Pathogen Safety Data Sheet - Bovine Spongiform Encephalopathy

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SECTION I: DISEASE / INFECTIOUS AGENT

SYNONYM / CROSS REFERENCE: Bovine Spongiform Encephalopathy (BSE) \ Mad cow Disease \ Bovine TSE

ETIOLOGY / TAXONOMY
Prion - small proteinaceous particles

CHARACTERISTICS:

• abnormal prion protein which has ability to convert normal prion protein to an abnormal form

SURVEILLANCE :

• BSE is a reportable disease in Canada. Animal owners, veterinarians and laboratories are required to immediately report the presence of an animal that is contaminated or suspected of being contaminated to a CFIA district veterinarian. Control or eradication measures will be applied immediately.
• A program of active, targeted surveillance of high risk cattle (adults over 24 month of age) was implemented in 1992. High risk cattle includes BSE suspects, dead stock, emergency slaughter and non-ambulatory cattle.

DISTRIBUTION :

• The Status of BSE in Canada is indigenous.
• Adult cattle, mean age of on-set 5 years (range: 2 years to aged)
• Diagnosed from indigenous animals in Austria, Belgium, Canada, Czech Republic, Denmark, Finland, France, Germany, Greece, Ireland, Israel, Italy, Japan, Liechtenstein, Luxembourg, Netherlands, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, the United Kingdom and the United States.
• Diagnosed from imported animals in Falkland Islands and Oman.

SECTION II: ANIMAL HEALTH HAZARD AND EPIDEMIOLOGY

Clinical signs:

• fatal, progressive debilitating central nervous system disease characterized by aggressive or nervous behavior, degenerated motor skills and posture
• poor body condition despite no decrease in appetite, decreased milk production
• clinical animals appear alert but are agitated, anxious and apprehensive
• no immune response
• symptoms may exist for 2-6 months before death

2) Infectious dose:

• To cattle: 1 gram of infected brain material (by oral ingestion)

3) Incubation period:

• 2-8 years

SOURCE / MODE OF TRANSMISSION / COMMUNICABILITY:

• Central nervous system and other tissues are infectious throughout symptomatic illness; central nervous system, ileum and palatine tonsil may be a source of infectivity during preclinical stages of the disease in experimental BSE after oral inoculation in Cattle
• the brain, spinal cord, trigeminal ganglia, dorsal root ganglia, ileum and retina of infected cattle (Bovidae family)
• bone marrow considered slightly infectious when animals are exhibiting clinical signs
• Ingestion of contaminated food stuffs containing tissues from infected animals
• Some evidence suggests that there may be maternal transmission but at a very low level
• No evidence of horizontal transmission

VECTORS: none

HOST RANGE:

• Cattle (OIE lists all members of the Bovidae family)
• Felidae family (Feline Spongiform Encephalopathy - FSE)
• Experimentally infected: sheep, goats, pigs, mice, mink and marmosets
• Humans (Variant Creutzfeldt-Jakob Disease - vCJD) see zoonosis for details

ZOONOSIS:

• It is believed that humans have developed Variant Creutzfeldt-Jakob disease (vCJD) from consumption of BSE contaminated products.

RESERVOIR: Cattle

Section III: DIAGNOSIS

NECROPSY / HISTOPATHOLOGY FINDINGS:

• lesions associated with trauma due to falling, tripping
• brain: bilaterally symmetrical spongiform degeneration (vacuolation of the gray matter neutrophils and neurons)
• astrocytic gliosis affecting the nerve cells of the brain stem

SAMPLE SUBMISSION:

• Whole blood
• Serum
• Fixed and fresh tissues

All samples should be transported at 4°C.

For more information regarding the type of samples necessary for BSE diagnosis, please contact the National Centre for Foreign Animal Disease:

Diagnostic Co-ordinator National Centre for Foreign Animal Disease 1015 Arlington Street Winnipeg, Manitoba R3E 3M4 Telephone : 204-789-2012 Fax: 204-789-2038

Associate Diagnostic Co-ordinator National Centre for Foreign Animal Disease 1015 Arlington Street Winnipeg, Manitoba R3E 3M4 Telephone: 204-789-2113 Fax: 204-789-2143

LABORATORY DIAGNOSIS ⁽³⁾:

• Histopathology
• Immunohistochemistry
• Immunoblotting
• Electron Microscopy
• Experimental transmission: in vivo inoculation or ingestion in mouse models

DRUG SUSCEPTIBILITY: not applicable

DIFFERENTIAL DIAGNOSIS :
The following diseases may show clinical similarities to BSE:

• Rabies
• Listeriosis
• nervous ketosis
• hypomagnesemia
• hypocalcemia
• thromboembolic meningoencephalitis
• spinal cord or brain abscess or neoplasia
• traumatic injury
• lead poisoning or other toxicity
• polioencephalomalacia

SECTION IV: DECONTAMINATION PROCEDURES

Select a registered disinfectant with a drug identification number (DIN). Use according to label directions for concentration and contact time. Consider organic load and temperature. It is recommended that laboratories evaluate the effectiveness of the disinfectant using a validated method (eg. Quantitative Carrier Test). See table 1 to help select a registered disinfectant for use against BSE.

TABLE 1 : RECOMMENDED PROCEDURES FOR INACTIVATION OF BSE

Note : Table 1 has been developed for use by for veterinary diagnostic laboratories¹.
Complete inactivation may not be possible with chemicals or by physical inactivation

SURVIVAL OUTSIDE OF HOST:

• Similar TSE’s (ie. Hamster scrapie) have been found to remain infective after 3 years in soil
• Contaminated electrodes stored in ethanol-formalin for several years were found to cause CJD in a chimpanzee

SECTION V: LABORATORY HAZARDS FOR HUMANS

LABORATORY-ACQUIRED INFECTIONS: No documented laboratory acquired infections.

PRIMARY HAZARDS: Accidental inoculation or ingestion (see sources for specimens with high infectivity)

SPECIAL HAZARDS:
Cuts and punctures are to be avoided:

• the use of sharp knives, scalpels and blades are to be minimized.
• when the use of sharps can not be avoided, cut resistant gloves should be used
• blunt cannula should be substituted where possible for needles
• break resistant or shatterproof plasticware should be substituted for glassware where possible

CONTAINMENT REQUIREMENTS:
TSE diagnostic and surveillance facilities:
TSE diagnostic laboratories must at a minimum meet the physical requirements for containment level 2 as per the Containment Standards for Veterinary Facilities (http://www.inspection.gc.ca/english/sci/lab/convet/convete.shtml) plus the following physical and operational requirements:

• Entrance to laboratory should provide for the separation of PPE from staff clothing, preferably in a separate anteroom.
• Surfaces should be non-porous, cleanable and able to withstand chemicals used for decontamination.
• Penetrations in areas where spills may be likely should be sealed to allow for containment and thorough surface decontamination.
• Bag-in/bag-out HEPA biological safety cabinet are recommended. If they are not available, then a procedure must be in place for contained removal of HEPA filters.
• Autoclave should be located in the laboratory. If located elsewhere in the facility, then protocols should be in place that will allow for proper identification of the waste and the secure transport within the building.
• Operational requirements are listed in the Containment Standards for Laboratories, Animal Facilities and Post Mortem Rooms Handling Prion Disease Agents (http://www.inspection.gc.ca/english/sci/bio/prion/prionindexe.shtml).

Facilities working with known positive TSE material:
Physical and operational requirements described in the Containment Standards for Laboratories, Animal Facilities and Post Mortem Rooms Handling Prion Disease Agents (http://www.inspection.gc.ca/english/sci/bio/prion/prionindexe.shtml) must be met.

PROTECTIVE CLOTHING:
Laboratory:

• Personnel entering the laboratory must remove jewellery and should don solid-front gowns with tight-fitting cuffs, gloves, shoe covers or dedicated footwear. In general, solid front gowns are preferable to lab coats for preventing contamination of clothing. Consideration should be given to disposable labwear.
• Double gloves must be worn when handling infectious materials. Disposable sleeve covers are recommended for handling and manipulating infectious tissue.
• Full face protection such as dedicated eye protection with mask or a face shield should be worn for any procedures in which splashing and flying particles may be a hazard.
• A respirator is not a requirement however when respirators are used a respiratory protection program must be in place as per the Canada Labor Code.

Post Mortem:

• The minimal PPE to be worn while working with BSE is full protection clothing, double gloves (when using sharps also use cut resistant gloves), scrubs, disposable impermeable suit, waterproof apron, head cover, dedicated footwear or disposable impermeable footwear.
• Exposure to mucous membranes or accidental ingestion of contaminated tissues must be prevented by use of full face shield or safety goggles and surgical mask or N95.
• A respirator is not a requirement however when respirators are used a respiratory protection program must be in place as per the Canada Labor Code.

HANDLING INFORMATION
Spills in laboratory:
Spill protocol must be in place and include the following scenarios:

• spills inside the Biological Safety Cabinet (BSC)
• spills outside the BSC
• spills while performing aerosol generating procedures
• also consider entry and exit procedure modifications if necessary, appropriate PPE, disinfection of spill and surroundings including contact time, flow (pattern) of the clean up and disposal of contaminated materials.

Refer to Table 1 for inactivation of BSE.

STORAGE: All cultures and infected material should be stored in leak proof, sealed containers that are accurately labeled and clearly identified as a biohazard risk. The access to infectious material should be controlled at all times. Records must be kept to describe the use, inventory and disposal of infectious material.

DISPOSAL: Decontaminate all infectious material prior to disposal. Use steam sterilization, incineration or chemical disinfection.

REFERENCES:

1. Guidance from the Advisory Committee on Dangerous Pathogens and the Spongiform Encephalopathy Advisory Committee. Transmissble Spongiform Encephalopathy Agents: Safe Working and the Prevention of Infection. Part 3. December 15, 2003. http://www.dh.gov.uk/PolicyAndGuidance/HealthAndSocialCareTopics
   /CJD/CJDGeneralinformation/CJDGeneralArticle/fs/en?CONTENT_ID=
   4031067&chk=4gOe2r
2. European Comission, Scientific Steering Committee. Final Opinion and Report on: A Treatment of Animal Waste by Means of High Temperature (150 °C, 3 hours) and High Pressure Alkaline Hydrolysis. April 10-11, 2003. http://europa.eu.int/comm/food/fs/sc/ssc/out358_en/pdf
3. World Health Organization Communicable Disease Surveillance and Control. WHO Infection Control Guidelines for Transmissible Spongiform Encephalopathies; Report of a WHO Consultation Geneva, Switzerland, 23-26 March 1999. http://whqlibdoc.who.int/hq/2000/WHO_CDS_CSR_APH_2000.3.pdf
4. Guidance from the Advisory Committee on Dangerous Pathogens and the Spongiform Encephalopathy Advisory Committee. Decontamination and Waste Disposal - PDF (151 kb). Appendix C. December 15, 2003. http://www.dh.gov.uk/assetRoot/04/07/32/01/04073201.pdf
5. Infection Control Guidelines, Classic Creutzfeldt-Jakob Disease in Canada. Ottawa: Health Canada, Volume: 28S5, November 2002. http://www.hc-sc.gc.ca/pphb-dgspsp/publicat/ccdr-rmtc/02vol28
   /28s5/index.html
6. Taylor DM. Inactivation of prions by physical and chemical means. J Hosp Infect. 1999 Dec;43 Suppl:S69-76. Review.

LAST UPDATED (DATE): April 25, 2005
PREPARED BY: The Biohazard Containment and Safety Unit, CFIA

Disclaimer: Although the information and recommendations in this Pathogen Safety Data Sheet are compiled from reliable sources, there is no guarantee, warranty or any assurance that the information and recommendations are correct, accurate, sufficient, reliable or current and the Canadian Food Inspection Agency shall not be responsible for any loss or damage resulting from or in connection with the use of or reliance upon the information and recommendations.

The user assumes all risks and responsibility for and shall be liable for the use of and any reliance on the information and recommendations and the results thereof and any loss or damage resulting therefrom.

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