Nearly 600 brain and lymph node tissue samples taken from white-tailed deer in all three counties of Delaware in 2009 showed no evidence of chronic wasting disease (CWD), the DNREC Division of Fish and Wildlife announced today.

The samples were submitted to the University of Pennsylvania’s School of Veterinary Medicine’s New Bolton Center for testing. Final test results just received showed all the 2009 samples to be negative for the disease for the seventh straight year. This latest sampling brings the total number of Delaware deer tested since 2003 to nearly 3,500, and none so far have been positive for CWD.

During the October muzzleloader and November shotgun deer seasons last fall, 592 tissue samples were collected at meat processors across the state from deer harvested by hunters. The Division’s goal is to test and sample 200 deer within each county. Last year, the Division achieved this goal in Kent and Sussex Counties but despite collecting samples from two deer processors, it came up a little short in New Castle County.

“A full 600 samples would have provided us a 99 percent probability of detecting the disease if it existed in one percent or more of the deer population. The only way to be certain that every deer in Delaware is free of CWD would be to test every deer, and that would not be practical. While this doesn’t provide 100 percent assurance of no disease, we are encouraged by these results,” said DNREC Game Mammal Biologist Joe Rogerson.

CWD is a neurological condition found in deer and elk in which an abnormal protein material called a prion invades and gradually destroys the animal’s brain. It is thought to be 100 percent fatal and believed to be transmitted from close contact with infected deer. The disease wasn’t known until the 1960s. In the 1970s, CWD was identified as a transmittable neurological disease. Extensive research has found no evidence that the disease can be transmitted to humans.

Surveillance programs such as Delaware’s have been established in all eastern states and monitoring will continue in future years. So far, most eastern herds seem to be disease free. The closest state to Delaware in which CWD has been detected is West Virginia, while the most recent states to detect the disease are Missouri and Virginia, which found CWD in their state’s deer herd this past year. DNREC will continue monitoring in Delaware for the disease with plans for more tissue sampling this fall.

Several years ago, the Division passed two regulations in an attempt to ensure that Delaware remains CWD free. The first regulation bans the importation of high risk parts such as the brain, spine and lymph nodes from deer harvested in areas where CWD has been detected. A second regulation requires mandatory notification to the Division by a hunter if a deer harvested out of state by a Delaware resident tests positive for CWD.

Hunters should be aware that more news regarding CWD will likely be available as more information is learned about this disease. In the event a deer does test positive for CWD in Delaware, or a surrounding state (Maryland or Pennsylvania), the Division is in the process of finalizing a CWD Response Plan so that action can be taken immediately. Under the plan, additional regulations also may be created in an attempt to keep Delaware free of CWD.

More information can be found in the 2010-2011 Delaware Hunting and Trapping Guide (available soon), on the Division’s CWD Awareness Page or the CWD Alliance’s website,

For more information about CWD in Delaware or any other deer related issue, please contact Wildlife Biologist Joe Rogerson at 302-735-3600.

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