Mad Cows and Sick Sheep: Why the European Epidemic Shouldn't Change Your Travel Plans
WebMD News Archive
March 23, 2001 -- Your dream trip to Europe is just around the corner. You've got your passport, your plane tickets -- and, now, your fears. Recent outbreaks of mad cow disease and foot-and-mouth disease are forcing farmers in the U.K. and elsewhere to slaughter thousands upon thousands of animals, and American travelers to affected countries face the specter of rigorous questioning and disinfecting upon their return.
So, should these events affect your travel plans -- and, if so, how much?
First, you should know that although people can carry foot-and-mouth disease and transmit this highly contagious disease to certain animals, humans are generally immune from the condition. Second, foot-and-mouth disease is a completely separate entity from bovine spongiform encephalopathy (BSE), otherwise known as "mad cow" disease.
"The danger from foot-and-mouth disease is its impact on agriculture, to meat and dairy industries, because the illness spreads very easily," says Richard A. Levinson, MD, associate executive director of the American Public Health Association.
"Foot-and-mouth disease, also known as hoof-and-mouth disease, affects animals with cloven or split hooves," D. L. Step, DVM, tells WebMD. "This includes cattle, sheep, goats, and swine. In addition, certain wild animals such as deer can be infected. Although single-hoofed animals such as horses are not typically susceptible, they can be carriers."
The organisms that spread foot-and-mouth diseases are picornaviruses. These viruses are typically airborne, although they can also spread through ingestion, says Step, assistant professor of food animal medicine and surgery at Oklahoma State University in Stillwater, Okla.
The disease typically causes ulcers to form in the mouth and in the tissue between the hoof and the foot. In young animals such as calves or lambs, the disease can cause inflammation of the heart. Although animals can survive the illness, they are often lame afterward and may have lost considerable weight. Dairy animals' milk production is severely reduced after surviving foot-and-mouth disease.
Because these viruses can spread over a radius of up to 40 miles, experts say that slaughtering herds in affected areas, as is currently happening in the U.K. is the most prudent way to contain the illness. Approximately 1 million livestock animals in that country have been targeted for slaughter. Cases of foot-and-mouth disease have also been reported in Argentina.
BSE, or "mad-cow disease," is thought to be transmitted by a protein fragment known as a prion. As with other spongiform encephalopathies, BSE causes the affected animal's brain to develop holes -- therefore becoming spongelike in appearance; the animal eventually dies. A human variant, human spongiform encephalopathy, causes the degenerative dementia known as new variant Creutzfeldt-Jakob disease. Humans may also be susceptible to BSE, but that isn't yet clear.
Prions are resistant to conventional sterilization techniques. The infection may be spread from prions present in the affected animal's central nervous system, such as the spinal cord and brain.