Sunday, November 3, 2013

Environmental Impact Statements; Availability, etc.: Animal Carcass Management [Docket No. APHIS-2013-0044]

Environmental Impact Statements; Availability, etc.: Animal Carcass Management This Notice document was issued by the Animal and Plant Health Inspection Service (APHIS)
 
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Show agency attachment(s) DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection Service [Docket No. APHIS-2013-0044] Environmental Impact Statement; Animal Carcass Management Agency Animal and Plant Health Inspection Service, USDA.
 
Action Notice of intent to prepare an environmental impact statement and proposed scope of study.
 
Summary We are announcing to the public that the Animal and Plant Health Inspection Service intends to prepare an environmental impact statement (EIS) to examine the potential environmental effects of animal carcass management options used throughout the United States. This notice identifies potential alternatives and environmental effects that will be examined in the EIS and requests that the public comment on these proposed alternatives and environmental effects and identify other issues that could be examined in the EIS.
 
Dates We will consider all comments that we receive on or before November 25, 2013.
 
Addresses You may submit comments by either of the following methods:
 
Federal eRulemaking Portal: Go to http://www.regulations.gov/#!documentDetail;D=APHIS-2013-0044-;0001. Postal Mail/Commercial Delivery: Send your comment to Docket No. APHIS-2013-0044, Regulatory Analysis and Development, PPD, APHIS, Station 3A-03.8, 4700 River Road Unit 118, Riverdale, MD 20737-1238. Supporting documents and any comments we receive on this docket may be viewed at http://www.regulations.gov/#!docketDetail;D=APHIS-2013-0044 or in our reading room, which is located in room 1141 of the USDA South Building, 14th Street and Independence Avenue SW., Washington, DC. Normal reading room hours are 8 a.m. to 4:30 p.m., Monday through Friday, except holidays. To be sure someone is there to help you, please call (202) 799-7039 before coming.
 
For Further Information Contact For questions related to the carcass management program, contact Ms. Lori P. Miller, PE, Senior Staff Officer, National Center for Animal Health Emergency Management, VS, APHIS, 4700 River Road Unit 41, Riverdale, MD 20737; (301) 851-3512. For questions related to the EIS, contact Ms. Samantha Floyd, Environmental Protection Specialist, Environmental and Risk Analysis Services, PPD, APHIS, 4700 River Road Unit 149, Riverdale, MD 20737; (301) 851-3053.
 
Supplementary Information Background The Animal Health Protection Act (7 U.S.C. 8301 et seq.) authorizes the Secretary of Agriculture to order the destruction or removal of animals to prevent the introduction and spread of livestock pests or diseases. Large numbers of animals and carcasses may need to be disposed of or otherwise managed during or after an animal health emergency. Examples of an animal health emergency include, but are not limited to, an outbreak of a foreign animal disease, a natural disaster, or the introduction of a chemical or radiological agent. As carcasses begin to degrade, bodily fluids, chemical and biological leachate components, and hazardous gases such as methane are released into the environment, potentially impacting the health and safety of surrounding humans, livestock, and wildlife. Therefore, the management of large numbers of carcasses during an animal health emergency must be timely, safe, biosecure, aesthetically acceptable, and environmentally responsible.
 
Current Animal and Plant Health Inspection Service (APHIS) regulations regarding carcass management, including those found in 9 CFR 53.4, are based on World Organization for Animal Health (OIE) recommendations and sound science. APHIS regulations specify that animals infected by or exposed to foot-and mouth disease, pleuropneumonia, rinderpest, and certain other communicable diseases of livestock or poultry are required to be disposed of by burial or burning, unlessotherwise specified by the APHIS Administrator. Traditionally, burial has involved placement of carcasses in unlined pits or trenches, and burning has involved open pyres (i.e., combustible heaps). APHIS may work in conjunction with States to manage animal carcasses during or after an animal health emergency. However, State regulations concerning carcass management vary, and Federal and State regulations are not always based on the most current scientific information with regard to impacts of such activities on the environment and public health.
 
Environmental Impact Statement To examine the potential environmental effects of animal carcass management options used throughout the United States, APHIS is preparing an environmental impact statement (EIS). The EIS will analyze and compare all major and readily available mass carcass management options that may be utilized during an animal health emergency. APHIS is considering classifying mass carcass management as management of 50 tons or more of biomass per premises. In the EIS, we intend to compare unlined burial and open-air burning disposal methods with other available carcass management options. These may include composting (on- or off-site), rendering, landfills compliant with the Resource Conservation and Recovery Act (RCRA), and other fixed facility options, such as incinerators compliant with the Clean Air Act, that could accommodate a large volume of carcasses over a short period of time.
 
The findings of the EIS will be used for planning and decision making and to inform the public about the potential environmental effects of currently available carcass management options. Additionally, when mass carcass management options are utilized, site-specific environmental documents may be required. If such documents are needed, APHIS may use information presented and analyzed in the EIS, which will help APHIS to promptly fulfill its environmental compliance obligations when an emergency situation arises requiring immediate action.
 
We are requesting public comment to help us identify or confirm potential alternatives and environmental effects, as well as any other issues, that could and should be examined in the EIS. The EIS will be prepared in accordance with: (1) The National Environmental Policy Act of 1969 (NEPA), as amended (42 U.S.C. 4321 et seq.), (2) regulations of the Council on Environmental Quality for implementing the procedural provisions of NEPA (40 CFR parts 1500-1508), (3) USDA regulations implementing NEPA (7 CFR part 1b), and (4) APHIS' NEPA Implementing Procedures (7 CFR part 372).
 
Alternatives We have identified the following alternatives for further examination in the EIS:
 
Take no action. Under the no action alternative, existing APHIS regulations that recommend unlined burial and open-air burning will be used as the baseline against which alternative carcass management methods may be compared. This action does not involve changes to the current situation.
 
Alternative action. Under the alternative action, APHIS is considering alternatives in addition to unlined burial and open-air burning as carcass management options. Alternative actions may include one or some combination of the following: Composting (on- or off-site), rendering, RCRA-compliant landfills, and other fixed facility options, such as incinerators compliant with the Clean Air Act.
 
Environmental Effects for Consideration We have identified the following potential environmental effects for examination in the EIS. We are requesting that the public comment on them during the scoping period:
 
Effects on soil, air, and water quality. Effects on humans: Health and safety. Agricultural lands. Industries and the economy. Public perception. Cultural and historic resources. Effects on wildlife populations, including effects on federally listed threatened and endangered species. Effects on plant populations, including effects on federally listed threatened and endangered species. Comments that identify other issues or alternatives that could be considered for examination in the EIS would be especially helpful. All comments received during the scoping period will be carefully considered in developing the final scope of the EIS. Upon completion of the draft EIS, a notice announcing its availability and an opportunity to comment on it will be published in theFederal Register.
 
Authority 7 U.S.C. 8301-8317; 7 CFR 2.22, 2.80, and 371.4.
 
Done in Washington, DC, this 21st day of October 2013. Kevin Shea, Administrator, Animal and Plant Health Inspection Service. [FR Doc. 2013-25158 Filed 10-24-13; 8:45 am] BILLING CODE 3410-34-P
 
 
 
 
Environmental Impact Statements; Availability, etc.: Animal Carcass Management [Docket No. APHIS-2013-0044]. COMMENT SUBMISSION TERRY S. SINGELTARY SR.
 
 
Greetings APHIS et al, and thank you kindly for allowing me to comment on Environmental Impact Statements; Availability, etc.: Animal Carcass Management [Docket No. APHIS-2013-0044].
 
I don’t believe I saw the BSE TSE prion aka mad cow type listed in this, but I thought I should list my concerns there from anyway, with relations to this Environmental Impact Statements; Availability, etc.: Animal Carcass Management [Docket No. APHIS-2013-0044]. With the USDA/APHIS et al now letting the mad cow disease freely trade between countries, I was surprised to see this concern for animal disease and pyres there from, even though it seems anymore, the USDA/APHIS et al can’t even say the word anymore. I well remember what was said long ago ;
 
 
In Confidence - Perceptions of unconventional slow virus diseases of animals in the USA - APRIL-MAY 1989 - G A H Wells
 
3. Prof. A. Robertson gave a brief account of BSE. The US approach was to accord it a very low profile indeed. Dr. A Thiermann showed the picture in the ''Independent'' with cattle being incinerated and thought this was a fanatical incident to be avoided in the US at all costs. ...
 
 
 
with the recent mass bovine deaths from the floods, the drought, the recent snow storm, and the known fact that mad cow disease of the c-BSE, atypical h,g-BSE, atypical h-BSE, and the atypical l-type BASE BSE, two strains of CWD in cervids, and the deaths there from in the cervid populations from cwd, and ehd, all this proves the USA is, and has been, far from being prepared for any type of major animal disease outbreak, foreign or domestic. also, with all the mass cattle deaths of late, it would have been a perfect time to test for mad cow type disease, if anyone would have attempted such a task, but we know how mad cow TSE testing goes by the USDA et al, that would have just made too much sense to test a mass cattle death for mad cow disease, and of course difficult, with such short time available when turning in and testing samples for a TSE prion disease, but still, a perfect opportunity gone by and missed.  
 
I have long been concerned with the Transmissible Spongiform Encephalopathy TSE prion disease, and all it’s strains in the many different species in North America, and the ramifications there from when considering carcass disposal, and I recent put together the following, about soil contamination from the TSE prion, along with other recent science on the potential update of prions to plants.
 
 
Chronic Wasting Disease CWD, and other TSE prion disease, these TSE prions aka mad cow type disease know no borders.
 
these TSE prions know no age restrictions.
 
The TSE prion disease survives ashing to 600 degrees celsius, that’s around 1112 degrees farenheit.
 
you cannot cook the TSE prion disease out of meat.
 
you can take the ash and mix it with saline and inject that ash into a mouse, and the mouse will go down with TSE.
 
Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production as well.
 
the TSE prion agent also survives Simulated Wastewater Treatment Processes.
 
IN fact, you should also know that the TSE Prion agent will survive in the environment for years, if not decades.
 
you can bury it and it will not go away.
 
The TSE agent is capable of infected your water table i.e. Detection of protease-resistant cervid prion protein in water from a CWD-endemic area.
 
it’s not your ordinary pathogen you can just cook it out and be done with. that’s what’s so worrisome about Iatrogenic mode of transmission, a simple autoclave will not kill this TSE prion agent.
 
I wish to submit the following recent and old TSE prion science, some from PRION2013, PRION2012, PRION 2011, data on mass livestock mortality death disposal methods such as Alkaline hydrolysis, composting, burial, rendering, incineration, and some data from the BSE Inquiry submissions going back to 1989, some of which I hope you may find useful. the BSE Inquiry submissions will be at the bottom of my submission here. First, the latest science on the TSE prion disease and reports there from, then what do other countries think of the USA and it’s capability of carcass disposal, and types of methods to dispose of large animal mortality events, and last, the old science from the BSE INQUIRY and what they thought on carcass disposal and the TSE PRION.
 
 
‘’There are many disposal options for dead livestock currently in use throughout the world; however, the knowledge that TSEs and some pathogens may not be completely destroyed may limit their utility in the wake of changing legislation (e.g. the amended EU Animal By-Products Regulation (1069/2009) which comes into effect in March 2011). On-farm disposal methods are favoured by the farming community due to the perceived environmental, practical, economical and biosecurity benefits, therefore processes such as composting and anaerobic digestion have found favour in countries such as the USA and Canada. Under the ABPR in the EU, these options are not deemed safe’’
 
 
I lost my Mom to the hvCJD back in December 14, 1997, and have been disturbed and fascinated at the same time of the science of the TSE prion aka mad cow type disease.
 
I find even more disturbing at some of the regulations, and or lack of, for the TSE prion disease, and how it seems that the OIE, and the USDA et al, have dumbed down the science for the TSE prion disease, and then regulations there from. by now allowing all countries trade in the TSE prion disease, the relaxing of the BSE TSE testing, the relaxing of the feed bans, the relaxing of BSE surveillance now, is a very bad decision, and was not based on sound science to date, all of which I have listed why, below in references as follows ;
 
 
New studies on the heat resistance of hamster-adapted scrapie agent: Threshold survival after ashing at 600°C suggests an inorganic template of replication
 
The infectious agents responsible for transmissible spongiform encephalopathy (TSE) are notoriously resistant to most physical and chemical methods used for inactivating pathogens, including heat. It has long been recognized, for example, that boiling is ineffective and that higher temperatures are most efficient when combined with steam under pressure (i.e., autoclaving). As a means of decontamination, dry heat is used only at the extremely high temperatures achieved during incineration, usually in excess of 600°C. It has been assumed, without proof, that incineration totally inactivates the agents of TSE, whether of human or animal origin.
 
 
 
Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production
 
Histochemical analysis of hamster brains inoculated with the solid residue showed typical spongiform degeneration and vacuolation. Re-inoculation of these brains into a new cohort of hamsters led to onset of clinical scrapie symptoms within 75 days, suggesting that the specific infectivity of the prion protein was not changed during the biodiesel process. The biodiesel reaction cannot be considered a viable prion decontamination method for MBM, although we observed increased survival time of hamsters and reduced infectivity greater than 6 log orders in the solid MBM residue. Furthermore, results from our study compare for the first time prion detection by Western Blot versus an infectivity bioassay for analysis of biodiesel reaction products. We could show that biochemical analysis alone is insufficient for detection of prion infectivity after a biodiesel process.
 
 
 
Detection of protease-resistant cervid prion protein in water from a CWD-endemic area
 
The data presented here demonstrate that sPMCA can detect low levels of PrPCWD in the environment, corroborate previous biological and experimental data suggesting long term persistence of prions in the environment2,3 and imply that PrPCWD accumulation over time may contribute to transmission of CWD in areas where it has been endemic for decades. This work demonstrates the utility of sPMCA to evaluate other environmental water sources for PrPCWD, including smaller bodies of water such as vernal pools and wallows, where large numbers of cervids congregate and into which prions from infected animals may be shed and concentrated to infectious levels.
 
 
 
A Quantitative Assessment of the Amount of Prion Diverted to Category 1 Materials and Wastewater During Processing
 
Keywords:Abattoir;bovine spongiform encephalopathy;QRA;scrapie;TSE
 
In this article the development and parameterization of a quantitative assessment is described that estimates the amount of TSE infectivity that is present in a whole animal carcass (bovine spongiform encephalopathy [BSE] for cattle and classical/atypical scrapie for sheep and lambs) and the amounts that subsequently fall to the floor during processing at facilities that handle specified risk material (SRM). BSE in cattle was found to contain the most oral doses, with a mean of 9864 BO ID50s (310, 38840) in a whole carcass compared to a mean of 1851 OO ID50s (600, 4070) and 614 OO ID50s (155, 1509) for a sheep infected with classical and atypical scrapie, respectively. Lambs contained the least infectivity with a mean of 251 OO ID50s (83, 548) for classical scrapie and 1 OO ID50s (0.2, 2) for atypical scrapie. The highest amounts of infectivity falling to the floor and entering the drains from slaughtering a whole carcass at SRM facilities were found to be from cattle infected with BSE at rendering and large incineration facilities with 7.4 BO ID50s (0.1, 29), intermediate plants and small incinerators with a mean of 4.5 BO ID50s (0.1, 18), and collection centers, 3.6 BO ID50s (0.1, 14). The lowest amounts entering drains are from lambs infected with classical and atypical scrapie at intermediate plants and atypical scrapie at collection centers with a mean of 3 × 10−7 OO ID50s (2 × 10−8, 1 × 10−6) per carcass. The results of this model provide key inputs for the model in the companion paper published here.
 
 
 
PPo4-4:
 
Survival and Limited Spread of TSE Infectivity after Burial
 
Karen Fernie, Allister Smith and Robert A. Somerville The Roslin Institute and R(D)SVS; University of Edinburgh; Roslin, Scotland UK
 
Scrapie and chronic wasting disease probably spread via environmental routes, and there are also concerns about BSE infection remaining in the environment after carcass burial or waste 3disposal. In two demonstration experiments we are determining survival and migration of TSE infectivity when buried for up to five years, as an uncontained point source or within bovine heads. Firstly boluses of TSE infected mouse brain were buried in lysimeters containing either sandy or clay soil. Migration from the boluses is being assessed from soil cores taken over time. With the exception of a very small amount of infectivity found 25 cm from the bolus in sandy soil after 12 months, no other infectivity has been detected up to three years. Secondly, ten bovine heads were spiked with TSE infected mouse brain and buried in the two soil types. Pairs of heads have been exhumed annually and assessed for infectivity within and around them. After one year and after two years, infectivity was detected in most intracranial samples and in some of the soil samples taken from immediately surrounding the heads. The infectivity assays for the samples in and around the heads exhumed at years three and four are underway. These data show that TSE infectivity can survive burial for long periods but migrates slowly. Risk assessments should take into account the likely long survival rate when infected material has been buried.
 
The authors gratefully acknowledge funding from DEFRA.
 
 
 
PPo3-22:
 
Detection of Environmentally Associated PrPSc on a Farm with Endemic Scrapie
 
Ben C. Maddison,1 Claire A. Baker,1 Helen C. Rees,1 Linda A. Terry,2 Leigh Thorne,2 Susan J. Belworthy2 and Kevin C. Gough3 1ADAS-UK LTD; Department of Biology; University of Leicester; Leicester, UK; 2Veterinary Laboratories Agency; Surry, KT UK; 3Department of Veterinary Medicine and Science; University of Nottingham; Sutton Bonington, Loughborough UK
 
Key words: scrapie, evironmental persistence, sPMCA
 
Ovine scrapie shows considerable horizontal transmission, yet the routes of transmission and specifically the role of fomites in transmission remain poorly defined. Here we present biochemical data demonstrating that on a scrapie-affected sheep farm, scrapie prion contamination is widespread. It was anticipated at the outset that if prions contaminate the environment that they would be there at extremely low levels, as such the most sensitive method available for the detection of PrPSc, serial Protein Misfolding Cyclic Amplification (sPMCA), was used in this study. We investigated the distribution of environmental scrapie prions by applying ovine sPMCA to samples taken from a range of surfaces that were accessible to animals and could be collected by use of a wetted foam swab. Prion was amplified by sPMCA from a number of these environmental swab samples including those taken from metal, plastic and wooden surfaces, both in the indoor and outdoor environment. At the time of sampling there had been no sheep contact with these areas for at least 20 days prior to sampling indicating that prions persist for at least this duration in the environment. These data implicate inanimate objects as environmental reservoirs of prion infectivity which are likely to contribute to disease transmission.
 
 
 
Wednesday, July 10, 2013
 
Rapid assessment of bovine spongiform encephalopathy prion inactivation by heat treatment in yellow grease produced in the industrial manufacturing process of meat and bone meals
 
BMC Veterinary Research 2013, 9:134 doi:10.1186/1746-6148-9-134
 
 
 
AD.81: Detection of prion protein associated with cervid chronic wasting disease in environmental samples
 
Chad J. Johnson, Christen B. Smith, Michael D. Samuel and Joel A. Pedersen University of Wisconsin; Madison. WI USA
 
Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) or prion disease affecting North American members of the deer family (cervids). The disease agent may enter the environment through decomposition of carcasses and shedding in feces, saliva, and urine. Once in the environment disease associated prion protein (PrPTSE) can bind to soil components and remain bioavailable for extended time periods. Assessment of the environmental load of the disease agent is difficult because relevant levels are below the detection limits of immunochemical methods and bioassay is prohibitively expensive to use as a surveillance technique. Here, we report that a combination of detergent extraction and protein misfolding cyclic amplification with beads (PMCAb) substantially improves the sensitivity of PrPTSE detection in environmental samples. Using this technique we are able to achieve detection limits substantially lower than animal bioassay. Working with amended soils we are able to extract and amplify PrPTSE to detectable levels. We have investigated factors contributing to PMCAb inhibition and methods to circumvent those inhibitions. This technique holds promise for helping to clarify the relative importance of direct and indirect transmission of CWD, assess the effectiveness of environmental remediation, and determine environmental loads of infectious agent.
 
=====
 
 
AD.80: Kinetics of chronic wasting disease prion shedding in cervid saliva and urine
 
Nicholas J. Haley, Davin Henderson, Glenn C. Telling and Edward A. Hoover
 
Colorado State University; Fort Collins. CO USA
 
Efficient horizontal transmission is a unique hallmark of chronic wasting disease (CWD) of deer, elk, and moose. Saliva trans- fer, for example via grazing or mutual grooming, is thought to be the primary mechanism of horizontal transmission, although urine and feces are also thought ro play an important role. It is not known how shortly after exposure an animal may begin shedding PrPCWD, though it has been reported that both clinical and pre-clinical animals may successfully transmit CWD to naive deer. We hypothesized that transmission would occur primarily in end-stage disease, though the purpose of this study was to identify earlier time points during the course of CWD infection in which saliva and urine may carry infectivity. Using both transgenic mouse bioassay and real-rime quaking-induced conversion (RT-QuIC), we evaluated saliva and urine from two experimentally infected white tail deer for which samples were available from multiple time points post-inoculation (p.i.) (e.g., 3, 6 and 12 mo p.i., as well as immediately prior to euthanasia at 24-27 mos). We found that while saliva collected during clinical disease was infectious in mouse bioassay, saliva collected 12 mo p.i., prior to the onset of clinical signs was also variably infectious. Saliva from time points earlier than 12 mo p.i. failed to transmit infection, while urine collected from clinically affected deer had very low potential to transmit infection, as has been reported previously. These findings extend our understanding of CWD shedding in the natural host, and may improve control of CWD transmission in captive and free-ranging settings.
 
 
 
 
PRION UPDATE VIA VEGETABLE PLANTS FROM THE SOIL
 
56. Members considered that there is no evidence that crops grown on the land which received composted excreta from BSE-challenged animals pose a TSE risk to humans or animals. One member suggested that, as some of these animals are orally challenged with high doses of BSE-infected materials, and the distribution of infectivity in the digestive system is not completely understood, it might be premature to conclude that there is no infective agent in the manure.
 
Furthermore, an unpublished study had indicated low level absorption of PrP from soil by tomato plants although it should be noted that this study had not been repeated. Details of this work would be sent to the SEAC Secretary. Dr Matthews explained that most of the manure from animals challenged with high doses of BSE had already been composted and used for coppicing. Members agreed that the risks from disposal of residual manure from experimental animals would be much less than historic risks of on farm contamination from naturally infected animals at the height of the BSE epidemic. ...SNIP...END
 
 
 
SRM are certain cattle tissues capable of transmitting BSE. There is no human health risk assessment to indicate the absence of human health concerns associated with use of composted SRM domestically. To date, scientific evidence has not been able to demonstrate that composting destroys prions. Although domestic use would pose a negligible risk to livestock, there is a potential risk to humans via direct ingestion of the compost or of compost particles adhered to skin or plant material (e.g. carrots). Another potential route of exposure is by ingestion of prions that have been taken up by plants. It has been proven that bacteria are readily taken up by some plants (e.g. E. coli in lettuce) thus the uptake of prions by plants cannot be precluded or dismissed at this time. As a science-based regulator, the CFIA cannot change the policy on this issue without a risk assessment demonstrating that the use of composted SRM poses an acceptable risk to humans.
 
 
 
 
Tuesday, October 29, 2013
 
***Risk of Prion Disease Transmission through Bovine-Derived Bone Substitutes: A Systematic Review
 
 
 
Saturday, November 2, 2013
 
***APHIS Finalizes Bovine Import Regulations in Line with International Animal Health Standards while enhancing the spread of BSE TSE prion mad cow type disease around the Globe
 
 
 
Saturday, November 2, 2013
 
***Exploring the risks of a putative transmission of BSE to new species
 
 
 
Wednesday, October 30, 2013
 
***SPECIFIED RISK MATERIAL (SRM) CONTROL VERIFICATION TASK FSIS NOTICE 70-13 10/30/13
 
 
 
Monday, August 26, 2013
 
***The Presence of Disease-Associated Prion Protein in Skeletal Muscle of Cattle Infected with Classical Bovine Spongiform Encephalopathy
 
 
 
Saturday, November 2, 2013
 
*** Recommendation of the Swiss Expert Committee for Biosafety on the classification of activities using prion genes and prion protein January 2013 ***
 
 
 
Tuesday, October 29, 2013
 
*** VARIANT CJD PRESENTS DIFFERENTLY IN OLDER PATIENTS
 
 
 
 
 
Friday, February 08, 2013
 
*** Behavior of Prions in the Environment: Implications for Prion Biology
 
 
 
 
PO-031: Aerosol transmission of chronic wasting disease to white-tailed deer
 
 
Nathaniel Denkers,1 Jeanette Hayes-Klug,1 Kelly Anderson,1 Sally Dahmes,2 David Osborn,3 Karl Miller,3 Robert Warren,3 Candace Mathiason,1 Edward Hoover1 1Colorado State University; Fort Collins, CO USA; 2WASCO Inc.; Monroe, GA USA; 3Warnell School of Forestry and Natural Resources, University of Georgia; Athens, GA USA
 
Purpose. A signature feature of chronic wasting disease (CWD) is its efficient lateral transmission in nature, almost surely by mucosal exposure. Our previous studies employing Tg(cerPrP) mice determined that CWD can be transmitted to a susceptible host by aerosol exposure, a route with relatively little investigation. The present study was designed to determine whether CWD is transmissible by aerosol to a native cervid host, white-tailed deer.
 
Materials and Methods. Nine white-tailed deer were exposed to two (2) aerosol doses of a 5% w/v CWD+ (n = 6) or CWD- (n = 3) brain homogenate, delivered via the nasal passages using a customized aerosol apparatus. At 3-month intervals post inoculation (mpi), tonsil and recto-anal mucosa-associated lymphoid tissue (RAMALT) biopsies were collected and assayed for CWD infection by protein misfolding cyclic amplification (PMCA), western blotting (WB), and immunohistochemistry (IHC).
 
Results. At 3 mpi and 6 mpi, tonsil and RAMALT biopsies were collected from 5 of the 6 CWD + aerosol-exposed deer. Three of the 5 (60%) tested positive for CWD by PMCA but not IHC or western blot analysis at 3 mpi. By 6 mpi, 5 of 5 (100%) were tonsil and/or RAMALT biopsy positive by at least two of the three assays. Biopsies were collected from all CWD+ aerosol-exposed deer at 9 mpi, with 6 of 6 (100%) tonsil and/ or RAMALT positive by western blot or IHC. At 10 mpi 3 of the 6 prion-exposed deer have developed early clinical signs of CWD infection (hyperphagia, polydypsia, wide leg stance and head/neck dorsi-flexion). All sham-inoculated deer are showing no clinical signs and have remained CWD negative as assessed by all three assays. Interestingly, the prion dose delivered to the deer by aerosol-exposure is estimated to be 20-fold lower than the historical oral dose that has resulted in detectable CWD infection at 6 or 12 mpi.
 
Conclusions. This study documents the first aerosol transmission of CWD in deer. These results further infer that aerosolized prions facilitate CWD transmission with greater efficiency than does oral exposure to a larger prion dose. Thus exposure via the respiratory mucosa may be significant in the facile spread of CWD in deer and perhaps in prion transmission overall.
 
 
 
 
PO-073: Multiple routes of prion transepithelial transport in the nasal cavity following inhalation
 
Anthony Kincaid, Shawn Feilmann, Melissa Clouse, Albert Lorenzo, Jason Bartz Creighton University; Omaha, NE USA
 
Introduction. Inhalation of either prion-infected brain homogenate or aerosolized prions has been shown to cause disease, and in the case of inhalation of infected brain homogenate, the nasal route of infection has been shown to be 10–100 times more efficient than the oral route. The cell types involved in the in vivo transport of prions across the nasal cavity epithelium have not been determined. M cells in the follicular associated epithelium have been shown to mediate transcellular transport of prions in vitro and in the gut of experimentally infected mice. We tested the hypothesis that M-cell mediated transport was responsible for prion entry across nasal cavity epithelium following inhalation.
 
Materials and Methods. Hamsters were inoculated extranasally with 50 or 100ul of infected (n = 31) or mock-infected (n = 13) brain homogenate. Control animals were inoculated with buffer (n = 4) or were untreated (n = 5). Following survival periods ranging from 15 to 180 min, animals were perfused, skulls were decalcified and nasal cavities were embedded in paraffin. Tissue sections were cut and processed immunohistochemically for glial fibrillary acidic protein to identify brain homogenate, or for the disease-associated form of the prion protein. Tissue sections not further than 112 um apart through the entire extent of the nasal cavity were analyzed using light microscopy; photomicrographs were obtained wherever inoculum was observed on the surface of, within, or deep to the nasal mucosa for each animal.
 
Results. Infected or uninfected brain homogenate was identified within the nasal cavities of animals at all time points and was seen crossing the nasal cavity epithelium within minutes of inoculation; the transepithelial transport of brain homogenate continued for up to 3 h after inoculation. Infected or uninfected brain homogenate was seen adhering to, or located within, M cells at all time points. However, larger volumes of infected or uninfected brain homogenate were identified crossing between cells of the olfactory and respiratory epithelia in multiple locations. In addition, infected or uninfected brain homogenate was identified within the lumen of lymphatic vessels in the lamina propria beneath the nasal mucosa at all time points.
 
Conclusion. Transepithelial transport of prions across nasal cavity mucosa begins within minutes of inhalation and can continue for up to 3 h. While M cells appear to transport prions across the follicular associated epithelium, larger amounts of prions are transported between the cells of the respiratory and olfactory epithelia, where they immediately enter the lymphatic vessels in the lamina propria. Thus, inhaled prions can be spread via lymph draining the nasal cavity and have access to somatic and autonomic nerves in the lamina propria of the nasal cavity. The increased efficiency of the nasal cavity route of infection compared with the oral route may be due to the rapid and prolonged transport of prions between cells of the respiratory and olfactory epithelia.
 
 
 
 
PO-033: Replication efficiency of soil-bound prions varies with soil type
 
Shannon Bartelt-Hunt,1 Samuel Saunders,1 Ronald Shikiya,2 Katie Langenfeld,2 Jason Bartz2 1University of Nebraska-Lincoln; Omaha, NE USA; 2Creighton University; Omaha, NE USA
 
Prion sorption to soil is thought to play an important role in the transmission of scrapie and chronic wasting disease (CWD) via the environment. Sorption of PrP to soil and soil minerals is influenced by the strain and species of PrPSc and by soil characteristics. However, the ability of soil-bound prions to convert PrPc to PrPSc under these wide-ranging conditions remains poorly understood. We developed a semiquantitative protein misfolding cyclic amplification (PMCA) protocol to evaluate replication efficiency of soil-bound prions. Binding of the hyper (HY) strain of transmissible mink encephalopathy (TME) (hamster) prions to a silty clay loam soil yielded a greater-than-1-log decrease in PMCA replication efficiency with a corresponding 1.3-log reduction in titer. The increased binding of PrPSc to soil over time corresponded with a decrease in PMCA replication efficiency. The PMCA efficiency of bound prions varied with soil type, where prions bound to clay and organic surfaces exhibited significantly lower replication efficiencies while prions bound to sand exhibited no apparent difference in replication efficiency compared to unbound controls. PMCA results from hamster and CWD agent-infected elk prions yielded similar findings. Given that PrPSc adsorption affinity varies with soil type, the overall balance between prion adsorption affinity and replication efficiency for the dominant soil types of an area may be a significant determinant in the environmental transmission of prion diseases.
 
PO-039: A comparison of scrapie and chronic wasting disease in white-tailed deer
 
Justin Greenlee, Jodi Smith, Eric Nicholson US Dept. Agriculture; Agricultural Research Service, National Animal Disease Center; Ames, IA USA
 
Interspecies transmission studies afford the opportunity to better understand the potential host range and origins of prion diseases. The purpose of these experiments was to determine susceptibility of white-tailed deer (WTD) to scrapie and to compare the resultant clinical signs, lesions, and molecular profiles of PrPSc to those of chronic wasting disease (CWD). We inoculated WTD intracranially (IC; n = 5) and by a natural route of exposure (concurrent oral and intranasal (IN); n = 5) with a US scrapie isolate.
 
All deer were inoculated with a 10% (wt/vol) brain homogenate from sheep with scrapie (1ml IC, 1 ml IN, 30 ml oral). All deer inoculated by the intracranial route had evidence of PrPSc accumulation. PrPSc was detected in lymphoid tissues as early as 7 months-post-inoculation (PI) and a single deer that was necropsied at 15.6 months had widespread distribution of PrPSc highlighting that PrPSc is widely distributed in the CNS and lymphoid tissues prior to the onset of clinical signs. IC inoculated deer necropsied after 20 months PI (3/5) had clinical signs, spongiform encephalopathy, and widespread distribution of PrPSc in neural and lymphoid tissues.
 
The results of this study suggest that there are many similarities in the manifestation of CWD and scrapie in WTD after IC inoculation including early and widespread presence of PrPSc in lymphoid tissues, clinical signs of depression and weight loss progressing to wasting, and an incubation time of 21-23 months. Moreover, western blots (WB) done on brain material from the obex region have a molecular profile similar to CWD and distinct from tissues of the cerebrum or the scrapie inoculum. However, results of microscopic and IHC examination indicate that there are differences between the lesions expected in CWD and those that occur in deer with scrapie: amyloid plaques were not noted in any sections of brain examined from these deer and the pattern of immunoreactivity by IHC was diffuse rather than plaque-like.
 
After a natural route of exposure, 100% of WTD were susceptible to scrapie. Deer developed clinical signs of wasting and mental depression and were necropsied from 28 to 33 months PI. Tissues from these deer were positive for PrPSc by IHC and WB. Similar to IC inoculated deer, samples from these deer exhibited two different molecular profiles: samples from obex resembled CWD whereas those from cerebrum were similar to the original scrapie inoculum. On further examination by WB using a panel of antibodies, the tissues from deer with scrapie exhibit properties differing from tissues either from sheep with scrapie or WTD with CWD. Samples from WTD with CWD or sheep with scrapie are strongly immunoreactive when probed with mAb P4, however, samples from WTD with scrapie are only weakly immunoreactive. In contrast, when probed with mAb’s 6H4 or SAF 84, samples from sheep with scrapie and WTD with CWD are weakly immunoreactive and samples from WTD with scrapie are strongly positive. This work demonstrates that WTD are highly susceptible to sheep scrapie, but on first passage, scrapie in WTD is differentiable from CWD. ... snip...see more here ;
 
 
 
Thursday, May 31, 2012
 
CHRONIC WASTING DISEASE CWD PRION2012 Aerosol, Inhalation transmission, Scrapie, cats, species barrier, burial, and more
 
 
 
Saturday, March 10, 2012
 
CWD, GAME FARMS, urine, feces, soil, lichens, and banned mad cow protein feed CUSTOM MADE for deer and elk
 
 
 
Monday, July 16, 2012
 
Persistence of the bovine spongiform encephalopathy infectious agent in sewage
 
 
 
Thursday, August 08, 2013
 
Characterization of the first case of naturally occurring chronic wasting disease in a captive red deer (Cervus elaphus) in North America
 
 
 
Friday, December 14, 2012
 
*** DEFRA U.K. What is the risk of Chronic Wasting Disease CWD being introduced into Great Britain?
 
A Qualitative Risk Assessment October 2012
 
snip...
 
In the USA, under the Food and Drug Administration’s BSE Feed Regulation (21 CFR 589.2000) most material (exceptions include milk, tallow, and gelatin) from deer and elk is prohibited for use in feed for ruminant animals. With regards to feed for non-ruminant animals, under FDA law, CWD positive deer may not be used for any animal feed or feed ingredients. For elk and deer considered at high risk for CWD, the FDA recommends that these animals do not enter the animal feed system. However, this recommendation is guidance and not a requirement by law. Animals considered at high risk for CWD include:
 
1) animals from areas declared to be endemic for CWD and/or to be CWD eradication zones and
 
2) deer and elk that at some time during the 60-month period prior to slaughter were in a captive herd that contained a CWD-positive animal.
 
Therefore, in the USA, materials from cervids other than CWD positive animals may be used in animal feed and feed ingredients for non-ruminants.
 
The amount of animal PAP that is of deer and/or elk origin imported from the USA to GB can not be determined, however, as it is not specified in TRACES. It may constitute a small percentage of the 8412 kilos of non-fish origin processed animal proteins that were imported from US into GB in 2011. Overall, therefore, it is considered there is a __greater than negligible risk___ that (nonruminant) animal feed and pet food containing deer and/or elk protein is imported into GB. There is uncertainty associated with this estimate given the lack of data on the amount of deer and/or elk protein possibly being imported in these products.
 
snip...
 
36% in 2007 (Almberg et al., 2011). In such areas, population declines of deer of up to 30 to 50% have been observed (Almberg et al., 2011). In areas of Colorado, the prevalence can be as high as 30% (EFSA, 2011). The clinical signs of CWD in affected adults are weight loss and behavioural changes that can span weeks or months (Williams, 2005). In addition, signs might include excessive salivation, behavioural alterations including a fixed stare and changes in interaction with other animals in the herd, and an altered stance (Williams, 2005). These signs are indistinguishable from cervids experimentally infected with bovine spongiform encephalopathy (BSE). Given this, if CWD was to be introduced into countries with BSE such as GB, for example, infected deer populations would need to be tested to differentiate if they were infected with CWD or BSE to minimise the risk of BSE entering the human food-chain via affected venison.
 
snip...
 
The rate of transmission of CWD has been reported to be as high as 30% and can approach 100% among captive animals in endemic areas (Safar et al., 2008).
 
snip...
 
In summary, in endemic areas, there is a medium probability that the soil and surrounding environment is contaminated with CWD prions and in a bioavailable form. In rural areas where CWD has not been reported and deer are present, there is a greater than negligible risk the soil is contaminated with CWD prion.
 
snip...
 
In summary, given the volume of tourists, hunters and servicemen moving between GB and North America, the probability of at least one person travelling to/from a CWD affected area and, in doing so, contaminating their clothing, footwear and/or equipment prior to arriving in GB is greater than negligible. For deer hunters, specifically, the risk is likely to be greater given the increased contact with deer and their environment. However, there is significant uncertainty associated with these estimates.
 
snip...
 
Therefore, it is considered that farmed and park deer may have a higher probability of exposure to CWD transferred to the environment than wild deer given the restricted habitat range and higher frequency of contact with tourists and returning GB residents.
 
snip...
 
 
 
SNIP...SEE ;
 
Friday, December 14, 2012
 
*** DEFRA U.K. What is the risk of Chronic Wasting Disease CWD being introduced into Great Britain? A Qualitative Risk Assessment October 2012
 
 
 
Sunday, September 01, 2013
 
*** hunting over gut piles and CWD TSE prion disease ***
 
 
 
CWD TO CATTLE OR BSE TO CERVIDS, potential risk factors ??? LET’S see what the science says to date ;
 
 
UPDATED DATA ON 2ND CWD STRAIN
 
 
Wednesday, September 08, 2010
 
CWD PRION CONGRESS SEPTEMBER 8-11 2010
 
 
 
UPDATED CORRESPONDENCE FROM AUTHORS OF THIS STUDY I.E. COLBY, PRUSINER ET AL, ABOUT MY CONCERNS OF THE DISCREPANCY BETWEEN THEIR FIGURES AND MY FIGURES OF THE STUDIES ON CWD TRANSMISSION TO CATTLE ;
 
CWD to cattle figures CORRECTION
 
 
Greetings,
 
I believe the statement and quote below is incorrect ;
 
"CWD has been transmitted to cattle after intracerebral inoculation, although the infection rate was low (4 of 13 animals [Hamir et al. 2001]). This finding raised concerns that CWD prions might be transmitted to cattle grazing in contaminated pastures."
 
Please see ;
 
Within 26 months post inoculation, 12 inoculated animals had lost weight, revealed abnormal clinical signs, and were euthanatized. Laboratory tests revealed the presence of a unique pattern of the disease agent in tissues of these animals. These findings demonstrate that when CWD is directly inoculated into the brain of cattle, 86% of inoculated cattle develop clinical signs of the disease.
 
 
 
" although the infection rate was low (4 of 13 animals [Hamir et al. 2001]). "
 
 
shouldn't this be corrected, 86% is NOT a low rate. ...
 
 
kindest regards,
 
Terry S. Singeltary Sr. P.O. Box 42 Bacliff, Texas USA 77518
 
Thank you!
 
Thanks so much for your updates/comments. We intend to publish as rapidly as possible all updates/comments that contribute substantially to the topic under discussion.
 
 
 
 
re-Prions David W. Colby1,* and Stanley B. Prusiner1,2 + Author Affiliations
 
1Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, California 94143 2Department of Neurology, University of California, San Francisco, San Francisco, California 94143 Correspondence: stanley@ind.ucsf.edu
 
 
Mule deer, white-tailed deer, and elk have been reported to develop CWD. As the only prion disease identified in free-ranging animals, CWD appears to be far more communicable than other forms of prion disease. CWD was first described in 1967 and was reported to be a spongiform encephalopathy in 1978 on the basis of histopathology of the brain. Originally detected in the American West, CWD has spread across much of North America and has been reported also in South Korea. In captive populations, up to 90% of mule deer have been reported to be positive for prions (Williams and Young 1980). The incidence of CWD in cervids living in the wild has been estimated to be as high as 15% (Miller et al. 2000). The development of transgenic (Tg) mice expressing cervid PrP, and thus susceptible to CWD, has enhanced detection of CWD and the estimation of prion titers (Browning et al. 2004; Tamgüney et al. 2006). Shedding of prions in the feces, even in presymptomatic deer, has been identified as a likely source of infection for these grazing animals (Williams and Miller 2002; Tamgüney et al. 2009b). CWD has been transmitted to cattle after intracerebral inoculation, although the infection rate was low (4 of 13 animals [Hamir et al. 2001]). This finding raised concerns that CWD prions might be transmitted to cattle grazing in contaminated pastures.
 
snip...
 
 
 
 
----- Original Message -----
 
From: David Colby To: flounder9@verizon.net
 
Cc: stanley@XXXXXXXX
 
Sent: Tuesday, March 01, 2011 8:25 AM
 
Subject: Re: FW: re-Prions David W. Colby1,* and Stanley B. Prusiner1,2 + Author Affiliations
 
Dear Terry Singeltary,
 
Thank you for your correspondence regarding the review article Stanley Prusiner and I recently wrote for Cold Spring Harbor Perspectives. Dr. Prusiner asked that I reply to your message due to his busy schedule. We agree that the transmission of CWD prions to beef livestock would be a troubling development and assessing that risk is important. In our article, we cite a peer-reviewed publication reporting confirmed cases of laboratory transmission based on stringent criteria. The less stringent criteria for transmission described in the abstract you refer to lead to the discrepancy between your numbers and ours and thus the interpretation of the transmission rate. We stand by our assessment of the literature--namely that the transmission rate of CWD to bovines appears relatively low, but we recognize that even a low transmission rate could have important implications for public health and we thank you for bringing attention to this matter.
 
Warm Regards, David Colby -- David Colby, PhD
 
Assistant Professor Department of Chemical Engineering University of Delaware
 
 
===========END...TSS==============
 
 
SNIP...SEE FULL TEXT ;
 
 
 
 
UPDATED DATA ON 2ND CWD STRAIN
 
Wednesday, September 08, 2010
 
CWD PRION CONGRESS SEPTEMBER 8-11 2010
 
 
 
 
never say never with the potential transmission of one of the strains of CWD transmitting to cattle OR humans, OR ANY OTHER SPECIES. ...TSS
 
 
Wednesday, September 04, 2013
 
***cwd - cervid captive livestock escapes, loose and on the run in the wild...
 
 
 
*** The potential impact of prion diseases on human health was greatly magnified by the recognition that interspecies transfer of BSE to humans by beef ingestion resulted in vCJD. While changes in animal feed constituents and slaughter practices appear to have curtailed vCJD, there is concern that CWD of free-ranging deer and elk in the U.S. might also cross the species barrier. Thus, consuming venison could be a source of human prion disease. Whether BSE and CWD represent interspecies scrapie transfer or are newly arisen prion diseases is unknown. Therefore, the possibility of transmission of prion disease through other food animals cannot be ruled out. There is evidence that vCJD can be transmitted through blood transfusion. There is likely a pool of unknown size of asymptomatic individuals infected with vCJD, and there may be asymptomatic individuals infected with the CWD equivalent. These circumstances represent a potential threat to blood, blood products, and plasma supplies.
 
 
 
Prion2013 Chronic Wasting Disease CWD risk factors, humans, domestic cats, blood, and mother to offspring transmission
 
 
HD.13: CWD infection in the spleen of humanized transgenic mice
 
Liuting Qing and Qingzhong Kong
 
Case Western Reserve University; Cleveland, OH USA
 
Chronic wasting disease (CWD) is a widespread prion disease in free-ranging and captive cervid species in North America, and there is evidence suggesting the existence of multiple CWD strains. The susceptibility of human CNS and peripheral organs to the various CWD prion strains remains largely unclear. Current literature suggests that the classical CWD strain is unlikely to infect human brain, but the potential for peripheral infection by CWD in humans is unknown. We detected protease-resistant PrpSc in the spleens of a few humanized transgenic mice that were intracerebrally inoculated with natural CWD isolates, but PrpSc was not detected in the brains of any of the CWD-inoculated mice. Our ongoing bioassays in humanized Tg mice indicate that intracerebral challenge with such PrpSc-positive humanized mouse spleen already led to prion disease in most animals. These results indicate that the CWD prion may have the potential to infect human peripheral lymphoid tissues.
 
=====
 
 
HD.12: Comparative study of the distribution of the prion protein in the squirrel monkey (Saimiri sciureus) following experimental challenge with variant and sporadic CJD
 
Diane L. Ritchie,1 Paul Brown,2 Susan Gibson,3 Thomas R. Kreil,4 Christian Abee3 and James W. Ironside1
 
1National CJD Surveillance Unit; Edinburgh, UK; 2Bethesda; Bethesda, MD USA; 3Deparment of Comparative Medicine; University of South Alabama; Mobile, AL USA; 4Baxter Bioscience; Vienna, Austria
 
Introduction, Reports suggest that the number of tissues and organs showing the presence of the abnormal prion protein (PrPTSE) in variant CJD (vCJD) patients may be greater than previously thought. A limited peripheral involvement in some cases of sporadic CJD (sCJD) has also been reported. This accumulation of PrPTSE outside the brain has raised concerns about the possible iatrogenic transmission risk of vCJD. The squirrel monkey (Saimiri sciureus) has been shown to be highly susceptible to experimental challenge with human prion disease. Neuropathological and biochemical analyses of CNS tissue have shown that sCJD and vCJD can be distinguished in the squirrel monkey and that many of the strain characteristics that define these agents are conserved after transmission. Following on from these initial studies, immunohistochemistry and western blot analysis were performed on a wide range of peripheral tissues including, lymphoreticular tissues and peripheral neural tissue to establish the full-body distribution of PrPTSE in this primate animal model.
 
Materials and Methods. Brain homogenates from sCJD or vCJD patients were inoculated into the frontal cortex of squirrel monkeys. Animals were kept under constant clinical surveillance. At post-mortem, formalin fixed CNS tissue and a wide range of peripheral tissues were taken for immunohistochemical analysis together with frozen tissues taken for the biochemical detection of PrPTSE.
 
Results. Immunohistochemical analysis showed no evidence of PrPTSE deposition in peripheral tissues in either variant or sporadic CJD-infected animals. However, western blot assays detected PrPTSE in the spleen of a proportion of the vCJD- infected animals. The PrPTSE isotype resembled that detected in CNS tissue from the vCJD- infected animals and from human vCJD cases. ***In addition, western blot analysis detected PrPTSE in the spleen of a single animal following challenge with sporadic CJD. The PrPTSE type in this animal resembled that found in CNS tissue from the same animal, with a PrPTSE type similar to that found in human sCJD type 1 cases.
 
Conclusion. This study confirms the accumulation of PrPTSE in the CNS and spleen of a proportion of squirrel monkeys infected intra-cerebrally with human vCJD. Furthermore, this study extends the evidence that there may be a peripheral involvement in some cases of sCJD. PrPTSE typing confirms the conservation of PrPTSE type on transmission to the squirrel monkey and suggests that there are no tissue-specific adaptations in the biochemical phenotype of the agent strain following primate-to-primate transmission.
 
=====
 
 
Oral.15: Molecular barriers to zoonotic prion transmission: Comparison of the ability of sheep, cattle and deer prion disease isolates to convert normal human prion protein to its pathological isoform in a cell-free system
 
Marcelo A.Barria,1 Aru Balachandran,2 Masanori Morita,3 Tetsuyuki Kitamoto,4 Rona Barron,5 Jean Manson,5 Richard Kniqht,1 James W. lronside1 and Mark W. Head1
 
1National CJD Research and Surveillance Unit; Centre for Clinical Brain Sciences; School of Clinical Sciences; The University of Edinburgh; Edinburgh, UK; 2National and OIE Reference Laboratory for Scrapie and CWD; Canadian Food Inspection Agency; Ottawa Laboratory; Fallowfield. ON Canada; 3Infectious Pathogen Research Section; Central Research Laboratory; Japan Blood Products Organization; Kobe, Japan; 4Department of Neurological Science; Tohoku University Graduate School of Medicine; Sendai. Japan; 5Neurobiology Division; The Roslin Institute and R(D)SVS; University of Edinburgh; Easter Bush; Midlothian; Edinburgh, UK
 
Background. Bovine spongiform encephalopathy (BSE) is a known zoonotic prion disease, resulting in variant Creurzfeldt- Jakob disease (vCJD) in humans. In contrast, classical scrapie in sheep is thought to offer little or no danger to human health. However, a widening range of prion diseases have been recognized in cattle, sheep and deer. The risks posed by individual animal prion diseases to human health cannot be determined a priori and are difficult to assess empirically. The fundamemal event in prion disease pathogenesis is thought to be the seeded conversion of normal prion protein (PrPC) to its pathological isoform (PrPSc). Here we report the use of a rapid molecular conversion assay to test whether brain specimens from different animal prion diseases are capable of seeding the conversion of human PrPC ro PrPSc.
 
Material and Methods. Classical BSE (C-type BSE), H-type BSE, L-type BSE, classical scrapie, atypical scrapie, chronic wasting disease and vCJD brain homogenates were tested for their ability to seed conversion of human PrPC to PrPSc in protein misfolding cyclic amplification (PMCA) reactions. Newly formed human PrPSc was detected by protease digestion and western blotting using the antibody 3F4.
 
Results. C-type BSE and vCJD were found to efficiently convert PrPC to PrPSc. Scrapie failed to convert human PrPC to PrPSc. Of the other animal prion diseases tested only chronic wasting disease appeared to have the capability ro convert human PrPC to PrPSc. The results were consistent whether the human PrPC came from human brain, humanised transgenic mouse brain or from cultured human cells and the effect was more pronounced for PrPC with methionine at codon 129 compared with that with valine.
 
Conclusion. Our results show that none of the tested animal prion disease isolates are as efficient as C-type BSE and vCJD in converting human prion protein in this in vitro assay. However, they also show that there is no absolute barrier ro conversion of human prion protein in the case of chronic wasting disease.
 
=====
 
 
Invited.16: Studies of chronic wasting disease transmission in cervid and non-cervid species
 
Edward A, Hoover,1 Candace K. Mathiason,1 Davin M. Henderson,1 Nicholas J. Haley,1 Davis M. Seelig,1 Nathaniel D. Denkers,1 Amy V. Nalls,1 Mark D. Zabe,1 Glenn C. Telling,1 Fernando Goni2 and Thomas Wisniewski,2
 
1Prion Research Center; Colorado State University; Fort Collins, CO USA; 2New York University School of Medicine; New York, NY USA
 
How and why some misfolded proteins become horizontally transmitted agents and occasionally cross species barriers are issues fundamental to understanding prion disease. Chronic wasting disease (CWD) of cervids is perhaps a prototype of horizontal prion transmission, encompassing efficient mucosal uptake, lymphoid amplification, neuroinvasion, peripheralization, and dissemination via mucosal excretion. Efficient mucosal transmission of CWD in deer has been demonstrated by oral, nasal, aerosol, and indirect contact exposure. In addition, other studies (Mathiason CK, et al.) reported at the symposium support a significant role for pre- and/or postnatal transmission of CWD from doe to offspring. Accumulating, yet still incomplete, evidence also suggests that the period of relatively covert CWD infection may be longer than originally thought. Given the above, minimally invasive sensitive assays based on body fluids from live animals would aid substantially in understanding the biology of CWD. We have been applying seeded realtirne quaking-induced amplification of recombinant PrP substrates (i.e., RT-QuIC methodology) to: (1) investigate antemortem CWD detection, and (2) model PrP-based species barriers and trans-species adaptation-topics we previously explored using sPMCA and in vivo bioassays. At this symposium, we report sensitive and specific detection CWD prions in saliva, urine, blood (Mathiason lab), and rectal and pharyngeal lymph node samples (Haley NJ, et al.) from pre-symptomatic and symptomatic experimentally and naturally exposed deer. Other ongoing studies are employing RT-QuIC methodology to model amplification barriers among CWD, FSE, BSE, and CJD prions using cervine, feline, bovine, human, and promiscuous rPrP substrates and the above species prion seeds, cellular co-factors, and transgenic mice. Finally, in collaboration with the Wisniewski laboratory, we are conducting of experimental CWD vaccination studies in deer employing oral administration of an attenuated Salmonella vector expressing cervid PrP epitopes.
 
=====
 
 
AD.06: Detecting prions in the brain and blood of TSE-infected deer and hamsters
 
Alan Elder,1 Davin Henderson,1 Anca Selariu,1 Amy Nalls,1 Byron Caughey,2 Richard Bessen,1 Jason Bartz3 and Candace Mathiason1
 
1Colorado State University; Fort Collins, CO USA; 2NIH Rocky Mountain Laboratories; Hamilton, MT USA; 3Creighton University; Omaha, NE USA
 
While large quantities of protease resistant prion protein (PrPres) can be demonstrated by western blot or IHC in lymphoid biopsies or post-mortem brain tissues harvested from prion-infected animals, these conventional assays are less reliable as means to detect the small quantities of prions thought to be present in bodily fluids or associated with early and asymptomatic phases of TSE disease. The Real Time-Quaking Induced Conversion (RT-QuIC) assay is capable of detecting prions at concentrations below the level of sensitivity of conventional assays and provides a real-time fluorescent readout negating the use of proteases. We have made modifications to the RT-QuIC assay to utilize it for the detection of PrPres in brain and blood harvested from various species infected with prions. In this study, we analyzed CWD-infected deer and CWD/TME-infected hamster whole blood to determine the effect of:
 
(1) various anticoagulants,
 
(2) freezing and
 
(3) NaPTA precipitation.
 
Brain tissue and blood collected from naive deer and hamsters served as negative controls.
 
We were able to demonstrate amplifiable prions in
 
(1) brain and blood samples harvested from CWD/TME-infected animals,
 
(2) heparinized blood,
 
(3) frozen vs. fresh blood and
 
(4) NaPTA treated samples.
 
The RT-QuIC assay is able to detect PrPres in various species of animals and shows promise as an antemortem diagnostic tool for blood-borne TSEs.
 
=====
 
 
Oral.08: Mother to offspring transmission of chronic wasting disease in Reeve's Muntjac deer
 
Amy Nalls,1 Erin McNulty,1 Jenny Powers,2 Davis Seelig,1 Clare Hoover,1 Nicholas Haley,1 Jeanette Hayes-Klug,1 Kelly Anderson,1 Paula Stewart,3 Wilfred Goldmann,3 Edward A. Hoover1 and Candace K. Mathiason1
 
1Colorado State University; Fort Collins, CO USA; 2National Park Service; Fort Collins, CO USA; 3The Roslin Institute and Royal School of Veterinary Studies; Edinburgh, UK
 
To investigate the role mother to offspring transmission plays in chronic wasting disease (CWD), we have developed a cervid model employing the Reeve's muntjac deer (Muntiacus reevesi). Eight muntjac doe were orally inoculated with CWD and tested PrPCWD lymphoid positive by 4 mo post infection. Fourteen fawns were born to these eight CWD-infected doe-3 were born viable, 6 were born non-viable and 5 were harvested as fetuses from early or end-stage CWD-infected doe. All three viable fawns have demonstrated CWD IHC lymphoid biopsy positivity between 43 d post birth and 11 mo post birth. Two of these three CWD positive viable offspring have developed clinical signs consistent with TSE disease (28-33 mo post birth). Moreover, CWD prions have been detected by sPMCA in 11 of 16 tissues harvested from 6 full-term non-viable fawns and in 7 of 11 fetal tissues harvested in utero from the second and third trimester fetuses. Additional tissues and pregnancy related fluids from doe and offspring are being analyzed for CWD prions. In summary, using the muntjac deer model we have demonstrated CWD clinical disease in offspring born to CWD-infected doe, and in utero transmission of CWD from mother to offspring. These studies provide basis to further investigate the mechanisms of maternal transfer of prions.
 
=====
 
 
AD.63: Susceptibility of domestic cats to chronic wasting disease
 
Amy V.Nalls,1 Candace Mathiason,1 Davis Seelig,2 Susan Kraft,1 Kevin Carnes,1 Kelly Anderson,1 Jeanette Hayes-Klug1 and Edward A. Hoover1
 
1Colorado State University; Fort Collins, CO USA; 2University of Minnesota; Saint Paul, MN USA
 
Domestic and nondomestic cats have been shown to be susceptible to feline spongiform encephalopathy (FSE), almost certainly caused by consumption of bovine spongiform encephalopathy (BSE)-contaminated meat. Because domestic and free-ranging nondomestic felids scavenge cervid carcasses, including those in areas affected by chronic wasting disease (CWD), we evaluated the susceptibility of the domestic cat (Felis catus) to CWD infection experimentally. Cohorts of 5 cats each were inoculated either intracerebrally (IC) or orally (PO) with CWD-infected deer brain. At 40 and 42 mo post-inoculation, two IC-inoculated cats developed signs consistent with prion disease, including a stilted gait, weight loss, anorexia, polydipsia, patterned motor behaviors, head and tail tremors, and ataxia, and progressed to terminal disease within 5 mo. Brains from these two cats were pooled and inoculated into cohorts of cats by IC, PO, and intraperitoneal and subcutaneous (IP/SC) routes. Upon subpassage, feline-adapted CWD (FelCWD) was transmitted to all IC-inoculated cats with a decreased incubation period of 23 to 27 mo. FelCWD was detected in the brains of all the symptomatic cats by western blotting and immunohistochemistry and abnormalities were seen in magnetic resonance imaging, including multifocal T2 fluid attenuated inversion recovery (FLAIR) signal hyper-intensities, ventricular size increases, prominent sulci, and white matter tract cavitation. Currently, 3 of 4 IP/SQ and 2 of 4 PO inoculared cats have developed abnormal behavior patterns consistent with the early stage of feline CWD. These results demonstrate that CWD can be transmitted and adapted to the domestic cat, thus raising the issue of potential cervid-to- feline transmission in nature.
 
 
 
 
Sunday, July 21, 2013
 
*** As Chronic Wasting Disease CWD rises in deer herd, what about risk for humans?
 
 
 
 
*** PRION2013 ***
 
 
Sunday, August 25, 2013
 
Prion2013 Chronic Wasting Disease CWD risk factors, ***humans, domestic cats, blood, and mother to offspring transmission
 
 
 
Prion2013
 
 
Friday, August 09, 2013
 
***CWD TSE prion, plants, vegetables, and the potential for environmental contamination
 
 
 
Uptake of Prions into Plants
 
 
 
Wednesday, September 04, 2013
 
*** cwd - cervid captive livestock escapes, loose and on the run in the wild...
 
 
 
Thursday, August 08, 2013
 
*** Characterization of the first case of naturally occurring chronic wasting disease in a captive red deer (Cervus elaphus) in North America
 
 
 
*** The discovery of previously unrecognized prion diseases in both humans and animals (i.e., Nor98 in small ruminants) demonstrates that the range of prion diseases might be wider than expected and raises crucial questions about the epidemiology and strain properties of these new forms. We are investigating this latter issue by molecular and biological comparison of VPSPr, GSS and Nor98.
 
 
Saturday, July 6, 2013
 
*** Small Ruminant Nor98 Prions Share Biochemical Features with Human Gerstmann-Sträussler-Scheinker Disease and Variably Protease-Sensitive Prionopathy
 
Research Article
 
 
 
 
Saturday, November 02, 2013
 
OREGON DETECTS SCRAPIE
 
Sheep disease pops up in Douglas County; 300 animals euthanized
 
 
 
 
Friday, July 26, 2013
 
Voluntary Scrapie Program USA UPDATE July 26, 2013 increase in FY 2013 is not statistically meaningful due to the sample size
 
 
 
 
Wednesday, October 09, 2013
 
*** WHY THE UKBSEnvCJD ONLY THEORY IS SO POPULAR IN IT'S FALLACY, £41,078,281 in compensation REVISED ***
 
 
 
Thursday, October 10, 2013
 
*** CJD REPORT 1994 increased risk for consumption of veal and venison and lamb ***
 
 
 
Monday, October 14, 2013
 
*** Researchers estimate one in 2,000 people in the UK carry variant CJD proteins ***
 
 
 
Friday, August 16, 2013
 
*** Creutzfeldt-Jakob disease (CJD) biannual update August 2013 U.K. and Contaminated blood products induce a highly atypical prion disease devoid of PrPres in primates
 
 
 
WHAT about the sporadic CJD TSE proteins ?
 
WE now know that some cases of sporadic CJD are linked to atypical BSE and atypical Scrapie, so why are not MORE concerned about the sporadic CJD, and all it’s sub-types $$$
 
 
Sunday, August 11, 2013
 
Creutzfeldt-Jakob Disease CJD cases rising North America updated report August 2013
 
*** Creutzfeldt-Jakob Disease CJD cases rising North America with Canada seeing an extreme increase of 48% between 2008 and 2010
 
 
 
Sunday, October 13, 2013
 
CJD TSE Prion Disease Cases in Texas by Year, 2003-2012
 
 
 
Sunday, September 08, 2013
 
Iatrogenic Creutzfeldt-Jakob disease via surgical instruments and decontamination possibilities for the TSE prion
 
 
 
Thursday, September 26, 2013
 
Minimise transmission risk of CJD and vCJD in healthcare settings Guidance
 
 
 
Sunday, June 9, 2013
 
TSEAC March 14, 2013: Transmissible Spongiform Encephalopathies Advisory Committee Meeting Webcast
 
 
 
Tuesday, May 28, 2013
 
Late-in-life surgery associated with Creutzfeldt-Jakob disease: a methodological outline for evidence-based guidance
 
 
 
*** U.S.A. 50 STATE BSE MAD COW CONFERENCE CALL Jan. 9, 2001 ***
 
 
 
 
Tuesday, March 05, 2013
 
A closer look at prion strains Characterization and important implications Prion
 
7:2, 99–108; March/April 2013; © 2013 Landes Bioscience
 
 
 
 
Number 41 January 2009
 
*** Ruminant Carcass Disposal Options for Routine and Catastrophic Mortality ***
 
An optimal disposal method should mitigate the disease agent or other cause of mortality. For complete effectiveness, certain disease agents or other causes of mortality may require specific disposal methods or technologies (e.g., high-temperature incineration or alkaline hydrolysis for transmissible spongiform encephalopathy (TSE)-infected material).
 
snip...
 
The disposal of carcasses associated with confirmed mortalities from chronic wasting disease (CWD) in landfill sites is not recommended in the United States at the present time. The behavior of the infectious agent associated with TSEs, the prion, in a landfill presently is not clearly understood. (See Appendix 1, page 14, for more information about disposal of TSE-infected carcasses.) If a catastrophic situation arose in which thousands of diseased carcasses needed to be disposed of in a landfill, the liability likely would have to be accepted and indemnified by the federal government.
 
snip...
 
Fungi and protozoans do not remain active in an anaerobic environment. Discussions about prions in landfills have taken place only recently. In the early stages of the bovine spongiform encephalopathy (BSE) epidemic in the U.K., some BSE-infected carcasses were disposed of in landfill sites before routine incineration was introduced. Most of these sites were unlined municipal solid waste disposal landfills. Nevertheless, a risk assessment carried out for the Environment Agency concluded that the potential risks to people through contaminated drinking water were extremely small. But the fate of prions in landfills and leachate presently is unknown, and no clear method of study or testing exists. There are current studies to address these questions, but the results will not be known for some time. Presently, the majority of landfill owners in the United States are not accepting prion-infected ruminant carcasses for disposal because of (1) the inability to monitor for the long-term viability of prions and (2) potential liability issues. (See Appendix 1 for further information on the disposal of TSE-infected carcasses.)
 
snip...
 
 
Composting also is attractive because it can be performed on-site, eliminating the need to transport infected or potentially infected material during a disease outbreak. It is advisable, however, to consult local and state authorities regarding regulations governing composting of ruminant carcasses; there may be issues with composting carcasses infected with certain biological agents or TSEs. The regulations may describe what can be done with the composted material or may prevent composting altogether.
 
 
Research assessing the environmental impacts and biosecurity issues associated with composting livestock mortalities during an emergency suggests that composting can be a relatively biosecure process when performed properly (Glanville et al. 2006). (See Appendix 1 for a more in-depth discussion of disposal options for TSE-infected carcasses.)
 
 
Table 8. Summary of potential health risks for various methods of handling animal by-products1, 2
 
Exposure of Humans to Hazards from Each Option
 
Disease/Hazardous Agent Rendering Incineration Landfill Pyre Burial
 
Prions for BSE, scrapie3 Moderate Very small Moderate Moderate High
 
Rendering, Incineration, Landfill, Pyre, Burial
 
Moderate, Very small, Moderate, Moderate, High
 
3Risk of human exposure to TSEs was rated as very small when solid products of rendering were incinerated
 
 
snip...
 
 
Comparisons Open-air burning can be relatively inexpensive, but it is not suitable for destroying prions of TSE-infected carcasses. The method is dependent on weather and fuel availability, has the potential for environmental contamination, and may pose a problem for public acceptance. Fixed-facility incineration is capable of effectively destroying prions of TSE-infected carcasses and is highly biosecure (Kastner and Phebus 2004; TAHC 2005). Disadvantages of fixedfacility incineration are limited availability, high cost of operation, necessity of transporting carcasses to the facility, difficulty of securing local licensure or allowance, and inability of equipment to burn large volumes of carcasses. Air-curtain incineration is mobile and relatively environmentally acceptable. In addition, this method is suitable for combination with combustible debris removal, such as downed trees from weather-related damage, if dry. Air-curtain incinerators are fuel intensive and require experienced personnel operators. Currently, open air-curtain incinerators are not validated to dispose of TSE-infected carcasses safely.
 
snip...
 
Alkaline Hydrolysis
 
Description of Process
 
Alkaline hydrolysis is a natural process by which complex molecules are broken down into the constituent small molecules from which they were synthesized. The process of alkaline hydrolysis occurs through the action of the hydroxyl ions (OH¯) on the bonds connecting the small molecules. This process occurs in nature when animal tissues and carcasses are buried in soil of neutral or alkaline (high) pH, aided by the digestive processes of soil organisms. In digestion, alkaline hydrolysis is the primary process whereby the complex molecules of proteins, fats, and nucleic acids are broken down in the small intestine into small nutrient molecules that are absorbed by the intestinal cells. Alkaline hydrolysis for carcass disposal is based on the same chemical reaction, with strong alkali and heat used to speed the process.
 
The current process for application of alkaline hydrolysis to the disposal of animal carcasses and tissues—including infectious and radioactive tissues, carcasses, and biohazardous and hazardous materials— dates back to 1992. The method was introduced for the release of radionuclides from experimental animal carcasses so that this type of low-level radioactive waste could be disposed of safely and economically (Kaye, Methe, and Weber 1993; Kaye and Weber 1994). Subsequently, the method was applied to the disposal of other research animals and infectious human and animal tissues and carcasses. Equipment is commercially available for disposal of animal carcasses by this process.
 
In the simplest current application, whole animal carcasses and tissues are loaded into a stainless steel, steam-heated pressure vessel. Once the vessel is loaded and the lid is sealed, an appropriate amount of concentrated alkali solution and water are added. The vessel is heated to 302ºF (150ºC) and maintained at that temperature for a minimum of 3 hours (depending on the target pathogen, vessel, and carcass sizes) and up to 6 hours for destruction of prions. At the end of the process, the hydrolyzate— a solution of amino acids, small peptides, sugars, soaps, and electrolytes— is cooled and drained, leaving only “bone shadows” (i.e., the pure calcium phosphate remains of bones and teeth from which all the collagen has been digested). The hydrolyzate is a resource that can be used directly as liquid fertilizer, dried or absorbed to make a dry fertilizer, used as feedstock for anaerobic fermentation biogas generation, or further treated to precipitate the lipid components for subsequent conversion to biodiesel, still leaving the nutrient solution for other uses.
 
Alkaline hydrolysis leads to the random breaking of nearly 40% of all peptide bonds in proteins, the major solid constituent of animal cells and tissues. Under the extreme conditions of high temperature and alkali concentration, the protein coats of viruses are destroyed and the peptide bonds of prions are broken. Validation testing has demonstrated that all pathogens in animal tissue (Kaye et al. 1998), including prions, are completely destroyed under the combined operating conditions of heat, moisture, and pH.
 
Alkaline hydrolysis has been written into European Union Animal By-Products legislation as the only alternative technology approved for all categories of animal by-products, including the most highly infectious and prion-contaminated material (EC 2005).
 
Types of Systems
 
Alkaline hydrolysis systems may be fixed or mobile. The capacity of currently available equipment is up to 10,000 lb/cycle for fixed systems and 4,000 lb/cycle for mobile systems. Designs are available, however, for systems that combine pulverization and initial steam disinfection with the tissue destruction and resource conservation capability of mobile systems capable of processing more than 25,000 lb/hr.
 
Fixed-base and mobile systems currently are able to handle the routine disposal of infectious and suspect animal carcasses and tissues brought to state and federal veterinary diagnostic laboratories. These systems also could serve for disposal of materials, such as specified risk material, at livestock processing facilities.
 
Since 2004, a single 4,000 lb-capacity mobile system has been used to dispose of more than one million pounds of deer confirmed or suspected of having CWD, a TSE, in a depopulation program near Madison, Wisconsin.
 
It is important to distinguish between the issues related to disposal of routine infectious and TSE-infected or suspect animals and the issues related to disposal in mass animal epidemics or other catastrophic situations. Fixed-base systems are able to handle routine and TSE material because the volumes are relatively small. Also, TSE outbreaks can be managed by isolation and transport of the affected animals without risk to noninfected animals. In mass animal epidemics or natural disasters, however, disposal often must take place at the site of the outbreak and be done quickly to prevent spread of infectious disease; for these situations, mobile systems can be used. The hydrolyzate from such a system is only partly hydrolyzed; it exits the system as slurry into a tanker truck or rail tank car in which hydrolysis continues until the hydrolyzate is emptied into a fertilizer storage trench, fed into a biogas generation system, field spread, or otherwise processed for resource recovery.
 
Fixed-base systems generally use institutional steam supplies for heating the vessels and domestic water for filling and cooling. Mobile systems require “slave trucks” carrying diesel or propane-fired electrical and steam generators, as well as alkali and water (if needed). In theory, a fleet of large volume mobile comminution-disinfection- digestion systems, strategically distributed around the country in a sort of “fire station” pattern, could be gathered on short notice to deal with mass animal disposals. When not in use in emergency situations, these units could be kept operable and their operators trained by using the units for routine depopulations of avian and ruminant livestock and control of small outbreaks. The fixed-base units would always be in use for disposal of animal carcasses and tissues after routine necropsy and diagnostic procedures.
 
 
snip...
 
Appendix 1: Special Considerations for Material Potentially Infected with TSEs
 
Introduction to TSEs
 
Transmissible spongiform encephalopathies
 
(TSEs) are a group of rare neurodegenerative diseases, sometimes called prion diseases, that can affect both animals and humans. The discovery of prion-related cattle diseases in England between 1986 and 2002 changed the disposal industry’s perception of the risk involved in disposing of even a small number of ruminant carcasses (Karesh and Cook 2005). The occurrence of bovine spongiform encephalopathy (BSE) in England changed policies in the United States as well, even though there have been only two cases of BSE identified in the United States (OIE 2008) and a relatively small number of TSEs identified in other susceptible species.
 
The main characteristics of TSE diseases are
 
• Progressive debilitating neurological illness that is always fatal
 
• Spongiform change in grey matter areas of the brain
 
• Long incubation period of months to several years
 
• No detectable specific immune response in the host.
 
These diseases are experimentally transmissible and some (e.g., familial Creutzfeldt-Jakob Disease [CJD], Gerstmann-Sträussler-Scheinker syndrome (GSS), and fatal familial insomnia) are genetically inherited.
 
Types of TSEs
 
There are several forms of TSEs in different animal species and humans.
 
Scrapie is a TSE disease of sheep and goats that has been recognized for more than 200 years and is endemic in North America and many parts of Europe. Despite this occurrence, there has never been any proven association between scrapie in sheep and any human disease. In cattle, BSE first appeared in the U.K. in 1986. There have been approximately 184,000 cases of BSE in the U.K., plus an additional 5,200 cases in 21 other countries. In 1996, the identification of a new form of Creutzfeldt-Jakob Disease (vCJD) in young people in the U.K. raised the concern that the causative agent for BSE had transmitted from cattle to humans. There is strong evidence that this is the case, and it is now generally accepted that vCJD in humans is caused by exposure to material from BSE-infected cattle, although many questions remain about the exact nature of the route of transmission. There are other forms of TSEs in humans; sporadic CJD is the most common. Other TSEs in animals include CWD, present in wild and farmed deer and elk populations in some areas of North America, and transmissible mink encephalopathy that appeared in farmed mink populations.
 
TSEs and Prions
 
The commonly accepted infectious agent for TSEs (generally designated as PrPSc or PrPTSE 3) is a misfolded isoform of a normal cellular protein (PrPc) and is called a prion (Prusiner 1998). The term prion was derived from proteinaceous and infectious and is defined by Prusiner (1998) as a proteinaceous infectious particle that lacks nucleic acid. The normal isoform is soluble and primarily monomeric in solution, whereas the infectious form creates insoluble aggregates. Prions are not deactivated by the normal procedures that would destroy most disease agents. They are resistant to inactivation by heat, chemical disinfection, radiation, and proteolytic enzymes (Taylor 2000). Disposal of prion-infected carcasses requires high heat, is costly, and is not practical.
 
snip...
 
 
Considerations for Specific Disposal Options
 
Burial and Landfill
 
Concerns about worker and public safety, associated with the fate and transport of prions disposed in landfills, have prompted the U.S. disposal industry to reassess the long-term risks of this type of disposal.
 
Analytical methods presently do not exist to quantify the destruction and retention of prions in the landfill mass. The majority of landfill operators will not accept even rendered carcasses that are known to be infected with prions. Discussants and presenters at the National Carcass Disposal Symposium in December 2006 generally agreed that disposal of carcasses potentially infected with TSEs may not be a conservative option (Hater, Hoffman, and Pierce 2006; Lin 2006).
 
There are no data on what might happen to the infective agent in a landfill, although some studies are now in progress. The original limited data on the behavior of a TSE agent when buried in the ground is from a single experiment reported by Brown and Gajdusek (1991); this research has been used to support the assumption that TSE infectivity will degrade in the ground. Comer and colleagues (1998) indicated that 98% of TSE infectivity will degrade in the ground over 3 years (or longer). The results also showed only limited leaching, with most of the residual infectivity remaining in the originally contaminated soil. Johnson and colleagues (2006) have studied the interaction of PrPTSE with common soil minerals and soils. They showed that PrPTSE can bind strongly to soils and could be difficult to desorb, and they found that the PrPTSE bound to the soil particles remained infectious. Leita and colleagues (2006) also showed that PrPTSE was absorbed in all three soil types tested. More recently, Seidel and colleagues (2007) have shown that the scrapie agent can transmit disease by the oral route after persistence in soil for up to 29 months. The change in infectivity over time was not measured, but Western blot analysis clearly showed a marked decrease in the strength of the target protein after one month and further decrease over time up to 29 months.
 
The Institute for Animal Health in Edinburgh currently is conducting a study of the behavior of infectivity in carcasses buried in the ground. An initial report was given at Prion 2006 (Fernie et al. 2006), which stated that TSE infectivity may bind strongly to soil components and has very limited mobility in soils with controlled rates of water percolation.
 
These results and the biophysical properties of the prion protein suggest that any infectivity released from decaying animal material is likely to remain bound to solid matter in the landfill and, thus, is unlikely to be present in the leachate. With current knowledge, however, it is not possible to be certain that TSE infectivity could not be present at some level in leachate.
 
A number of risk assessment studies have considered the risks from TSE material deposited in landfill sites or by burial. Not all these studies are in the public domain, but they have shown that the potential risk to people or other livestock through contamination of drinking water is extremely small (DNV 1997a, 2001b).
 
Isolation using macro-encapsulation in the landfill is an option for TSE-related deaths. Macroencapsulation, however, is an unusual practice in subtitle D landfills and does add significant costs to landfill disposal. Current research may determine whether the additional costs are justified.
 
 
Rendering
 
Research has demonstrated that rendering lowers the infectivity of prions, but no currently available rendering processes totally inactivate the prions (Taylor, Woodgate, and Atkinson 1995). Cohen and colleagues (2001) reported that batch rendering systems achieved a 1,000- fold reduction in BSE infectivity, whereas continuous systems with and without fat recycling reduced infectivity 100-fold and 10-fold, respectively. Because rendering does not totally inactivate prion infectivity, any product from the disposal of TSEdiseased carcasses should not be used in animal feeds.
 
There may be other practical difficulties with rendering as an option for prion-contaminated materials. As was found during the 2001 FMD outbreak in the U.K.—when rendering was regarded as the preferred option— rendering facilities may already have existing functions and requirements, limiting their capacity. In addition, rendering plants may rely on the sale of meat and bone meal and tallow as part of their production cycle; use of those end products would almost certainly cease to be an option if there was risk of TSE-agent contamination in them.
 
Composting
 
Presently, no work has been done to demonstrate TSE-agent inactivation by composting. There has been some laboratory work related to prion destruction by specific enzymes, but no field research has been done involving the addition of such enzymes to composting operations.
 
Certain challenges exist in using composting for prion disposal, including (1) the need for some form of enclosed vessel to avoid environmental contamination and to prevent scavenger access, (2) the need for complete mixing, (3) potential difficulties in accessing neural tissue encased within bone (skull and spinal cord), and (4) ensuring the correct conditions are maintained (e.g., temperature and levels of microbial degradation).
 
Incineration
 
Incineration is one of the most effective techniques for removal of infectivity from prion-contaminated material. Disadvantages, however, include the large energy requirement, environmental concerns, location of incinerators, and the need to ensure a consistent and complete burn.
 
Incinerators vary from small animal incinerators, used to dispose of small amounts of material, to large commercial operations, or even to power station furnaces used to dispose of the products of rendering. Analysis of the ash for protein content after incineration of BSE-infected carcasses suggests that prion infectivity is reduced by at least 1 million-fold (DNV 1997b, 2001a). Some facilities in the U.K. currently use fixed gasification units for processing carcasses that potentially contain prions. Research continues in the United States on similar portable gasification equipment that should offer a daily capacity of more than 25 tons per unit.
 
Alkaline Hydrolysis
 
The alkaline hydrolysis process has been through a validation study by the Institute of Animal Health, and an Opinion has been issued by the Scientific Steering Committee of the European Commission (EC 2002) on the effectiveness of the process. There was detectable infectivity from samples held for 3 hours, but not from samples held for 6 hours. The committee concluded that the by-products after 3 hours of processing could contain some residual TSE infectivity and that this risk may decrease with increased duration of processing.
 
Glossary
 
snip...see ;
 
 
 
 
Alkaline Hydrolysis
 
 
 
 
 
 
 
========================================
 
 
There are many disposal options for dead livestock currently in use throughout the world; however, the knowledge that TSEs and some pathogens may not be completely destroyed may limit their utility in the wake of changing legislation (e.g. the amended EU Animal By-Products Regulation (1069/2009) which comes into effect in March 2011). On-farm disposal methods are favoured by the farming community due to the perceived environmental, practical, economical and biosecurity benefits, therefore processes such as composting and anaerobic digestion have found favour in countries such as the USA and Canada. Under the ABPR in the EU, these options are not deemed safe;
 
 
========================================
 
 
Review
 
The environmental and biosecurity characteristics of livestock carcass disposal methods: A review
 
Ceri L. Gwyther a, A. Prysor Williams a,⇑, Peter N. Golyshin b, Gareth Edwards-Jones a, David L. Jones a a School of Environment, Natural Resources and Geography, College of Natural Sciences, Bangor University, Gwynedd, LL57 2UW, UK b School of Biological Sciences, College of Natural Sciences, Bangor University, Gwynedd, LL57 2UW, UK
 
a b s t r a c t
 
Livestock mortalities represent a major waste stream within agriculture. Many different methods are used throughout the world to dispose of these mortalities; however within the European Union (EU) disposal options are limited by stringent legislation. The legal disposal options currently available to EU farmers (primarily rendering and incineration) are frequently negatively perceived on both practical and economic grounds. In this review, we assess the potential environment impacts and biosecurity risks associated with each of the main options used for disposal of livestock mortalities in the world and critically evaluate the justification for current EU regulations. Overall, we conclude that while current legislation intends to minimise the potential for on-farm pollution and the spread of infectious diseases (e.g. transmissible spongiform encephalopathies, bacterial pathogens), alternative technologies (e.g. bioreduction, anaerobic digestion) may provide a more cost-effective, practical and biosecure mechanism for carcass disposal as well as having a lower environmental footprint. Further social, environmental and economic research is therefore warranted to assess the holistic benefits of alternative approaches for carcass disposal in Europe, with an aim to provide policy-makers with robust knowledge to make informed decisions on future legislation.
 
snip...
 
4. Conclusions
 
There are many disposal options for dead livestock currently in use throughout the world; however, the knowledge that TSEs and some pathogens may not be completely destroyed may limit their utility in the wake of changing legislation (e.g. the amended EU Animal By-Products Regulation (1069/2009) which comes into effect in March 2011). On-farm disposal methods are favoured by the farming community due to the perceived environmental, practical, economical and biosecurity benefits, therefore processes such as composting and anaerobic digestion have found favour in countries such as the USA and Canada. Under the ABPR in the EU, these options are not deemed safe; however, the legal alternatives are not favoured by the farming community leading to widespread non-compliance and potentially greater environmental risk (due to illegal dumping, etc. (Kirby et al., 2010)). There is therefore a real need for new methods to be developed and validated and the legislation reconsidered following submission of new evidence. From this perspective, bioreduction and freezing seems to be promising on-farm storage methods for livestock mortalities, limiting the need for offfarm transport thus reducing associated biosecurity risks. While the implementation of highly precautionary, risk-averse mortality disposal systems is admirable in many ways, similar risk assessments and legislation do not apply to other components of the livestock sector which may pose a similar or even greater risk to human health or environmental contamination (e.g. spreading of animal waste, animal access to watercourses, public access to grazing land). It is important therefore that mortality disposal systems are based on a realistic and proportionate level of acceptable risk in comparison to other components of the food chain, rather than the current zero-risk approach. It is clear that more evidence is needed on each disposal and storage method in order to make substantiated risk assessments, e.g. the effects of spreading carcass ash on crops or the potential of leachate from burial to contaminate ground or surface water. This review has initiated this process by applying a simple five-star award system to each livestock disposal and storage method (Table 3 and Table 4, respectively) in order to rudimentarily classify various biosecurity and environmental factors based on current scientific evidence. Methods in need of greater research have also been highlighted where there is either limited or no existing published literature. Further research into the economic impacts of dead livestock disposal is necessary for legislators to appreciate the cost implications on the livestock sector, whilst life-cycle assessments are needed to help provide more environmentally sustainable disposal solutions.
 
 
 
 
 
OPINION AND REPORT ON : THE TREATMENT OF ANIMAL WASTE BY MEANS OF HIGH TEMPERATURE (150°C, 3 HOURS) AND CORRESPONDING HIGH PRESSURE ALKALINE HYDROLYSIS.
 
ADOPTED BY THE SCIENTIFIC STEERING COMMITTEE AT ITS MEETING OF 16 MAY 2002
 
 
 
 
 
 
FINAL OPINION AND REPORT ON : A TREATMENT OF ANIMAL WASTE BY MEANS OF HIGH TEMPERATURE (150°C, 3 HOURS) AND HIGH PRESSURE ALKALINE HYDROLYSIS.
 
ADOPTED BY THE SCIENTIFIC STEERING COMMITTEE AT ITS MEETING OF 10-11 APRIL 2003
 
 
 
 
 
BSE INQUIRY 1989 TO ...
 
 
The BSE Inquiry / Statement No 19B (supplementary) Dr Alan Colchester Issued 06/08/1999 (not scheduled to give oral evidence)
 
SECOND STATEMENT TO THE BSE INQUIRY
 
Dr A Colchester BA BM BCh PhD FRCP Reader in Neurosciences & Computing, University of Kent at Canterbury; Consultant Neurologist, Guy’s Hospital London and William Harvey Hospital Ashford April 1999
 
snip...
 
88. Natural decay: Infectivity persists for a long time in the environment. A study by Palsson in 1979 showed how scrapie was contracted by healthy sheep, after they had grazed on land which had previously been grazed by scrapie-infected sheep, even though the land had lain fallow for three years before the healthy sheep were introduced. Brown also quoted an early experiment of his own (1991), where he had buried scrapie-infected hamster brain and found that he could still detect substantial infectivity three years later near where the material had been placed. 89. Potential environmental routes of infection: Brown discusses the various possible scenarios, including surface or subsurface deposits of TSE-contaminated material, which would lead to a build-up of long-lasting infectivity. Birds feeding on animal remains (such as gulls visiting landfill sites) could disperse infectivity. Other animals could become vectors if they later grazed on contaminated land. "A further question concerns the risk of contamination of the surrounding water table or even surface water channels, by effluents and discarded solid wastes from treatment plants. A reasonable conclusion is that there is a potential for human infection to result from environmental contamination by BSE-infected tissue residues. The potential cannot be quantified because of the huge numbers of uncertainties and assumptions that attend each stage of the disposal process". These comments, from a long established authority on TSEs, closely echo my own statements which were based on a recent examination of all the evidence. 90. Susceptibility: It is likely that transmissibility of the disease to humans in vivo is probably low, because sheep that die from scrapie and cattle that die from BSE are probably a small fraction of the exposed population. However, no definitive data are available.
 
91. Recommendations for disposal procedures: Brown recommends that material which is actually or potentially contaminated by BSE should be: 1) exposed to caustic soda; 2) thoroughly incinerated under carefully inspected conditions; and 3) that any residue should be buried in landfill, to a depth which would minimise any subsequent animal or human exposure, in areas that would not intersect with any potable water-table source.
 
92. This review and recommendations from Brown have particular importance. Brown is one of the world's foremost authorities on TSEs and is a senior researcher in the US National Institutes of Health (NIH). It is notable that such a respected authority is forthright in acknowledging the existence of potential risks, and in identifying the appropriate measures necessary to safeguard public health. Paper by SM Cousens, L Linsell, PG Smith, Dr M Chandrakumar, JW Wilesmith, RSG Knight, M Zeidler, G Stewart, RG Will, "Geographical distribution of variant CJD in the UK (excluding Northern Ireland)". Lancet 353:18-21, 2 nd January 1999 93. The above paper {Appendix 41 (02/01/99)} (J/L/353/18) examined the possibility that patients with vCJD (variant CJD) might live closer to rendering factories than would be expected by chance. All 26 cases of vCJD in the UK with onset up to 31 st August 1998 were studied. The incubation period of vCJD is not known but by analogy with other human TSEs could lie within the range 5-25 years. If vCJD had arisen by exposure to rendering products, such exposure might plausibly have occurred 8-10 years before the onset of symptoms. The authors were able to obtain the addresses of all rendering plants in the UK which were in production in 1988. For each case of vCJD, the distance from the place of residence on 1st January 1998 to the nearest rendering plant was calculated
 
snip...
 
 
 
BSE INQUIRY DATA 1989 through the 1990’s REPORT ON BOVINE CARCASE INCINERATION, incinerations temps., plume, etc. ...tss
 
some unofficial info. from a source on the inside looking out;
 
Confidential!!!!
 
As early as 1992-3 there had been long studies conducted on small pastures containing scrapie infected sheep at the sheep research station associated with the Neuropathogenesis Unit in Edinburgh, Scotland. Whether these are documented...I don't know. But personal recounts both heard and recorded in a daily journal indicate that leaving the pastures free and replacing the topsoil completely at least 2 feet of thickness each year for SEVEN years....and then when very clean (proven scrapie free) sheep were placed on these small pastures.... the new sheep also broke with scrapie and passed it to offspring. I am not sure that TSE contaminated ground could ever be free of the agent!! A very frightening revelation!!!
 
xxxxxxxxxxx
 
you can take that with however many grains of salt you wish, and we can debate these issues all day long, but bottom line, this is not rocket-science, all one has to do is some experiments and case studies, but for the life of me, i don't know what they are waiting on?
 
kind regards, Terry S. Singeltary Sr., Bacliff, Texas USA
 
more here;
 
 
 
 
INCINERATION TEMPS
 
requirements include;
 
a. after burning to the range of 800 to 1000*C to eliminate smell;
 
well heck, this is just typical public relations fear factor control. do you actually think they would spend the extra costs for fuel, for such extreme heat, just to eliminate smell, when they spread manure all over your veg's. i think not. what they really meant were any _TSE agents_.
 
b. Gas scrubbing to eliminate smoke -- though steam may be omitted;
 
c. Stacks to be fitted with grit arreaters;
 
snip...
 
1.2 Visual Imact
 
It is considered that the requirement for any carcase incinerator disign would be to ensure that the operations relating to the reception, storage and decepitation of diseased carcasses must not be publicly visible and that any part of a carcase could not be removed or interfered with by animals or birds.
 
REPORT ON BOVINE CARCASE INCINERATION
 
IF GOD DEMANDED
 
full text;
 
 
 
 
New studies on the heat resistance of hamster-adapted scrapie agent: Threshold survival after ashing at 600Ò à °C suggests an inorganic template of replication
 
Paul Brown*, [dagger ] , Edward H. Rau [Dagger ] , Bruce K. Johnson*, Alfred E. Bacote*, Clarence J. Gibbs Jr.*, and D. Carleton GajdusekÒ à §
 
* Laboratory of Central Nervous System Studies, National Institute of Neurological Disorders and Stroke, and [Dagger ] Environmental Protection Branch, Division of Safety, Office of Research Services, National Institutes of Health, Bethesda, MD 20892; and Ò à § Institut Alfred Fessard, Centre National de la Recherche Scientifique, 91198 Gif sur Yvette, France
 
Contributed by D. Carleton Gajdusek, December 22, 1999
 
Abstract Top Abstract Introduction Materials and Methods Results Discussion References
 
One-gram samples from a pool of crude brain tissue from hamsters infected with the 263K strain of hamster-adapted scrapie agent were placed in covered quartz-glass crucibles and exposed for either 5 or 15 min to dry heat at temperatures ranging from 150Ò à °C to 1,000Ò à °C. Residual infectivity in the treated samples was assayed by the intracerebral inoculation of dilution series into healthy weanling hamsters, which were observed for 10 months; disease transmissions were verified by Western blot testing for proteinase-resistant protein in brains from clinically positive hamsters. Unheated control tissue contained 9.9 log10LD50/g tissue; after exposure to 150Ò à °C, titers equaled or exceeded 6 log10LD50/g, and after exposure to 300Ò à °C, titers equaled or exceeded 4 log10LD50/g. Exposure to 600Ò à °C completely ashed the brain samples, which, when reconstituted with saline to their original weights, transmitted disease to 5 of 35 inoculated hamsters. No transmissions occurred after exposure to 1,000Ò à °C. These results suggest that an inorganic molecular template with a decomposition point near 600Ò à °C is capable of nucleating the biological replication of the scrapie agent.
 
transmissible spongiform encephalopathy | scrapie | prion | medical waste | incineration
 
Introduction Top Abstract Introduction Materials and Methods Results Discussion References
 
The infectious agents responsible for transmissible spongiform encephalopathy (TSE) are notoriously resistant to most physical and chemical methods used for inactivating pathogens, including heat. It has long been recognized, for example, that boiling is ineffective and that higher temperatures are most efficient when combined with steam under pressure (i.e., autoclaving). As a means of decontamination, dry heat is used only at the extremely high temperatures achieved during incineration, usually in excess of 600Ò à °C. It has been assumed, without proof, that incineration totally inactivates the agents of TSE, whether of human or animal origin. It also has been assumed that the replication of these agents is a strictly biological process (1), although the notion of a "virus" nucleant of an inorganic molecular cast of the infectious [beta ] -pleated peptide also has been advanced (2). In this paper, we address these issues by means of dry heat inactivation studies.
 
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GUTTING DEER/ELK AND THOSE THIN GLOVES;
 
Distribution of prion protein in the ileal Peyer?s patch of scrapie-free lambs and lambs naturally and experimentally exposed to the scrapie agent
 
Ragna HeggebÃ’â¬"à ¸1, Charles McL. Press1, Gjermund Gunnes1, Kai Inge Lie1, Michael A. Tranulis2, Martha Ulvund3, Martin H. Groschup4 and Thor Landsverk1
 
Department of Morphology, Genetics and Aquatic Biology1 and Department of Biochemistry, Physiology and Nutrition2, Norwegian School of Veterinary Science, PO Box 8146 Dep., N-0033, Oslo, Norway Department of Sheep and Goat Research, Norwegian School of Veterinary Science, Kyrkjevegen 332/334, 4300 Sandnes, Norway3 Federal Research Centre for Virus Diseases of Animals, Paul-Ehrlich-Str. 28, 72076 TÃ’â¬"à ¼bingen, Germany4
 
Author for correspondence: Charles Press. Fax +47 22964764. e-mail Charles.Press@veths.no
 
A sensitive immunohistochemical procedure was used to investigate the presence of prion protein (PrP) in the ileal Peyer?s patch of PrP-genotyped lambs, including scrapie-free lambs and lambs naturally and experimentally exposed to the scrapie agent. The tyramide signal amplification system was used to enhance the sensitivity of conventional immunohistochemical procedures to show that PrP was widely distributed in the enteric nervous plexus supplying the gut wall. In scrapie-free lambs, PrP was also detected in scattered cells in the lamina propria and in the dome and interfollicular areas of the Peyer?s patch. In the follicles, staining for PrP was mainly confined to the capsule and cells associated with vascular structures in the light central zone. In lambs naturally exposed to the scrapie agent, staining was prominent in the dome and neck region of the follicles and was also found to be associated with the follicle-associated epithelium. Similar observations were made in lambs that had received a single oral dose of scrapie-infected brain material from sheep with a homologous and heterologous PrP genotype 1 and 5 weeks previously. These studies show that the ileal Peyer?s patch in young sheep may be an important site of uptake of the scrapie agent and that the biology of this major gut-associated lymphoid tissue may influence the susceptibility to oral infection in sheep. Furthermore, these studies suggest that homology or heterology between PrP genotypes or the presence of PrP genotypes seldom associated with disease does not impede uptake of PrP.
 
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BSE, KURU, DENTAL AND ___CUT ABRASIONS___ from gutting a deer perhaps;
 
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since there was a suggestion that kuru had been transmitted through the gums and/or gum abrasions...
 
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Summary of Conclusions on the Vulnerability of Groundwater to Contamination by BSE Prions at Thruxted Mill.
 
[PDF]BSE INQUIRY Statement of behalf of the Environment Agency ... File Format: PDF/Adobe Acrobat - View as HTML ... his Statement of March 1998 to the BSE Inquiry ... systems subject to regular or intermittent contamination by rapid movement of recharge water ... www.bse.org.uk/files/ws/s490.pdf
 
BSE INQUIRY
 
Statement of behalf of the Environment Agency Concerning Thruxted Mill By Mr C. P. Young Principal Hydrogeologist, Soil Waste and Groundwater Group WRc plc; Medmenham, Bucks
 
 
 
 
OPINION ON SIX ALTERNATIVE METHODS FOR SAFE DISPOSAL OF ANIMAL BY-PRODUCTS ADOPTED BY THE SCIENTIFIC STEERING COMMITTEE AT ITS MEETING OF 10-11 APRIL 2003
 
 
 
OPINION on the use of small incinerators for BSE risk reduction (Scientific Steering Committee Meeting of 16-17 January 2003)(158KB)
 
 
 
OPINION on open burning of potentially TSE-infected animal materials (Adopted by the Scientific Steering Committee at its meeting of 16-17 January 2003)
 
 
 
OPINION n the use of burial for dealing with animal carcasses and other animal materials that might contain BSE/TSE (Adopted by the Scientific snip...
 
4. CONCLUSION In the absence of new evidence the opinion of the SSC â¬SOpinion on Fallen Stock⬝ (SSC 25th June 1999) must be endorsed strongly that land burial of all animals and material derived from them for which there is a possibility that they could incorporate BSE/TSEs poses a significant risk. Only in exceptional circumstances where there could be a considerable delay in implementing a safe means of disposal should burial of such materials be considered. Guidelines should be made available to aid on burial site selection.
 
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> What about alkaline tissue digestion?
 
 
UPDATED OPINION AND REPORT ON : A TREATMENT OF ANIMAL WASTE BY MEANS OF HIGH TEMPERATURE (150°C, 3 HOURS) AND HIGH PRESSURE ALKALINE HYDROLYSIS. INITIALLY ADOPTED BY THE SCIENTIFIC STEERING COMMITTEE AT ITS MEETING OF 16 MAY 2002 AND REVISED AT ITS MEETING OF 7-8 NOVEMBER 2002
 
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OPINION BACKGROUND AND MANDATE Commission Services received a submission and accompanying dossier from a commercial company requesting endorsement of a process for the safe disposal of animal waste which may be contaminated by TSEs. This process consists of a treatment of animal waste by means of high temperature (150°C, 3 Hours) and corresponding high pressure alkaline hydrolysis. Scientific Steering Committee (SSC) was requested to address the following questions: 1. Can the treatment of animal waste, as described by the dossier, be considered safe in relation to TSE risk? Can the liquid residues be considered safe in relation to TSE risk? 2. Can the by-products resulting from this treatment (i.e. ash of the bones and teeth of vertebrates ) be considered safe in relation to TSE risk? It is not in the remit of the SSC to endorse specific commercial products and processes. This opinion therefore relates only to the nature of the process in regard to possible human health and environmental risks arising from possible exposure to BSE / prion proteins. The opinion does not address practical issues such as economics and potential throughput of carcasses/tissues. An opinion was initially adopted on 16 May 2002. Subsequently, comments, substantial additional data including analytical results, a risk assessment as well as a number of proposals for the safe recycling or disposal of the residues were submitted to the SSC secretariat by the company in June 2002. These were analysed by the rapporteurs, the TSE/BSE ad hoc Group (at its meeting of 5 September 2002) and the SSC (at its meeting of 7-8 November 2002). The amended opinion and report follow hereafter.
 
OPINION 1. Regarding the first question of the mandate the SSC concludes that the liquid residue after a 3-hour digestion cycle could retain infective potential. Under controlled laboratory conditions in a single experiment the treatment of animal waste by means of high temperature (150°C, 3 Hours) and high pressure alkaline hydrolysis has been shown to reduce the infectivity of TSE/BSE by a factor of 103.5 ⬠104.5. Due to constraints specific to this experiment, further studies on the combination of heat, pH and time in clearance studies are needed before any final assurance could be given regarding the safety of the process with respect to TSE risks. No infectivity was found after 6 hours. This may indicate that the clearance after 6 hours processing time is higher than after 3 hours. However, these experiments can only give a measure of the minimum clearance possible and do not permit the quantification of the clearance factor after 6 hours. Regarding the second question of the mandate, the SSC concludes that, on the basis of the data available, by-products of the 3-hour process could carry a risk of BSE/TSE infectivity and that this risk may decrease with the duration of processing; further data would be needed in order to make a definitive statement.
 
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The SSC refers to the attached report for some comments on the experimental conditions, which were considered when drawing the above conclusions.
 
2. The possible human BSE exposure and/or environmental contamination risks under field conditions not only depends on the maintenance of the efficiency of the equipment during processing, but also on factors such as: the probability that a TSE-infected animal is processed, the type of material processed (e.g., carcasses as compared to byproducts and waste from animals that tested negative for BSE), the relationship between effectiveness and throughput and workplace control, dilution of the possible residual infectivity, and environmental protection measures. The consideration whether or not the inactivation capacity of a process is effective must take fully into account such factors, but the SSC nevertheless considers, as a principle, that the release into the environment of residual TSE infectivity should be avoided.
 
3. The dossier supporting the request for the endorsement of the process states that the levels of 68 priority pollutant semi-volatiles was low and that odour emission was moderate. Detailed analyses provided recently1 by the company shows that dioxins in the air could not be detected nor chlorophenols and other polychlorinated hydrocarbons in the residual fluid of the alkaline process, but high biological oxygen demand (BOD) and chemical oxygen demand (COD) values were identified in the residual fluid. Most of the volatile organic compounds (VOCs) were reported to be below the given chemical detection limits. For the compounds detected most concentrations were below their respective odour thresholds. Emissions of some reduced sulphur compounds and amines require special attention in order to avoid potential odour impacts. Appropriate emission-reduction measures and air ventilation exhaust systems are recommended. The SSC is nevertheless concerned about the fact that, if formed in a liquid medium, dioxin is most unlikely to pass into air, instead it will adsorb to solids or to the sides of the processing chamber. The analyses of air emissions are therefore not a sufficient method to exclude the possible presence of dioxins in the effluent (either as â¬Snatural⬝ environmental background contamination or as newly formed substances during the alkaline treatment). As the air emission analysis is not sufficient to confirm the possible presence of dioxins in the effluent, additional data/ analyses are needed to verify whether during the alkaline hydrolysis process described in the attached report, dioxins are formed in addition to background levels that may already have been present. For that purpose samples taken both before and after the process would need to be analyzed using a method of sufficient sensitivity. Such results would also provide the basis to decide whether or not the levels of possibly newly produced dioxins and dibenzofurans (if any) would exceed pre-set safety margins. The solidification of the digestate is reported by the company to be uncommon. However, from the test experiments that exclusively used materials of sheep carcass (with a high fat content) it appears that, if hydrolysate is released on a large scale to a sewer in a warm condition without extensive dilution, it might solidify under certain circumstances. In the absence of data to the contrary it must thus be assumed that any 1 On 18 July 2002, following a recommendation in the initial opinion adopted on 16 May 2002.
 
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4 residual BSE/TSE material could co-precipitate and hence be accessible to sewer vermin. On the basis of the above evidence, the SSC considers that for the time being the direct discharge of the liquid residues to the sewer without further treatment is not appropriate. The SSC opinion of 24-25 June 1999 on â¬SFallen Stock⬝ 2provides some further guidance on the disposal or possible recycling for certain uses of the residues. As a summary this opinion implies: - If the risk of TSE infectivity can be excluded, recycling of residues from the treatment of animal waste by means of high temperature (150°C, 3 Hours) and high pressure alkaline hydrolysis could be acceptable for various purposes provided the other risks discussed in the SSC opinion of 24-25 June 1999 are excluded (e.g., presence of heavy metals, toxic substances, etc.). If analyses of the various types of residues (air, effluent, sludge) from the field equipment, carried out as part of a risk analysis prior to its installation, show that such is the case3, the use of the sludge as fertiliser, as soil additive or as feed is acceptable provided the standards4 for these uses are met. - If the presence of residual TSE infectivity cannot be excluded, residues should be disposed of as described in the SSC opinion of 24-25 June 1999. This opinion of 1999 did not consider anaerobic digestion as safe because the TSE clearance level by anaerobic digestion process is unknown. However, should reliable published data show that the levels of residual TSE infectivity in biogas are likely to be very low and would be eliminated during the burning of the gas, the recovery of bio-energy from anaerobically produced biogas could be acceptable if sufficient precautions (e.g., filters) are taken to exclude contamination of the gas. As the anaerobic process for the production of biogas may result in sludge containing infectious activity, burning, incineration or controlled landfill should be the methods of disposal for the residual sludge, filter contents, etc.
 
Note: The formation of chlorophenols, dioxins and polychlorinated hydrocarbons in a combustion process can use any form of chlorine including chloride ions. Combustion of the effluent could thus give rise to dioxin formation. However, the SSC considers that this risk is minimized/excluded if the standards set for that purpose are respected, i.e., a rapid combustion at 900°C or above followed by rapid chilling (quenching) and with appropriate filtration by adding charcoal to the emissions or other air pollution devices. 4. Like for all waste disposal and recycling processes, a site-specific risk assessment of the process as a whole (from animal collection to final disposal of the residues) is required when considering the installation of the equipment in a particular situation, so as to minimise workers exposure, environmental impacts, etc. 2 Scientific Opinion on The risks of non conventional transmissible agents, conventional infectious agents or other hazards such as toxic substances entering the human food or animal feed chains via raw material from fallen stock and dead animals (including also: ruminants, pigs, poultry, fish, wild/exotic/zoo animals, fur animals, cats, laboratory animals and fish) or via condemned materials. Adopted By the Scientific Steering Committee at its meeting of 24-25 June 1999 and re-edited at its meeting of 22-23 July 1999. 3 The dossier and the additional effluent analysis data submitted for this opinion, and taking into account the scientific report attached to its opinion of 24-25 June 1999, indicate that these other risks are probably minimal or excluded. But this would need to be confirmed for each installation and for each type and source of waste to be processed. 4 For example: Na or K concentrations and pH of the fertiliser. C:\WINNT\Profiles\bredagi.000\Desktop\WR2_0209_REVISED_OPINION_0211_FINAL.doc
 
5 UPDATED REPORT ON : A TREATMENT OF ANIMAL WASTE BY MEANS OF HIGH TEMPERATURE (150°C, 3 HOURS) AND HIGH PRESSURE ALKALINE HYDROLYSIS
 
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MANDATE AND BACKGROUND According to the EU regulation in force on 1 January 2001, animals, animal waste or products derived thereof (e.g., animal meat and bone meal), potentially contaminated with TSE agent by-products, shall be disposed of by incineration or co-incineration. Alternative ways may be allowed following a positive scientific opinion. The Scientific Steering Committee (SSC) has previously provided opinions on the use of rendering and incineration to reduce the risk from TSEs in animal tissues and products derived from these. It has also provided a framework for evaluating the risks involved in the storage, transport and handling of animal materials which may contain TSEs. The Commission has now received a submission from a commercial company requesting endorsement of a process for the safe disposal of animal waste which may be contaminated by TSEs. This process consists of a treatment of animal waste by means of high temperature (150°C, 3 Hours) and high pressure alkaline hydrolysis5. The Commission Services therefore submitted the following questions for opinion to the Scientific Steering Committee (SSC):
 
1. Can the treatment of animal waste, as described by the dossier, be considered safe in relation to TSE risk? Can the liquid residues be considered safe in relation to TSE risk?
 
2. Can the by-products resulting from this treatment (i.e. ash of the bones and teeth of vertebrates ) be considered safe in relation to TSE risk?
 
A report was initially prepared for the SSC, who discussed it at its meeting of 16 May 2002. Subsequently, comments, substantial additional data including analytical results, a risk assessment as well as a number of proposals for the safe recycling or disposal of the residues were submitted to the SSC secretariat by the company at various dates between June and November 2002 (see list of references at the end of the report). At the request of the SSC, the secretariat also organised additional external expertise. All this information was analysed by the rapporteurs Prof.Dr.J.Bridges and Prof.Dr.Em.M.Vanbelle, the TSE/BSE ad hoc Group (at its meeting of 5 September 2002) and the SSC (at its meeting of 7-8 November 2002). The amended opinion and report follow hereafter.
 
III BASIS FOR THE OPINION III.1. NATURE OF THE PROCESS
 
A whole carcass or parts of a carcass is placed in a steel alloy container. A measured amount of alkali is added either in solid form or as a solution of NaOH or KOH, (starting concentration: 1 molar), the vessel is sealed and the contents heated at 150° for 3 to 6 hours and at a high pressure (approximately 5 Bars). (In practice, the volume of alkali solution is and the duration of the process may be adjusted according to the load and composition of the material). In respect to basicity at ~ 1 N base 5 This process is currently applied in the USA on high volumes of several carcasses of deer and elk carcasses with CWD. concentration, almost no difference exists between NaOH and KOH. At the beginning of the process, entire animal carcasses can be used. Six parts of aqueous alkaline solution are used to 4 parts of tissue material. The physical energy generated by a constant pumping action continually circulates the liquid material present in the vessel thereby aiding the digestion process. Under these conditions the tissues are dissolved and bones and teeth softened. The solid residue is a small fraction of the original weight. The use of alkaline conditions minimises gaseous emissions of gases such as CO2, NO2, SO2.
 
III.2. HUMAN HEALTH AND ENVIRONMENTAL CONSIDERATIONS
 
In evaluating the process in respect of the questions posed by the Commission Services, three issues need to be addressed:
 
i) Does the process destroy/inactivate TSEs (including BSE) and if so how effective is the destruction/inactivation?
 
ii) Are there pathogens and/or chemicals whose potency is not reduced significantly or inactivated by the process?
 
iii) Are any of the end products of the process of concern from a human health risk or an environmental risk viewpoint?
 
In considering the evidence available to deal with these issues it is important to consider whether the data has been generated under very controlled laboratory conditions or under practical large scale working conditions. In this context it should be noted that it is often the case that data derived under laboratory conditions demonstrates higher efficiency in destruction/inactivation and lower levels of contamination than will occur in regular use at the industrial scale.
 
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EUROPEAN COMMISSION HEALTH & CONSUMER PROTECTION DIRECTORATE-GENERAL Directorate C - Scientific Opinions C1 - Follow-up and dissemination of scientific opinions
 
OPINION ON THE USE OF BURIAL FOR DEALING WITH ANIMAL CARCASSES AND OTHER ANIMAL MATERIALS THAT MIGHT CONTAIN BSE/TSE ADOPTED BY THE SCIENTIFIC STEERING COMMITTEE MEETING OF 16-17 JANUARY 2003 1 OPINION
 
On 17 May 2002, the Scientific Steering Committee (SSC) was invited by Commission Services to advice on the examples of conditions under which safe burial of potentially TSE-infected (animal) materials can be achieved. The details of the SSC's evaluation are provided in the attached report. The SSC concludes as follows:
 
(1) The term "burial" includes a diversity of disposal conditions. Although burial is widely used for disposal of waste the degradation process essential for BSE/TSE infectivity reduction is very difficult to control. The extent to which such an infectivity reduction can occur as a consequence of burial is poorly characterised. It would appear to be a slow process in various circumstances.
 
(2) A number of concerns have been identified including potential for groundwater contamination, dispersal/transmission by birds/animals/insects, accidental uncovering by man.
 
(3) In the absence of any new data the SSC confirms its previous opinion that animal material which could possibly be contaminated with BSE/TSEs, burial poses a risk except under highly controlled conditions (e.g., controlled landfill).
 
The SSC reiterates the consideration made in its opinion of 24-25 June 1999 on "Fallen Stock"1. The limited capacity for destruction of animal wastes in certain countries or regions in the first place justifies the installation of the required facilities; it should not be used as a justification for unsafe disposal practices such as burial.
 
However, the SSC recognises that for certain situations or places or for certain diseases (including animals killed and recycled or disposed of as a measure to control notifiable diseases), the available rendering or incinerator or disposal capacity within a region or country could be a limiting factor in the control of a disease. Thus if hundreds or even millions of animals need to be rendered after killing or if the transport of a material to a rendering or disposal plant proved to be impractical, an appropriate case by case risk assessment2 should be carried out before deciding upon the most appropriate way of disposal. In principle, the risk is expected to be the lower for small incinerators3 as compared to burial. As such decisions in practice may have to be taken at very short notice, risk management scenarios according to various possible risks should be prepared in advance to allow for a rapid decision when the need arises.
 
1 Scientific Opinion on The risks of non conventional transmissible agents, conventional infectious agents or other hazards such as toxic substances entering the human food or animal feed chains via raw material from fallen stock and dead animals (including also: ruminants, pigs, poultry, fish, wild/exotic/zoo animals, fur animals, cats, laboratory animals and fish) or via condemned materials. Adopted By the Scientific Steering Committee at its meeting of 24-25 June 1999. (and re-edited at its meeting of 22-23 July 1999).
 
2 See also the relevant sections and footnotes on risk assessment in the report accompanying the SSC opinion of 24-25 June 1999. 3 See SSC opinion of 16-17 January 2003 on the use of small incinerators for BSE risk reduction. 2 THE USE OF BURIAL FOR DEALING WITH CARCASSES AND OTHER MATERIALS THAT MIGHT CONTAIN BSE/TSE REPORT
 
1. MANDATE On 17 May 2002, the Scientific Steering Committee (SSC) was invited by Commission Services to advice on the examples of conditions under which safe burial of potentially TSE-infected animal materials can be achieved. The SSC appointed Prof.J.Bridges as rapporteur. His report was discussed and amended by the TSE/BSE ad hoc Group at its meeting of 9 January 2003 and by the SSC at its meeting of 16-17 January 2003.
 
2. GENERAL CONSIDERATIONS "Burial" covers a range of disposal situations ranging from the practice of burying animals on farms and other premises in a relatively shallow trench (with or without treatment such as lining) to deep disposal to a lined and professionally managed landfill site (SSC 2001). Buried organic material is normally decomposed by microbial and chemical processes. However this is not a process amenable to control measures. As noted by the SSC "Opinion on Fallen Stock" (SSC 25th June 1999) there is little reliable information on the extent and rate of infectivity reduction of BSE/TSEs following burial. An old paper by Brown and Gajdusek 1991 assumed a reduction of 98% over 3 years. However it is noted that the rate of degradation of materials following burial can vary very considerably between sites. This is not surprising because the degradation process is strongly influenced by factors such as water content of the site, temperature inside the site, nature of adsorptive "material" present etc. The previous SSC opinion noted that BSE/TSEs appear to be resistant to degradation when stored at room temperature over several years. It also raised concerns that mites could serve as a vector and/or reservoir for the infected scrapie material. Burial sites may have a thriving animal population. Uncovering of risk material that is not deeply buried is therefore possible. The SSC in its opinion of 28th-29th June 2001 set out a framework for assessing the risk from different waste disposal processes. These criteria may be applied to burial as follows:
 
(1) Characterisation of the risk materials involved. Unlike many other waste disposal options there are no technical or economic factors that would limit the nature of the material that can be disposed of by burial. Moreover in many cases the location of burial sites is uncertain. The potential for transmission of BSE/TSEs for SRM that is buried near the surface is also poorly characterised.3
 
(2) Risk reduction. The extent to which the infectivity is reduced is likely to vary substantially according to the nature of the site depth of burial whether pre-treatment by burning or through the addition of lime is used etc. There appears to be no scientific basis at present for the prediction of the rate of loss of infectivity. In the absence of such data, as a worst case, it has to be assumed that over a three-five year period the loss of infectivity may be slight. In principle on a well-managed fully contained landfill the risks from infective material can approach zero. However this requires rigorous management over many years. This is difficult to guarantee.
 
(3) Degree to Which the Risks can be Contained The principal concerns are: * Prevention of access to the SRM by animals that could result in the transmission (directly or indirectly) of the BSE/TSE.
 
* Penetration of prions into the leachate/groundwater. It is noted that on some landfill sites leachate is sprayed into the air to facilitate oxidation of some organic components. Such a practice could in principle lead to dispersal of BSE/TSEs. It is also noted that it is not uncommon for landfill sites to be re-engineered to increase their stability, gas and leachate flow and/or total capacity. If this re-engineering involved an area where previous burial of BSE/TSE contaminated material had taken place and additional risk could accrue. The possibility of contaminated material being dug up in shallow and unmarked burial sites on farms etc constitutes a considerably greater risk.
 
3. FURTHER INVESTIGATIONS Research is needed on specific aspects of the behaviour of prion like molecules in controlled landfills i.e.:
 
* Potential for adsorption to other material present in the waste that might limit their mobility.
 
* Principal factors influencing rates of degradation.
 
* Effectiveness of encasement in cement in controlling/reducing the risk.
 
4. CONCLUSION In the absence of new evidence the opinion of the SSC "Opinion on Fallen Stock" (SSC 25th June 1999) must be endorsed strongly that land burial of all animals and material derived from them for which there is a possibility that they could incorporate BSE/TSEs poses a significant risk.
 
Only in exceptional circumstances where there could be a considerable delay in implementing a safe means of disposal should burial of such materials be considered. Guidelines should be made available to aid on burial site selection.
 
 
 
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EUROPEAN COMMISSION HEALTH & CONSUMER PROTECTION DIRECTORATE-GENERAL
 
Directorate C - Scientific Opinions C1 - Follow-up and dissemination of scientific opinions
 
OPINION ON OPEN BURNING OF POTENTIALLY TSE-INFECTED ANIMAL MATERIALS ADOPTED BY THE SCIENTIFIC STEERING COMMITTEE AT ITS MEETING OF 16-17 JANUARY 2003
 
2 OPINION
 
On 17 May 2002, the Scientific Steering Committee (SSC) was invited by Commission Services to advice on the examples of conditions under which safe burning of potentially TSE-infected (animal) materials can be achieved. The details of the SSC's evaluation are provided in the attached report. The SSC concludes as follows:
 
(1) "Burning" covers a wide variety of combustion conditions. This opinion is concerned with the process of open burning e.g. bonfires.
 
(2) There are serious concerns regarding the use of open burning for the destruction of pathogen contaminated animal waste, particularly for waste which may be contaminated with relatively heat stable pathogens. Issues include: the potentially very high variability of the pathogen inactivation, the nature of the gaseous and particulate emissions, and the risks from the residual ash.
 
(3) The SSC recommends that open burning is only considered for pathogen destruction under exceptional circumstances following a specific risk assessment.
 
In the case of animal waste possibly contaminated with BSE/TSE in view of the uncertainty of the risk open burning should be considered a risk.
 
Suitable monitoring methods for TSE contamination of both air and ash are needed.
 
Protocols for safe burning in emergency situations need to be established.
 
The SSC reiterates the consideration made in its opinion of 24-25 June 1999 on "Fallen Stock"1.
 
The limited capacity for destruction of animal wastes in certain countries or regions in the first place justifies the installation of the required facilities; it should not be used as a justification for unsafe disposal practices such as burial.
 
However, the SSC recognises that for certain situations or places or for certain diseases (including animals killed and recycled or disposed of as a measure to control notifiable diseases), the available rendering or incinerator or disposal capacity within a region or country could be a limiting factor in the control of a disease.
 
Thus if hundreds or even millions of animals need to be rendered after killing or if the transport of a material to a rendering or disposal plant proved to be impractical, an appropriate case by case risk assessment2 should be carried out before deciding upon the most appropriate way of disposal.
 
In principle, the risk is expected to be the lower for small incinerators3 as compared to open burning. As such decisions in practice may have to be taken at very short notice, risk management scenarios according to various possible risks should be prepared in advance to allow for a rapid decision when the need arises.
 
1 Scientific Opinion on The risks of non conventional transmissible agents, conventional infectious agents or other hazards such as toxic substances entering the human food or animal feed chains via raw material from fallen stock and dead animals (including also: ruminants, pigs, poultry, fish, wild/exotic/zoo animals, fur animals, cats, laboratory animals and fish) or via condemned materials. Adopted By the Scientific Steering Committee at its meeting of 24-25 June 1999. (and re-edited at its meeting of 22-23 July 1999).
 
2 See also the relevant sections and footnotes on risk assessment in the report accompanying the SSC opinion of 24-25 June 1999. 3 See SSC opinion of 16-17 January 2003 on the use of small incinerators for BSE risk reduction.
 
3 OPEN BURNING OF POTENTIALLY TSE-INFECTED ANIMAL MATERIALS REPORT 1. MANDATE On 17 May 2002, the Scientific Steering Committee (SSC) was invited by Commission Services to advice on the examples of conditions under which safe burning of potentially TSE-infected animal materials can be achieved. The SSC appointed Prof.J.Bridges as rapporteur. His report was discussed and amended by the TSE/BSE ad hoc Group at its meeting of 9 January 2003 and by the SSC at its meeting of 16-17 January 2003. 2. GENERAL CONSIDERATIONS Burning is a combustion process to which a range of control measures may be applied to contain emissions and to ensure the completeness of the degradation process for organic matter. Depending on the source (waste) material the burning process may or may not require addition of other energy sources. Incineration/pyrolysis are contained combustion processes are contained combustion processes and therefore have the potential for a high level of control. (However see opinion on small incinerators). At the other end of the control spectrum is open burning; such as bonfires. Typically combustion of animal waste requires the addition of a high calorific fuel in order to initiate (and for some materials to sustain) the process. It is recognised that open burning of animal waste is a very cheap and convenient method of disposal. However uncontained burning has a number of problems in terms of the potential risks involved:
 
(1) In the open burning situation a range of temperatures will be encountered. It is difficult therefore to ensure complete combustion of the animal waste. If the waste is contaminated with pathogens there will remain considerable uncertainty as to the degree of their inactivation.
 
(2) Gaseous and particulate emissions to the atmosphere will occur and consequently worker and public exposure is likely. There is very little data to indicate whether or not some pathogens could be dispersed to air as a consequence of open burning.
 
(3) The supporting/secondary fuel may be a source of contamination itself. For example in the recent foot and mouth disease outbreak in the UK timbers were used at some sites that were heavily contaminated with pentachlorophenol.
 
(4) The residual ash must be considered to be a risk source. Its safe disposal needs to be assured (see opinion on small incinerators) to prevent human and animal contact and protect from groundwater contamination. While careful selection of burning sites can reduce the risks open burning should only be considered in emergency situations. For each such emergency situation a specific risk assessment should be conducted which must include the risk 4 from the pathogen of immediate concern but also other pathogens that might be present.
 
3. RISK ASSESSMENT OF OPEN BURNING FOR BSE The SSC, at its meeting of 28th-29th June 2001, recommended "a framework for the assessment of the risk from different options for the safe disposal or use of meat and bone meal (MBM) and other products which might be contaminated with TSEs and other materials. Applying the framework to the practice of open burning, the following conclusions can be drawn:
 
3.1. Nature of the materials handled Potentially a wide variety of materials can be used provided suitable secondary fuel is available. The burning process is very simple in principle and difficult in practice to regulate effectively.
 
3.2. Risk reduction due to open burning There is no reliable data to indicate the extent of risk reduction that could be achieved by open burning. It is reasonable however to assume that overall it will be rather less effective in reducing the infectivity of BSE/TSE than wellconducted incineration. Moreover the reproducibility of the risk reduction is likely to be very variable even at a single location.
 
3.3. Airborne emissions and residue ash The composition of airborne emissions and residue ash is rarely monitored. From a risk assessment viewpoint particular attention needs to be given to the potential for the airborne dispersal of relatively heat stable pathogens as a consequence of open burning. In the absence of reliable data both airborne emissions and residual ash must be considered to constitute a significant risk if animal waste that might be contaminated with TSEs is being burnt.
 
4. FURTHER INVESTIGATION Research is needed particularly on:
 
* The potential for airborne dispersal of relatively heat stable pathogens.
 
* Methodologies to improve the efficacy of the combustion process to ensure the inactivation of pathogen contaminated animal waste.
 
5. CONCLUSION Open burning potentially represents a significant risk where the animal waste has the possibility of being contaminated with BSEs/TSEs.
 
Suitable monitoring methods for TSE contamination of both air and ash are needed. Protocols for safe burning in emergency situations need to be established.
 
 
 
C:\WINNT\Profiles\bredagi.000\Desktop\Incinerator_OPINION_0301_FINAL.doc
 
EUROPEAN COMMISSION HEALTH & CONSUMER PROTECTION DIRECTORATE-GENERAL Directorate C - Scientific Opinions C1 - Follow-up and dissemination of scientific opinions OPINION ON THE USE OF SMALL INCINERATORS FOR BSE RISK REDUCTION SCIENTIFIC STEERING COMMITTEE MEETING OF 16-17 JANUARY 2003 2 OPINION
 
On 17 May 2002, the Scientific Steering Committee (SSC) was invited by Commission Services to
 
(i) evaluate a risk assessment1 prepared for the UK's Spongiform Encephalopathy Advisory Committee (SEAC), on the potential risk arising from the use of small incinerators to dispose of specified risk materials and
 
(ii) to advise on the safety with regard to TSE risks of the use of such small incinerators.
 
The details of the SSC's evaluation are provided in the attached report. The SSC concludes as follows:
 
(i) The SSC, at its meeting of 28th -29th June 2001, recommended "a framework for the assessment of the risk from different options for the safe disposal or use of meat and bone meal (MBM) and other products which might be contaminated with TSEs and other materials." This framework comprised five components:
 
(1) Identification and characterisation of the risk materials involved, the possible means for their transmission and potential at risk groups.
 
(2) The risk reduction achieved by the particular process.
 
(3) The degree to which the risks can be contained under both normal and emergency operating conditions. This inevitably includes consideration of the effectiveness of control measures.
 
(4) Identification of interdependent processes for example transport, storage, loading of any TSE related risk materials.
 
(5) The intended end-use of the products for example disposal, recycling etc.
 
The risk assessment prepared for SEAC focuses on the risks involved steps 1 and 2 in respect of BSE/TSEs only and is based on a visit to 10 incinerators out of a total of 263 in the UK of which 60% had after burners. The risk assessment is also using a number of assumptions and data that may be valid for certain incinerator types under certain conditions, but are not necessarily applicable either for all types of materials to be disposed of, or to the whole range of types of small incinerators in use the EU and the UK.
 
(ii) Small incinerators are widely used to meet the needs of local communities. These incinerators vary greatly in their design, nature of use and performance characteristics and the quality of their management. As a consequence of this variability there are many uncertainties in identifying risks posed by small incinerators that are used to treat SRM materials and each type should eventually receive its own assessment. Also, general operating and control criteria should be established for 1 DNV Consulting (Det Norske Veritas), 2001. Risk assessment of SRM incinerators. Prepared for the UK Ministry of Agriculture, Fisheries and Food. Revision 2 of the Draft report, February 2001. 24 pages. 3 Potential risk sources arising from the incineration process include: gaseous emissions and residual ash. Research is currently ongoing mimicking incineration of TSE-infected brain tissue to assess the infectivity clearance level under various scenarios2. However, there are no final reported measurements that enable the risk to be assessed from either the emissions or the ash from small incinerators. It has been argued that the protein content of the ash is a reasonable surrogate measure of the degree of risk deduction caused by the incineration process. This assumption is questionable in view of the resistance to heat of prions as compared to other proteins. Protein measurements in ash are however probably a useful general measure of the overall efficiency and reproducibility of the incineration process. Results in the aforementioned report1 indicate a large degree of variability in performance among the small incinerators in the UK that have been evaluated. It is anticipated that small incinerators, used by other Member States will also show a considerable variation in performance. In evaluating the risk of small incinerators, consideration should be given to the risk of potential contamination of the ash and of the gaseous emissions. In the absence of generally accepted and enforced performance standards for small incinerators handling SRMs each such facility therefore needs to be the subject of a specific risk assessment. The SSC considers that the standards set up by the new Waste Incinerator Directive (2000/76/EC) and in its opinion of June 1999 on waste disposal should serve as guidance. In the absence of reliable data on the possible residual infectivity of the ash, it should be disposed of, i.e., in controlled landfills as described in the SSC opinion of June 1999 on safe disposal of waste. The SSC finally wishes to emphasise the need for suitable monitoring methods in order that risks can be assessed readily for individual types of small incinerators. 2 P.Brown, pers.comm., December 2002. Publication in progress.4
 
THE USE OF SMALL INCINERATORS FOR BSE RISK REDUCTION REPORT
 
1. MANDATE
 
On 17 May 2002, the Scientific Steering Committee (SSC) was invited by Commission Services to
 
(i) evaluate a risk assessment3 prepared for the UK's Spongiform Encephalopathy Advisory Committee (SEAC), on the potential risk arising from the use of small incinerators to dispose of specified risk materials and
 
(ii) to advise on the safety with regard to TSE risks of the use of such small incinerators.
 
The SSC appointed Prof. J. Bridges as rapporteur. His report was discussed and amended by the TSE/BSE ad hoc Group at its meeting of 9 January 2003 and by the SSC at its meeting of 16-17 January 2003.
 
2. CURRENT LEGISLATIVE FRAMEWORK
 
Until 2000, small incinerators were exempt from the emission limits set by the EC for MSW and hazardous waste incinerators with throughputs greater than 50 kg/hour. An "incineration plant" is defined by the new Incineration of Waste Directive (2000/76/EC) as "any stationary or mobile technical equipment dedicated to the thermal treatment of waste with or without recovery of the combustion heat generated". This definition would appear to exclude open burning of waste. The new Directive, which must be transposed into the legislation of each Member State by December 2002, replaces a range of previous directives on incineration. It applies to all new incinerator installations from December 28th 2002 and all existing installations from December 28th 2005. The principal aim of the Directive is to prevent and/or limit negative environmental effects due to emissions into air, soil, surface and ground water and the resulting risks to human health from the incineration and co-incineration of waste. It covers many aspects from a requirement for afterburners to airborne emission limits and criteria for the composition of residual ash. Previous EC legislation has exempted small incinerators (i.e. those operating at less than 50 kg per hour). The Waste Incinerator Directive (WID) (2000) allows such small incinerators to be exempt from licensing at the national level however they will still be subjected to the same onerous requirements of the WID as larger incinerators. In the UK it is proposed that in future incinerators dealing with non-hazardous waste but with a throughput of less than 1 tonne per hour will be regulated by local authorities whereas those with a larger throughput will be regulated by the national authority. It is possible that different regulatory mechanisms may result in differences in the rigour with which the new standards are enforced. The position on the disposal of animal waste is complicated. Animal carcass incineration use not covered by the WID and therefore the existing regulatory framework (90/66/EEC which covers animal and public health requirements to ensure destruction of pathogens) will continue to be applied. A new Animal By-Products Regulation 3 DNV Consulting (Det Norske Veritas), 2001. Risk assessment of SRM incinerators. Prepared for the UK Ministry of Agriculture, Fisheries and Food. Revision 2 of the Draft report, February 2001. 24 pages. 5 (ABPR) will apply in Member States during the first part of 2003. The relationship to WID has been included in the ABPR. It is important that it does not result in less strict standards being applied for animal carcass incineration. In contrast to whole carcasses WID will apply to the burning of meat and bone meal, tallow or other material (even if they burn animal carcasses too). Additional specific directives will continue to apply to waste that could be contaminated with BSE/TSEs. (96/449/EC)
 
3. CURRENT USE OF SMALL INCINERATORS TO DISPOSE OF ANIMAL WASTE
 
Small incinerators are used for a variety of purposes and in a range of locations among Member States. Many are located alongside small abattoirs, knackers, hunt kennels, or laboratories. Thus they meet the needs of relatively small communities. Across Member States these small incinerators include a variety of designs and operating conditions (as indicated above in principle they will probably be required to meet specific standards for emissions and for the composition of the residual ash by December 28th 2005). In the UK there are indications (see DNV Report 2001) that a considerable quantity of SRM which would have previously been sent for rendering is now being incinerated directly in small incinerators. Thus evaluation of the risks from such incinerators is of increasing importance.
 
4. RISK ASSESSMENT FOR SMALL INCINERATORS
 
The SSC, at its meeting of 28th -29th June 2001, recommended "a framework for the assessment of the risk from different options for the safe disposal or use of meat and bone meal (MBM) and other products which might be contaminated with TSEs and other materials. This framework comprised five components: (1) Identification and characterisation of the risk materials involved, the possible means for their transmission and potential at risk groups. (2) The risk reduction achieved by the particular process. (3) The degree to which the risks can be contained under both normal and emergency operating conditions. This inevitably includes consideration of the effectiveness of control measures. (4) Identification of interdependent processes for example transport, storage, loading of any TSE related risk materials.
 
(5) The intended end-use of the products for example disposal, recycling etc.
 
Recently a report has been prepared by DNV consulting (2001) for the UK Ministry of Agriculture, Fisheries and Food (now known as DEFRA) that assesses the risks from small incinerators in the UK that receive SRMs. This report focuses on the risks involved steps 1 and 2 in respect of BSE/TSEs only. 10 incinerators out of a total of 263 in the UK were visited of which 60% had after burners.
 
(1) Nature of the materials handled.
 
The DNV report 2001 starts with the assumption that "the materials incinerated at small abattoirs will be mainly SRM and bones from animals that are fit for human consumption. It may also include material from animals failed by meat inspectors. The likelihood of there being an animal 6 with significant BSE infectivity is very small and certainly much less than for the fallen stock handled by hunt kennels and knackers4. For this reason the study has concentrated on the latter type of operation". The Report notes that "the material handled by both knacker and hunt kennels is highly variable and difficult to characterise". In terms of input the key factors to consider are:
 
* The number of adult bovines processed and the proportion of these carcasses that are likely to be infected.
 
* The extent of infectivity (in terms of human oral Infectious Units) that may occur (average and worst case).
 
In the DNV (2001) risk assessment only the BSE risk from processing bovine SRMs was considered. For quantitative risk assessment purposes the mean value of the oral ID50 for cattle was taken as 0.1 gram. A range of values was taken to cover uncertainty in the inter-species barrier from 104 to 1 (as recommended by the SSC 2000). In order to assess the likelihood that a particular carcass could be infected, UK and Swiss monitoring data was used. An incidence rate based on Prionics test findings of between 0.013 and 0.0025 was calculated. The DNV Report notes that prevalence rates are progressively reducing from these 1998/99 figures. Finally the report concludes that the SRM from an infected bovine could contribute 700 Infectious Units.
 
(2) Risk reduction due to incineration
 
Once a carcass/SRM has been introduced into a small incinerator there are two main sources for the potential release of BSE infectivity
 
(a) Airborne emissions
 
(b) Residual ash There is no direct data on the TSE levels that may occur in those two media.
 
The SSC however is aware of currently ongoing heat studies mimicking various incineration conditions and scenarios and aiming at assessing the TSE clearance efficacy of these processes (P.Brown, pers.comm., 16.01.03) on both the residual ash and the trapped emission gases. In the absence of final data from such experiments for individual (small) incinerator types, the DNV Report (2001) assumes that measurement of the total protein content of ash is a relevant surrogate for BSE/TSE material. Protein content is a useful indicator of the general performance of an incinerator. However it is much more problematic whether it is also a valid marker for possible BSE/TSE contamination as it known that BSE/TSE are relatively heat resistant as compared to other proteins. Failure to detect certain amino acids present in prions is encouraging but the sensitivity limits for amino acids are relatively poor for reassurance purposes. Equally important, the data provided in the DNV report shows moderate split sample 4 It may be mentioned that this assumption may be valid for the UK as a whole, but note necessarily for all other Member States. 7 variation but often substantial inter sampling variation (up to 600 fold). This indicates a wide span of performance standards among the small SRM incinerators in the UK and most likely across the whole of the EU. Typically performance was substantially poorer than is the case for larger incinerators. Unburned material is not uncommonly noted in the ash from small incinerators. If the reduction in protein content due to incineration is accepted as a valid indicator, typical infectivity reduction can be calculated to be of the order of 1600 (DNV Report 2001). Incinerators are known to emit particulate matter from their stacks. Larger incinerators have much higher stacks to facilitate disposal of emissions, they also have gas cleaning equipment to minimise the emission of particulate matter, metals and acidic gases. Small incinerators generally do not have any gas cleaning equipment. It can be speculated (as in the DNV Report 2001) that unburned materials (and therefore potentially infections is much less likely to be emitted in the form of particulate matter than burnt material. Nonetheless there is no data to support this assumption.
 
(3) Other considerations.
 
(a) Disposal of ash. In the case of small incinerators ash is often dispersed of locally to a trench, which is typically neither lined, nor is the residue buried deeply. In contrast for larger incinerators in the UK ash is normally disposed of to a contained landfill. The risk from disposal to a trench is difficult to gauge in the absence of reliable data on the possible infectivity of the ash.
 
(b) Management factors. Almost inevitably the level of expertise available for the management of small incinerators is highly variable because few such facilities can afford to employ specialists in incineration. This is also likely to be often the case for the inspectors as well. While such considerations cannot formally be taken into account in a risk assessment, they are not the less relevant factors that need to be considered in assessing the risk from a particular plant.
 
(c) Benchmarking. The DNV 2001 risk assessment relies greatly on the assumption that BSE/TSE contaminated material is very unlikely to be processed. The Report seeks to compare the risks from a small incinerator with that from large SRM incinerators which the author had assessed previously (DNV, 1997). It identifies that the risk is four-five -fold less from a typical small incinerator because the scale of activities is much lower. However it is noted that the amount of experimental data to back this conclusion is extremely limited and does not take into account either risks from the residual ash or any consequences of a substantially lower stack height limiting the dilution of the emitted particulate and gaseous matter. 8
 
5. FURTHER INVESTIGATIONS
 
In view of the uncertainty regarding the risks due to BSE/TSE contamination of the fly and bottom ash and airborne emissions it is recommended that further research is conducted to identify the residual risks (along with attendant uncertainties) from the burial of ash (without further treatment,) in uncontained sites. It is essential that suitable monitoring methods are developed.
 
6. LITERATURE EC (European Commission), 1999.
 
Opinion on The risks of non conventional transmissible agents, conventional infectious agents or other hazards such as toxic substances entering the human food or animal feed chains via raw material from fallen stock and dead animals (including also: ruminants, pigs, poultry, fish, wild/exotic/zoo animals, fur animals, cats, laboratory animals and fish) or via condemned materials. Adopted By the Scientific Steering Committee at its meeting of 24-25 June 1999 and re-edited at its meeting of 22-23 July 1999. DNV Consulting (Det Norske Veritas), 1997. Risks from disposing of BSE infected cattle in animal carcass incinerators. Report prepared for the UK Environment Agency. DNV Consulting (Det Norske Veritas), 2001. Risk assessment of SRM incinerators. Prepared for the UK Ministry of Agriculture, Fisheries and Food. Revision 2 of the Draft report, February 2001. 24 pages. SEAC (Spongiform Encephalopathy Advisory Committee, UK), 2001. Public summary of the SEAC meeting of 25 April 2001.
 
 
 
Revised TSE Guidance Part 4 Part 4 Infection control of CJD and related disorders in the healthcare setting Summary of revised advice published: 2 June 2003
 
snip...
 
Use of laser for tonsillectomy : smoke plumes 4.45 Some ENT surgeons may use laser techniques as an alternative to conventional surgery for tonsillectomy. There is no evidence of the transmission of TSEs by the respiratory route. Any risk to surgeons from smoke plumes is thought to be very low, but there are no data on vCJD. General guidance on the safe use of lasers, Guidance on the safe use of lasers in medical and dental practice, Medical Devices Agency (MDA) (1995) is available from MDA Business Services on tel: 0207 972 8360.
 
snip...
 
 
 
 
 
some other data on incineration and plume, filters, etc;
 
what about those healthy looking deer/elk everyone wants to bury?
 
> The DOW Web site advises hunters "not to shoot, handle or consume any animal
 
> that appears sick" and to avoid consuming the "brain, spinal cord, eyes, spleen, tonsils
 
> and lymph nodes of harvested animals."
 
THOSE HEALTHY LOOKING DEER/ELK ''SUB-CLINICAL'' INFECTION
 
DEAD DEER WALKING
 
Issued: Monday, 28 August 2000 NEW EVIDENCE OF SUB-CLINICAL PRION INFECTION: IMPORTANT RESEARCH FINDINGS RELEVANT TO CJD AND BSE
 
A team of researchers led by Professor John Collinge at the Medical Research Council Prion Unit1 report today in the Proceedings of the National Academy of Sciences, on new evidence for the existence of a 'sub-clinical' form of BSE in mice which was unknown until now.
 
The scientists took a closer look at what is known as the 'species barrier' - the main protective factor which limits the ability of prions2 to jump from one species to infect another. They found the mice had a 'sub-clinical' form of disease where they carried high levels of infectivity but did not develop the clinical disease during their normal lifespan. The idea that individuals can carry a disease and show no clinical symptoms is not new. It is commonly seen in conventional infectious diseases.
 
Researchers tried to infect laboratory mice with hamster prions3 called Sc237 and found that the mice showed no apparent signs of disease. However, on closer inspection they found that the mice had high levels of mouse prions in their brains. This was surprising because it has always been assumed that hamster prions could not cause the disease in mice, even when injected directly into the brain.
 
In addition the researchers showed that this new sub-clinical infection could be easily passed on when injected into healthy mice and hamsters.
 
The height of the species barrier varies widely between different combinations of animals and also varies with the type or strain of prions. While some barriers are quite small (for instance BSE easily infects mice), other combinations of strain and species show a seemingly impenetrable barrier. Traditionally, the particular barrier studied here was assumed to be robust.
 
Professor John Collinge said: "These results have a number of important implications. They suggest that we should re-think how we measure species barriers in the laboratory, and that we should not assume that just because one species appears resistant to a strain of prions they have been exposed to, that they do not silently carry the infection. This research raises the possibility, which has been mentioned before, that apparently healthy cattle could harbour, but never show signs of, BSE.
 
"This is a timely and unexpected result, increasing what we know about prion disease. These new findings have important implications for those researching prion disease, those responsible for preventing infected material getting into the food chain and for those considering how best to safeguard health and reduce the risk that theoretically, prion disease could be contracted through medical and surgical procedures."
 
ISSUED FRIDAY 25 AUGUST UNDER EMBARGO. PLEASE NOTE THAT THE EMBARGO IS SET BY THE JOURNAL.
 
 
 
Aguzzi warns of CWD danger
 
The TSE family of diseases also includes chronic wasting disease (CWD) in deer, a condition that has spread in the US in recent years (Nature 416, 569; 2002). Speaking at the Days of Molecular Medicine conference in La Jolla in March, prion expert Adriano Aguzzi issued a strong warning against underestimating this form of TSE.
 
"For more than a decade, the US has by-and-large considered mad cows to be an exquisitely European problem. The perceived need to protect US citizens from this alien threat has even prompted the deferral of blood donors from Europe," he said. "Yet the threat-from-within posed by CWD needs careful consideration, since the evidence that CWD is less dangerous to humans than BSE is less-than-complete. Aguzzi went on to point out that CWD is arguably the most mysterious of all prion diseases.
 
"Its horizontal spread among the wild population is exceedingly efficient, and appears to have reached a prevalence unprecedented even by BSE in the UK at its peak. The pathogenesis of CWD, therefore, deserves a vigorous research effort. Europeans also need to think about this problem, and it would be timely and appropriate to increase CWD surveillance in Europe too." Aguzzi has secured funding from the National Institutes of Health to investigate CWD, and the effort will be lead by Christina Sigurdson in his department at the University of Zurich. KAREN BIRMINGHAM, LONDON
 
This quote from Dr. Gambetti is especially significant since he is the rather cautious TSE researcher under contract with the Centers for Disease Control to examine the brains of individuals who have died of CJD. -----------------
 
Pierluigi Gambetti, director of the National Prion Disease Pathology Surveillance Center at Case Western Reserve University in Cleveland, said all deer should be tested for chronic wasting disease before any processing is done.
 
"There is no way around it," he said. "Nobody should touch that meat unless it has been tested."
 
--------------------------------------
 
 
 
Greetings again,
 
extreme caution should be used, plume should be taken very seriously, with the best filters available being used, but by far, incineration is the only way to go, with present knowledge of agent...
 
do not bury this material in any land fill!
 
TSS
 
 
 
END...NOV...2013
 
LAYPERSON
 
MOM DOD 12/14/97 HEIDENHAIN VARIANT OF CREUTZFELDT JAKOB DISEASE a rare sub-type of the infamous sporadic CJDs, just one of many strains of the sporadic CJDs. ...UNKNOWN ROUTE AND SOURCE. ...TSS
 
Terry S. Singeltary Sr.
 
 
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see my full text submission with source references in attachment...TSS
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end...November 2013...TSS
 
 

1 comment:

  1. Friday, October 09, 2015

    Texas TWA Chronic Wasting Disease TSE Prion Webinars and Meeting October 2015

    http://chronic-wasting-disease.blogspot.com/2015/10/texas-twa-chronic-wasting-disease-tse.html


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