Pathogen Safety Data Sheet - Hog Cholera

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SECTION I : DISEASE / INFECTIOUS AGENT

SYNONYM / CROSS REFERENCE : Classic Swine Fever ⁽¹⁾, Classical Swine Fever, CSF ⁽²⁾, Peste du Porc, Colera Porcina, Virusschweinepest ⁽³⁾

ETIOLOGY / TAXONOMY : ⁽¹⁾

Family: Flaviviridae
Genus: Pestivirus

ORGANISM CHARACTERISTICS :

• Small (40-50nm in diameter), single-stranded RNA ⁽⁴⁾
• Lipid-containing envelope ⁽²⁾
• Only one serotype exists ; although minor antigenic variability among strains can be shown ⁽⁵⁾
• Moderately fragile ⁽⁶⁾

SURVEILLANCE :

Classical swine fever 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 CFIA district veterinarian. Control or eradication measures will be applied (http://laws.justice.gc.ca/en/H-3.3/fulltoc.html).

DISTRIBUTION: ⁽²⁾

• The status of CSF in Canada is non-indigenous.
• Present throughout Europe with the exception of Ireland, Iceland, Switzerland and Scandinavian countries; prevalence in Western Europe has decreased in recent years.
• Outbreaks occurred in the United Kingdom in 1986 and 2000, but it has since been eradicated.
• Also present in East and Central Africa, the Indian subcontinent, China, East and Southeast Asia, Mexico and most other countries in Central America and throughout most of South America.

SECTION II : ANIMAL HEALTH HAZARD AND EPIDEMIOLOGY

CLINICAL DISEASE / PATHOGENESIS :

1) Clinical signs:

Peracute form: ⁽²⁾

• Pigs found dead with no prior clinical signs. Currently this form is rare.

Acute form: ⁽²⁾

• Fever up to 42°C
• Hyperaemia or cyanosis of extremities, particularly ears and snout
• Loss of appetite or irregular appetite
• Inability or unwillingness to stand up and possibly convulsions
• Incoordination and/or stiff gait
• Huddling together and piling on top of another
• Laboured breathing and coughing
• Dysentery or diarrhea
• Conjunctivitis
• Nasal discharge
• Vomiting
• Abortion
• Severe leucopenia
• Death may occur in 10-20 days

Subacute form: ⁽²⁾

• Clinical signs as listed under acute form, but milder and persisting longer (3-4 weeks)
• Fever may fluctuate irregularly (>40.5°C)
• Case fatality rate lower

Chronic form: ⁽²⁾

• Failure to thrive
• Pneumonia
• Loss of appetite, fever, diarrhea, alopecia, dermatitis
• Death is often due to secondary bacterial infections
• Pigs may become chronic carries without showing any clinical symptoms

Piglets: ⁽³⁾

• Born with congenital tremor or congenital malformations of the visceral organs and central nervous system
• Persistently viremic and become clinically ill after several months
• Mild anorexia, depression, stunted growth, dermatitis, diarrhea, conjunctivitis, ataxia, paresis, and may die

2) infectious dose: Unknown

3) incubation period: 2 to 14 days

SOURCE / MODE OF TRANSMISSION / COMMUNICABILITY :

• The source of infection is blood and all tissues, secretions and excretions of sick and dead animals ⁽⁷⁾
• Congenitally infected piglets are persistently viraemic and may shed the virus for months ⁽⁷⁾
• Infection can occur through mucous membranes, conjunctiva, skin abrasions, insemination, or percutaneous blood transfer ⁽³⁾
• Direct contact with infected pigs or by ingestion of products from infected pigs can lead to infection ⁽²⁾
• Indirect contact through premises, implements, vehicles, clothes, fomites, instruments, and needles ⁽⁷⁾
• Insufficiently cooked waste food fed to pigs can cause infection ⁽⁷⁾
• Transplacental infection may occur ⁽⁷⁾
• Virus is excreted in the highest concentration in oral fluids, smaller quantities in the urine, faeces and nasal and lachrymal fluid ⁽⁷⁾
• Large quantities of virus may be disseminated when carrier sows farrow ⁽⁷⁾
• Aerosol spread is sometimes seen in confined spaces; virus does not travel long distances in the air ⁽³⁾

VECTORS : ⁽³⁾

• CSF virus is not transmitted biologically by any insect/arthropod vectors
• Virus may be spread mechanically by pets, birds and arthropods

HOST RANGE : ⁽³⁾

• Domestic and wild pigs

ZOONOTIC POTENTIAL : ⁽³⁾

• CSF cannot be transmitted to humans

RESERVOIR :

• Pig and wild boar are the only natural reservoir of CSF virus ⁽⁷⁾

SECTION III : DIAGNOSIS

NECROPSY / HISTOPATHOLOGY FINDINGS: ^(2,7)

Acute form:

• Leucopenia and thrombocytopenia
• Petechiae and ecchymoses in the skin, lymph nodes, larynx, bladder, kidney, ileocaecal junction
• Multifocal infarction of the margin of the spleen is characteristic, but not always present
• Enlarged hemorrhagic lymph nodes
• Encephalomyelitis with perivascular cuffing
• Pin-pont hemorrhages on the tonsils which are often enlarged and necrotic
• Septal oedema of lungs

Chronic form:

• Enlarged lymph nodes
• Button ulcers in the caecum and large intestine
• Generalized depletion of lymphoid tissue
• Thymic atrophy
• Fibrinous pericarditis and pleurisy

Congenital form:

• Central dysmyelinogenesis, cerebellar hypoplasia, microencephaly, pulmonary hypoplasia, hydrops and other malformations

SAMPLE SUBMISSION:

• Whole blood
• Serum
• Fixed and fresh tissues - particularly palatine tonsil, spleen, kidney, lymph nodes and terminal ileum

All samples should be transported at 4°C.
For more information regarding the type of samples necessary for CSF diagnosis, please contact the National Centre for Foreign Animal Disease:

Diagnostic Co-ordinator National Centre for Foreign Animal Disease 1015 Arlington Street Associate Diagnostic Co-ordinator 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: ⁽⁸⁾

Identification of the agent:

• Direct fluorescent antibody test (FAT)
• Reverse transcriptase polymerase chain reaction (RT-PCR)
• Virus isolation

Serological tests:

• Neutralizing peroxidase-linked assay (NPLA)
• Enzyme-linked immunosorbent assay (ELISA)
• Competive enzyme-linked immunosorbent assay (cELISA)

DRUG SUSCEPTIBILITY : ⁽²⁾

• None
• Attenuated virus vaccines used to control CSF; Chinese lapinised strain (CLS), Japanese guinea pig cell culture adapted (GPE- ) and Thiveral (the French PK-15 cell adapted) vaccine strains
• Stable and suitable for use in pregnant sows and new-born piglets

DIFFERENTIAL DIAGNOSIS : ^(2,3,6)

The following diseases may show clinical similarity to CSF:

• African swine fever
• Aujesky's disease
• Erysipelas
• Salmonellosis
• Warfarin poisoning
• Pasteurellosis/ pneumonia
• Pseudorabies
• Mulberry heart disease
• Thrombocytopenia purpura
• Viral encephalomyelitis
• Glasser's disease
• Eperythrozoonosis
• Post-weaning multisystemic wasting syndrome
• Swine erysipelas
• Swine dysentery

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 CSF virus.

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

PHYSICAL INACTIVATION:

• Sensitive to ultraviolet radiation ⁽⁴⁾
• Inactivated at a pH below 3 and above 10 ⁽²⁾
• Inactivated at 60°C for 10 minutes ⁽²⁾

SURVIVAL OUTSIDE OF HOST :

• Virus is moderately fragile and does not persist in the environment long or spread long distances by the airborne route ⁽⁹⁾
• Survives for prolonged periods in a moist, protein-rich medium such as meat, other tissues, and body fluids, particularly if kept cold or frozen ⁽⁹⁾
• Virus survival times in meat ^(6,9)
  • Years at -20°C
  • 45 days at 4°C
  • 85 days in cured and smoked ham
  • 180 days in salted and dried hams
• Survives 7-14 days at 37°C in blood ⁽²⁾
• In pens and dung the virus appears to be inactivated in a few days ⁽²⁾

SECTION V : LABORATORY HAZARDS FOR HUMANS

LABORATORY-ACQUIRED INFECTIONS :

• None, CSF does not affect humans ⁽³⁾

BIOSAFETY PRECAUTIONS:

• None

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. The Standards can be accessed at : http://www.inspection.gc.ca/english/sci/lab/convet/convete.shtml

PERSONAL PROTECTIVE EQUIPMENT :

Laboratory:

• Primary layer of protective clothing should include dedicated laboratory clothing (e.g. scrubs ) and laboratory dedicated footwear.
• Secondary layer of protective clothing (e.g. solid-front gowns with tight-fitting wrists, 1 pair of gloves) should be worn over laboratory clothing when directly handling infectious materials.
• A shower is required on exit.

Post Mortem:

• Primary layer of protective clothing should include dedicated laboratory clothing (e.g. scrubs) and laboratory dedicated footwear.
• Secondary layer of protective clothing (e.g. solid-front gowns with tight-fitting wrists, 1 pair 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.
• 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. 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 1019-26.
2. Australian Veterinary Emergency Plan. 1996. Disease Strategy, Classical Swine Fever:
   http://www.animalhealthaustralia.com.au/
   aahc/index.cfm?E9711767-B85D-D391-45FC-CDBC07BD1CD4
3. The Center for Food Security and Public Health. Classical Swine Fever Fact Sheet - PDF (139 kb). Updated Sept 21, 2004. http://www.cfsph.iastate.edu/Factsheets/pdfs/classical_
   swine_fever.pdf.
4. Australian Veterinary Emergency Plan. Operational Procedures Manual: Decontamination. 2000. Pages 6, 28 and 50.
5. Buisch W.W., Hyde J.L. & C.A. Mebus. Foreign Animal Diseases. Sixth Edition. American Public Health Association. 2000. Pages 273-82.
6. John Pasick. Classical swine fever and African swine fever. CFIA-FAD (Dry) Course. November 14-18, 2005.
7. World Organization for Animal Health, OIE. Animal Disease Data, Classical Swine Fever (Hog cholera), updated 22/04/2002. http://www.oie.int/eng/maladies/fiches/a_A130.htm.
8. Manual of Diagnostic Tests and Vaccines for Terrestrial Animals, OIE World Organisation for Animal Health. Classical Swine Fever, updated 2004/07/23. http://www.oie.int/eng/normes/mmanual/A_00036.htm.
9. The Merck Veterinary Manual, Eighth Edition. 1998. Pages 509-512.

LAST UPDATED: 2005/12/06
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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