What is the scientific name of the virus that causes FMD?
How many serotypes of FMD are there?
How many subtypes of FMD are there?
Why is it so difficult to vaccinate for FMD?
vaccines aren't cross protective
What species are primarily affected by FMD?
Swine, sheep, goats, cattle and water buffalo
FMD has a high rate of mortality in _______ animals and a high rate of morbidity in ______ animals.
What are some non-production animals that FMD can affect?
elephants, hedgehogs, nutrias, armadillos, capybara, rodents
Where is FMD considered absent?
Australia, North America, Europe
Where is FMD considered sporadic?
Where is FMD considered endemic?
Africa and Asia
When was the last case of FMD in the USA?
When was the last case of FMD in Canada?
1952- 1343 cattle and 401 swine, sheep and goats slaughtered (estimated cost of $1million)
When was the last case of FMD in Taiwan?
When were the last cases of FMD in the UK?
2001 and 2007
How does the aphthovirus bind to cells?
binds to integrin proteins on cell surface (docks onto cell)
What are the 2 special requirements for the picornavirus?
- 1). 100 nucleotide has cloverleaf structure that binds viral polypeptide 3C and host proteins to form a nucleoprotein complex: NEED for viral replication
- 2). Needs an internal ribosome entry site (IRES) to bind and perform translation of proteins
Describe the cell manipulations performed by the picornavirus pathogen.
- 1. rapid shut down of host cell protein translation
- 2. leaves more materials (aa and ribosomes) to build more virus
- 3. switching of pro and anti apoptotic signals to keep the cell living for as long as possible
- -pro : shut down of host cell transcription and translation
- -anti : reduces interferon and tumor necrosis factor
What are the requirements for the inactivation of picornavirus?
- pH below 6.5 or above 11
- ultra-high pasteurization
- dry surfaces and UV light
In which products can FMD survive?
milk, milk products, bone marrow, lymph glands, dried serum, organic rich material
Describe the ways in which FMD is transmitted.
- respiratory aerosols- direct: animal indirect: man
- fomites- contact
- feeding infected animal products- milk, meat, other organs
- Other: AI, biological (vx, hormone preparations)
- MAIN SOURCE: infected vesicle (blister)
What is the incubation period for natural exposure of FMD?
What is the incubation period for experimental exposure?
What is a maintenance host?
An animal that is sick with the disease, but doesn't show clinical signs for a prolonged period of time= Transmitters!!
What are two common maintenance hosts of FMD?
sheep and goats- can have virus in pharynx for 4-6 months
What are some clinical symptoms of FMD in a maintenance host?
- mild to moderate fever
What is an amplifier host?
increases the dose of a virus- ramps up virus production
What animal is a common amplifier host of FMD?
swine- will exhale 30-1000 times more virus than sheep or cattle
What are the clinical symptoms of FMD in an amplifier host?
- lameness- painful to stand
- anorexia- vessicles around snout
What is an indicator host?
The host that shows obvious signs of sickness (disease)
What is the indicator host for FMD?
What are the clinical symptoms of FMD in an indicator host?
- severe lesions that manifest earlier than in swine or sheep
- depression/ dullness
- drooling, serous discharge
What are some of the production problems associated with FMD in cattle?
- low milk production
- decreased fertility
- unthriftness- failure to gain weight
What are some of the lameness issues associated with FMD in cattle?
hoof lesions in the interdigital space and coronary bands
What is a major concern of FMD in young animals?
Tiger heart: myocardial degeneration and necrosis, usually results in 100% mortality
How long is the incubation of FMD before vessicle formation?
How many human cases of FMD have been reported since 1921?
How long is the incubation period for human FMD?
What are the clinical symptoms of human FMD?
- burning in hands and feet prior to vessicle formation
What strain of Picornaviridae is responsible for FMD in people?
coxsackie A group virus
Why is FMD considered the most devastating livestock disease present worldwide?
The economic impacts!!
What are the direct costs of FMD?
- loss of capital (livestock)
- compensation to producers
- eradication costs***- infected animal and welfare slaughter
- carcass disposal
What are the indirect costs of FMD?
- empty farms
- animals stuck in transition- at the border
- loss of export markets**
- loss of consumer confidence in product
Describe the economic catastrophe between a small outbreak and a larger outbreak.
Quite similar both cost a lot of money due to closed borders and welfare slaughter
What is the effect of an embargo on swine?
- Prices drop
- more animals used in domestic markets
- surplus of hogs, retail price drops 10%
What is the effect of an embargo on cattle?
- cow prices dropped 3x faster than steer
- Surplus of beef in domestic markets= decreased breeding therefore population drops
- once markets reopen Canada can no longer meet demand for beef and other countries meat is imported instead
Which other commodities can be affected by an embargo on beef or swine?
- Poultry or grain industries
- drop in domestic price of beef or pork= less people purchasing poultry
- less cattle to feed= lowered demand for grains
What were the eradication costs for the 1987 FMD outbreak?
$2 billion (2006 price with inflation= $3.54 billion)
In the 2002 government study what was the presumed cost of an outbreak affecting 50 herds in Canada?
What are four methods of detecting FMD?
- 1. Serology
- 2. Virus isolation
- 3. Clinical examination
- 4. Nucleic acid tests
What is the OIE FMD surveillance strategy?
have a continuing program to ensure an acceptable level of confidence that the disease is not present.
What are the needs for FMD surveillance?
- 1.) early warning system throughout production, marketing and processing chain to report suspicious cases
- 2.) regular and frequent clinical inspection and serology testing of high risk animals
- 3.) An effective program to follow up on suspicious cases
What are the three types of OIE surveillance?
Clinical, virological and serological
Define clinical surveillance.
- Aims at detecting suspect animals displaying clinical signs
- -used to confirm lab testing positive animals
Define Virological Surveillance.
used to monitor risk, population, confirm clinical cases and positive serological tested animals and to test normal mortality
Define Serological testing.
antibody testing for positive animals (either vaccinated or infected)
What control measure are put in place for animals that are suspect for FMD?
quarantine and kill
What are 4 reasons not to vaccinated animals for exotic diseases?
- Vaccinated animals will be seropostive for the disease, thus difficult to differentiate
- Not all animals become 100% protected when vaccinated- could still contract disease
- Vaccination will not protect against pre-infected animals- there for could be carriers/shedders
- Vaccines could be ineffective if they are not properly stored (refrigerated)
How can someone differentiate between an infected animal and a vaccinated animal?
- Serology- infected has non-structural proteins (NSP)
- - vaccinated has structural proteins (SP)
What is a marker vaccine?
A vaccine that has been modified to allow for differentiation between infected and vaccinated animals.