TSE Glossary

GLOSSARY: Transmissible Spongiform Encephalopathies (TSE): TSEs are infectious diseases of animals and humans that are caused by a deterioration of brain tissue. These diseases are progressive and always fatal. The infectious agents are thought to be abnormal proteins called prions. Examples of TSEs are scrapie in sheep, bovine spongiform encephalopathy (known as mad cow disease) in cows, kuru in cannibals on New Guinea, chronic wasting disease in deer and elk, feline spongiform encephalopathy in cats, variant Creutzfeldt-Jakob Disease (CJD) and classical CJD in humans. Usually, the diseases either cannot be transmitted between species or are difficult to transmit between species. For example, it is hard but not impossible to infect a hamster with scrapie. However, with BSE and vCJD it appears that a bovine infectious agent has easily crossed over into humans, perhaps because of a mutation or something else very different about this particular strain of BSE. Bovine Spongiform Encephalopathy (BSE): Widely referred to as "mad cow disease," BSE is a chronic degenerative disease affecting the central nervous system of cattle. The disease was first diagnosed in 1986 in Great Britain. Affected animals may display changes in temperament, such as nervousness or aggression, abnormal posture, incoordination, decreased milk production or loss of body weight despite continued appetite. There is no treatment or vaccine to prevent the disease and affected cattle die. BSE may have been caused by feeding cattle rendered protein produced from the carcasses of scrapie-infected sheep or cattle with previously unidentified Transmissible Spongiform Encephalopathies (TSE). Creutzfeldt-Jakob Disease (kroits ' felt - yä ' kôp) (CJD): A degenerative, invariably fatal brain disorder also known as "classic CJD." CJD affects about one person in every 1 million people per year worldwide. In the United States, there are about 200 cases per year. CJD usually appears in later life and runs a rapid course. Typically, onset of symptoms occurs about age 60, and about 90 percent of patients die within a year. In the early stages of the disease, patients may have failing memory, behavioral changes, lack of coordination and visual disturbances. As the illness progresses, mental deterioration becomes pronounced and involuntary movements, blindness, weakness of extremities and coma may occur. There is no cure for the disease. variant Creutzfeldt-Jakob Disease (kroits ' felt - yä ' kôp) (vCJD): vCJD is the human form of bovine spongiform encephalopathy (BSE) or "mad cow disease." Both the human and bovine disorders are fatal brain diseases with unusually long incubation periods measured in years and are caused by an unconventional transmissible agent, a prion, resulting in a breakdown of brain tissue leaving the infected brain with a "spongy" appearance. The disease in humans is sometimes called new variant Creutzfeldt-Jakob disease (nvCJD). Foot and Mouth Disease (FMD): Foot-and-mouth disease is a severe, highly communicable viral disease of cattle and swine. It also affects sheep, goats, deer and other cloven-hooved ruminants. The disease is characterized by fever and blister-like lesions followed by erosions on the tongue and lips, in the mouth, on the teats and between the hooves. Many affected animals recover, but the disease leaves them debilitated. It causes severe losses in the production of meat and milk. The disease is caused by a virus. There are at least seven separate types and many subtypes of the FMD virus. Immunity to one type does not protect an animal against other types. FMD viruses can be spread by humans, but humans are not susceptible to the virus. Chronic Wasting Disease (Deer and Elk Disease): Chronic wasting disease is a neurological disease found in wild deer and elk herds in portions of northeastern Colorado, southeastern Wyoming and western Nebraska. It is also found in captive deer and elk in five states and one Canadian province. It belongs to a family of transmissible spongiform encephalopathies. The disease attacks the brains of infected deer and elk, causing the animals to become emaciated, display abnormal behavior, lose bodily functions and die. Epidemiologists with the federal Centers for Disease Control and Prevention (CDC) and epidemiologists at the Colorado Department of Public Health and Environment have studied chronic wasting disease and found no link between it and any neurological disease that affects humans. Specifically, chronic wasting disease in animals is not associated with Creutzfeld Jacob Disease or variant CJD in humans.