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PATHOGEN SAFETY DATA SHEET

EPIZOOTIC HEMORRHAGIC DISEASE

SECTION I: DISEASE / INFECTIOUS AGENT

SYNONYM / CROSS REFERENCE: EHD

ETIOLOGY / TAXONOMY:
Family: Reoviridae ⁽¹⁾
Genus: Orbivirus

ORGANISM CHARACTERISTICS:

• Orbirivirus are complex nonenveloped viruses with seven structural proteins (VP1-7) organized in a two layered capsid ⁽²⁾.
• Virions have an icosahedral morphology ⁽²⁾.
• The genome consists of 10 variously sized double-stranded RNA segments, three large, designated L1-L3, three medium, M4-M6, and four small, S7-S10 ⁽³⁾.
• There are at least 10 serotypes and some have antigenic relations with serotypes of Bluetongue virus ⁽³⁾.

SURVEILLANCE :

• Epizootic hemorrhagic disease is an immediately notifiable disease in Canada. The CFIA can undertake control measures for such diseases when notified of their presence in Canada. (http://laws.justice.gc.ca/en/H-3.3/fulltoc.html).

DISTRIBUTION :

• The status of epizootic hemorrhagic disease in Canada is non-indigenous.
• The geographic occurrence of EHD is similar to that of Bluetongue virus. The virus occurs on the North American, Australian, Asian and African continents ⁽⁴⁾.
• In North America, infection occurs in all areas of the United States, except the northeast and the arid southwest and in southern Canada ⁽⁴⁾.

SECTION II: ANIMAL HEALTH HAZARD AND EPIDEMIOLOGY

CLINICAL DISEASE / PATHOGENESIS:
1) Clinical signs :
EHD in Deer

• In North America, EHD is considered one of the most important diseases of deer, particularly of white-tailed deer (Odocoileus virginianus) but also mule deer (O. Hemionus) and pronghorn antelope (antilocapra americana) ⁽⁴⁾.
• All ages are susceptible, morbidity can be as high as 90% and mortality as high as 60% in some deer herds ⁽⁴⁾.
• Disease causes swelling of the face, tongue, neck and conjunctiva of the eyes, lack of appetite, weakness and in-coordination, excessive salivation (often blood-tinged), nasal discharge (often blood-tinged), bloody diarrhea, breathing difficulty and extensive hemorrhaging in many tissues including skin, gastrointestinal tract, heart and testicles.
• There is also a per-acute course of disease and a sudden death form. ⁽⁵⁾

EHD in Cattle

• EHD virus rarely causes disease in cattle. However, Ibaraki virus (EHD-2) has been associated with sporadic outbreaks of severe disease in cattle in Japan. Mortality rates have been as high as 10% ^{(1, 3)}.
• Clinical signs consist of fever, erosive and ulcerative lesions of the oral and esophageal mucosa, stiffness, lameness, and thickened, edematous skin ⁽¹⁾.
• In pregnant cows, EHD virus infection can result in fatal resorption or hydranencephaly if infection occurs between days 70 and 120 of gestation ⁽¹⁾.

2) Infectious dose: Unknown

3) Incubation period: Unknown

SOURCE / MODE OF TRANSMISSION / COMMUNICABILITY:

• Transmitted primarily by Culicoides species which are biological vectors ⁽¹⁾.
• Some species of gnats and mosquitos can also transmit the virus ⁽⁴⁾

VECTORS:

• Culicoides species

HOST RANGE :

• Virus infects wild and domestic ruminants with a great range of variability ⁽⁵⁾.
• Sheep can be infected experimentally but not goats or pigs.
• Deer

ZOONOTIC POTENTIAL :
EHD cannot be transmitted to humans.

RESERVOIR : generally waterfowl

• Deer

Section III: DIAGNOSIS

NECROPSY / HISTOPATHOLOGY FINDINGS:
EHD in Deer

• The widespread hemorrhages in mucous membranes, skin, and viscera are the result of disseminated intravascular clotting.
• Certain strain can cause widespread vascular lesions similar to those described for Bluetongue virus in cattle. Degenerative changes (focal hemorrhage or dry and gray-white appearance, or both) in striated musculature are prominent in the esophagus, larynx, tongue, and skeletal muscles ⁽¹⁾.
• Lesions vary with virulence of virus strain.
• In the per-acute form, there is sudden death with edema of the head, neck, eye and lungs.
• The acute form shows “classical” signs.
• The chronic form shows growth interruptions on hooves, or sloughing and loss of papillae on rumen mucosa ⁽⁵⁾.

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 EHD diagnosis, please contact the National Centre for Foreign Animal Disease:

LABORATORY DIAGNOSIS ⁽³⁾:

• virus isolation
• ELISA
• PCR
• AGID

DRUG SUSCEPTIBILITY: none

DIFFERENTIAL DIAGNOSIS:
The following diseases may show clinical similarity to EHD.

• Foot-and-mouth disease
• Bluetongue
• Plant photosensitization.

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 EHD virus.

Table 1: Active ingredients considered to be effective against EHD virus.

PHYSICAL INACTIVATION:

• Resistant to lipid solvents, is acid labile and resistant to slow freezing (-10°-20° C)
• Inactivated by 50°C for 3 hours; 60°C for 15 minutes ⁽⁶⁾; 121 C for 15 minutes (autoclaving)

SURVIVAL OUTSIDE OF HOST: Unknown

SECTION V: LABORATORY HAZARDS FOR HUMANS

LABORATORY ACQUIRED INFECTIONS: None

BIOSAFETY PRECAUTIONS : None

SECTION VI: PHYSICAL AND OPERATIONAL REQUIREMENTS

CONTAINMENT REQUIREMENTS:
All physical containment and operational practices for containment level 3, indigenous agents, as per the Containment Standards for Veterinary Facilities must be met. The Standards can be accessed at : http://www.inspection.gc.ca/english/sci/lab/convet/convete.shtml

PROTECTIVE CLOTHING:
Laboratory:

• Primary layer of protective clothing should include dedicated laboratory clothing (e.g. scrubs and headwear) and laboratory dedicated footwear.
• Secondary layer of protective clothing (e.g. solid-front gowns with tight-fitting wrists, 2 pairs of gloves) should be worn over laboratory clothing when directly handling infectious materials.
• A risk assessment should be conducted to determine if a respiratory protection is required when directly handling infectious material outside BSC.
• A shower is required on exit.

Post Mortem:

• Primary layer of protective clothing should include dedicated laboratory clothing (e.g. scrubs and headwear) and laboratory dedicated footwear.
• Secondary layer of protective clothing (e.g. solid-front gowns with tight-fitting wrists, 2 pairs of gloves) should be worn over laboratory clothing when directly handling infectious materials.
• Cut resistant gloves, adequate respiratory protection, steel toed/steel shanked rubber boots should also be worn when handling infectious materials.
• A shower is required on exit.

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 disinfectant selection.

STORAGE: All cultures and infected material should be stored in leakproof, 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. Committee on Foreign Animal Diseases of the United States Animal Health Association. Foreign Animal Diseases. Revised 1998, Library of Congress Catalog Card Number, 17-12842, Pages 106-11.
2. Roy P, Orbivirus Structure and Assembly, Virology 216, 1-11 (1996).
3. Field Manual of Wildlife Diseases in the Southeastern United States, 2nd Edition, Pages 24 - 33.
4. Radostits, O.M. Gay, C.C. Blood, D.C. & K.W. Hinchcliff. Veterinary Medecine, A Textbook of the Disease of Cattle, Sheep, Pigs, Goats and Horses. Ninth Edition. W.B. Saunders Company Ltd. 2000. Pages 1134.
5. OIE, Maladies animales, Fièvre catarrhale du mouton, http://www.oie.int/fr/maladies/fiches/f_a090.htm
6. Australian Veterinary Emergency Plan. Operational Procedures Manual: Decontamination. 2000.

LAST UPDATED (DATE): March 29th, 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.