Chronic wasting disease is a transmissible spongiform encephalopathy

Transmissible spongiform encephalopathy

Transmissible spongiform encephalopathies , also known as prion diseases, are a group of progressive conditions that affect the brain and nervous system of many animals, including humans. According to the most widespread hypothesis they are transmitted by prions, though some other data suggest an...

 (TSE) of mule deer

Mule Deer

The mule deer is a deer indigenous to western North America. The Mule Deer gets its name from its large mule-like ears. There are believed to be several subspecies, including the black-tailed deer...

, whitetailed deer, elk

Elk

The Elk is the large deer, also called Cervus canadensis or wapiti, of North America and eastern Asia.Elk may also refer to:Other antlered mammals:...

 (wapiti), and moose

Moose

The moose or Eurasian elk is the largest extant species in the deer family. Moose are distinguished by the palmate antlers of the males; other members of the family have antlers with a dendritic configuration...

. TSEs are caused by unusual infectious agents

Infectious disease

Infectious diseases, also known as communicable diseases, contagious diseases or transmissible diseases comprise clinically evident illness resulting from the infection, presence and growth of pathogenic biological agents in an individual host organism...

 known as prion

Prion

A prion is an infectious agent composed of protein in a misfolded form. This is in contrast to all other known infectious agents which must contain nucleic acids . The word prion, coined in 1982 by Stanley B. Prusiner, is a portmanteau derived from the words protein and infection...

s. To date, CWD has been found mainly in cervids (members of the deer family). First recognized as a clinical "wasting" syndrome in 1967 in mule deer

Mule Deer

The mule deer is a deer indigenous to western North America. The Mule Deer gets its name from its large mule-like ears. There are believed to be several subspecies, including the black-tailed deer...

 in a wildlife research facility in northern Colorado

Colorado

Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...

, USA

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, it was identified as a TSE in 1978 and has spread to a dozen states and two Canadian provinces.