Transmissible spongiform encephalopathy (TSE) has been studied in sheep, mink, cattle, and humans. Zoonosis (transmission from animals to humans) is a concerning risk factor - since the National School Lunch Programs have recently fed processed, dying or dead, downer cattle to school children throughout the United States. Downer cattle presents the highest risk for transmission of TSE, especially downer cattle exhibiting signs of transmissible spongiform encephalopathy (explanation later in this writing). Cattle have been known to cause a variant of transmissible spongiform encephalopathy (usually known as CJD) in humans, via several routes of transmission including but not limited to medical procedures that utilize bovine derivatives.
Cover-up, with regard to the scope of the danger that TSE presents, is implicated by some who have taken an exhaustive amount of time to research the issue. Many have closely covered the history and emerging scientific understandings with regard to transmissible spongiform encephalopthies' varied presentation in different animal populations and humans - but perhaps due to the complicated nature of the information it remains a neglected issue where the popular media and general public is concerned.
A little of the history behind the transmissible spongiform encephalopathies...
In sheep, TSE is called Scrapie. One source defines Scrapie as... a fatal, degenerative disease that affects the nervous systems of sheep and goats. It is one of several transmissible spongiform encephalopathies (TSEs), which are related to bovine spongiform encephalopathy (BSE or "mad cow disease") and chronic wasting disease of deer. Like other spongiform encephalopathies, scrapie is caused by a prion. Scrapie has been known since the 18th century (1732) and does not appear to be transmissible to humans. (link)
However, Sheep Feed and Scrapie in France points out that confounding components are at play, whilst trying to determine transmission routes of the various of transmissible spongiform encephalopathies - in order to assess overall risks. The research's introduction pointed to the fact that while Scrapie had not been considered a zoonosis (transmissible from animals to humans), emergence of cases where bovine spongiform encephalopathy (BSE) had been transmitted to humans - and also experimentally transmitted to sheep, indicates that risk exists for small ruminant transmissible spongiform encephalopathy TSE in humans. Scrapie is a small ruminant transmissible spongiform encephalopathy.
TSE seems to be transmissible via feeding conditions. For the above research, the role of feed eaten by the sheep was associated with higher risk of acquiring TSE. Additionally, ...The use of proprietary concentrates, and more precisely the use of feed containing meat and bone meal, was shown to have a major role in BSE infection of cattle (in 1992). There is a real risk of sheep succumbing to the bovine spongiform encephalopathy (BSE), and an already identified risk of BSE being transmitted to humans.
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 at a low level...
It seems to be all in the feed, in a manner of speaking. Evidence That Transmissible Mink Encephalopathy Results From Feeding Infected Cattle (an epidemiological perspective) states that there is both; a transmissible mink spongiform encephalopathy similar to that found in scrapie affected sheep - that was identified to be caused from feeding scrapie - infected sheep to mink, and a transmissible mink encephalopathy that was caused from predominantly feeding "dead stock" downer or dairy cattle.
In April of 1985 a mink rancher in Stetsonville, Wisconsin reported that many of his mink were "acting funny", and some had died. At this time, we visited the farm and found that approximately 10% of all adult mink were showing typical signs of TME: insidious onset characterized by subtle behavioral changes, loss of normal habits of cleanliness, deposition of droppings throughout the pen rather than in a single area, hyperexciteability, difficulty chewing and swallowing, and tails arched over their backs like squirrels...
Progressive deterioration, and then death followed.
Another TSE, called chronic wasting disease (CWD) has been diagnosed in deer or elk in Alberta, Saskatchewan, South Dakota, Oklahoma, Nebraska, Wyoming and Colorado. It has been referred to as a slow motion epidemic by Mike Miller, of the Colorado Division of Wildlife. (link) The FDA has determined that there is no proof that CWD can be transmitted to humans, even as it has been suspected. A CDC document, Chronic Wasting Disease and Potential Transmission to Humans, relents to the following conclusion.
...the transmission of BSE to humans and the resulting vCJD indicate that, provided sufficient exposure, the species barrier may not completely protect humans from animal prion diseases. Because CWD has occurred in a limited geographic area for decades, an adequate number of people may not have been exposed to the CWD agent to result in a clinically recognizable human disease. The level and frequency of human exposure to the CWD agent may increase with the spread of CWD in the United States. Because the number of studies seeking evidence for CWD transmission to humans is limited, more epidemiologic and laboratory studies should be conducted to monitor the possibility of such transmissions.
All tranmissibility aside, by the later part of the 1980's it became necessary to alert bovine practitioners to the fact that there is the possibility of - an as of yet unrecognized scrapie like disease of cattle in the United States. All of this according to the Agriculture and Life Sciences, University of Wisconsin Madison. It would be important that those in the cattle industry know about the possibility of TSE in cattle, so that they do not use it for feed - or process it for human consumption.
Sadly, from January 2004 to Sept 2007 a major supplier of meat for the nation's school lunch program was proven to slaughter cattle that exhibited signs of illness - and process the remains in order to provide them as food for our children. The Humane Society released video in late 2007 showing "downer" cows — animals too weak or sick to walk — being dragged by chains, rammed by forklifts and sprayed with high-pressure water by plant employees who wanted them to stand for processing. (Associated Press Writer, Gilligan Flaccus, 9/24/2009)
From Terry S. Singeltary: ...feeding those dead stock downer cows to children for over 4 years was something they should never ever be able to forget about. Dead stock downer cows are the most high risk animal for mad cow disease, and they knew this - when the feeding to our children of this product was taking place. The USDA et al via the NSLP fed our children all across the USA, from state to state... they fed our children dead stock downer cows, the most HIGH RISK CATTLE FOR MAD COW DISEASE. They fed them to our children, and hid the largest beef recall in USA history; hid this recall under the guise of 'animal abuse'. (What about child abuse?) Then told the parents not to worry because none of the kids had been sick or died from it to date. CJD can incubate for decades...
With regard to this particular meat recall, most of the product had been eaten by the time of the recall.
It seems that CJD type illness, or transmissible spongiform encephalopathies present enough of a risk to write about - in order that the information is available for individuals to take hold of and consider. Recent research points to the fact that transmissible spongiform encephalopathies' susceptibility factors have a lot to do with each individual's genetics - which determine onset patterns of the disease. The presentation of CJD can be quite varied. I am struck by how the disease can be transmitted in various ways between animals, and from animals to humans.
Do the agencies in place to ensure that we are protected, engage in more politics than protection? And when the protection finally comes, why does it come so late? For every governmental agency standard, there seems to be a hedge on the safety bet - the let us wait and see what happens hedge, but let us not assume any responsibility for the disaster if and when it comes. By 2009, those in power began to announce that it might not be a good idea to use cattle that are non ambulatory (exhibiting sickness) for processing and public consumption. While the epidemiology and research on CJD type illness pointed to danger early on, our agencies seem to linger. Perhaps they were hanging out with the lobbies; the special interests that are defending their bottom line.
WASHINGTON, March 14, 2009 – Agriculture Secretary Tom Vilsack today announced a final rule to amend the federal meat inspection regulations to require a complete ban on the slaughter of cattle that become non-ambulatory disabled after passing initial inspection by Food Safety and Inspection Service (FSIS) inspection program personnel.
The final rule amends the federal meat inspection regulations to require that all cattle that are non-ambulatory disabled ("downer") cattle at any time prior to slaughter at an official establishment, including those that become non-ambulatory disabled after passing ante-mortem inspection, be condemned and properly disposed of according to FSIS regulations. Additionally, the final rule requires that establishments notify inspection program personnel when cattle become non-ambulatory disabled after passing the ante-mortem, or pre-slaughter, inspection. The rule will enhance consumer confidence in the food supply and improve the humane handling of cattle. (link)
Recently some researchers have begun to look into the possibility that CJD / prion disease, are affecting many who have been identified with neurodegenerative disease - autism may even be determined as part of that mix.
From Birth of Designer Cells... :Researchers have established a link between HIV and Creutzfeldt-Jakob and the onset of dementia, and dementia is proposed to have a number of possible causes including; infectious viruses, bacteria, disease-carrying parasites and fungi. The Center For Prions and Protein Folding Diseases in Alberta finds that... there may be common factors between prion diseases and other human diseases such as autism and Alzheimer’s.
Recent investments by the Alberta Prion Research Institute (APRI), and the Alberta Ingenuity Fund (AIF), which total nearly $15 million, have been committed to support new research infrastructure, university and industry-led research projects, and the recruitment of new prion researchers to Alberta. Support from APRI and AIF has attracted additional funding from industry and other provincial and federal agencies, amounting to $26 million, for basic pre-commercial research and development across the province.
The New England Journal of Medicinehas an interesting writing (a Health Policy and Reform writing) about differing responsibilities with regard to reporting exposures. ...disclosure would allow patient access to testing and treatment, but there is also greater ethical justification for nondisclosure in this case (CJD exposure) than in the other types of large-scale adverse events. The challenge of disclosing large-scale adverse events related to prion diseases is an important topic for further analysis.
I look at everything through the lens of autism, and wonder how TSE might affect the very young - if exposed. I just hope we never need to find out. A no cost biography about one autism experience can be viewed on scribd, and is called Hello, Dr. Wells.