as well as their unclear origin and the emergence of new prion diseases in animals consumed by humans, underline the need of sustaining an active surveillance.
Introduction Transmissible spongiform encephalopathies (TSEs), also known as prion diseases, are rare transmissible neurodegenerative disorders that are invariably fatal. They are caused by a non-conventional agent called a prion, short for ‘proteinaceous infectious particle’ [1], formed by assemblies of a misfolded isoform (PrPsc) of the host-encoded cellular prion protein (PrPc) [2,3]. In humans, TSEs are observed in different forms: sporadic Creutzfeldt–Jakob disease (sCJD), infectious forms including iatrogenic Creutzfeldt–Jakob disease (iCJD), variant Creutzfeldt–Jakob disease (vCJD) and kuru, and genetic forms with genetic Creutzfeldt–Jakob disease (gCJD), Gerstmann–Sträussler–Scheinker syndrome (GSS) and fatal familial insomnia (FFI), which have autosomal dominant transmission with variable penetrance [4]. The incidence of TSEs in humans is around 1 to 2 cases per million person-years in Europe, with sCJD being the most frequent form, accounting for 85% of cases in countries where an active surveillance was implemented in the early 1990s [5-8].
Sporadic CJD occurs in late middle age (ca 60–80 years) and is typically characterised by specific neurological symptoms including rapidly progressive dementia associated with ataxia, pyramidal and extrapyramidal signs, myoclonus and visual disorders [9]. Genetic forms of prion disease are caused by different pathogenic point mutations or nucleotide insertions in the prion protein gene (PRNP). Clinical features, which are similar to sCJD, can differ according to the mutation/insertion. Infectious vCJD was first observed in the United Kingdom (UK) [10,11] and France [12] in 1995, linked to cross-species contamination by the agent of classical bovine spongiform encephalopathy (BSE) [13-16]. Variant CJD has mainly impacted younger individuals (< 40 years); the mean age of vCJD cases is 26.5 years in UK [5] and 36 years in France [17], which are the two most affected countries worldwide. Cases with vCJD show a peculiar clinical presentation with early psychiatric disorders and sensory symptoms including atypical pains that affect the face or the limbs and are often drug-resistant. Cases of iCJD appeared from the late 1970s and were associated with corneal transplantations or neurosurgery, primarily with human dura mater grafts or cadaver-sourced human pituitary growth hormone (hGH-iCJD) and more rarely with gonadotrophin treatment [18]. In contrast to sCJD, hGH-iCJD typically affects younger individuals (< 50 years) and is characterised by ataxia and motor disorders followed by myoclonus and dementia [19]. The highest numbers of hGH-iCJD cases have been observed in France followed by the UK, where the first cases occurred in 1989 and 1985, respectively [20].
Because TSEs have led to several public health crises [21,22] given intra-species and inter-species transmissibility of prions and their resistance to conventional procedures of inactivation, many countries implemented nationwide surveillance networks, mostly in 1990s, that are still active. We describe the TSE data from national surveillance between 1992 to 2016 in France, with a particular focus on infectious forms and young patients with sCJD.
Surveillance system and data collection
A national surveillance network of TSEs was established in France in 1992 and included in the European CJD surveillance network (EuroCJD) [23]. The French network is coordinated by the French Institute on Health and Medical Research (INSERM) and Santé Publique France, and involves biochemistry laboratories performing 14-3-3 detection in cerebrospinal fluid (CSF), the neuropathology department of the Salpetriere hospital (Paris) that coordinates the neuropathological CJD network, the French national reference centre for prion diseases and the French national unit for CJD care.
CJD is a notifiable disease since 19 September 1996. Suspected cases are mostly notified to the surveillance network by the biochemistry laboratories that systematically send the results of 14-3-3 detection weekly or monthly, but also by physicians through direct contact with the expert neurologists of the network (JPB and SH) and rarely by neuropathology laboratories.
The network collects demographic and clinical data, including clinical signs, results of 14-3-3 protein detection in the cerebrospinal fluid, electroencephalogram (EEG) and magnetic resonance imaging (MRI)), family history, genetic data (PRNP analysis [24]), results from neuropathological examination and molecular typing of brain PrPsc protease-resistant core (PrPres) by Western blot visualisation after proteinase K (PK) treatment [25].
All cases registered are investigated until obtaining a final diagnosis (at death for TSE diagnosis). Clinical data are transmitted by the treating physician who is asked to fill in a questionnaire and to send a hospitalisation summary to the French TSE coordinator in the network. Only cases of vCJD are systematically examined by the expert neurologists of the French surveillance network. For autopsied cases, neuropathological laboratories organised in the CJD network transmit neuropathological data. Data on blood donors and recipients were provided by the ‘Etablissement Français du Sang’. The French Ministry of Health requested the national surveillance network to follow up the recipients through a yearly interview with their general practitioner since 2005.
Case definition and diagnosis
Each individual notified to the French surveillance network with a progressive neurological syndrome and at least one clinical sign included in case definitions of CJD was considered as a suspected case of CJD. The case definition for possible, probable or definite TSEs was established by EuroCJD [26]. Diagnostic criteria have been modified since the creation of the French surveillance network, notably for the classification of sCJD. The results from additional paraclinical tests were gradually included, such as those from EEG in 1992, CSF 14-3-3 protein detection in 1998 and striatal high signals from MRI in 2010. The combination of typical clinical symptoms (including cognitive disorders, myoclonus, visual or cerebellar disorders, pyramidal or extrapyramidal features and akinetic mutism) with results from paraclinical testing, enables the classification of a case as possible or probable (evolution of diagnostic criteria can be found in Supplementary Figure S1). The methionine (M)/valine (V) polymorphism at codon 129 of PRNP gene that is known to influence susceptibility to prion disease, age at onset and clinicopathological phenotype was regularly analysed [27-29].
The diagnosis of definite TSE is based on a neuropathological examination showing typical lesions including neuronal loss, spongiosis, astrogliosis and in some cases amyloid plaques, PrPsc deposits as detected by immunohistochemistry and, when frozen brain samples are available, molecular PrPres typing. Type 1 and type 2A, observed in sCJD, are indicated by an electrophoretic mobility of the PK-resistant fragment of the unglycosylated form of PrPres at 21 kDa and 19 kDa, respectively [30]. Type 2B, observed in vCJD, is defined by a molecular weight of 19 kDa of unglycosylated forms associated to predominant biglycosylated forms of PrPres [13,31].
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Results Between 1992 and 2016, 25,676 suspected cases of prion disease were notified to the French surveillance network. A diagnosis of probable or definite prion disease was retained for 2,907 (11%) of the 25,676 suspected cases. Among those, 2,510 (86%) were classified with a diagnosis of sCJD, 240 (8%) as genetic prion diseases, and 157 (5%) as infectious prion diseases (Figure 1).
Figure 1.Number of suspicions and cases with a diagnosis of probable or definite prion disease by form, France, 1992–2016
For the 2,907 prion disease cases, the age at disease onset ranged from 10 to 93 years (median: 68 years; IQR: 60-75); 1,562 females and 1,345 males were observed. The youngest patients were observed among hGH-iCJD cases (n = 116) with a median age at onset of 27 years (IQR: 22–31). Disease duration was the longest in GSS and the shortest in iCJD after dura mater graft and in sCJD cases. Gene analysis of PRNP was performed for 2,077 (71%) cases for whom consent was obtained. An autopsy was performed in 2,114 suspected patients and 1,476 (70%) were confirmed as definite cases of TSE. Molecular type was studied in 926 cases (63%; 926/1,476). Patient characteristics are presented for each form in Table 1. Clinical and diagnostic test characteristics of patients are described for each form in Table 2.
Table 1.Case characteristics for each form of prion disease, France, 1992–2016 (n = 2,907)
Table 2.Clinical characteristics at the terminal stage of disease by form of prion disease, France, 1992–2016 (n = 2,907)
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Sporadic Creutzfeldt–Jakob disease
Median age at disease onset for the 2,510 sCJD cases was 69 years (IQR: 63–76). A genetic analysis was performed on 1,704 cases, and 1,347 were homozygotes at codon 129 (79%) including 1,014 (60%) MM. Age at onset was not significantly different between genotypes at codon 129 (p = 0.057) and no sex difference was observed (p = 0.509). However, cases with MM showed a significantly shorter disease duration (p = 0.001) than those with VV and MV genotypes (Table 3). A total of 842 sCJD cases were pathologically confirmed with information on the molecular type. The most frequent molecular subtype was MM/MV1 and the less frequent VV1. Age at disease onset and disease duration were significantly different between cases with different molecular subtypes (p < 0.001). Cases with VV1 subtypes were younger at disease onset and the highest median disease duration was observed in MV2. Detailed characteristics of each codon 129 polymorphism and molecular subtypes are shown in Table 3 and the repartition of molecular subtypes over time are provided in Supplementary Figure S2.
Table 3.Characteristics of PRNP codon 129 genotypes and molecular subtypes of probable and definite sporadic Creutzfeldt–Jakob disease cases, France, 1992–2016 (n = 1,704)
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The sensitivity of the diagnostic tests was respectively 52% for the EEG, 82% for the detection of the 14-3-3 protein, and 46% for the MRI. The specificity was equal to 85%, 58% and 93% respectively. Moreover, sensitivity and specificity of diagnostic criteria over time are described in Supplementary Material S2.
Patients aged 90 years and above represented 0.3% (8/2,510) of our sCJD population and had a significantly shorter disease duration (median: 2 months) than sCJD cases aged less than 90 years (2,502/2,510; median: 4 months; p = 0.04). In contrast, patients aged 50 years and under (n = 85) had a longer disease duration compared with patients aged more than 50 years (p < 0.001). Supplementary Table S1 provides a comparison of disease duration between vCJD and sCJD cases, which showed a significant longer disease duration for vCJD compared with sCJD aged 50 years and under (p = 0.002) or above than 50 years (p = 0.028).
Younger sCJD patients (≤ 50 years) had a significantly different distribution of molecular subtypes compared with cases aged above 50 years (p = 0.03) with a higher proportion of VV1 (23%) and MM2 (11%), which are rare in older patients (0.3% and 4%, respectively). The proportion of MM1/MV1 was 59% for cases above 50 years and 39% for 50 years and under (Table 4). Supplementary Table S2 provides the diagnostic test characteristics of patients aged 50 years and under and we observed a significant difference only for the presence of PSWCs on EEG with 29% in younger sCJD cases and 37% in older cases (p = 0.027).
Table 4.Molecular subtypes of cases of sporadic Creutzfeldt–Jakob disease by age groups, France, 1992–2016 (n = 2,510)
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Genetic prion diseases
Between 1992 and 2016, 8% (240/2,907) of cases were diagnosed with a genetic prion disease; half of them were confirmed as definite cases (120/240). The median age at onset of genetic prion diseases was 58 years (IQR: 50–68) and the median disease duration was 7 months (IQR: 4–12). Among the 240 cases, 118 were females and 122 males. The most frequent mutation was E200K with a phenotype of gCJD, except for one autopsied case who had a phenotype of FFI. The second most frequent mutation was D178N-129M in cases with FFI phenotype, followed by the mutations V201I and D178N-129V in cases with a CJD phenotype. The most frequent insertion was the 192 bp insertion with a phenotype of GSS. Characteristics by form of observed cases in France with genetic prion diseases are presented in Table 1 and Table 2, and additional information on each mutation and insertion are given in Supplementary Table S3.
Variant Creutzfeldt–Jakob disease
A diagnosis of vCJD was made in 27 patients (18 definite and 9 probable) including 15 females and 12 males. The median age at onset was 35 years (IQR: 23–47) and the median disease duration was 14 months (IQR: 11–19). All patients were MM at codon 129 of PRNP gene (Table 1). Of 22 vCJD cases who had a tonsil biopsy, 21 were positive for the detection of abnormal prion protein. The patient with a negative tonsil biopsy was classified as definite vCJD after autopsy. Thirteen cases had both a tonsil biopsy and an autopsy.
Three vCJD patients with disease onset in 2004 were blood donors, and 42 individuals received labile blood products (i.e. red blood cells, platelets, plasma) from these donors. Of these 42, 31 died from another cause, 22 during the year of the impacted blood transfusion and nine between 4 and 21 years following the transfusion. Of the remaining 11 patients, four were not followed up because they were transfused in 1984 before the BSE outbreaks. The other seven patients, transfused between 1994 and 2004, were still alive with no symptoms of CJD at the time of the surveillance. One of these living individuals received a blood transfusion in 2004 from a donor whose plasma retrospectively tested positive by protein misfolding cyclic amplification (PMCA) assay during the incubation period [32].
Iatrogenic Creutzfeldt–Jakob disease
From 1992 to 2016, 130 iCJD cases have been reported. Of these, 14 were due to a Lyodura brand dura mater grafted between the mid-1980s and 1994 [6]. The other 116 iCJD were linked to a treatment with growth hormone of human cadaveric origin from at-risk batches during the at-risk treatment period in France (between 1983 and 1985) [33]. Median age at onset was 56 years (IQR: 42–70) in cases related to a dura mater graft and 27 years (IQR: 22–31) in hGH-iCJD, with a median disease duration of 4 and 15 months, respectively. More men than women experienced hGH-iCJD disease (sex ratio: 3.8). Half of the cases were homozygous MM at codon 129 of the PRNP gene (Table 1).
The temporal distribution and incubation period of cases by codon 129 genotype are shown in Figure 2. From 1992 to 1995, all cases were MM or VV. The first heterozygous cases were reported in 1996 and no VV case was observed after 2000 [20] except one in 2015. This case had an incubation period of 31 years, whereas no other homozygous VV cases had an incubation period over 16 years. The incubation period of MM and MV cases was up to 25 years.
Figure 2.Temporal distribution and incubation perioda of cases with iatrogenic Creutzfeldt–Jakob disease linked to human growth hormone treatment, reported by genotype at codon 129 of the prion protein gene, France, 1992–2016 (n = 116)
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Discussion Following the emergence of hGH-iCJD cases and the increasing number of BSE cases in the UK, several European countries, including France, implemented an epidemiological surveillance of human TSEs [23]. This enabled the rapid identification of a new form of CJD linked to a cross-species contamination with the BSE agent (vCJD) [10,11,13-16]. The active CJD surveillance network initiated at the national level in France in 1992 has provided long-term data on this rare group of diseases.
Consistent with series collected by other surveillance systems, we report the same distribution of sporadic CJD (around 85%) [5-8]. Genetic CJD represent 10–15% of cases worldwide [4,34,35]. The occurrence of infectious forms varies between countries: vCJD is primarily reported in UK (n = 178 cases) and France (n = 27 cases), while in some other countries, only 1 to 5 cases of vCJD have been observed since the initiation of CJD surveillance [8,36]. With respect to hGH-iCJD cases, the most affected countries in Europe are the UK [5] and France (n = 79 and 116, respectively); fewer hGH-iCJD cases are observed in the other European countries [37].
The number of TSE suspicions increased progressively over time in France, as reported in other countries with a similar surveillance system, such as the UK and Italy [7,38]. This can be explained by network implementation, improvement in case identification [39] (especially for the first years of surveillance) and by population ageing, with an increasing number of older people (≥ 65 years) (‘The National Institute of Statistics and Economic Studies’ (Insee, https://www.insee.fr/en/accueil) who are the most affected by dementias including CJD.
We observed yearly variations in the number of sCJD cases, as reported in other countries by the EuroCJD network [38]. An annual variation of almost 50% in the sCJD mortality is not unusual and not necessarily worrying. However, in the last decades, an increasing trend of sCJD mortality over time occurred in France as well as in other countries [38,40]. Our data show that the evolution of sCJD diagnostic criteria increased the sensitivity contributing to better case detection. More recently, detection of cortical high signals on MRI sequences in at least two different regions of the brain were introduced on criteria in 2017 as well as the results of real-time quaking-induced conversion (RT-QuIC), an amplification method used to detect low amount of PrPsc in cerebrospinal fluid (CSF). The impact of improved diagnosis criteria on measured sCJD mortality should be evaluated in large series. However, even if an intense surveillance system can explain better case ascertainment [39], it cannot be excluded that an actual concurrent increase of sCJD cases occurred over time because of unknown factors [40].
Analyses of PRNP codon 129 of sCJD patients showed an excess proportion of homozygotes at codon 129 (79%, including 60% of MM) in comparison with the French general population (50% of homozygotes) [41]. This observation supports that methionine homozygosity is a susceptibility factor for sCJD occurrence [27,42]. Of the different subtypes, MM1/MV1 was the commonest sCJD subtype with the shortest disease duration (median: 3 months), as previously described [30]. In our study, we merged data from MM1 and MV1 into one subtype, as performed in previous studies, since these molecular subtypes share common clinicopathological characteristics and are both associated with the M1 sCJD prion strain as shown by strain typing in experimental models [9,43,44]. It is worth noting, however, that disease duration was longer in French MV1 than in MM1 cases. More precisely, a subgroup of MV1 cases showed a longer disease duration (data not shown) suggesting that MM1/MV1 subtype might be divided into two subtypes. Gelpi et al. [45] recently identified a new subtype of sCJD in patients carrying MV at PRNP codon 129 with PrPres type 1. These patients presented distinctive clinicopathological features and a long duration (mean: 20.5 months). Further investigations are needed to assess whether the French MV1 patients with longer duration we studied are consistent with this recent observation from Spanish and Italian patients.
The subtype distribution was different for younger sCJD cases with a more frequent proportion of VV1 and MM2 subtypes. The shorter frequency of typical cases (MM1/MV1) in young people compared with patients with sCJD over 50 years old remains to be explained. Indeed, taking the hypothesis of a stochastic conversion of PrP as the event causing sCJD occurrence, the subtype distribution should be the same regardless of the age of the individuals. The specific strain distribution we observed in younger patients compared with older ones might be related to a specific strain selection pressure modulated by age-related endogenous factors (such as the proteostasis system) or to a distinct causative event in some younger patients such as an exposure to exogenous factors.
The largest series of hGH-iCJD cases has been observed in France and the present study confirms a specific time distribution of cases according to the codon 129 genotype, as suggested by Brandel et al. in 2003 [20]. The first French hGH-iCJD cases were all homozygous and the first MV patient was reported 5 years after the onset of the epidemic. More precisely, all valine homozygous hGH-iCJD cases occurred in 2000 and before except for one case that was reported in 2015. A neuropathological examination was not performed and even if the case was actually treated with at-risk batches of cadaverous human pituitary growth hormone [33], we cannot exclude the possibility of a misclassification of a sCJD into a hGH-iCJD case because of his medical history. Clinical characteristics resembled those of sCJD VV2 subtype: 3-month survival time, early ataxia and no dementia at onset, no typical EEG, positive CSF 14-3-3 detection and high signals in basal ganglia on MRI. Of note, our study from 2020 showed that the incubation period was significantly shorter in valine homozygotes than heterozygotes [46], whereas this last hGH-iCJD case showed an extreme incubation period (31 years) in comparison with the other homozygous valine (16 years or less) and with MM and MV cases (25 years or less).
France was the second most affected country by vCJD after the UK. In France, 27 cases of primary vCJD were reported during our study period and the last one occurred in 2014. Two additional cases were observed in 2020 and in 2021 that occurred after occupational exposure to the BSE agent in research laboratories. In 2020, we reported a definite vCJD case in a research technician who experienced an accidental occupational exposure to the classical BSE agent in a prion research laboratory 7.5 years before the disease onset [47]. Even if oral transmission related to contaminated cattle product consumption cannot be formally excluded, the hypothesis of an occupational contamination was reinforced in 2021 with the occurrence of a case of probable vCJD in a retired laboratory worker who also experienced an accidental occupational exposure to the BSE agent 15 years before clinical onset. Both patients were homozygous methionine at codon 129. In 2016, a heterozygous vCJD case was reported in the UK, raising fears of the emergence of a second wave of MV individuals related to a longer incubation period [48]. However, to date, no further heterozygous cases have been reported worldwide, which does not support this hypothesis.
One of the remaining concerns is the risk of secondary contamination in individuals that received blood transfusion from donors incubating vCJD. In the UK, all transfusion-transmitted vCJD cases occurred within 10 years following the transfusion with non-leuco-depleted blood (measure used to prevent bloodborne transmission). In France, last vCJD donors died in 2004 and, up to 2023, no patient who has received labile leuco-depleted blood products from these donors developed symptoms of CJD, not even the patient that received red blood cells prepared from blood donation that retrospectively tested positive by PMCA in plasma [32].
Another concern comes from chronic wasting disease (CWD), a contagious form of prion diseases responsible for epidemics in cervids, the zoonotic potential of which is still debated. The emergence of new CWD strains in European countries was recently demonstrated [49-51].
During our 25-year surveillance, genetic analyses of the PRNP gene revealed 240 cases of TSE caused by a genetic mutation, and identified several new mutations [24,52]. The commonest observed one was the E200K responsible for a gCJD phenotype [34]. The mutation D178N associated with two distinct phenotypes depending on the genotype at codon 129 on the allele carrying the mutation constitutes the second most frequent mutation in France. Among patients with a FFI phenotype, one had E200K mutation. This genotype/phenotype combination, which was neuropathologically confirmed, has been very rarely reported [53-55].
Our study has some limitations. Firstly, the two neurologists in charge of the French surveillance network did not systematically consult all CJD patients (except for vCJD suspected cases) meaning that clinical signs at disease onset are not known with certainty for each patient. They do not have access to all EEGs and MRI data for all patients (only medical reports) and some data might be missed or misinterpreted. Secondly, genetic analyses of PRNP gene and neuropathological examination of suspected cases are not systematically performed, which may lead to some form misclassifications, especially cases considered as sporadic instead of genetic because of missing genetic information. However, this limitation is encountered in the majority of surveillance systems. Finally, in our sCJD population, few patients were aged more than 89 years at disease onset (n = 8). This population had very short disease duration (median: 2 months) that might make the diagnosis more difficult, and we cannot exclude the fact that some cases in the oldest age group were missed by the surveillance system or misdiagnosed.
Conclusion An active nationwide surveillance was implemented in France in 1992 providing 25 years of data. This enabled us to describe the epidemiology and subtypes of sCJD, including those cases observed in unexpected age groups, and on the epidemic profiles of infectious human prion diseases notably those acquired after peripheral contamination. Sustaining an active surveillance is needed regarding uncertainties about future primary or secondary vCJD cases, the recent occurrence of chronic wasting disease in European cervids with possible zoonotic potential and the tendency towards a regular increase of sCJD mortality observed in various countries.
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Prospective 25-year surveillance of prion diseases in France, 1992 to 2016: a slow waning of epidemics and an increase in observed sporadic forms separator commenting unavailable
Total Cases of Sporadic CJD (Deaths)
Sporadic CJD: Definite and probable cases
Country 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 Total
France 35 45 59 68 80 81 92 88 109 107 108 97 83 124 138 105 114 146 76 1755
Total Cases of CJD/GSS (Deaths)
All Definite And Probable Cases:
Sporadic, Familial/Genetic, FFI, GSS and Iatrogenic Deaths (excluding vCJD)
France 55 60 74 88 92 103 105 105 129 124 127 114 98 137 154 122 132 155 80 2054
France iatrogenic CJD TSE Prion
Friendly fire, pass it forward, they call it iatrogenic cjd, or what i call 'tse prion poker', are you all in $$$
all iatrogenic cjd is, is sporadic cjd, before the iatrogenic event is discovered, traced back, proven, documented, put into the academic domain, and then finally the public domain, this very seldom happens, thus problem solved, it's all sporadic cjd...
Direct neural transmission of vCJD/BSE in macaque after finger incision CORRESPONDENCE
Direct neural transmission of vCJD/BSE in macaque after finger incision
Jacqueline Mikol1 · Jérôme Delmotte1 · Dolorès Jouy1 · Elodie Vaysset1 · Charmaine Bastian1 · Jean‑Philippe Deslys1 ·
Emmanuel Comoy1 Received: 10 July 2020 / Revised: 8 September 2020 / Accepted: 25 September 2020 / Published online: 6 October 2020 © The Author(s) 2020
Non-human primates appeared as the closest model to study human iatrogenic prion diseases [14]: we report here the consequences of variant Creutzfeldt–Jakob disease/bovine spongiform encephalopathy (vCJD/BSE) inoculation in a cynomolgus macaque finger, with the demonstration of an original mode of propagation and the practical risk for professional exposure.
The distal right middle finger handpad of a 4-year-old macaque was incised on both lateral sides to induce local inflammation, and then injected with the equivalent of 10 mg of a BSE, orally challenged macaque brain [18]. After an 18 months period of finger clumsiness, the clinical disease (behaviour abnormalities, fear, hyperesthesia, gait disturbances, shaking) began 7.5 years after inoculation and euthanasia took place 2 months later for welfare reasons. Motor conduction velocity of the right median nerve was reduced to one-third of the left counterpart and sensory potential was not detected.
Histological and biochemical studies were performed as previously described. All the elements of the triad were present [7–9]: spongiform change was moderate in neocortex, striatum, brain stem, mild in spinal cord but severe in thalamus and cerebellum; neuronal loss was globally moderate, but severe in cerebellum and sacral spinal cord (vacuolated neurons); gliosis was severe in thalamus, cerebellum and brain stem and moderate elsewhere (Supplementary Fig. 1). ELISA and western blot (WB) showed the expected accumulation of PrPres with BSE glycophoretic pattern at all levels of brain and spinal cord (Supplementary Fig. 2).
In the brain, PrPd deposits were laminar into the cortical deep layers, massive into thalamus, basal ganglia, cerebellum, and brain stem. In spinal cord, PrPd was symmetrically distributed, intense in the Substantia gelatinosa and nucleus dorsal of Clarke while decreased at sacral level. Deposits were diverse into the whole CNS: synaptic, perineuronal, reticular aggregates, mini-plaques, plaques, and incomplete florid plaques. The retinal plexiform layers were labelled (Supplementary Fig. 1i). There were no amyloid or tau deposits.
Unusual PrPd deposits were observed along dendrites, short and long axons, neuritic threads tracing fne networks of straight lines or like strings of pearls (Supplementary Fig. 3). They were present into deep neocortex, basal ganglia, and motoneurons. Such long processes are not frequent but have been reported in human [13] and experimental studies [10, 22]. PrPd deposits were also noted as very mild into striato-pallidal projections, both limbs of internal capsule and fornix (Supplementary Fig. 3). The presence of PrPd in white matter has been reported (Supplementary text 4).
Peripherally, the expected PrPd was undetectable in lymphoid organs, including spleen, through biochemical or immunohistochemical analyses, while prion replication was detected in the peripheral nervous system (PNS): PrPd staining was visualized in many dorsal root ganglia (DRG) but only in nerves innervating the forelimb site of injection (median and ulnar nerves). At the cellular level, PrPd was limited to ganglia and satellite cells in DRG and Schwann cells (Scs) all along nerves whereas axons were never labelled (Fig. 1). Previously, using postmortem immunohistochemical studies (listed in Supplementary text 5), PrPd has been shown in peripheral nervous system in all forms of human neuropathies, albeit more frequently in vCJD, mostly in posterior root nerve fbres at adaxonal location and/or in ganglion and satellite cells. The restricted amount of PrPd was repeatedly underlined but, recently, prion RTQuiC was positive in all nerves examined [2]. PrPd has also been described, frst in scrapie [17] then in BSE, as limited “adaxonal deposits” or/and Sc deposits, with or without DRG cell involvement (review in [4] and Supplementary text 6). Previous studies of the mode of propagation of PrPd have reported variable observations and analyses depending on strains, host species and genotype (Supplementary text 6); the authors discussed the role of the sensory route of trafficking of prions, the modifications of axonal transport, the centrifugal versus centripetal spread of PrPd .
After peripheral infection, accumulation of infectious agent is reputed to occur in lymphoid tissues before direct neuroinvasion [18, 19], even with very little apparent peripheral lymphoreticular deposition [6, 20]. Here, there is no apparent replication/amplification of vCJD/BSE agent in the lymphoid tissues of the exposed macaque. In this model, the neural contamination occurred directly in the highly innervated finger while neuroinvasion appears to occur in Scs along the median nerve to the DRG, with the appearance of the classical labelling of ganglion cells which indicates the onset of the first level of neuronal infection. This model provides direct evidence of the hypothesis of a sequential infection of Scs from the periphery to the CNS, followed by a secondary diffusion into the spinal cord, as already considered by our group [15] and others [1, 3, 11, 12, 21]. It is to note that studies based on intra-sciatic nerve injections in hamsters [16] and transgenic mice [12] had established a rate of transport of infectivity of, respectively, 0.5–2 mm and 0.7 mm per day. This key role of Scs could explain both the low speed of propagation and the discrepancy between the paucity of PrPd into the distal part of the sensory nerves followed by the positivity of DRG, satellite cells and proximal roots.
In conclusion, we have observed that the exposure of a primate to vCJD/BSE through a distal finger lesion induces, after more than 7.5 years of silent incubation, a massive deposit of PrPd , strictly restricted to the nervous system and the eye.
Our data suggest a new type of pure unique peripheral nervous contamination in which the Scs would have a major role in the mode of centripetal progression of PrPd in the peripheral nervous system. Moreover, considering the fact that, recently, “a variant CJD diagnosed 7.5 years after occupational exposure” (cryomicrotomy) in a technician was observed [5], this experimental case report supports the risk linked to professional exposure and reinforces the necessity of adequate measures of prevention.
Second death in France in a laboratory working on prions
Creutzfeldt-Jakob disease has killed a person who handled this infectious agent at Inrae in Toulouse. After a first death in 2019, a moratorium on work on this pathogen has been extended.
By Hervé Morin
Creutzfeldt-Jakob disease killed a few days ago a retired research technician from the National Research Institute for Agriculture, Food and the Environment (Inrae), who had worked in Toulouse in contact of biological tissue infected with prions. This death sows consternation and concern in the scientific community working with these infectious agents. It follows the death, on June 17, 2019, of Emilie Jaumain, a 33-year-old laboratory technician, suffering from the same incurable neurodegenerative disease. The young woman is said to have contracted it in 2010, cutting herself while handling fragments of the brains of mice infected with prions, in another unit of INRAE, in Jouy-en-Josas.
Computer representation of part of a prion protein on a light micrograph of pyramidal nerve cells (neurons, in black) in the cerebellum of the brain. ALFRED PASIEKA / SCIENCE PHOTO LIBRARY
Regarding the retiree from Toulouse, it will be necessary to determine whether she was the victim of a genetic or sporadic form of Creutzfeldt-Jakob disease, if the disease may have been caused by the ingestion of meat contaminated by the agent of encephalopathy. bovine spongiform (BSE, also called mad cow disease) or, as in the case of Emilie Jaumain, if accidental occupational exposure can be claimed. Prion diseases are caused by proteins taking an aberrant conformation, which gives them the property of replicating to form aggregates that are deleterious for neurons. There are around 150 cases per year in France, resulting in fatal degeneration of the central nervous system.
Temporary suspension of work on prions in French public research laboratories
PRESS RELEASE - The general directorates of ANSES, CEA, CNRS, INRAE and Inserm, have decided jointly and in agreement with the Ministry of Higher Education, Research and Innovation to suspend as a precaution all their research and experimentation work relating to prion diseases, for a period of three months.
This precautionary measure is motivated by the knowledge of a possible new case of a person suffering from Creutzfeldt-Jakob disease and who worked in a laboratory for research on prions.
Posted on July 27, 2021
The suspension period put in place as of this day will make it possible to study the possibility of a link between the observed case and the person's former professional activity and to adapt, if necessary, the preventive measures in force in the research laboratories.
The person with Creutzfeldt-Jakob disease (CJD)1, whose form is not yet known, is a retired INRAE agent. This could be the second case of infectious CJD affecting a scientist who worked on prions, after that of an assistant engineer who died of the disease in 2019, and who was injured in 2010 during of an experiment.
Following this death, a general inspection mission was launched in July 2019 by the ministries of research and agriculture with French laboratories handling prions. Submitted in October 2020, the report concluded on the regulatory compliance of the laboratories visited as well as the presence of a risk control culture within the research teams.
Research around prion proteins, with high public health issues, allows major advances in the understanding of the functioning of these infectious pathogens, and contributes to results that are transferable to other related degenerative diseases such as Alzheimer's and Alzheimer's diseases. Parkinson's.
At the level of each establishment, regular and transparent information will be provided to all the working communities concerned by this measure.
1 The disease Creutzfeldt-Jakob disease (CJD) is one of prion diseases - still called encephalopathies subacute spongiform transmitted(TSE) - of diseases rare, characterized by a degeneration rapid and fatal the system nervous central. They are caused by the accumulation in the brain of a normally expressed protein but poorly conformed - the prion protein - which leads to the formation of deleterious aggregates for neurons. For now , no treatment will allow to change the course of these diseases. It can be of origin sporadic , form the most frequent , original genetic or finally to form infectious following a contamination.
France issues moratorium on prion research after fatal brain disease strikes two lab workers
By Barbara CasassusJul. 28, 2021 , 4:35 AM
PARIS—Five public research institutions in France have imposed a 3-month moratorium on the study of prions—a class of misfolding, infectious proteins that cause fatal brain diseases—after a retired lab worker who handled prions in the past was diagnosed with Creutzfeldt-Jakob disease (CJD), the most common prion disease in humans. An investigation is underway to find out whether the patient, who worked at a lab run by the National Research Institute for Agriculture, Food and Environment (INRAE), contracted the disease on the job.
If so, it would be the second such case in France in the past few years. In June 2019, an INRAE lab worker named Émilie Jaumain died at age 33, 10 years after pricking her thumb during an experiment with prion-infected mice. Her family is now suing INRAE for manslaughter and endangering life; her illness had already led to tightened safety measures at French prion labs.
The aim of the moratorium, which affects nine labs, is to “study the possibility of a link with the [new patient’s] former professional activity and if necessary to adapt the preventative measures in force in research laboratories,” according to a joint press release issued by the five institutions yesterday.
“This is the right way to go in the circumstances,” says Ronald Melki, a structural biologist at a prion lab jointly operated by the French national research agency CNRS and the French Alternative Energies and Atomic Energy Commission (CEA). “It is always wise to ask questions about the whole working process when something goes wrong.” "The occurrence of these harsh diseases in two of our scientific colleagues clearly affects the whole prion community, which is a small 'familial' community of less than 1000 people worldwide," Emmanuel Comoy, deputy director of CEA's Unit of Prion Disorders and Related Infectious Agents, writes in an email to Science. Although prion research already has strict safety protocols, "it necessarily reinforces the awareness of the risk linked to these infectious agents," he says.
In Jaumain’s case, there is little doubt she was infected on the job, according to a paper published in The New England Journal of Medicine (NEJM) in 2020. She had variant CJD (vCJD), a form typically caused by eating beef contaminated with bovine spongiform encephalopathy (BSE), or mad cow disease. But Europe’s BSE outbreak ended after 2000 and vCJD virtually disappeared; the chance that someone of Jaumain’s age in France would contract food-borne vCJD is “negligible or non-existent,” according to the paper.
A scientist with inside knowledge says the new patient, a woman who worked at INRAE’s Host-Pathogen Interactions and Immunity group in Toulouse, is still alive. French authorities were apparently alerted to her diagnosis late last week. The press release suggests it’s not yet clear whether the new case is vCJD or “classic” CJD, which is not known to be caused by prions from animals. Classic CJD strikes an estimated one person per million. Some 80% of cases are sporadic, meaning they have no known cause, but others are genetic or contracted from infected human tissues during transplantations. The two types of CJD can only be distinguished through a postmortem examination of brain tissue.
Lab infections are known to occur with many pathogens, but exposure to CJD-causing prions is unusually risky because there are no vaccines or treatments and the condition is universally fatal. And whereas most infections reveal themselves within days or weeks, CJD’s average incubation period is about 10 years.
For Jaumain, who worked at INRAE’s Molecular Virology and Immunology Unit in Jouy-en-Josas, outside Paris, that long period of uncertainty began on 31 May 2010, when she stabbed her left thumb with a curved forceps while cleaning a cryostat—a machine that can cut tissues at very low temperatures—that she used to slice brain sections from transgenic mice infected with a sheep-adapted form of BSE. She pierced two layers of latex gloves and drew blood. “Émilie started worrying about the accident as soon as it had happened, and mentioned it to every doctor she saw,” says her widower, Armel Houel.
In November 2017, Jaumain developed a burning pain in her right shoulder and neck that worsened and spread to the right half of her body over the following 6 months, according to the NEJM paper. In January 2019, she became depressed and anxious, suffering memory impairment and hallucinations. “It was a descent into hell,” Houel says. She was diagnosed with “probable vCJD” in mid-March of that year and died 3 months later. A postmortem confirmed the diagnosis.
“The occurrence of these harsh diseases in two of our scientific colleagues clearly affects the whole prion community.” Emmanuel Comoy, French Alternative Energies and Atomic Energy Commission
INRAE only recently admitted the likely link between Jaumain’s illness and the accident. “We recognize, without ambiguity, the hypothesis of a correlation between Emilie Jaumain-Houel’s accident … and her infection with vCJD,” INRAE chair and CEO Philippe Mauguin wrote in a 24 June letter to an association created by friends and colleagues to publicize Jaumain’s case and lobby for improvements in lab safety. (Science has obtained a copy of the letter, which has not been made public.)
Jaumain’s family has filed both criminal charges and an administrative suit against INRAE, alleging a range of problems at Jaumain’s lab. She had not been trained in handling dangerous prions or responding to accidents and did not wear both metal mesh and surgical gloves, as she was supposed to, says Julien Bensimhon, the family’s lawyer. The thumb should have been soaked in a bleach solution immediately, which did not happen, Bensimhon adds.
Independent reports by a company specializing in occupational safety and by government inspectors have found no safety violations at the lab; one of them said there was a “strong culture” of risk management. (Bensimhon calls the reports “biased.”)
The government inspectors’ report concluded that Jaumain’s accident was not unique, however. There had been at least 17 accidents among the 100 or so scientists and technicians in France working with prions in the previous decade, five of whom stabbed or cut themselves with contaminated syringes or blades. Another technician at the same lab had a fingerprick accident with prions in 2005, but has not developed vCJD symptoms so far, Bensimhon says. “It is shocking that no precautionary measures were taken then to ensure such an accident never happened again,” he says.
In Italy, too, the last person to die of vCJD, in 2016, was a lab worker with exposure to prion-infected brain tissue, according to last year’s NEJM paper, although an investigation did not find evidence of a lab accident. That patient and the lab they worked at have not been identified.
After Jaumain’s diagnosis, “We contacted all the research prion labs in France to suggest they check their safety procedures and remind staff about the importance of respecting them,” says Stéphane Haïk, a neuroscientist at the Paris Brain Institute at Pitié-Salpêtrière Hospital who helped diagnose Jaumain and is the corresponding author on the paper. Many labs tightened procedures, according to the government inspectors' report, for instance by introducing plastic scissors and scalpels, which are disposable and less sharp, and bite and cut-resistant gloves. A team of experts from the five research agencies is due to submit proposals for a guide to good practice in prion research to the French government at the end of this year.
The scientific community has long recognized that handling prions is dangerous and an occupational risk for neuropathologists, says neuropathologist Adriano Aguzzi of the University of Zurich. Aguzzi declined to comment on the French CJD cases, but told Science his lab never handles human or bovine prions for research purposes, only for diagnostics. “We conduct research only on mouse-adapted sheep prions, which have never been shown to be infectious to humans,” Aguzzi says. In a 2011 paper, his team reported that prions can spread through aerosols, at least in mice, which “may warrant re-thinking on prion biosafety guidelines in research and diagnostic laboratories,” they wrote. Aguzzi says he was “totally shocked” by the finding and introduced safety measures to prevent aerosol spread at his own lab, but the paper drew little attention elsewhere.
The moratorium will "obviously" cause delays in research, but given the very long incubation periods in prion diseases, the impact of a 3-month hiatus will be limited, Comoy says. His research team at CEA also works on other neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease, and will shift some of its efforts to those.
Although Jaumain’s diagnosis upset many in the field, it hasn't led to an exodus among researchers in France, Haïk says: “I know of only one person who resigned because they were so worried.”
With reporting by Martin Enserink.
Posted in: EuropeHealthScientific Community
doi:10.1126/science.abl6587
Variant Creutzfeldt–Jakob Disease Diagnosed 7.5 Years after Occupational Exposure
Variant Creutzfeldt–Jakob disease was identified in a technician who had cut her thumb while handling brain sections of mice infected with adapted BSE 7.5 years earlier. The long incubation period was similar to that of the transfusion-transmitted form of the disease.
Variant Creutzfeldt–Jakob Disease Diagnosed 7.5 Years after Occupational Exposure
TO THE EDITOR:
We report a case of variant Creutzfeldt–Jakob disease (CJD) that was plausibly related to accidental occupational exposure in a technician who had handled murine samples contaminated with the agent that causes bovine spongiform encephalopathy (BSE) 7.5 years earlier.
In May 2010, when the patient was 24 years of age, she worked in a prion research laboratory, where she handled frozen sections of brain of transgenic mice that overexpressed the human prion protein with methionine at codon 129. The mice had been infected with a sheep-adapted form of BSE. During this process, she stabbed her thumb through a double pair of latex gloves with the sharp ends of a curved forceps used to handle the samples. Bleeding was noted at the puncture site.
In November 2017, she began having burning pain in the right shoulder and neck. The pain worsened and spread to the right half of her body during the following 6 months. In November 2018, an examination of a sample of cerebrospinal fluid (CSF) obtained from the patient was normal. Magnetic resonance imaging (MRI) of the brain showed a slight increase in the fluid-attenuated inversion recovery (FLAIR) signal in the caudates and thalami (Fig. S1A and S1B in the Supplementary Appendix, available with the full text of this letter at NEJM.org). In January 2019, she became depressed and anxious and had memory impairment and visual hallucinations. There was hypertonia on the right side of her body. At that time, an analysis of CSF for 14-3-3 protein was negative. In March 2019, MRI showed an increased FLAIR signal in pulvinar and dorsomedial nuclei of thalami (Fig. S1C through S1E).
Figure 1.
Detection of Abnormal Prion Protein in Biologic Fluid Samples and Postmortem Findings.
The patient was found to be homozygous for methionine at codon 129 of the prion protein gene without mutation. An analysis of a sample of CSF on real-time quaking-induced conversion analysis was negative for a diagnosis of sporadic CJD. However, an analysis of plasma and CSF by means of protein misfolding cyclic amplification was positive for the diagnosis of variant CJD (Figure 1A and 1B). The patient died 19 months after the onset of symptoms. Neuropathological examination confirmed the diagnosis of variant CJD (Figure 1C and 1D). Western blot analysis showed the presence of type 2B protease-resistant prion protein in all sampled brain areas. The clinical characteristics of the patient and the postmortem neuropathological features were similar to those observed in 27 patients with variant CJD who had previously been reported in France.1 (Additional details are provided in the Supplementary Appendix.)
There are two potential explanations for this patient’s condition. Oral transmission from contaminated cattle products cannot be ruled out because the patient was born at the beginning of the French BSE outbreak in cattle. However, the last two patients who had confirmed variant CJD with methionine homozygosity at codon 129 in France and the United Kingdom died in 2014 and 2013, respectively, which makes oral transmission unlikely. In France, the risk of variant CJD in 2019 was negligible or nonexistent in the post-1969 birth cohort.2
Percutaneous exposure to prion-contaminated material is plausible in this patient, since the prion strain that she had handled was consistent with the development of variant CJD.3 The 7.5-year delay between the laboratory accident and her clinical symptoms is congruent with the incubation period in the transfusion-transmitted form of the disease. The ability of this strain to propagate through the peripheral route has been documented, and experimental studies with scrapie strains have shown that scarification and subcutaneous inoculation are effective routes.4,5 The last known Italian patient with variant CJD, who died in 2016, had had occupational contact with BSE-infected brain tissues, although subsequent investigation did not disclose a laboratory accident (Pocchiari M, Italian Registry of CJD: personal communication). Thus, the last two cases of variant CJD outside the United Kingdom have been associated with potential occupational exposure. Such cases highlight the need for improvements in the prevention of transmission of variant CJD and other prions that can affect humans in the laboratory and neurosurgery settings, as outlined in the Supplementary Appendix.
Jean-Philippe Brandel, M.D. Assistance Publique–Hôpitaux de Paris, Paris, France
M. Bustuchina Vlaicu, M.D. Groupe Hospitalier Nord-Essonne, Orsay, France
Audrey Culeux, B.Sc. INSERM Unité 1127, Paris, France
Maxime Belondrade, M.Sc. Daisy Bougard, Ph.D. Etablissement Français du Sang, Montpellier, France
Katarina Grznarova, Ph.D. Angeline Denouel, M.Sc. INSERM Unité 1127, Paris, France
Isabelle Plu, M.D. Elodie Bouaziz-Amar, Pharm.D., Ph.D. Danielle Seilhean, M.D., Ph.D. Assistance Publique–Hôpitaux de Paris, Paris, France
Michèle Levasseur, M.D. Groupe Hospitalier Nord-Essonne, Orsay, France
Stéphane Haïk, M.D., Ph.D. INSERM Unité 1127, Paris, France stephane.haik@upmc.fr
Supported by a grant (ANR-10-IAIHU-06) from Programme d’Investissements d’Avenir and Santé Publique France.
Disclosure forms provided by the authors are available with the full text of this letter at NEJM.org.
5 References
July 2, 2020
N Engl J Med 2020; 383:83-85
DOI: 10.1056/NEJMc2000687
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The threat from iatrogenic TSE Prion disease, is a real threat today, one that should be taken seriously across the medical/surgical arenas, considering the recent potential TSE iatrogenic events in Spain, and confirmed iatrogenic TSE, France several years back, where lab workers were exposed to sheep BSE, and died from vCJD. The USA must be very cautious with CWD TSE Prion in Cervid, consumption, exposure of the Cwd, and friendly fire there from, This is my greatest fear now, and this is why all this matters.
Iatrogenic TSE Prion
FRIDAY, DECEMBER 22, 2023
The Mad Cow That Stole Christmas, 20 Years Later
The Mad Cow That Stole Christmas, 20 Years Later, What Has Changed, Nothing
THE USA has systematically covered up mad cow disease, in my honest opinion, the USA mad cow disease today, is Chronic Wasting Disease CWD TSE Prion disease in Cervid, they can't cover that up.
TUESDAY, NOVEMBER 28, 2023
EFSA TSE Report 2022 First published 28 November 2023
The European Union summary report on surveillance for the presence of transmissible spongiform encephalopathies (TSE) in 2022
THURSDAY, DECEMBER 7, 2023
Chronic Wasting Disease CWD TSE Prion Cervid Update By State December 2023 (Long Version)
(Short Version)
FRIDAY, DECEMBER 08, 2023
TEXAS CWD TSE PRION DIRE CONSEQUENCES ARE HERE!
Why is USDA "only" testing 25,000 samples a year?
USDA's surveillance strategy is to focus on the targeted populations where we are most likely to find disease if it is present. This is the most effective way to meet both OIE and our domestic surveillance standards. After completing our enhanced surveillance in 2006 and confirming that our BSE prevalence was very low, an evaluation of the program showed that reducing the number of samples collected to 40,000 samples per year from these targeted, high risk populations would allow us to continue to exceed these standards. In fact, the sampling was ten times greater than OIE standards. A subsequent evaluation of the program in 2016 using data collected over the past 10 years showed that the surveillance standards could still be met with a further reduction in the number of samples collected by renderers and 3D/4D establishments which have a very low OIE point value because the medical history of these animals is usually unknown. Therefore, in 2016, the number of samples to be tested was reduced to 25,000 where it remains today.
Bottom line, you don’t test, you don’t find$ FRIDAY, MAY 19, 2023
USDA Announces Atypical L-Type Bovine Spongiform Encephalopathy BSE Detection
SATURDAY, MAY 20, 2023
Tennessee State Veterinarian Alerts Cattle Owners to Disease Detection Mad Cow atypical L-Type BSE
Wednesday, May 24, 2023
WAHIS, WOAH, OIE, United States of America Bovine spongiform encephalopathy Immediate notification
ABOUT 2+ WEEKS BEFORE THE DETECTION OF BSE IN THE USA IN 2023, I WROTE THIS;
May 2, 2023, i submitted this to the USDA et al;
Docket No. APHIS–2023–0027 Notice of Request for Revision to and Extension of Approval of an Information Collection; National Veterinary Services Laboratories; Bovine Spongiform Encephalopathy Surveillance Program Singeltary Submission
ONLY by the Grace of God, have we not had a documented BSE outbreak, that and the fact the USDA et al are only testing 25K cattle for BSE, a number too low to find mad cow disease from some 28.9 million beef cows in the United States as of Jan. 1, 2023, down 4% from last year. The number of milk cows in the United States increased to 9.40 million. U.S. calf crop was estimated at 34.5 million head, down 2% from 2021. Jan 31, 2023.
ALL it would take is one BSE positive, yet alone a handful of BSE cases, this is why the Enhanced BSE was shut down, and the BSE testing shut down to 25k, and the BSE GBRs were replaced with BSE MRRs, after the 2003 Christmas Mad cow, the cow that stole Christmas, making it legal to trade BSE, imo.
Document APHIS-2023-0027-0001 BSE Singeltary Comment Submission
see full submission;
WEDNESDAY, NOVEMBER 08, 2023
Ireland Atypical BSE confirmed November 3 2023
TUESDAY, NOVEMBER 14, 2023
Ireland Atypical BSE case, 3 progeny of case cow to be culled
SUNDAY, JULY 16, 2023
Switzerland Atypical BSE detected in a cow in the canton of St. Gallen
WAHIS, WOAH, OIE, REPORT Switzerland Bovine Spongiform Encephalopathy Atypical L-Type
Switzerland Bovine Spongiform Encephalopathy Atypical L-Type
Switzerland - Bovine spongiform encephalopathy - Immediate notification
Monday, March 20, 2023
WAHIS, WOAH, OIE, REPORT United Kingdom Bovine Spongiform Encephalopathy Atypical H-Type
BRAZIL BSE START DATE 2023/01/18
BRAZIL BSE CONFIRMATION DATE 2023/02/22
BRAZIL BSE END DATE 2023/03/03
SPAIN BSE START DATE 2023/01/21
SPAIN BSE CONFIRMATION DATE 2023/02/03
SPAIN BSE END DATE 2023/02/06
NETHERLANDS BSE START DATE 2023/02/01
NETHERLANDS BSE CONFIRMATION DATE 2023/02/01
NETHERLANDS BSE END DATE 2023/03/13
EFSA atypical Scrapie
***> AS is considered more likely (subjective probability range 50–66%) that AS is a non-contagious, rather than a contagious, disease.
SNIP...SEE;
THURSDAY, JULY 8, 2021
EFSA Scientific report on the analysis of the 2‐year compulsory intensified monitoring of atypical scrapie
***> AS is considered more likely (subjective probability range 50–66%) that AS is a non-contagious, rather than a contagious, disease.
Monday, November 13, 2023
Food and Drug Administration's BSE Feed Regulation (21 CFR 589.2000) Singeltary Another Request for Update 2023
Professor John Collinge on tackling prion diseases, sCJD accounts for around 1 in 5000 deaths worldwide
MONDAY, SEPTEMBER 11, 2023
Professor John Collinge on tackling prion diseases
“The best-known human prion disease is sporadic Creutzfeldt-Jakob disease (sCJD), a rapidly progressive dementia which accounts for around 1 in 5000 deaths worldwide.”
There is accumulating evidence also for iatrogenic AD. Understanding prion biology, and in particular how propagation of prions leads to neurodegeneration, is therefore of central research importance in medicine.
MONDAY, DECEMBER 18, 2023
Change in Epidemiology of Creutzfeldt-Jakob Disease in the US, 2007-2020
TUESDAY, DECEMBER 12, 2023
CREUTZFELDT JAKOB DISEASE TSE PRION DISEASE UPDATE USA DECEMBER 2023
SUNDAY, NOVEMBER 26, 2023
The role of environmental factors on sporadic Creutzfeldt-Jakob disease mortality: evidence from an age-period-cohort analysis
FRANCE HISTORY MAD COW DISEASE
Terry S. Singeltary Sr.
posted by Terry S. Singeltary Sr. at
4:15 PM
