Foot-and-Mouth Disease
by Carla Everett
North America is currently free of foot-and-mouth disease. Let's
keep it that way. Australia and Antarctica are the only other continents that
are free of the terrible virus.
In the past 18 months foot-and-mouth
disease (FMD) has been diagnosed in 34 countries. The latest outbreaks occurred
in Great Britain, Northern Ireland, Argentina, and France. These outbreaks
disrupt the animal industry, including the export of animals and animal
products.
Once the infection is introduced, containing it becomes
difficult because the disease is caused by a fast-spreading virus. Nearly 100%
of the animals in an exposed herd become ill, and young animals may die. All
cloven-footed animals are susceptible, including cattle, bison, llamas, swine,
sheep, goats, deer, and elk.
Characteristic signs of the infection are
blisters in the animal's mouth or on its muzzle, causing slobbering and
drooling. Later the blisters break, forming raw patches or ulcers. Blisters and
sores may also develop on the animal's teats, causing mastitis in dairy cattle.
Blisters on the feet result in lameness. Affected animals are reluctant or
unable to drink, eat, or walk and rapidly lose weight.
Swine and
cattle usually show signs of disease within two to seven day after being exposed
to the virus. Sheep and goats may show only minimal clinical signs after an
incubation period of up to14 days.
The disease is transmitted in a
variety of ways, the most common being direct contact with an infected animal.
Once animals are infected they become virus factories, capable of spreading high
numbers of viral particles to other animals and into the environment. Infected
swine, in particular, can release millions of viral particles each time they
exhale. The airborne virus may be breathed in by nearby susceptible animals.
Humans who have been around infected animals may carry the virus in their nasal
passages for as long as 28 hours. Although the disease does not affect humans, a
person may spread the virus to susceptible animals.
The disease may
also be spread when susceptible animals come into contact with contaminated
feed, feeding utensils, vehicles, clothing, or holding facilities.
The
FMD virus can be carried in the raw meat, animal products, or milk from
FMD-exposed or infected animals. The FMD outbreak in South Africa started after
waste food, containing raw meat scraps collected from international ships, was
fed to swine.
A single case of FMD would affect every segment of our
country's multi-billion dollar animal industry and animal product export market:
- Consumers would lose confidence in the safety of meat food products.
- Prohibitions would be placed on the sale and international shipment of
animals and animal products.
- Eradication costs are high. All animals exposed to the virus must be
destroyed to prevent its spread.
- Vaccines provide only temporary protection and revaccination is needed at
six-month intervals. Vaccine use is limited to outbreaks only, and vaccinated
animals must be slaughtered before international trade can be resumed.
- For at least three months after the eradication of an outbreakor at
least three months after the slaughter of the last vaccinated animalan
affected country is banned from shipping meat or meat products to international
trading partners.
The United States. has regulations in place to prevent the introduction of
FMD-infected animals and animal products, but so did many of the currently
affected countries. Please do your part:
If you will be traveling
abroad, or you live overseas and plan to visit the United States, avoid contact
with animals or areas where animals have been held for at least five days before
you enter to the United States. If you have had contact with livestock, or you
live on or have visited a farm abroad, before you travel launder or dry clean
all clothing, jackets, and coats, and shower and shampoo. Remove all dirt and
organic material from your shoes, luggage, and other personal items. Wipe these
items with a disinfectant. Don't bring prohibited products. After arriving in
the United States, avoid contact with livestock or wildlife for at least five
days.
Suitable Disinfectants
The following products may be used effectively to disinfect against FMD:
- Sodium hydroxide (lye) 2% solution. Mix a 13-ounce can in five gallons of
water.
- Sodium carbonate (soda ash) 4% solution. Mix one pound in three gallons of
water.
- Citric acid 0.2% solution.
- Acetic acid (vinegar) 2% solution. Mix one gallon of 4% vinegar in one
gallon of water.
- Virkon S (Antec International) at a 1:200 dilution.
- Sodium Hypochlorite (household bleach) Mix three parts bleach to two parts
water.
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FMD spreads fast. Early detection and reporting are critical. The disease
may have been present in the United Kingdom for three weeks before it was
detected.
If you suspect a disease problem, report it immediately to
your local veterinarian or regulatory animal health official. Don't move animals
that may be affected. If you suspect a problem, stop all visitors from entering
your farm. Report suspicious cases immediately by calling the USDA's Veterinary
Services at 512-916-5552. Additional information may be obtained from the USDA's
Public Information Office at 301-734-8073.
Carla Everett of Austin, Texas, is with the Texas Animal Health
Commission, which was deluged with calls for information regarding
foot-and-mouth disease during the latest European outbreak. A world map
depicting affected areas is available by calling toll-free 800-550-8242
extension 710, or by visiting the Commission's website at
tahc.state.tx.us. This
article appeared in the
Summer 2001
issue of
Rural Heritage.
Since then foot-and-mouth disease has been winding down in Europe,
reducing the threat that it might spread to North America. |