Chronic Wasting Disease: More Similar to Scrapie than Mad Cow

Photo: Colorado Division of Wildlife

Photo: Colorado Division of Wildlife

Tarah Cordier (11 AM Micro) saw a recent news report on Chronic Wasting Disease, a neurological disease of wild deer populations. Long time BIO230 readers may recall my take on this menace from a previous semester. Here is Tarah’s update on CWD:

The Patriot News recently published an article stating that chronic wasting disease is now being found in Pennsylvania’s wild deer population.  The first case of CWD in Pennsylvania was recorded only five months prior, primarily being found in confined deer.  Although there is no evidence to show that the disease can be transmitted to humans, it is both communicable and deadly among the Cervidae family (deer, elk and moose).  The State Game Commission began observing our local deer and checking for CWD in 1998.  Roughly 5,000 deer have been tested since then, with most of the results coming back negative.  Last fall it was reported that two animals died from the neurological disease on an Adams County farm.

So, what is chronic wasting disease?  There is no cure or vaccine for the neurological disorder found in cervids.  Ultimately, prions cause little holes to be made in the brains of animals that are infected.  It affects the brain, nervous system and lymph nodes.  It is highly infectious and can be transmitted directly and indirectly via excretions as well as prions in decaying or even already dead carcasses, which is evident by recent research studies finding early accumulation in alimentary tract-associated lymphoid tissues during incubation.  Residual infections are also a problem because prions are extremely long-winded proteins and they survive even after the death of other cells.  Current research is basing their studies on the spread of chronic wasting disease via mineral licks and other environmental factors.  The CDC recommends “boning out” your animal if you are a hunter.  This will prevent CWD from spreading after the death of an infected animal.

Since the first case of CWD, tests have improved and the disease can now be detected in advance, before signs can be clinically observed.  This is good news, seeing as how we are now able to test deer shot by local hunters and steer clear of eating any infected game.  Recent documentation of CWD being found in wild deer has led to public outcry, probably because of fear of transmission to humans like what happened with mad cow disease.  The disease, however, most resembles scrapie in sheep and goats and not bovine spongiform encephalopathy (mad cow disease).  Scrapie is another fatal degenerative disease affecting the central nervous system.  Scrapie is classified as transmissible spongiform encephalopathy (TSE), as is chronic wasting disease.  Furthermore, the CDC reports that there is absolutely no evidence of chronic wasting disease having the ability to be transferred to humans.


About ycpmicro

My name is David Singleton, and I am an Associate Professor of Microbiology at York College of Pennsylvania. My main course is BIO230, a course taken by allied-health students at YCP. Views on this site are my own.

Posted on April 8, 2013, in Guest Post, Yikes! and tagged , . Bookmark the permalink. Comments Off on Chronic Wasting Disease: More Similar to Scrapie than Mad Cow.

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