Pathogen Safety Data Sheet - Swine Vesicular Disease

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Section I: Disease / Infectious Agent

Synonym / Cross Reference

SVD ⁽¹⁾

Etiology / Taxonomy

Family: Picornaviridae ⁽²⁾
Genus: Enterovirus ⁽²⁾

Antigenically related to human Coxsackie B-5 virus , and unrelated to other porcine enteroviruses ⁽³⁾.

Organism Characteristics

• Single-strand RNA genome virus ⁽⁴⁾
• Positive-sense RNA of low molecular weight, about 2.5 x 106 ⁽⁵⁾
• Non-enveloped ⁽⁵⁾
• Virion measures 28 nm ⁽⁴⁾
• Only one serotype, although minor antigenic differences have been noted between some isolates ⁽¹⁾
• Isolates vary in virulence ⁽¹⁾

Surveillance

Swine Vesicular Disease is a reportable disease in Canada. Animal owners, veterinarians and laboratories are required to immediately report the presence of an animal that is infected or suspected of being infected to a Canadian Food Inspection Agency (CFIA) district veterinarian. Control or eradication measures will be applied immediately. For more information, please see the Health of Animals Act.

Distribution

• The status of Swine Vesicular Disease in Canada is non-indigenous ⁽¹⁾
• First recognized in Italy in 1966 ⁽¹⁾
• Outbreak in Hong Kong in 1971, followed by Britain, Austria and Poland in 1972 ⁽⁶⁾
• Occurred also in France, Germany, Switzerland, the Netherlands, Greece, Spain, Japan and Taiwan ⁽¹⁾

Section II: Animal Health Hazard and Epidemiology

Clinical Disease / Pathogenesis

Clinical Swine vesicular disease is an acute, highly contagious virus disease of pigs, clinically similar to foot and mouth disease, but only occurs in swine.

1. Clinical signs:

   • Fever ⁽⁷⁾
   • Salivation ⁽⁷⁾
   • Lameness ⁽⁷⁾
   • Vesicles appear around coronary bands of digits, rupture easily within 36 hours, leaving a shallow ulcer ⁽¹⁾
   • Coronary band, horn and sole may separate from the underlying tissue, the line of separation appears as a dark horizontal line that progressively moves down the hoof with new horn growth ⁽¹⁾
   • Rarely vesicles can be seen on the snout, particularly on the dorsal surface, on the lips, tongue and teats ⁽⁸⁾
   • Neurological signs due to encephalitis are rare; shivering, unsteady gait, chorea of the legs ⁽⁷⁾
   • Infection may be subclinical, mild or severe depending on the virulence of the strain ⁽⁷⁾
   • Recovery usually occurs in 2-3 weeks with little residual damage ⁽³⁾
   • Low morbidity when compared to FMD and low mortality ⁽⁹⁾
   
   

2. Infectious dose: Unknown

3. Incubation period:

   • 2-7 days following exposure to infected pig ⁽¹⁰⁾
   • 2-3 days following ingestion of infected material ^(3,9)

Source / Mode of Transmission / Communicability

• Direct contact between pigs, virus enters the host through damaged epithelia, usually in the skin of the feet and multiplies in epithelial cells ⁽¹⁾
• Ingestion of contaminated meat scraps and contact with infected feces ⁽⁷⁾
• When exposed to large amounts of virus, by ingestion, infection can then occur via entry through the tonsils and digestive mucosa ⁽¹⁾
• Fomites such as materials contaminated with infected feces or urine can act as a source of transmission, however erratic ⁽¹⁾
• Virus survives for many months in contaminated buildings, vehicles and on pastures ⁽¹⁾
• Pigs excrete virus from nose, mouth, and in feces up to 48 hours before clinical signs appear ⁽³⁾
• Virus is shed in vesicular fluids and other excretions and secretions starting within 1 day of infection and usually ceases within 14 days ⁽¹⁾
• Virus can be shed in the feces for up to 3 months following infection ⁽⁷⁾
• Airborne spread

Vectors

• Mechanical spread by people, rodents, insects and birds can occur, but is of relatively minor importance ^(1,10)

Host Range

• Swine are only natural host ⁽⁴⁾
• Humans: laboratory personnel may seroconvert ⁽²⁾

Zoonotic Potential

• Not a factor, but slight zoonotic capability is suspected ⁽¹⁰⁾
• Seroconversion and mild clinical disease with one case of meningitis has been seen in laboratory workers ^(4,7)
• SVD virus is related to human Coxsackie virus B5 ⁽⁴⁾

Reservoir

• No reservoir hosts are known ⁽¹⁾

Section III: Diagnosis

Necropsy / Histopathology Findings ^(1,5)

• Vesicle formation and resolution ^(1,7)
• Mild to moderate diffuse encephalomyelitis with perivascular cuffing ⁽¹⁾
• Formation of neuroglia foci has been described in experimentally-produced disease ⁽¹⁾

Sample Submission

• Whole blood from febrile swine
• Vesicular fluid in a sterile container
• Fecal samples
• Vesicular epithelium
• Serum
• Fixed and fresh tissues

All samples should be transported at 4°C.

For more information regarding the type of samples necessary for Swine Vesicular Disease 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

• Enzyme-linked immunosorbent assay (ELISA) ⁽⁸⁾
• Virus neutralization ⁽⁸⁾
• Direct compliment fixation test ⁽²⁾
• Cell-culture virus isolation ^(2,9)

Drug Susceptibility

None ⁽²⁾

Differential Diagnosis ⁽¹⁾

The following diseases may show clinical similarity to Swine Vesicular Disease:

Exotic viral diseases:

• Foot-and-mouth disease
• Vesicular stomatitis
• Vesicular exanthema

Dermatitis:

• Scalding, wetting, contact dermatitis, photosensitization, chemical or thermal burns

Phytophotodermatitis:

• Contact with certain plants containing furocoumarins

Lameness:

• Laminitis

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 (e.g. Quantitative Carrier Test). See table 1 to help select a registered disinfectant for use against Swine Vesicular Disease virus.

Table 1: Active ingredients considered to be effective against Swine Vesicular Disease virus.

Active Ingredient	Concentration	Contact Time
Oxidising agents: Sodium hypochlorite Calcium hypochlorite	2-3% (20,000-30,000 ppm)	10 minutes (10)
Alkalis: Sodium hydroxide	2% (w/v)	10 minutes (10)
Acids: Hydrochloric acid Citric acid	2% (v/v) 0.2% (w/v)	10 minutes (10) 30 minutes (10)

Physical Inactivation

• Inactivated by 56°C for 1 hour ⁽²⁾
• Very resistant over a wide pH range (pH 2-12) ⁽¹⁰⁾

Survival Outside of Host

• Can survive in pig feces for at least 5 months ⁽¹⁰⁾
• Persists for four to six weeks in slaughterhouse effluents at temperatures of 18-22°C ⁽⁴⁾
• Can survive up to 2 years in lymphoid tissue contained in dried, salted or smoked meat ⁽⁷⁾

Section V: Laboratory Hazards for Humans

Laboratory-acquired Infections

• SVD virus is related to human Coxsackie B-5 virus and respiratory, signs possibly due to the virus, have been reported in people working with it in the laboratory ^(1,9)
• There have been no cases with vesicular eruption ⁽⁴⁾

Biosafety Precautions

• Laboratory workers should observe the same caution that applies to any microbiologically contaminated material that may have the potential to cause human infection

Section VI: Physical and Operational Requirements

Containment Requirements

All physical containment and operational practices for containment level 3, as per the Containment Standards for Veterinary Facilities must be met.

Personal Protective Equipment (PPE)

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.
• Adequate respiratory protection should be worn when directly handling infectious material outside Biological Safety Cabinet.
• 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.
• Adequate respiratory protection should be worn when directly handling infectious material outside Biological Safety Cabinet.
• 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.
• Spills outside the biological safety cabinet.
• 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. Australian Veterinary Emergency Plan. 1996. Disease Strategy, Swine vesicular disease.
2. World Organization for Animal Health, OIE. Animal diseases data, Swine vesicular disease, updated 22/04/2002.
3. Spicler, A., Roth, J., Emerging And Exotic Diseases of Animals, Iowa state University Press 2004. Page 180.
4. Acha, P.D. and Szyfres, B. Zoonoses and Communicable Diseases Common to Man and Animals. Third Edition. Volume II. Chlamydioses, Rickettsioses, and Viroses. Scientific and Technical Publication Number 580. Pan American Health Organization. 2003. Pages 326-30.
5. Murray PR, Baron EJ, Pfaller MA, Tenover FC, and Yolken RH. Manual of Clinical Microbiology. Seventh Edition. American Society for Microbiology. 1999. Pages 835-9.
6. Radostits OM, Gay CC, Blood DC, and KW Hinchcliff. Veterinary Medicine, A Textbook of the Diseases of Cattle, Sheep, Pigs, Goats and Horses. Ninth Edition. W.B. Saunders Company Ltd. 2000. Pages 1066-8.
7. The Center for Food Security and Public Health. Swine Vesicular Disease Fact Sheet - PDF (77 kb). December 10, 2003.
8. World Organisation for Animal Health, OIE. Manual of Diagnostic Tests and Vaccines for Terrestrial Animals, Swine Vesicular Disease, updated 2004/07/23.
9. The National Centre for Foreign Animal Diseases Laboratory. 2006. Canadian Food Inspection Agency. Winnipeg, Manitoba.
10. Australian Veterinary Emergency Plan. Operational Procedures Manual: Decontamination. 2000. Page 39 and 50-51.

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.