There have been 434 cases of the foot-and-mouth disease in the United Kingdom since the outbreak first appeared last month - the worst epidemic of the disease in the area since a devastating outbreak occurred in 1967. There has been no outbreak in the United States.
Luckily, the disease generally does not strike humans. It is a virus that affects sheep, pigs and cattle, according to Ernest Hovingh, assistant professor at the Virginia Maryland Regional College of Veterinary Medicine. Infected livestock lose weight, give less milk and develop sores on their mouths and feet. About 5 percent of animals who contract the disease die, and farmers slaughter even more to prevent suffering.
While there are isolated reports of the virus infecting humans - symptoms are mild and spread rapidly - doctors treat the disease simply by quarantining the ill until symptoms disappear. In general, humans can come into contact with infected animals and even eat infected animal products without endangering their health. "There isn't any need to panic," said Greg Hicks, communication director for the Virginia Farm Bureau.
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So if foot-and-mouth disease doesn't hurt people, why is it causing such an uproar around the globe? The answer: economics. Foot-and-mouth disease decimates livestock populations in a matter of weeks, destroying entire herds and bankrupting farmers without warning. "It's perhaps the most highly contagious animal virus," Hovingh said. Officials caution tourists and other visitors against traveling in outbreak areas - significantly depressing tourism industries in affected countries.
Governments have been able to contain the virus by slaughtering infected animals and incinerating their bodies at the first sign of the disease. They also have killed apparently healthy animals living in the vicinity of infected populations. So far, the United Kingdom has slaughtered over 50,000 animals. The European Union has halted all animal product exports from the United Kingdom to help prevent the spread of foot-and-mouth disease.
But foot-and-mouth disease cases still have been confirmed in France, Argentina and most recently Saudi Arabia. As a result, the United States has banned the import of all animal products from the European Union and Argentina. "The food supply is safe, it continues to be so," said J. Carlton Courter III, commissioner of the Virginia Department of Agriculture and Consumer Services.
The economic effect of these bans is enormous - the U.S. Department of Agriculture estimates the bans have had a trade impact of over $300 million.
While humans do not get sick from foot-and-mouth disease, they are excellent vectors - or carriers - for transmitting the disease. Thus the USDA has begun an ad campaign to prevent international travelers from carrying foot-and-mouth disease into the country. "Its in the consumers' best interest to work with authorities to keep diseases like this out of the country," said Scott Byarn, agriculture extension agent for Animal Science. "If this effort is not successful, the price of meat could just skyrocket."
Locally, Courter cautions travelers and farmers to exercise common sense to prevent transmitting many kinds of animal diseases. "We coined the term 'biosecurity' several years ago. It means that people should use good sense, just like when you go to the hospital, to keep yourself and other safe," he said. "After traveling to countries where there have been cases of foot-and-mouth disease, wash you clothes, limit visits to farms. Albemarle could be a point of entry because we have an airport with international carriers."
There still is debate amongst scientists about how the virus spreads. Virus particles can adhere to people, farm equipment, cars and wild animals - virtually anything that travels - and infect new populations. "Scientists believe it takes between one to 10 virus particles to create a new infection, which is a very small infectious dose," Hovingh said.
Some scientists concluded that the particles from the virus' 1967 U.K. outbreak traveled airborne for several miles to infect new populations. But studies cited by the USDA indicate that all animals are infected through direct contact. "We're fairly sure that the virus travels on vehicles and feed trucks. Air doesn't carry it," Courter said.
Scientists are confident they understand its behavior in animals. The virus enters the bloodstream shortly after it comes into contact with the skin. The virus then migrates "to the mucousal areas, such as the nose and mouth, where it replicates, causing the tissue to break out in blisters," Hovingh said. "The virus also causes blisters in the feet and udder of infected animals," he added. The incubation period for the virus ranges from 24 hours to 10 days.
With this much money and politics involved, it may seem surprising that the best weapon farmers have against the disease is killing all the animals that contract it. Even more surprising is that scientists have created a vaccine but do not use it. This is partly because the vaccine causes animals to develop antibodies to the foot-and-mouth virus. However, these are the same antibodies that sick animals develop. "There is no way to tell the difference between a sick animal and a vaccinated animal," Hovingh said.
The European Union, United States and other countries have a zero-tolerance policy toward the foot-and-mouth disease. As a result, policy makers believe it is possible to completely eradicate the disease from livestock populations, much as smallpox has been eradicated from human populations.
The USDA's official position is that if any outbreak occurs here, the animals and surrounding livestock will be immediately killed and incinerated, Courter said.
So what are the chances that foot-and-mouth disease will find its way to Virginia? "Today a state veterinarian put it at 50/50," said Courter. "We have precautionary plans to keep [the virus] from getting here and contingency plans in case we find it," he said.
But some are a bit more skeptical. "There's a good chance that it could happen here, because it's so easily transmittable by humans," Hicks said.