Yup -ITK - I think you are right - to figure out how an animal with FMD at the CA fair would affect things you would need to know about the disease (hopefully that will follow - it is in a table so I am not sure how it will appear!), who was exposed and where they went....ITK you are stalled next to the exposed show heifer (oh no!), ELBEE your handy person used my water bucket (oh no!), aj your heifer stood next to mine (oh no!)....
Disease Foot and Mouth Disease
Other names FMD, Aftosa
Importance Highly contagious viral disease of cloven-hoofed animals that can rapidly spread throughout an area. A quick response is vitally important in containing an outbreak of FMD. State and Federal veterinarians should be immediately informed of any suspected vesicular disease.Severe economic loss and international trade embargoes can result from an outbreak of FMD.
Etiology The FMD virus is in the family Picornaviridae, genus Aphthovirus. There are 7 immunologically distinct serotypes and over 60 subtypes.The virus is fairly hardy. It can survive regular pasteurization procedures, but is inactivated with ultra high pasteurization. The virus can also survive freezing in tissues and drying when in organic material, such as serum. It can remain active for days to weeks on organic rich material in moist, cool conditions. It is inactivated on dry surfaces and by sunlight. FMD virus can survive for 24 hours in the human respiratory tract.
Species affected FMD primarily infects cloven-hoofed animals, including cattle, pigs, sheep, goats, and water buffalo. Other susceptible species include hedgehogs, armadillos, nutrias, elephants, capybaras, rats, and mice.
Geographic distribution The FMD virus is distributed worldwide, and is endemic in Asia, Africa, Middle East, and parts of South America. Epidemics have recently occurred in Taiwan, South Korea, Japan, Mongolia, Britain, France, Netherlands. North America, Central America, Australia, and New Zealand have been FMD free for many years.
Transmission Transmission occurs through respiratory aerosols, direct and indirect contact with infected animals.Aerosol transmission has occurred from bulk milk trucks and the human respiratory tract. Feeding of infected animal products can transmit the virus by direct contact. Exposure to contaminated objects such as boots, hands or clothing results in indirect transmission of the disease. The disease can also be transmitted by artificial insemination, contaminated biological and hormone preparations.Sheep and goats are considered maintenance hosts; they have mild disease and the diagnosis may be delayed allowing time for spread of the virus. Pigs are considered amplifying hosts because of the higher concentration of virus particles in aerosols when compared to other species. Consequently, in pigs the disease spreads rapidly. Cattle are considered indicators of the disease because they are generally the first species to show signs of infection; their lesions are more severe and progress more rapidly. Cattle can carry the FMD virus in their pharyngeal tissues for long periods – they can be healthy carriers for 6 to 24 months. Sheep can be carriers for 4-6 months. Pigs are not carriers.
Incubation period The incubation period is 3-5 days for animals in contact with clinically infected animals, and 1-3 days for pigs fed contaminated feed. The peak time of shedding of virus and transmission usually occurs when vesicles rupture.
Clinical signs Consider FMD in animals with concurrent salivation and lameness with vesicular lesions. The vesicles progress to erosions, and are seen in the mouth, nares, muzzle, feet, and teats. Other clinical signs are fever, depression, anorexia, excessive salivation, serous nasal discharge, decreased milk production, lameness, and reluctance to move.
Post mortem lesions Single or multiple vesicles from 2 mm to 10 cm are seen on the mouth, nares, muzzle, feet, and teats. The vesicles may be in any stage of development. Ruptured vesicles leave a red eroded area that is then covered with gray fibrinous tissue. Coronary band lesions are similar, the skin and hoof separate and a line of coronitis appear on the hoof. Pigs may loose a hoof. There may be gray or yellow streaking of the myocardium secondary to necrosis called “Tiger heart”.
Morbidity and mortality Morbidity can be 100% in susceptible populations, however mortality is generally less than 1%. Mortality is increased in younger animals and with more severe strains
Diagnoses The diagnosis of FMD should be suspected in any animal with vesicles in the mouth, especially if the animal is lame. Suspect animals should be immediately quarantined and authorities notified. Diagnosis of the index case is made by virus isolation. Subsequent cases can be diagnosed by ELISA or complement fixation.
Differential diagnosis An index of suspicion must be maintained with any vesicular disease. Differential diagnosis includes vesicular stomatitis, swine vesicular disease, vesicular exanthema of swine, foot rot, and chemical and thermal burns. In cattle, oral lesions in the later stages may resemble rinderpest, IBP, BVD, malignant catarrhal fever and blue tongueIn sheep, later oral lesions can resemble blue tongue, contagious ecthyma, lip and leg ulceration.
Laboratory tests FMD can be diagnosed by virus isolation, ELISA, or complement fixation. Virus isolation and identification must be done on the initial case; subsequently antigen and nucleic acid detection can be used to diagnose additional cases.
Samples to collect Notify authorities prior to collecting and shipping samples.Vesicular fluid, epithelial covering of vesicles, esophageal-pharyngeal fluid, blood, and serum can be used.
Biosecurity Notify authorities is FMD is suspected. Quarantine premise. A quick response is essential for containment of the outbreak. Strict insecurity protocols should be followed for individuals entering a premise suspected or known of having FMD. Because the virus can remain viable and reside in the human respiratory tract for 24 hours, humans exposed to FMD should not visit clean livestock facilities within 2 days of exposure.
Public health FMD rarely infects humans and the disease is not considered a public health problem.
Bioterrorism potential The FMD virus can be easily spread among livestock, and an outbreak could occur by feeding pigs infected meat. As evidenced by the outbreak in the UK, the disease can cause high morbidity and significant economic, social and political upheaval.