REPORT ON THE INVESTIGATION OF THE TWELFTH CASE OF BOVINE SPONGIFORM ENCEPHALOPATHY (BSE) IN CANADA
On February 7, 2008 a private veterinarian in Northern Alberta euthanized and sampled a Holstein cow under Canada's National BSE Surveillance Program. Brain samples from this animal were sent to the Alberta Agriculture and Food (AAF) laboratory where they were screened for BSE using a Bio-Rad rapid test on February 13, 2008. The result of this preliminary test did not rule out BSE. In accordance with the prescribed testing protocol, the test was repeated and on February 14, 2008 produced a reaction a second time. Brain samples were then sent to the National BSE Reference Laboratory in Lethbridge, AB. Additional rapid tests for BSE (Prionics-Check PrioStrip and Prionics-Check Western) were conducted at the National BSE Reference Laboratory to validate the result of the screening test and were positive on February 19 and 20, 2008, respectively. The Hybrid Western Blot was positive on February 20, 2008 and on February 22, 2008, the Scrapie Associated Fibril Immunoblot was positive. On February 25, 2008, BSE was confirmed using the immunohistochemistry procedure. The carcass was secured at the sampling site, and was subsequently transferred to the CFIA Laboratory in Lethbridge for incineration. No part of the carcass entered the human food supply or animal feed chain.
The CFIA immediately initiated an epidemiological investigation based on the recommended BSE guidelines of the World Organisation for Animal Health, referred to as the OIE. Specifically, the CFIA followed the recommended BSE guidelines for a country with controlled risk status and investigated:
the feed cohort, comprising all cattle which, during their first year of life, were reared with the BSE case during its first year of life, and which investigation showed consumed the same potentially contaminated feed during that period, or the birth cohort, comprising all cattle born in the same herd as, and within 12 months of the birth of the BSE case, if the above cannot be identified and feed to which the animal may have been exposed early in its life. ANIMAL INVESTIGATION The positive animal was a registered Holstein cow born on December 21, 2001 and it was 73 months of age at the time of death. The animal was born, raised and had spent its entire life on the same farm. The producer reported the duration of illness was approximately one month, during which the animal displayed progressive signs of impaired locomotion, culminating in the animal becoming non-ambulatory (downer). When examined by a private practitioner on February 7, 2008, the animal was recumbent. The practitioner and producer determined that the animal should be euthanized . Since the inclusion criteria of Canada’s National BSE Surveillance Program were met, arrangements were made to forward appropriate samples for laboratory evaluation.
The birth farm was a dairy operation. The feed cohort was determined to comprise 114 animals, which along with the case animal, were raised on the farm. Animals which were sold at less than one week of age for fattening and subsequent slaughter, without having access to any commercially prepared feeds, were excluded from the feed cohort investigation, because they were not exposed to the same potentially contaminated feed as the case animal. The trace-out investigation of the feed cohort located 13 live animals on the case farm. Three of the animals have since been humanely destroyed; their carcasses, and that of the case animal, disposed of by incineration. In recognition of the fact that BSE in not a contagious disease, ten animals are being retained, under quarantine, to allow for calving or collection of valuable genetic material. Subsequent to these events, the animals will be humanely destroyed and their carcasses incinerated in accordance with the OIE recommendations. The following is the disposition of the remaining 101 animals in the feed cohort:
41 animals were traced and confirmed to have died or been slaughtered, 56 animals were traced and presumed to have died or been slaughtered, Three animals were traced and confirmed to have been exported for slaughter and the importing country has been notified, One animal was determined to be untraceable. The investigation revealed that the case animal had two calves born within the previous two years. The CFIA no longer requires the destruction of calves of BSE positive cows born within 24 months of the development of clinical signs, in accordance with the current Bovine Spongiform Encephalopathy Chapter of the OIE Terrestrial Animal Health Code (2007). However, the CFIA continues to trace calves born to a positive female in respect of the current export certification requirements of some importing countries. The 2006 and 2007 progeny were located on the case farm and were humanely destroyed to ensure Canada’s continued compliance with certain export certification requirements. Their carcasses were incinerated at the National BSE Reference Laboratory.
FEED INVESTIGATION The feed investigation focused on feeds to which the case animal may have had access during its first year of life and the manufacturing practices used to produce each of these feeds.
Investigation at the farm revealed cattle to be the only commercially farmed species present. Other animals present included a dog, several cats, and rabbits. Pet food is considered to contain prohibited material and investigators confirmed it was stored and fed separately from other feeds and animals.
There was no pasture use on the farm and all forages (hay and silages) were grown on land fertilized with commercial fertilizer and harvested using farm-owned equipment. Non-forage feed products included four different commercially prepared complete feeds, mineralized salt blocks, and loose mineral feeds supplied by two commercial feed manufacturers and one retail outlet.
Two of the complete feeds (the dairy ration and the heifer ration) were delivered in bulk and transferred directly into their respective bulk storage bins. A third feed, the dry cow ration, was delivered in 25 kg bags and fed directly to dry cows and pregnant heifers only. A complete starter ration for calves was also purchased in bags.
Consistent with management practices for all heifer calves on the farm, the case animal was housed in a single enclosed hutch for approximately the first eight weeks of life, and then moved through a series of group pens with other heifers of similar age and size. Calves were initially fed colostrum, followed by milk and calf starter beginning at three days of age and continuing to approximately eight weeks of age. Heifer calves were introduced to the commercial heifer and dairy rations beginning at approximately eight weeks of age and pail-fed increasing amounts (in mixed proportion) until approximately eight months of age. From approximately eight to 13 months of age, heifers were fed heifer ration with mineral feeds. Forages were provided throughout. Feed mixing and handling practices described for the farm preclude feeding of the dry cow ration to heifers less than 12 months of age. Therefore, feeds to which the case animal may have been exposed and which warranted investigation were: calf starter, heifer ration, dairy ration, mineralized salt blocks, and mineral feeds.
Investigation at the commercial manufacturer supplying the loose mineral products identified that production of these was in a facility handling prohibited material but with dedicated equipment and in accordance with procedures which ruled them out as a possible source of contamination. Similarly, the mineralized salt blocks were manufactured in a specialized facility which did not handle prohibited material.
Calf starter was supplied exclusively by one commercial manufacturer whereas supply of the heifer and dairy rations alternated between this facility and a second manufacturer. Both facilities cross utilized equipment in the manufacture and delivery of feeds for ruminants and those containing prohibited material. Prohibited material was supplied to both facilities from the same rendering facility which also supplied prohibited material to feed suppliers identified in previous BSE cases.
The facility supplying approximately half of the heifer and dairy rations had documented procedures in place to prevent contamination of ruminant feeds with prohibited material. The facility providing the remainder of the heifer and dairy rations and all the calf starter reported procedures were in place to prevent contamination but most production records did not include documentation that these procedures were followed.
Four deliveries of calf starter were identified during the time frame of interest and subsequently investigated. There was no means of tracing the deliveries to specific production lots so all lots manufactured during the time frame of interest (total of six) were investigated. Production records identified one of the lots followed a feed containing prohibited material without proper cleanout of the production equipment (pellet mill).
Seven deliveries of heifer ration were identified during the time frame of interest and investigated. None of the records examined indicated contamination with prohibited material occurred during their manufacture, transport or storage.
Twenty-eight deliveries of dairy ration were identified during the time frame of interest and investigated. Production records identified one of these feeds was manufactured after a feed containing prohibited material and without proper cleanout of the production equipment (pellet mill). This feed was delivered to the farm when the case animal was 38 days of age and precedes the estimated age (56 days) at which dairy ration was first offered. A later delivery of dairy ration when the case animal was slightly less than eight months of age may have also had carryover amounts of a feed containing prohibited material due to improper sequencing of a pre-pellet holding bin.
Feeding a contaminated calf starter within the first two months of life is one possible source of exposure to infectious material for the case animal. Additionally, evidence suggests that two other rations supplied to the farm during the time frame of interest may have been cross-contaminated with feeds containing prohibited material and potentially fed to the case animal. In the absence of complete documentation additional exposures can not be ruled out.
INVESTIGATION OVERVIEW The detection of this case does not change any of Canada’s BSE risk parameters. The location and age of the animal are consistent with previous cases, and the BSE surveillance results to date, including this new case, reflect an extremely low level of BSE in Canada. In essence, the case confirms what was already known about an extremely low level of BSE infectivity having existed in Canada’s feed system during the late 1990s and early 2000s within a previously determined geographic area and time interval.
Given current knowledge about the epidemiology of BSE, it is reasonable to presume that this animal was exposed to feed containing a low level of infectivity during its first year of life as supported by the feed investigation findings. The investigation into the current case identified a few possibilities but it was impossible to determine the exact source of exposure.
Since the confirmation of BSE in a native-born animal in May 2003, Canada has significantly increased its targeted testing of cattle in high-risk categories advocated by the OIE (including non-ambulatory animals). This effort is directed at determining the level of BSE in Canada, while monitoring the effectiveness of the suite of risk-mitigating measures in place. Canada’s National BSE Surveillance Program continues to demonstrate an extremely low level of BSE in Canada, with 12 positive animals detected among the over 212 000 targeted tests conducted since 2003. Such detections demonstrate the effectiveness and integrity of Canada's surveillance system. Canada’s controlled BSE risk status under the OIE’s science-based system also clearly recognizes the effectiveness of Canada’s surveillance, mitigation and eradication measures, and acknowledges the work done by all levels of government, the cattle industry, veterinarians and ranchers to effectively manage BSE in Canada.
OTHER RELEVANT INFORMATION With respect to BSE, the safety of beef produced in Canada is assured by public health measures enacted in 2003, following the first detection of BSE in a native-born animal in Canada. The removal of specified risk material (SRM)-those tissues that have been demonstrated to have the potential to harbour BSE infectivity-from all animals slaughtered for human consumption is the most effective single measure to protect consumers in Canada and importing countries from exposure to BSE infectivity in meat products.
As demonstrated by the surveillance system, the feed ban implemented in 1997 is effectively preventing the amplification of BSE in Canada. The detection of BSE in a few animals born after the 1997 feed ban is not unexpected and does not indicate a failure of the measures in place to reduce and eventually eradicate BSE.
Canada’s own BSE experience has served to emphasize the importance of addressing opportunities for cross-contamination of ruminant rations and cross-feeding of ruminants with rations containing prohibited proteins. Although the 1997 feed ban regulations include provisions addressing these risks, the detection of BSE cases in cattle born after 1997 contributed to Canada’s decision to implement additional regulations enhancing Canada’s feed ban on July 12, 2007. Principally, the enhancements require the removal and redirection of SRM from all animal feed, pet food and fertilizers.
The enhanced feed ban limits potential opportunities for BSE infectivity to contaminate feeds for ruminants by controlling all activities related to the movement of SRM, its distribution, processing, destruction, disposal or alternative uses through a system of permits. This ensures that these materials do not enter the human and animal food chains or the fertilizer system and effectively contains any potential BSE infectivity thereby preventing exposure of susceptible species to the BSE agent.
This enhancement will significantly accelerate progress toward eradicating BSE from the national cattle herd by preventing more than 99 per cent of potential BSE infectivity from entering the Canadian feed system.
What's New - Archives - July 2008
Food and Veterinary Office - Inspection reports
CA Canada - Bovine Spongiform Encephalopathy (BSE)
Canada Bovine spongiform encephalopathy (bse) 2007/7247
COMPETENT AUTHORITY RESPONSE TO RECOMMENDATIONS
Please click on the link below to open the Action Plan:
Annex A: Factual Corrections to Draft Report of FVO Mission Number DG(SANCO)/2007-7247: Mission to evaluate measures concerning BSE in Canada
ANNEX B Response of the Competent Authorities of Canada to the recommendations of Mission report ref. DG (SANCO)/2007-7247 – in order to evaluate measures concerning BSE – received on 27 May 2008
Scientific Report of the European Food Safety Authority on the Assessment of the Geographical BSE Risk (GBR) of Canada Question number: EFSA-Q-2003-083 Adopted date: 01/07/2004 Summary (0.1Mb)
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 to provide an up-to-date scientific report on the GBR in Canada, i.e. the likelihood of the presence of one or more cattle being infected with BSE, pre-clinically as well as clinically, in Canada. This scientific report addresses the GBR of Canada as assessed in 2004 based on data covering the period 1980-2003.
The BSE agent was probably imported into the country middle of the eighties and could have reached domestic cattle in the early nineties. 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 90s. It is possible that imported meat and bone meal (MBM) into Canada reached domestic cattle and led to an internal challenge in the early 90s.
A certain risk that BSE-infected cattle entered processing in Canada, and were at least partly rendered for feed, occurred in the early 1990s when cattle imported from UK in the mid 80s could have been slaughtered. 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 Canada is III, i.e. it is confirmed at a lower level that domestic cattle are (clinically or pre-clinically) infected with the BSE-agent. As long as the system remains unstable, it is expected that the GBR continues to grow, even if no additional external challenges occur.
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Publication date: 20/08/2004 Last updated: 08/09/2004
Wednesday, July 23, 2008 Audit says USDA lost track of imported cattle Report No. 50601-0012-Ch March 2008
[Docket No. FSIS-2006-0011] FSIS Harvard Risk Assessment of Bovine Spongiform Encephalopathy (BSE)
Docket APHIS-2006-0026 Docket Title Bovine Spongiform Encephalopathy; Animal Identification and Importation of Commodities Docket Type Rulemaking Document APHIS-2006-0026-0001 Document Title Bovine Spongiform Encephalopathy; Minimal-Risk Regions, Identification of Ruminants and Processing and Importation of Commodities Public Submission APHIS-2006-0026-0012 Public Submission Title Comment from Terry S Singletary
Docket APHIS-2006-0041 Docket Title Bovine Spongiform Encephalopathy; Minimal-Risk Regions; Importation of Live Bovines and Products Derived from Bovines Commodities Docket Type Rulemaking Document APHIS-2006-0041-0001 Document Title Bovine Spongiform Encephalopathy; Minimal-Risk Regions; Importation of Live Bovines and Products Derived From Bovines Public Submission APHIS-2006-0041-0028 Public Submission Title Comment from Terry S Singletary
Comment 2006-2007 USA AND OIE POISONING GLOBE WITH BSE MRR POLICY
THE USA is in a most unique situation, one of unknown circumstances with human and animal TSE. THE USA has the most documented TSE in different species to date, with substrains growing in those species (BSE/BASE in cattle and CWD in deer and elk, there is evidence here with different strains), and we know that sheep scrapie has over 20 strains of the typical scrapie with atypical scrapie documented and also BSE is very likely to have passed to sheep. all of which have been rendered and fed back to animals for human and animal consumption, a frightening scenario. WE do not know the outcome, and to play with human life around the globe with the very likely TSE tainted products from the USA, in my opinion is like playing Russian roulette, of long duration, with potential long and enduring consequences, of which once done, cannot be undone. These are the facts as I have come to know through daily and extensive research of TSE over 9 years, since 12/14/97. I do not pretend to have all the answers, but i do know to continue to believe in the ukbsenvcjd only theory of transmission to humans of only this one strain from only this one TSE from only this one part of the globe, will only lead to further failures, and needless exposure to humans from all strains of TSE, and possibly many more needless deaths from TSE via a multitude of proven routes and sources via many studies with primates and rodents and other species.
MY personal belief, since you ask, is that not only the Canadian border, but the USA border, and the Mexican border should be sealed up tighter than a drum for exporting there TSE tainted products, until a validated, 100% sensitive test is available, and all animals for human and animal consumption are tested. all we are doing is the exact same thing the UK did with there mad cow poisoning when they exported it all over the globe, all the while knowing what they were doing. this BSE MRR policy is nothing more than a legal tool to do just exactly what the UK did, thanks to the OIE and GW, it's legal now. and they executed Saddam for poisoning ???
go figure. ...
Docket APHIS-2006-0041 Docket Title Bovine Spongiform Encephalopathy; Minimal-Risk Regions; Importation of Live Bovines and Products Derived from Bovines Commodities Docket Type Rulemaking Document APHIS-2006-0041-0001 Document Title Bovine Spongiform Encephalopathy; Minimal-Risk Regions; Importation of Live Bovines and Products Derived From Bovines Public Submission APHIS-2006-0041-0028.1 Public Submission Title Attachment to Singletary comment
January 28, 2007
I would kindly like to submit the following to ;
BSE; MRR; IMPORTATION OF LIVE BOVINES AND PRODUCTS DERIVED FROM BOVINES [Docket No. APHIS-2006-0041] RIN 0579-AC01
Docket APHIS-2007-0033 Docket Title Agricultural Bioterrorism Protection Act of 2002; Biennial Review and Republication of the Select Agent and Toxin List Docket Type Rulemaking Document APHIS-2007-0033-0001 Document Title Agricultural Bioterrorism Protection Act of 2002; Biennial Review and Republication of the Select Agent and Toxin List Public Submission APHIS-2007-0033-0002.1 Public Submission Title Attachment to Singeltary comment
Docket No. 03-080-1 -- USDA ISSUES PROPOSED RULE TO ALLOW LIVE ANIMAL IMPORTS FROM CANADA
Importation of Whole Cuts of Boneless Beef from Japan [Docket No. 05-004-1] RIN 0579-AB93 TSS SUBMISSION Date: August 24, 2005 at 2:47 pm PST
BSE BASE MAD COW TESTING TEXAS, USA, AND CANADA
Scientific Report of the European Food Safety Authority on the Assessment of the Geographical BSE Risk (GBR) of the United States of America (USA) Question number: EFSA-Q-2003-083 Adopted date: 01/07/2004 Summary (0.1Mb)
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.
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Publication date: 20/08/2004 Last updated: 08/09/2004
Scientific Report of the European Food Safety Authority on the Assessment of the Geographical BSE Risk (GBR) of Mexico Question number: EFSA-Q-2003-083 Adopted date: 01/07/2004 Summary (0.1Mb)
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 Mexico, i.e. the likelihood of the presence of one or more cattle being infected with BSE, pre-clinically as well as clinically, in Mexico. This scientific report addresses the GBR of Mexico as assessed in 2004 based on data covering the period 1980-2003.
The BSE agent was probably imported into Mexico and could have reached domestic cattle. These cattle imported could have been rendered and therefore led to an internal challenge in the mid to late 1990s. It is possible that imported meat and bone meal (MBM) into Mexico reached domestic cattle and leads to an internal challenge around 1993.
It is likely that BSE infectivity entered processing at the time of imported ‘at - risk’ MBM (1993) and at the time of slaughter of imported live ‘at - risk’ cattle (mid to late 1990s). The high level of external challenge is maintained throughout the reference period, and the system has not been made stable. Thus it is likely that BSE infectivity was recycled and propagated from approximately 1993. The risk has since grown consistently due to a maintained internal and external challenge and lack of a stable system.
EFSA concludes that the current geographical BSE risk (GBR) level is III, i.e. it is likely but not confirmed that domestic cattle are (clinically or pre-clinically) infected with the BSE-agent. The GBR is likely to increase due to continued internal and external challenge, coupled with a very unstable system.
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Publication date: 20/08/2004 Last updated: 08/09/2004
UPDATE CJD AMERICA, CANADA, AND MEXICO
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
i hate to inform them, but sporadic CJD has increased.
sporadic CJD in the USA went from 28 cases _documented_ in 1997, to 170 cases of sporadic CJD _documented_ in 2007. i'm not a math wiz, but looks like an increase to me. ...
6 Includes 55 cases with type determination pending in which the diagnosis of vCJD has been excluded.
hmmm, they can exclude vCJD, but yet include them as a prion disease, but yet not know what the hell it is, and at the same time, keep telling everyone i.e. media, that ;
>>>Further tests will be conducted to determine the cause of the Cape patient's illness, but state disease trackers said there is nothing to suggest that the patient's case is associated with mad cow disease. Instead, like virtually all cases in the United States, it is almost certainly not linked to any obvious external cause.<<<
stupid is, as stupid does. ...TSS
10 people killed by new CJD-like disease
Public release date: 9-Jul-2008
Since Gambetti's team wrote a paper describing an initial 11 cases referred to his centre between 2002 and 2006 (Annals of Neurology, vol 63, p 697), another five have come to light. "So it is possible that it could be just the tip of the iceberg," Gambetti says.
sporadic CJD, the big lie
Thursday, July 10, 2008 A Novel Human Disease with Abnormal Prion Protein Sensitive to Protease update July 10, 2008
Thursday, July 10, 2008 A New Prionopathy update July 10, 2008
Creutzfeldt-Jakob Disease Surveillance System (CJD-SS)
Referrals of Suspected CJD Reported by CJD-SS(1), 1997-2007(2)
Year of Reporting Numbers of Referrals
1997 4 1998 43 1999 63 2000 82 2001 101 2002 103 2003 75 2004 89 2005 97 2006 78 2007 88
1CJD-SS began in April 1998 2Data before April 1998 are retrospective and partial, data from 1999 to 2005 are complete, and data for 2006 and 2007 are provisional As of December 1, 2007
Neuropathology Volume 27 Issue 5 Page 419-428, October 2007
To cite this article: Leora Velásquez-Pérez, Daniel Rembao-Bojorquez, Jorge Guevara, Rosa María Guadarrama-Torres, Araceli Trejo-Contreras (2007) Creutzfeldt-Jakob disease in Mexico
Neuropathology 27 (5), 419–428. doi:10.1111/j.1440-1789.2007.00807.x
Creutzfeldt-Jakob disease in Mexico
Leora Velásquez-Pérez,1Departments of 1Epidemiology and Leora Velásquez-Pérez, MD, MSc, Department of Epidemiology, National Institute of Neurology and Neurosurgery, Insurgentes Sur 3877 Col. La Fama Tlalpan 14269, México, DF, Mexico. Email: firstname.lastname@example.org Daniel Rembao-Bojorquez,22Pathology, and Jorge Guevara,33Neurodegenerative Diseases Laboratory, National Institute of Neurology and Neurosurgery, Mexico DF, Mexico Rosa María Guadarrama-Torres1Departments of 1Epidemiology and and Araceli Trejo-Contreras1Departments of 1Epidemiology and Departments of 1Epidemiology and 2Pathology, and 3Neurodegenerative Diseases Laboratory, National Institute of Neurology and Neurosurgery, Mexico DF, Mexico Leora Velásquez-Pérez, MD, MSc, Department of Epidemiology, National Institute of Neurology and Neurosurgery, Insurgentes Sur 3877 Col. La Fama Tlalpan 14269, México, DF, Mexico. Email: email@example.com
Creutzfeldt-Jakob disease (CJD) is classified within the group of transmissible spongiform encephalopathies (TSE). It is a rapidly progressive illness that affects mental functions. The average age of onset is 50 years. Various tests can help orient the clinical diagnosis, but the confirmatory test is still the post mortem analysis. The aim of this study was to describe the epidemiological, clinical and histopathological characteristics of patients diagnosed as suffering from CJD, at the National Institute of Neurology and Neurosurgery of Mexico (NINN). An observational, descriptive and transversal study was conducted. We collected information concerning these cases from the Departments of Epidemiology and Pathology, as well as the clinical charts of the patients with a diagnosis of CJD. Fifteen cases were registered of which three CJD cases were definite, five probable cases were identified, and seven were possible. The average age of the patients was 49 years. Two definite cases were female and one was male. It is important to improve the systems for surveillance of this type of disease and, furthermore, to permit greater accessibility to laboratories where the procedures necessary for supporting diagnosis can be followed.
In Mexico there are some deficiencies in the surveillance system, among other reasons due to limited knowledge concerning this disease on the part of administrative and medical staff, which causes a lack of notification of cases and an under-registration of these diseases. On the other hand, the National System of Epidemiological Surveillance has not rigorously integrated and made obligatory the notification and control of TSE, and there are no centers or laboratories of microbiology and genetics where tests to support the diagnosis of the disease can be conducted. Another problem in Mexico is the fact that many of the suspected or probable cases are never confirmed because of the refusal of relatives to allow deceased patients to undergo autopsies.
The aim of this study was to describe and present the epidemiological, clinical, and histopathological characteristics of CJD cases, detected between January 1, 2000 and May 31, 2005 in our institution; this being one of the world’s main neurological institutions.
Between January 1, 2000 and May 31, 2005, three definite CJD cases were identified (20%), five probable cases were identified (33%), and seven were classified as possible (47%). The laboratory investigations used for the patients are presented in Table 1. The year of diagnosis of these patients is shown in Table 2. By the end of May 2005, eight patients were still alive (53%), and seven had died (47%). Of the seven deceased patients, the neurohistophatological study was performed in three patients. Of these, autopsy was carried out in two and stereotactic biopsy was performed in one. Histopathological images of definite cases of CJD are presented in Figure 1. Of these 15 cases,47% were male and 53% were female. The youngest patient was 23 years old, while the oldest was 75 (average: 49 years). The clinical manifestations observed most frequently at the beginning of the disease included cognitive symptoms, behavioral changes, cephalalgia and depression.The rest of the symptoms are shown in Table 2. The elapsed time between the beginning of symptoms and the patient’s arrival at the NINN for medical attention consisted of a mean of 71 days (range: 10–210).The elapsed time from the beginning of clinical manifestations until the date of death and that between their arrival at the NINN and date of death are shown in Table 2. When analyzing their family history with respect to the presence of CJD and any type of dementia, all patients denied having this kind of antecedent. The past medical history of each patient is shown in Table 3. Ten patients (66.6%) were married or lived as couples, four (26.7%) were single, and only one (6.7%) was a widower. Regarding their educational level, nine (60%) had completed elementary education or had taken the first 3 years of courses and knew how to read and write; two (13%) had completed secondary education; three (20%) had completed high school or had at least a technical degree; and one (7%) had a bachelor degree. Concerning their residential locations, it was found that seven patients (47%) lived in Mexico City, five (33%) in the state of Mexico or suburban zones of the City, and three (20%) in other states of the Mexican Republic. The distribution of the cases in Mexico City, according to political divisions of the city, is shown in Figure 2. Regarding patients living in the state of Mexico, two (40%) were from Chalco, one (20%) was from Cuautitlan, one (20%) was from Ecatepec, and one (20%) from San JuanTeotihuacan. The three states of the Mexican Republic from where the other patients came were Guerrero, Hidalgo, and Sonora, each with one case. Regarding the occupational activities of the seven female patients, six (86%) were housewives and one (14%) was a secretary.With respect to the occupational activities of the male patients, two (25%) were retailers, two (25%) were office employees, and the remaining 50% was made up of farmers, drivers, bricklayers, and students, each with one case.
The average age in this study was 49 years, with an age range of 23–75 years. The age range reported by Bateman et al.13 is 45–75 years, and they mentioned that sCJD is extremely rare under age 30. However, in our study we had patients younger than this latter age. Nevertheless, gender frequency was similar, with 53% of female patients and 47% of male patients. Our results are more consistent with the work of Olov et al.32 who reported cases of CJD in younger patients, ranging from 34 to 84 years of age. Of the three definite cases, two were female, an interesting fact, as in 1995, in Mexico, Martínez et al.33 reported three cases, all of them female patients, but only one of them had a brain biopsy result. We are aware that PrP genotyping is important to classify prion diseases. However, in Mexico this technique is not available, a limitation of this study. However, we consider that this study reveals important information about CJD in Mexico. In the future, it would be interesting to perform a retrospective study with genetic analysis. Although seven cases died over a 5-year period, only 43% of them had a confirmed diagnosis. Despite the clinical profile, the laboratory, and the imaging studies that
could be made due to the refusal by the patients’ relatives. Unfortunately, Mexican culture is not oriented towards organ donation and post mortem studies. Besides this fact, specialized centers or laboratories where 14.3.3 protein determinations can be carried out are scarce. In Mexico, only one National Institute of Health conducts this type of analysis, which means blood samples have to be analyzed in foreign countries, making studies more expensive for patients, most of whom have low economic resources.This makes it impossible for them to obtain studies that support the CJD diagnosis. A tendency therefore exists to underestimate the real frequency of the disease, thus it may be more common in Mexico than it appears. In effect, the lack of knowledge among the population and among the medical staff of some institutions, as well as different levels of medical attention provided countrywide, may cause this disease not to be consistently diagnosed. This contrasts greatly with what happens in many European countries, where prompt post mortem studies for BSE have been carried out since January 1, 2001.
Fig. 2 Geographical areas of the Mexican Republic where the studied cases were located.
DELEGATIONS OF FEDERAL DISTRICT
GUSTAVO A MADERO 2 CASES
VENUSTIANO CARRANZA 1 CASE
IZTACALCO 1 CASE
COYOACAN 2 CASES
XOCHIMILCO 1 CASE
Table 2 indicates that most of the reported cases applied for medical attention 1–2 months after the appearance of symptoms, due to the limited importance patients give to behavioral and psycho-affective disorders. Early identification of the first symptoms in sporadic CJD, like depression, agitation, irritability, and memory loss, is important for public health reasons and potential timely interventions when treatments become available.34 No similarities were observed among the occupational activities of the studied male patients. Besides this, the fact that most of the female patients were housewives is most probably a reflection of the usual occupation of lowincome Mexican women. Forty-seven percent of the cases died, and the available information indicates that the elapsed time from the initiation of symptoms and the patient’s death is short – less than a year – indicating the damaging and aggressive impact of this disease. In spite of the fact that CJD is sporadic and its frequency of appearance is relatively low, it is necessary to make patients and their relatives aware of the importance of brain donation, to be able to reach more precise diagnoses and avoid many of these cases being classified either as probable or possible. Information about TSE must be widespread, particularly that concerning CJD; epidemiological surveillance and diagnostic systems must be established, so that more precise data concerning the incidence of these diseases are available, allowing for stricter control and prevention to be imposed. The training process should be enriched by increasing the number of autopsies performed in the NINN. From 1998 onwards, an institutional autopsy program has been established; however, proven cases of dementia including prion diseases are still low.35 It is necessary to increase the study of prion diseases by including autopsies as an integral part of medical education programs, along with a participating academic committee that should promote, assess, and evaluate the results obtained.
2007 Japanese Society of Neuropathology
PLEASE NOTE ABOVE CJD MEXICO ''The youngest patient was 23 years old,''... TSS
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) , Canada (1 H)15, Denmark (1 L)16, France (8 H, 6 L)17, Germany (1 H, 1 L) , Italy (3 L)18, Japan (1 L) , 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 . 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 , as well as between L-type BSE and CJD . 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.pdfUSDA Food Safety & Inspection ServiceFreedom of Information Act Requests received: February 1, 2008 to February 29, 2008http://www.fsis.usda.gov/PDF/FOIA_Requests_0208.pdfThursday, April 24, 2008 RE-FOIA OF DECLARATION OF EXTRAORDINARY EMERGENCY BECAUSE OF AN ATYPICAL T.S.E. OF FOREIGN ORIGIN IN THE UNITED STATES [Docket No. 00-072-1]http://foiamadsheepmadrivervalley.blogspot.com/2008/04/re-foia-of-declaration-of-extraordinary.htmlSEAC Draft minutes of the 100th meeting held on 25th April 2008http://seac992007.blogspot.com/2008/07/seac-draft-minutes-of-100th-meeting.htmlFriday, July 18, 2008 TSE risk assessment from carcasses of ovine and caprine animals below 6 months of age from TSE infected flocks intended for human consumptionhttp://nor-98.blogspot.com/2008/07/tse-risk-assessment-from-carcasses-of.htmlTuesday, June 3, 2008SCRAPIE USA UPDATE JUNE 2008 NOR-98 REPORTED PAhttp://nor-98.blogspot.com/2008/06/scrapie-usa-update-june-2008-nor-98.htmlTuesday, June 3, 2008 SCRAPIE USA UPDATE JUNE 2008 NOR-98 REPORTED PAhttp://nor-98.blogspot.com/2008/06/scrapie-usa-update-june-2008-nor-98.htmlThursday, April 03, 2008 A prion disease of cervids: Chronic wasting disease 20081: Vet Res. 2008 Apr 3;39(4):41http://chronic-wasting-disease.blogspot.com/2008/04/prion-disease-of-cervids-chronic.htmlTransmissible Mink Encephalopathy TMEhttp://transmissible-mink-encephalopathy.blogspot.com/
Published online before print January 2, 2008, 10.1073/pnas.0710824105 PNAS January 8, 2008 vol. 105 no. 1 11-12
Unraveling prion strains with cell biology and organic chemistry
Institute of Neuropathology, UniversitätsSpital Zürich, Schmelzbergstrasse 12, CH-8091 Zürich, Switzerland
Prions are the infectious agents causing transmissible spongiform encephalopathies (TSEs), which comprise human Creutzfeldt–Jakob disease (CJD), scrapie of sheep, bovine spongiform encephalopathy (BSE), and several other rare ailments of various species. According to the protein-only hypothesis (1), prions are composed solely of PrPSc, a misfolded form of the cellular protein PrPC. PrPSc typically forms highly ordered fibrillary aggregates, also termed "amyloid." The term "prion strain" denotes individual prion isolates sharing the same PrP sequence but giving rise to distinct, stable disease traits with different incubation periods and lesion profiles upon serial transmission in congenic hosts. The propagation of different strains in mice congenic with respect to their Prnp allelotypes is difficult to explain by the protein-only hypothesis because the epigenetic strain characteristics of prions appear to dominate over the primary prion protein sequence of the infected host (2, 3).
Circumstantial evidence suggests that strain phenotypes are encoded by distinct conformations of PrPSc (Fig. 1). This was first implied by experiments showing that distinct strains of transmissible mink encephalopathy went along with different protease-exposed sites within PrPSc (4). Great strides have been made since then, yet the final proof that conformational variants of PrPSc represent the biological basis of mammalian prion strains is still elusive. Distinct prion strains may bear highly divergent risks of transmission to humans: Sheep scrapie-derived strains may be mostly innocuous, whereas BSE-derived strains appear to induce variant CJD (vCJD) in humans. Also, two subtypes . . .see full text ;
MAD COW DISEASE terminology UK c-BSE (typical), atypical BSE H or L, and or Italian L-BASE
Saturday, June 21, 2008 HUMAN and ANIMAL TSE Classifications i.e. mad cow disease and the UKBSEnvCJD only theory JUNE 2008
Terry S. Singeltary Sr.
P.O. Box 42
Bacliff, Texas USA 77518