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Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) of mule deer, white-tailed deer, elk (or "wapiti"), and moose ("elk" in Europe). To date, CWD has only been found in members of the deer family. First recognized as a clinical "wasting" syndrome in 1967 in mule deer in a wildlife research facility in northern Colorado, USA, it was identified as a TSE in 1978 and has spread to free-ranging and captive populations in 23 US states and two Canadian provinces.〔 〕 CWD is typified by chronic weight loss leading to death. No relationship is known between CWD and any other TSE of animals or people. Although reports in the popular press have been made of humans being affected by CWD, a study by the Centers for Disease Control and Prevention suggests, "()ore epidemiologic and laboratory studies are needed to monitor the possibility of such transmissions."〔 〕 The epidemiological study further concluded, "()s a precaution, hunters should avoid eating deer and elk tissues known to harbor the CWD agent (e.g., brain, spinal cord, eyes, spleen, tonsils, lymph nodes) from areas where CWD has been identified."〔 == Clinical signs == Most cases of CWD occur in adult animals. The disease is progressive and always fatal. The most obvious and consistent clinical sign of CWD is weight loss over time. Behavioral changes also occur in the majority of cases, including decreased interactions with other animals, listlessness, lowering of the head, lethargy, repetitive walking in set patterns, and a smell like meat starting to rot. In elk, behavioral changes may also include hyperexcitability and nervousness. Affected animals continue to eat grain, but may show decreased interest in hay. Excessive salivation and grinding of the teeth also are observed. Most deer show increased drinking and urination. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「chronic wasting disease」の詳細全文を読む スポンサード リンク
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