Review on the epidemiology and dynamics of BSE epidemics
Vet. Res. (2008) 39:15 www.vetres.org DOI: 10.1051/vetres:2007053 c INRA, EDP Sciences, 2008 Review article
Review on the epidemiology and dynamics of BSE epidemics
Christian Ducrot1*, Mark Arnold2, Aline de Koeijer3, DagmarHeim4, Didier Calavas5 1 INRA Unité d’Épidémiologie Animale, 63122 Saint-Genès-Champanelle, France 2 VLA Sutton Bonington, The Elms, College Road, Sutton Bonington, Loughborough, LE12 5RB, England 3 Division of Infectious Diseases, Animal Sciences Group, Wageningen, University and Research Center, PO Box 65, 8200 AB Lelystad, The Netherlands 4 Office vétérinaire fédéral, Schwarzenburgstrasse 155, Case Postale 3003, Bern, Suisse 5 AFSSA Lyon, Unité Épidémiologie, 31 avenue Tony Garnier, 69364 Lyon Cedex 07, France (Received 24 April 2007; accepted 23 October 2007) Abstract – The paper describes how the comprehensive surveillance of bovine spongiform encephalopathy (BSE) and studies carried out on these data has enhanced our knowledge of the epidemiology of BSE. Around 7 000 BSE cases were detected through the screening of about 50 million cattle with rapid tests in Europe. It confirmed that the clinical surveillance had a poor capacity to detect cases, and also showed the discrepancy of this passive surveillance efficiency between regions and production types (dairy/beef). Other risk factors for BSE were being in a dairy herd (three times more than beef), having a young age at first calving (for dairy cattle), being autumn-born (dairy and beef), and being in a herd with a very high milk yield. These findings focus the risk on the feeding regimen of calves/heifers. Several epidemiological studies across countries suggest that the feedborne source related to meat and bone meal (MBM) is the only substantiated route of infection — even after the feed ban —, while it is not possible to exclude maternal transmission or milk replacers as a source of some infections. In most European countries, the average age of the cases is increasing over time and the prevalence decreasing, which reflects the effectiveness of control measures. Consistent results on the trend of the epidemic were obtained using back-calculation modelling, the R0 approach and Age-Period-Cohort models. Furthermore, active surveillance also resulted in the finding of atypical cases. These are distinct from previously found BSE and classified in two different forms based on biochemical characteristics; their prevalence is very low (36 cases up to 1st September 2007), affected animals were old and some of them displayed clinical signs. The origin and possibility of natural transmission is unknown.
BSE / epidemiology / modelling / review / control
Table of contents
1. Introduction ............................................................................ ........................................2 2. Passive and active surveillance for BSE......................................................................... ........2 2.1. Passive surveillance ............................................................................ .......................2 2.2. Active surveillance ............................................................................ ........................3 3. Risk factors and routes of infection................................................................... ....................5 3.1. Risk factors ............................................................................ .................................5 3.2. Routes of infection ............................................................................ ........................6 4. Control measures and evolution of the BSE epidemics..............................................................8 4.1. Evolvement of control measures.................................................................... ...............8 4.2. Evolution of the BSE epidemic analysed from modelling and age of cases.............................9 4.3. Evolution of the BSE prevalence over years .................................................................. 10 5. Atypical BSEs and their epidemiological meaning................................................................. 13 6. Conclusion.................................................................. .................................................. 14 * Corresponding author: ducrot@clermont.inra.fr Article available at http://www.vetres.org or http://dx.doi.org/10.1051/vetres:2007053
snip...
Cases of atypical BSE have only been found in countries having implemented large active surveillance programs. As of 1st September 2007, 36 cases (16 H, 20 L) have been described all over the world in cattle: Belgium (1 L) [23], Canada (1 H)15, Denmark (1 L)16, France (8 H, 6 L)17, Germany (1 H, 1 L) [13], Italy (3 L)18, Japan (1 L) [71], Netherlands (1 H, 2 L)19, Poland (1 H, 6 L)20, Sweden (1 H)21, United Kingdom (1 H)22, and USA (2 H)23. Another H-type case has been found in a 19 year old miniature zebu in a zoological park in Switzerland [56]. It is noteworthy that atypical cases have been found in countries that did not experience classical BSE so far, like Sweden, or in which only few cases of classical BSE have been found, like Canada or the USA.
And last but not least, similarities of PrPres between Htype BSE and human prion diseases like CJD or GSS have been put forward [10], as well as between L-type BSE and CJD [17]. These findings raise questions about the origin and inter species transmission of these prion diseases that were discovered through the BSE active surveillance.
full text 18 pages ;
http://www.vetres.org/index.php?option=article&access=standard&Itemid=129&url=/articles/vetres/pdf/2008/04/v07232.pdf
EFSA Scientific Report on the Assessment of the Geographical BSE-Risk (GBR) of the United States of America (USA)
Summary of the Scientific Report
The European Food Safety Authority and its Scientific Expert Working Group on the Assessment of the Geographical Bovine Spongiform Encephalopathy (BSE) Risk (GBR) were asked by the European Commission (EC) to provide an up-to-date scientific report on the GBR in the United States of America, i.e. the likelihood of the presence of one or more cattle being infected with BSE, pre-clinically as well as clinically, in USA. This scientific report addresses the GBR of USA as assessed in 2004 based on data covering the period 1980-2003.
The BSE agent was probably imported into USA and could have reached domestic cattle in the middle of the eighties. These cattle imported in the mid eighties could have been rendered in the late eighties and therefore led to an internal challenge in the early nineties. It is possible that imported meat and bone meal (MBM) into the USA reached domestic cattle and leads to an internal challenge in the early nineties.
A processing risk developed in the late 80s/early 90s when cattle imports from BSE risk countries were slaughtered or died and were processed (partly) into feed, together with some imports of MBM. This risk continued to exist, and grew significantly in the mid 90’s when domestic cattle, infected by imported MBM, reached processing. Given the low stability of the system, the risk increased over the years with continued imports of cattle and MBM from BSE risk countries.
EFSA concludes that the current GBR level of USA is III, i.e. it is likely but not confirmed that domestic cattle are (clinically or pre-clinically) infected with the BSE-agent. As long as there are no significant changes in rendering or feeding, the stability remains extremely/very unstable. Thus, the probability of cattle to be (pre-clinically or clinically) infected with the BSE-agent persistently increases.
http://www.efsa.europa.eu/en/science/tse_assessments/gbr_assessments/573.html
http://www.efsa.europa.eu/etc/medialib/efsa/science/tse_assessments/gbr_assessments/573.Par.0004.File.dat/sr03_biohaz02_usa_report_v2_en1.pdf
This study further confirms that BASE is caused by a distinct prion isolate and discloses a novel disease phenotype in cattle, closely resembling the phenotype previous reported in scrapie-inoculated cattle
*** and in some subtypes of inherited and sporadic Creutzfeldt-Jakob disease.
http://www.prion2007.com/pdf/Prion%20Book%20of%20Abstracts.pdf
The Italian cases (11 and 15 years of age) originally named bovine amyloidotic spongiform encephalopathy (BASE) were characterized by an unglycosylated protein band with a lower molecular mass (thus named L cases) and the predominance of the monoglycosylated band. In addition, immunohistochemical detection of PrPres in these cases found greater deposits in the cerebral cortex and thalamus versus the brain stem. The French cases found a higher molecular mass associated with the unglycosylated protein band and were called H cases (see figure 1). *** The different "strains" are now called atypical BSE. ...
full text, skroll down to page 6 ;
http://www.usaha.org/committees/reports/2006/report-fe-2006.pdf
However, unusual or "atypical" cases of BSE have been reported in the past 3 years by investigators from several countries. Most of these animals were greater than 8 years of age and of various breeds. There have been two molecular types of "atypical" BSE isolates described in the literature so far: (i) a type with a lower molecular mass of the unglycosylated isoform also called the L-type and (ii) a type with a higher molecular mass of the unglycosylated isoform, also called the H-type. The L-type has been found in cattle in Italy (10), Japan (11), Germany (12) and Belgium (13). So far, the H-type has been described in cattle from France (14), Germany (12) and the United States (15). The U.S. cases were animals born and raised in the U.S. (Texas, Alabama). Unusual cases of BSE are an unexpected finding since it was previously believed that BSE disease in cattle is caused by a single strain of infectious agent, which has been shown to be very consistent and uniform in appearance, even after transmission to other species. The reports of unusual phenotypes of BSE in cattle suggest that different PrPSc phenotypes exist in cattle with BSE. There are several hypotheses which can explain these findings: (i) there are variants of the BSE agent with different molecular features in cattle; (ii) cattle may have been infected by another source of an infectious prion agent (e.g. scrapie or CWD); or (iii) a rare sporadic or genetic form of TSE disease could exist in cattle as described for humans.
http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=208195
Please remember, the last two mad cows documented in the USA i.e. Alabama and Texas, both were of the 'atypical' BSE strain, and immediately after that, the USDA shut down the testing from 470,000 to 40,000 in the U.S. in 2007 out of about 35 million cattle slaughtered. also, science is showing that some of these atypical cases are more virulent to humans than the typical UK BSE strain ;
***Atypical forms of BSE have emerged which, although rare, appear to be more virulent than the classical BSE that causes vCJD.***
Progress Report from the National Prion Disease Pathology Surveillance Center
An Update from Stephen M. Sergay, MB, BCh & Pierluigi Gambetti, MD
April 3, 2008
http://www.aan.com/news/?event=read&article_id=4397&page=72.45.45
In this context, a word is in order about the US testing program. After the discovery of the first (imported) cow in 2003, the magnitude of testing was much increased, reaching a level of >400,000 tests in 2005 (Figure 4). Neither of the 2 more recently indigenously infected older animals with nonspecific clinical features would have been detected without such testing, and neither would have been identified as atypical without confirmatory Western blots. Despite these facts, surveillance has now been decimated to 40,000 annual tests (USDA news release no. 0255.06, July 20, 2006) and invites the accusation that the United States will never know the true status of its involvement with BSE.
In short, a great deal of further work will need to be done before the phenotypic features and prevalence of atypical BSE are understood. More than a single strain may have been present from the beginning of the epidemic, but this possibility has been overlooked by virtue of the absence of widespread Western blot confirmatory testing of positive screening test results; or these new phenotypes may be found, at least in part, to result from infections at an older age by a typical BSE agent, rather than neonatal infections with new "strains" of BSE. Neither alternative has yet been investigated.
http://www.cdc.gov/ncidod/EID/vol12no12/06-0965.htm
CDC DR. PAUL BROWN TSE EXPERT COMMENTS 2006
The U.S. Department of Agriculture was quick to assure the public earlier this week that the third case of mad cow disease did not pose a risk to them, but what federal officials have not acknowledged is that this latest case indicates the deadly disease has been circulating in U.S. herds for at least a decade.
The second case, which was detected last year in a Texas cow and which USDA officials were reluctant to verify, was approximately 12 years old.
These two cases (the latest was detected in an Alabama cow) present a picture of the disease having been here for 10 years or so, since it is thought that cows usually contract the disease from contaminated feed they consume as calves. The concern is that humans can contract a fatal, incurable, brain-wasting illness from consuming beef products contaminated with the mad cow pathogen.
"The fact the Texas cow showed up fairly clearly implied the existence of other undetected cases," Dr. Paul Brown, former medical director of the National Institutes of Health's Laboratory for Central Nervous System Studies and an expert on mad cow-like diseases, told United Press International. "The question was, 'How many?' and we still can't answer that."
Brown, who is preparing a scientific paper based on the latest two mad cow cases to estimate the maximum number of infected cows that occurred in the United States, said he has "absolutely no confidence in USDA tests before one year ago" because of the agency's reluctance to retest the Texas cow that initially tested positive.
USDA officials finally retested the cow and confirmed it was infected seven months later, but only at the insistence of the agency's inspector general.
"Everything they did on the Texas cow makes everything USDA did before 2005 suspect," Brown said. ...snip...end
http://www.upi.com/
CDC - Bovine Spongiform Encephalopathy and Variant Creutzfeldt ... Dr. Paul Brown is Senior Research Scientist in the Laboratory of Central Nervous System ... Address for correspondence: Paul Brown, Building 36, Room 4A-05, ...
http://www.cdc.gov/ncidod/eid/vol7no1/brown.htm
PAUL BROWN COMMENT TO ME ON THIS ISSUE
Tuesday, September 12, 2006 11:10 AM
"Actually, Terry, I have been critical of the USDA handling of the mad cow issue for some years, and with Linda Detwiler and others sent lengthy detailed critiques and recommendations to both the USDA and the Canadian Food Agency."
http://lists.ifas.ufl.edu/cgi-bin/wa.exe?A2=ind0703&L=sanet-mg&T=0&P=8125
MAD COW DISEASE terminology UK c-BSE (typical), atypical BSE H or L, and or Italian L-BASE (THE LAST TWO MAD COWS IN THE USA, IN ALABAMA AND TEXAS WERE ATYPICAL BSE, CONFIRMED!)
http://bse-atypical.blogspot.com/2008/03/mad-cow-disease-terminology-uk-c-bse.html
AS implied in the Inset 25 we must not _ASSUME_ that transmission of BSE to other species will invariably present pathology typical of a scrapie-like disease.
snip...
http://www.bseinquiry.gov.uk/files/yb/1991/01/04004001.pdf
NOT to forget the 5 cases of the NOR-98 atypical scrapie documented in the USA in 2007, in five different states. WHICH pathologically looks like some sub-types of sporadic CJD, of which Stanely Prusiner warns of a public health risk ;
***The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.
http://www.prion2007.com/pdf/Prion%20Book%20of%20Abstracts.pdf
Here we report that both Nor98 and discordant cases, including three sheep homozygous for the resistant PrPARR allele (A136R154R171), efficiently transmitted the disease to transgenic mice expressing ovine PrP, and that they shared unique biological and biochemical features upon propagation in mice. These observations support the view that a truly infectious TSE agent, unrecognized until recently, infects sheep and goat flocks and may have important implications in terms of scrapie control and public health.
Edited by Stanley B. Prusiner, University of California, San Francisco, CA, and approved September 12, 2005 (received for review March 21, 2005)
http://www.pnas.org/cgi/content/abstract/0502296102v1
http://nor-98.blogspot.com/
Tuesday, June 3, 2008SCRAPIE USA UPDATE JUNE 2008 NOR-98 REPORTED PA
http://nor-98.blogspot.com/2008/06/scrapie-usa-update-june-2008-nor-98.html
Journal of American Medical Association
Diagnosis and Reporting of Creutzfeldt-Jakob Disease Singeltary, Sr et al. JAMA.2001; 285: 733-734. Vol. 285 No. 6, February 14, 2001 JAMA
Diagnosis and Reporting of Creutzfeldt-Jakob Disease
To the Editor: In their Research Letter, Dr Gibbons and colleagues1 reported that the annual US death rate due to Creutzfeldt-Jakob disease (CJD) has been stable since 1985. These estimates, however, are based only on reported cases, and do not include misdiagnosed or preclinical cases. It seems to me that misdiagnosis alone would drastically change these figures. An unknown number of persons with a diagnosis of Alzheimer disease in fact may have CJD, although only a small number of these patients receive the postmortem examination necessary to make this diagnosis. Furthermore, only a few states have made CJD reportable. Human and animal transmissible spongiform encephalopathies should be reportable nationwide and internationally.
Terry S. Singeltary, Sr Bacliff, Tex
1. Gibbons RV, Holman RC, Belay ED, Schonberger LB. Creutzfeldt-Jakob disease in the United States: 1979-1998. JAMA. 2000;284:2322-2323. FREE FULL TEXT
http://jama.ama-assn.org/
2 January 2000 British Medical Journal
U.S. Scientist should be concerned with a CJD epidemic in the U.S., as well
http://www.bmj.com/cgi/eletters/320/7226/8/b#6117
15 November 1999 British Medical Journal vCJD in the USA * BSE in U.S.
http://www.bmj.com/cgi/eletters/319/7220/1312/b#5406
JOURNAL OF NEUROLOGY
MARCH 26, 2003
RE-Monitoring the occurrence of emerging forms of Creutzfeldt-Jakob disease in the United States
Terry S. Singeltary:
http://www.neurology.org/cgi/eletters/60/2/176#535
THE PATHOLOGICAL PROTEIN
Hardcover, 304 pages plus photos and illustrations. ISBN 0-387-95508-9
June 2003
BY Philip Yam
CHAPTER 14 LAYING ODDS
Answering critics like Terry Singeltary, who feels that the U.S. under- counts CJD, Schonberger conceded that the current surveillance system has errors but stated that most of the errors will be confined to the older population.
http://www.thepathologicalprotein.com/
***Atypical forms of BSE have emerged which, although rare, appear to be more virulent than the classical BSE that causes vCJD.***
Progress Report from the National Prion Disease Pathology Surveillance Center
An Update from Stephen M. Sergay, MB, BCh & Pierluigi Gambetti, MD
April 3, 2008
http://www.aan.com/news/?event=read&article_id=4397&page=72.45.45
Communicated by: Terry S. Singeltary Sr.
[In submitting these data, Terry S. Singeltary Sr. draws attention to the steady increase in the "type unknown" category, which, according to their definition, comprises cases in which vCJD could be excluded. The total of 26 cases for the current year (2007) is disturbing, possibly symptomatic of the circulation of novel agents. Characterization of these agents should be given a high priority. - Mod.CP]
http://pro-med.blogspot.com/2007/11/proahedr-prion-disease-update-2007-07.html
http://www.promedmail.org/pls/askus/f?p=2400:1001:6833194127530602005::NO::F2400_P1001_BACK_PAGE,F2400_P1001_PUB_MAIL_ID:1010,39963
There is a growing number of human CJD cases, and they were presented last week in San Francisco by Luigi Gambatti(?) from his CJD surveillance collection.
He estimates that it may be up to 14 or 15 persons which display selectively SPRPSC and practically no detected RPRPSC proteins.
http://www.fda.gov/ohrms/dockets/ac/06/transcripts/1006-4240t1.htm
http://www.fda.gov/ohrms/dockets/ac/06/transcripts/2006-4240t1.pdf
2008
The statistical incidence of CJD cases in the United States has been revised to reflect that there is one case per 9000 in adults age 55 and older. Eighty-five percent of the cases are sporadic, meaning there is no known cause at present.
http://www.cjdfoundation.org/fact.html
BSE YOUNGEST AGE STATISTICS UNDER 30 MONTHS
http://bseyoungestage.blogspot.com/
http://flounder068.vox.com/library/post/bse-youngest-age-statistics-under-30-months.html
Tuesday, May 27, 2008
FDA BSE/Ruminant Feed Inspections Firms Inventory Report Texas Legend Ranch OAI 05/10/2008
http://madcowfeed.blogspot.com/2008/05/fda-bseruminant-feed-inspections-firms.html
Tuesday, June 3, 2008
Thursday, April 03, 2008 A prion disease of cervids: Chronic wasting disease 2008
1: Vet Res. 2008 Apr 3;39(4):41
http://chronic-wasting-disease.blogspot.com/2008/04/prion-disease-of-cervids-chronic.html
Terry S. Singeltary Sr. P.O. Box 42 Bacliff, Texas USA 77518
Review on the epidemiology and dynamics of BSE epidemics
Christian Ducrot1*, Mark Arnold2, Aline de Koeijer3, DagmarHeim4, Didier Calavas5 1 INRA Unité d’Épidémiologie Animale, 63122 Saint-Genès-Champanelle, France 2 VLA Sutton Bonington, The Elms, College Road, Sutton Bonington, Loughborough, LE12 5RB, England 3 Division of Infectious Diseases, Animal Sciences Group, Wageningen, University and Research Center, PO Box 65, 8200 AB Lelystad, The Netherlands 4 Office vétérinaire fédéral, Schwarzenburgstrasse 155, Case Postale 3003, Bern, Suisse 5 AFSSA Lyon, Unité Épidémiologie, 31 avenue Tony Garnier, 69364 Lyon Cedex 07, France (Received 24 April 2007; accepted 23 October 2007) Abstract – The paper describes how the comprehensive surveillance of bovine spongiform encephalopathy (BSE) and studies carried out on these data has enhanced our knowledge of the epidemiology of BSE. Around 7 000 BSE cases were detected through the screening of about 50 million cattle with rapid tests in Europe. It confirmed that the clinical surveillance had a poor capacity to detect cases, and also showed the discrepancy of this passive surveillance efficiency between regions and production types (dairy/beef). Other risk factors for BSE were being in a dairy herd (three times more than beef), having a young age at first calving (for dairy cattle), being autumn-born (dairy and beef), and being in a herd with a very high milk yield. These findings focus the risk on the feeding regimen of calves/heifers. Several epidemiological studies across countries suggest that the feedborne source related to meat and bone meal (MBM) is the only substantiated route of infection — even after the feed ban —, while it is not possible to exclude maternal transmission or milk replacers as a source of some infections. In most European countries, the average age of the cases is increasing over time and the prevalence decreasing, which reflects the effectiveness of control measures. Consistent results on the trend of the epidemic were obtained using back-calculation modelling, the R0 approach and Age-Period-Cohort models. Furthermore, active surveillance also resulted in the finding of atypical cases. These are distinct from previously found BSE and classified in two different forms based on biochemical characteristics; their prevalence is very low (36 cases up to 1st September 2007), affected animals were old and some of them displayed clinical signs. The origin and possibility of natural transmission is unknown.
BSE / epidemiology / modelling / review / control
Table of contents
1. Introduction ............................................................................ ........................................2 2. Passive and active surveillance for BSE......................................................................... ........2 2.1. Passive surveillance ............................................................................ .......................2 2.2. Active surveillance ............................................................................ ........................3 3. Risk factors and routes of infection................................................................... ....................5 3.1. Risk factors ............................................................................ .................................5 3.2. Routes of infection ............................................................................ ........................6 4. Control measures and evolution of the BSE epidemics..............................................................8 4.1. Evolvement of control measures.................................................................... ...............8 4.2. Evolution of the BSE epidemic analysed from modelling and age of cases.............................9 4.3. Evolution of the BSE prevalence over years .................................................................. 10 5. Atypical BSEs and their epidemiological meaning................................................................. 13 6. Conclusion.................................................................. .................................................. 14 * Corresponding author: ducrot@clermont.inra.fr Article available at http://www.vetres.org or http://dx.doi.org/10.1051/vetres:2007053
snip...
Cases of atypical BSE have only been found in countries having implemented large active surveillance programs. As of 1st September 2007, 36 cases (16 H, 20 L) have been described all over the world in cattle: Belgium (1 L) [23], Canada (1 H)15, Denmark (1 L)16, France (8 H, 6 L)17, Germany (1 H, 1 L) [13], Italy (3 L)18, Japan (1 L) [71], Netherlands (1 H, 2 L)19, Poland (1 H, 6 L)20, Sweden (1 H)21, United Kingdom (1 H)22, and USA (2 H)23. Another H-type case has been found in a 19 year old miniature zebu in a zoological park in Switzerland [56]. It is noteworthy that atypical cases have been found in countries that did not experience classical BSE so far, like Sweden, or in which only few cases of classical BSE have been found, like Canada or the USA.
And last but not least, similarities of PrPres between Htype BSE and human prion diseases like CJD or GSS have been put forward [10], as well as between L-type BSE and CJD [17]. These findings raise questions about the origin and inter species transmission of these prion diseases that were discovered through the BSE active surveillance.
full text 18 pages ;
http://www.vetres.org/index.php?option=article&access=standard&Itemid=129&url=/articles/vetres/pdf/2008/04/v07232.pdf
EFSA Scientific Report on the Assessment of the Geographical BSE-Risk (GBR) of the United States of America (USA)
Summary of the Scientific Report
The European Food Safety Authority and its Scientific Expert Working Group on the Assessment of the Geographical Bovine Spongiform Encephalopathy (BSE) Risk (GBR) were asked by the European Commission (EC) to provide an up-to-date scientific report on the GBR in the United States of America, i.e. the likelihood of the presence of one or more cattle being infected with BSE, pre-clinically as well as clinically, in USA. This scientific report addresses the GBR of USA as assessed in 2004 based on data covering the period 1980-2003.
The BSE agent was probably imported into USA and could have reached domestic cattle in the middle of the eighties. These cattle imported in the mid eighties could have been rendered in the late eighties and therefore led to an internal challenge in the early nineties. It is possible that imported meat and bone meal (MBM) into the USA reached domestic cattle and leads to an internal challenge in the early nineties.
A processing risk developed in the late 80s/early 90s when cattle imports from BSE risk countries were slaughtered or died and were processed (partly) into feed, together with some imports of MBM. This risk continued to exist, and grew significantly in the mid 90’s when domestic cattle, infected by imported MBM, reached processing. Given the low stability of the system, the risk increased over the years with continued imports of cattle and MBM from BSE risk countries.
EFSA concludes that the current GBR level of USA is III, i.e. it is likely but not confirmed that domestic cattle are (clinically or pre-clinically) infected with the BSE-agent. As long as there are no significant changes in rendering or feeding, the stability remains extremely/very unstable. Thus, the probability of cattle to be (pre-clinically or clinically) infected with the BSE-agent persistently increases.
http://www.efsa.europa.eu/en/science/tse_assessments/gbr_assessments/573.html
http://www.efsa.europa.eu/etc/medialib/efsa/science/tse_assessments/gbr_assessments/573.Par.0004.File.dat/sr03_biohaz02_usa_report_v2_en1.pdf
This study further confirms that BASE is caused by a distinct prion isolate and discloses a novel disease phenotype in cattle, closely resembling the phenotype previous reported in scrapie-inoculated cattle
*** and in some subtypes of inherited and sporadic Creutzfeldt-Jakob disease.
http://www.prion2007.com/pdf/Prion%20Book%20of%20Abstracts.pdf
The Italian cases (11 and 15 years of age) originally named bovine amyloidotic spongiform encephalopathy (BASE) were characterized by an unglycosylated protein band with a lower molecular mass (thus named L cases) and the predominance of the monoglycosylated band. In addition, immunohistochemical detection of PrPres in these cases found greater deposits in the cerebral cortex and thalamus versus the brain stem. The French cases found a higher molecular mass associated with the unglycosylated protein band and were called H cases (see figure 1). *** The different "strains" are now called atypical BSE. ...
full text, skroll down to page 6 ;
http://www.usaha.org/committees/reports/2006/report-fe-2006.pdf
However, unusual or "atypical" cases of BSE have been reported in the past 3 years by investigators from several countries. Most of these animals were greater than 8 years of age and of various breeds. There have been two molecular types of "atypical" BSE isolates described in the literature so far: (i) a type with a lower molecular mass of the unglycosylated isoform also called the L-type and (ii) a type with a higher molecular mass of the unglycosylated isoform, also called the H-type. The L-type has been found in cattle in Italy (10), Japan (11), Germany (12) and Belgium (13). So far, the H-type has been described in cattle from France (14), Germany (12) and the United States (15). The U.S. cases were animals born and raised in the U.S. (Texas, Alabama). Unusual cases of BSE are an unexpected finding since it was previously believed that BSE disease in cattle is caused by a single strain of infectious agent, which has been shown to be very consistent and uniform in appearance, even after transmission to other species. The reports of unusual phenotypes of BSE in cattle suggest that different PrPSc phenotypes exist in cattle with BSE. There are several hypotheses which can explain these findings: (i) there are variants of the BSE agent with different molecular features in cattle; (ii) cattle may have been infected by another source of an infectious prion agent (e.g. scrapie or CWD); or (iii) a rare sporadic or genetic form of TSE disease could exist in cattle as described for humans.
http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=208195
Please remember, the last two mad cows documented in the USA i.e. Alabama and Texas, both were of the 'atypical' BSE strain, and immediately after that, the USDA shut down the testing from 470,000 to 40,000 in the U.S. in 2007 out of about 35 million cattle slaughtered. also, science is showing that some of these atypical cases are more virulent to humans than the typical UK BSE strain ;
***Atypical forms of BSE have emerged which, although rare, appear to be more virulent than the classical BSE that causes vCJD.***
Progress Report from the National Prion Disease Pathology Surveillance Center
An Update from Stephen M. Sergay, MB, BCh & Pierluigi Gambetti, MD
April 3, 2008
http://www.aan.com/news/?event=read&article_id=4397&page=72.45.45
In this context, a word is in order about the US testing program. After the discovery of the first (imported) cow in 2003, the magnitude of testing was much increased, reaching a level of >400,000 tests in 2005 (Figure 4). Neither of the 2 more recently indigenously infected older animals with nonspecific clinical features would have been detected without such testing, and neither would have been identified as atypical without confirmatory Western blots. Despite these facts, surveillance has now been decimated to 40,000 annual tests (USDA news release no. 0255.06, July 20, 2006) and invites the accusation that the United States will never know the true status of its involvement with BSE.
In short, a great deal of further work will need to be done before the phenotypic features and prevalence of atypical BSE are understood. More than a single strain may have been present from the beginning of the epidemic, but this possibility has been overlooked by virtue of the absence of widespread Western blot confirmatory testing of positive screening test results; or these new phenotypes may be found, at least in part, to result from infections at an older age by a typical BSE agent, rather than neonatal infections with new "strains" of BSE. Neither alternative has yet been investigated.
http://www.cdc.gov/ncidod/EID/vol12no12/06-0965.htm
CDC DR. PAUL BROWN TSE EXPERT COMMENTS 2006
The U.S. Department of Agriculture was quick to assure the public earlier this week that the third case of mad cow disease did not pose a risk to them, but what federal officials have not acknowledged is that this latest case indicates the deadly disease has been circulating in U.S. herds for at least a decade.
The second case, which was detected last year in a Texas cow and which USDA officials were reluctant to verify, was approximately 12 years old.
These two cases (the latest was detected in an Alabama cow) present a picture of the disease having been here for 10 years or so, since it is thought that cows usually contract the disease from contaminated feed they consume as calves. The concern is that humans can contract a fatal, incurable, brain-wasting illness from consuming beef products contaminated with the mad cow pathogen.
"The fact the Texas cow showed up fairly clearly implied the existence of other undetected cases," Dr. Paul Brown, former medical director of the National Institutes of Health's Laboratory for Central Nervous System Studies and an expert on mad cow-like diseases, told United Press International. "The question was, 'How many?' and we still can't answer that."
Brown, who is preparing a scientific paper based on the latest two mad cow cases to estimate the maximum number of infected cows that occurred in the United States, said he has "absolutely no confidence in USDA tests before one year ago" because of the agency's reluctance to retest the Texas cow that initially tested positive.
USDA officials finally retested the cow and confirmed it was infected seven months later, but only at the insistence of the agency's inspector general.
"Everything they did on the Texas cow makes everything USDA did before 2005 suspect," Brown said. ...snip...end
http://www.upi.com/
CDC - Bovine Spongiform Encephalopathy and Variant Creutzfeldt ... Dr. Paul Brown is Senior Research Scientist in the Laboratory of Central Nervous System ... Address for correspondence: Paul Brown, Building 36, Room 4A-05, ...
http://www.cdc.gov/ncidod/eid/vol7no1/brown.htm
PAUL BROWN COMMENT TO ME ON THIS ISSUE
Tuesday, September 12, 2006 11:10 AM
"Actually, Terry, I have been critical of the USDA handling of the mad cow issue for some years, and with Linda Detwiler and others sent lengthy detailed critiques and recommendations to both the USDA and the Canadian Food Agency."
http://lists.ifas.ufl.edu/cgi-bin/wa.exe?A2=ind0703&L=sanet-mg&T=0&P=8125
MAD COW DISEASE terminology UK c-BSE (typical), atypical BSE H or L, and or Italian L-BASE (THE LAST TWO MAD COWS IN THE USA, IN ALABAMA AND TEXAS WERE ATYPICAL BSE, CONFIRMED!)
http://bse-atypical.blogspot.com/2008/03/mad-cow-disease-terminology-uk-c-bse.html
AS implied in the Inset 25 we must not _ASSUME_ that transmission of BSE to other species will invariably present pathology typical of a scrapie-like disease.
snip...
http://www.bseinquiry.gov.uk/files/yb/1991/01/04004001.pdf
NOT to forget the 5 cases of the NOR-98 atypical scrapie documented in the USA in 2007, in five different states. WHICH pathologically looks like some sub-types of sporadic CJD, of which Stanely Prusiner warns of a public health risk ;
***The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.
http://www.prion2007.com/pdf/Prion%20Book%20of%20Abstracts.pdf
Here we report that both Nor98 and discordant cases, including three sheep homozygous for the resistant PrPARR allele (A136R154R171), efficiently transmitted the disease to transgenic mice expressing ovine PrP, and that they shared unique biological and biochemical features upon propagation in mice. These observations support the view that a truly infectious TSE agent, unrecognized until recently, infects sheep and goat flocks and may have important implications in terms of scrapie control and public health.
Edited by Stanley B. Prusiner, University of California, San Francisco, CA, and approved September 12, 2005 (received for review March 21, 2005)
http://www.pnas.org/cgi/content/abstract/0502296102v1
http://nor-98.blogspot.com/
Tuesday, June 3, 2008SCRAPIE USA UPDATE JUNE 2008 NOR-98 REPORTED PA
http://nor-98.blogspot.com/2008/06/scrapie-usa-update-june-2008-nor-98.html
Journal of American Medical Association
Diagnosis and Reporting of Creutzfeldt-Jakob Disease Singeltary, Sr et al. JAMA.2001; 285: 733-734. Vol. 285 No. 6, February 14, 2001 JAMA
Diagnosis and Reporting of Creutzfeldt-Jakob Disease
To the Editor: In their Research Letter, Dr Gibbons and colleagues1 reported that the annual US death rate due to Creutzfeldt-Jakob disease (CJD) has been stable since 1985. These estimates, however, are based only on reported cases, and do not include misdiagnosed or preclinical cases. It seems to me that misdiagnosis alone would drastically change these figures. An unknown number of persons with a diagnosis of Alzheimer disease in fact may have CJD, although only a small number of these patients receive the postmortem examination necessary to make this diagnosis. Furthermore, only a few states have made CJD reportable. Human and animal transmissible spongiform encephalopathies should be reportable nationwide and internationally.
Terry S. Singeltary, Sr Bacliff, Tex
1. Gibbons RV, Holman RC, Belay ED, Schonberger LB. Creutzfeldt-Jakob disease in the United States: 1979-1998. JAMA. 2000;284:2322-2323. FREE FULL TEXT
http://jama.ama-assn.org/
2 January 2000 British Medical Journal
U.S. Scientist should be concerned with a CJD epidemic in the U.S., as well
http://www.bmj.com/cgi/eletters/320/7226/8/b#6117
15 November 1999 British Medical Journal vCJD in the USA * BSE in U.S.
http://www.bmj.com/cgi/eletters/319/7220/1312/b#5406
JOURNAL OF NEUROLOGY
MARCH 26, 2003
RE-Monitoring the occurrence of emerging forms of Creutzfeldt-Jakob disease in the United States
Terry S. Singeltary:
http://www.neurology.org/cgi/eletters/60/2/176#535
THE PATHOLOGICAL PROTEIN
Hardcover, 304 pages plus photos and illustrations. ISBN 0-387-95508-9
June 2003
BY Philip Yam
CHAPTER 14 LAYING ODDS
Answering critics like Terry Singeltary, who feels that the U.S. under- counts CJD, Schonberger conceded that the current surveillance system has errors but stated that most of the errors will be confined to the older population.
http://www.thepathologicalprotein.com/
***Atypical forms of BSE have emerged which, although rare, appear to be more virulent than the classical BSE that causes vCJD.***
Progress Report from the National Prion Disease Pathology Surveillance Center
An Update from Stephen M. Sergay, MB, BCh & Pierluigi Gambetti, MD
April 3, 2008
http://www.aan.com/news/?event=read&article_id=4397&page=72.45.45
Communicated by: Terry S. Singeltary Sr.
[In submitting these data, Terry S. Singeltary Sr. draws attention to the steady increase in the "type unknown" category, which, according to their definition, comprises cases in which vCJD could be excluded. The total of 26 cases for the current year (2007) is disturbing, possibly symptomatic of the circulation of novel agents. Characterization of these agents should be given a high priority. - Mod.CP]
http://pro-med.blogspot.com/2007/11/proahedr-prion-disease-update-2007-07.html
http://www.promedmail.org/pls/askus/f?p=2400:1001:6833194127530602005::NO::F2400_P1001_BACK_PAGE,F2400_P1001_PUB_MAIL_ID:1010,39963
There is a growing number of human CJD cases, and they were presented last week in San Francisco by Luigi Gambatti(?) from his CJD surveillance collection.
He estimates that it may be up to 14 or 15 persons which display selectively SPRPSC and practically no detected RPRPSC proteins.
http://www.fda.gov/ohrms/dockets/ac/06/transcripts/1006-4240t1.htm
http://www.fda.gov/ohrms/dockets/ac/06/transcripts/2006-4240t1.pdf
2008
The statistical incidence of CJD cases in the United States has been revised to reflect that there is one case per 9000 in adults age 55 and older. Eighty-five percent of the cases are sporadic, meaning there is no known cause at present.
http://www.cjdfoundation.org/fact.html
BSE YOUNGEST AGE STATISTICS UNDER 30 MONTHS
http://bseyoungestage.blogspot.com/
http://flounder068.vox.com/library/post/bse-youngest-age-statistics-under-30-months.html
Tuesday, May 27, 2008
FDA BSE/Ruminant Feed Inspections Firms Inventory Report Texas Legend Ranch OAI 05/10/2008
http://madcowfeed.blogspot.com/2008/05/fda-bseruminant-feed-inspections-firms.html
Tuesday, June 3, 2008
Thursday, April 03, 2008 A prion disease of cervids: Chronic wasting disease 2008
1: Vet Res. 2008 Apr 3;39(4):41
http://chronic-wasting-disease.blogspot.com/2008/04/prion-disease-of-cervids-chronic.html
Terry S. Singeltary Sr. P.O. Box 42 Bacliff, Texas USA 77518
posted by Terry S. Singeltary Sr. at
4:54 PM
0 Comments:
Post a Comment
Subscribe to Post Comments [Atom]
<< Home