SECTION I: DISEASE /
INFECTIOUS AGENT
SYNONYM / CROSS REFERENCE: Aphthous Fever, Aphtosis,
Aftosa, Epizootic Aphthae, Hoof-and-Mouth Disease, FMD
ETIOLOGY / TAXONOMY:
Family: Picornaviridae (1,
2)
Genus: Aphthovirus
- 7 distinct serotypes: A, O, C, Southern African Territories (SAT) 1, SAT 2, SAT 3 and Asia 1(1, 3,
4)
- over 60 subtypes with varying degrees of virulence - new subtypes can arise
spontaneously (4)
- serotypes and subtypes differ significantly: cross-protection does not
occur (1).
- some biotypical strains become adapted to particular animal species (eg., porcinophilic strains) (1).
ORGANISM CHARACTERISTICS:
- positive-strand RNA genome
(~8500 nucleotides) (4)
- non-enveloped, relatively smooth capsids of icosahedral symmetry, 28-30
nm in diameter (4)
SURVEILLANCE :
- Foot and mouth disease 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
(http://laws.justice.gc.ca/en/H-3.3/fulltoc.html).
DISTRIBUTION :
- The status of FMD in
Canada is non-indigenous.
- See
OIE website for list of current disease free countries:
http://www.oie.int/eng/info/en_fmd.htm#Liste
- the most transmissible viral disease of animals (4).
- RNA is infectious on its own
when transfected into susceptible cells (4).
- FMD is highly contagious/
low mortality rate/ great economic impact worldwide (1).
- The last outbreak in Canada was in 1951-1952 (1) and in the
United States was in 1929 (1).
- There was a major outbreak in the UK in 2001 (5).
- FMD is endemic in areas
of South America, Central and Southern Africa, and South East Asia.
SECTION II: ANIMAL HEALTH
HAZARD AND EPIDEMIOLOGY
CLINICAL DISEASE / PATHOGENESIS:
1) Clinical signs :
- FMD is an acute systemic
vesicular disease characterized by fever, profuse salivation and vesicles in
the mouth and on the muzzle, teats, coronary band, and inter-digital
space.
- Foot lesions are accompanied by acute lameness and reluctance to move
(1)
- Additional clinical signs include depression and loss of appetite and milk
production (3).
- Death in young animals may be due to lesions in the myocardium (tiger
heart) (4).
- Vesicle rupture may result in ulcerations at site.
2) Infectious dose: as few as 10 infectious particles can
produce disease (4).
3) Incubation period:
- 12 - 48 hours depending on the infecting dose, susceptibility of the host
and virus strain (6)
- typically 3-6 days in cattle (1)
- swine fed infected material develop signs 1-3 days - virus enters through
oral abrasion or via tonsil (6)
- cattle act as indicators, sheep act as maintenance hosts and swine act as
amplifiers (6).
SOURCE / MODE OF TRANSMISSION / COMMUNICABILITY:
Endemic areas:
- Virus spread is by direct contact between animals moving as trade or
nomadism (1).
Non-endemic areas:
- Pigs are often first to contract the infection by ingestion of infected
meat scraps.
- Virus spreads from pigs to cattle is via movement of susceptible livestock,
contaminated clothing, people movement, farm equipment, abattoir waste, or
further spread by airborne means (1).
- Contact between infected animals or asymptomatic carriers and susceptible
animals is the most common method of transmission (1, 7).
- Virus spreads from one animal to another by inhalation and ingestion
(1).
- Virus can also penetrate through skin lesions (4).
- Animals, humans, inanimate objects, and animal products (meat, milk, semen,
hay, feed, waste, etc.) can also
spread the virus (3).
- All excretions and secretions from infected animals contain virus particles
(2).
- The nasopharynx is the main site of persistence of the FMD virus (up to 2 years)
(1).
- FMD virus may also
persist in the mammary tissue for up to 3-7 weeks (1).
VECTORS: none
HOST RANGE :
- all cloven hoofed animals: cattle, swine, sheep, goats, buffalo and
artiodactyl wildlife species (2)
- elephants, hedgehogs, and some rodents can be carriers, although clinical
signs are rare (8)
- horses are not affected (1, 3).
- camelidae have low susceptibility (6)
- sheep develop less pronounced lesions (6)
- mice, rats, armadillos, nutrias and capybaras are also susceptible
(6)
ZOONOTIC POTENTIAL:
- FMD can be transmitted to
humans.
- The infection in humans is rare and mild (even among people working with
infected carcasses). Vesicles may appear on hands, feet or tongue (1,
3).
- Most human cases resulted from drinking infected milk, direct inoculation,
or contamination of existing skin lesions or cuts (3).
RESERVOIR:
- Wild fauna may serve as a significant reservoir, especially the African
Buffalo (1).
- Ruminants that have recovered from the disease or vaccinated ruminants can
carry the virus in the pharyngeal region for up to 2 years (cattle), 6 months
(sheep), lifelong (African Bufflao)(2).
- Pigs are not long-term carriers (1).
- Strains can have predilection for certain species, i.e. swine not cattle, or cattle not sheep
(6)
Section III: DIAGNOSIS
NECROPSY / HISTOPATHOLOGY FINDINGS:
- vesicles and erosions in the mouth and on the feet and teats
(1)
- gross lesions (6)
- single or multiple vesicles ranging from 2 cm to 10 cm
- progression is from small blanched area in epithelium, to fluid filled area
and vesicle formation - vesicles may coalesce with adjacent ones, vesicles
rupture, vesicle covering sloughs leaving eroded area, grey fibrinous coating
forms over erosion, coating becomes yellow, brown or green, finally epithelium
is restored but demarcation line remains.
- a "dry" form can also occur with no vesicular fluid present -
area becomes necrotic and ulcerates.
- feet - coronary band and inter-digital space affected, hoof shell may
eventually slough.
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 FMD 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 (4):
- tissue culture
- ELISA
- DNA probes and PCR (RT-PCR)
- virus isolation from tissue or secretions
DRUG SUSCEPTIBILITY: none
DIFFERENTIAL DIAGNOSIS:
The following diseases may show clinical similarity to FMD.
- Vesicular stomatitis
- Swine vesicular disease
- Vesicular exanthema (1)
- Bluetongue in sheep (4)
- Foot rot
- Chemical burns
- Contagious ecthyma in sheep (6)
- Rinderpest in cattle (6)
- Bovine viral diarrhea in cattle (6)
- Malignant catarrhal fever in cattle (6).
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 FMD virus.
Table 1 : Active ingredients considered to be effective against
FMD virus.
| ACTIVE INGREDIENT |
CONCENTRATION |
CONTACT TIME |
Oxidising agents:
Sodium hypochlorite
Calcium hypochlorite |
20,000 -30,000 ppm (2-3 %) |
10-30 minutes |
Acids:
Hydrochloric acids
Citric acid |
2% (v/v)
0.2% (w/v) |
10 minutes
30 minutes |
| Sodium hydroxide |
2% (w/v) |
10 minutes |
PHYSICAL INACTIVATION:
- rapidly inactivated at temperatures above 50°C (9), 56°C
in 30 minutes (5)
- exposure to sunlight has little or no effect - any inactivation is usually
due to secondary dessication or heat (5)
- rapid inactivation at pH < 5.0
(3, 9, 10) and pH > 11
(9)
SURVIVAL OUTSIDE OF HOST:
- up to 1 year in the environment and 10-12 weeks on clothing and feed
(1)
- survives at low temperatures and when relative humidity is above 60%
(5).
- survives in dry fecal matter for 14 days (summer), in slurry for 6 months
(winter) (3), in urine for 39 days and in the soil for 26-200 days
(5)
- survives in frozen bull semen and in some fertilized ova, salt/cured meats,
hides, dairy products, wool, leather, straw, hair and soil (5).
- in milk and milk products - can survive 70°C for 15 seconds a pH 4.6 (6)
SECTION V: LABORATORY HAZARDS
FOR HUMANS
LABORATORY ACQUIRED INFECTIONS: None
BIOSAFETY PRECAUTIONS :
Avoid contact with the virus from infected animals, their tissue or other virus
containing products.
SECTION VI: PHYSICAL AND
OPERATIONAL REQUIREMENTS
CONTAINMENT REQUIREMENTS:
All physical containment and operational practices for containment level 3,
non-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:
- A 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.
- Respiratory protection should be worn when directly handling infectious
material outside BSC.
- A shower is required on exit.
Post Mortem:
- A 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:
- 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 1059-1066.
- The Merck Veterinary Manual. Eighth Edition. Merial Ltd. 1998. Pages 457-459.
- Palmer, S.R. Soulsby, L. & D.I.H. Simpson. Zoonoses. Oxford
University Press. 1998. Pages 319-321.
- Sobrino, F. Sáiz, M. et al. Foot-and-mouth disease virus: a long
known virus, but a current threat. Veterinary Research. 2001. Volume 32.
Pages 1-30.
- Australian Veterinary Emergency Plan. Disease Strategy: Foot and Mouth
Disease. 2002.
- Foreign Animal Diseases, United States Animal Health Association. 1998
- Institute for Animal Health.
Foot-and-Mouth Disease Fact File. 2003.
http://www.iah.ac.uk/disease/fmd.shtml
- Acha, N. Pedro, and Szyres, B. Zoonoses and Communicable Diseases
Common to Man and AnimalsAustralian Veterinary Emergency Plan.
Operational Procedures Manual: Decontamination. 2000.
- Second Edition. Pan American Health Organization. 1995. Pages 344-352.
- Sellers, R.F. The Inactivation of Foot-and-Mouth Disease Virus by
Chemicals and Disinfectants. The Veterinary Journal. 1968. Volume 83.
Pages 504-506.
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.