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), state officials said.
The samples taken by the Delaware Department of Natural Resources & Environmental Control’s Division of Fish and Wildlife were submitted to the University of Pennsylvania’s School of Veterinary Medicine’s New Bolton Center for testing, DNREC spokeswoman Joanna Wilson said Friday, June 11. Final test results 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, Wilson sia.d
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, she said. The Division of Fish and Wildlife’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 came up a little short in New Castle County despite collecting samples from two deer processors.
“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,” DNREC Wildlife Biologist Joe Rogerson said. ”A full 600 samples would have provided us a 99 percent probability of detecting the disease if it existed in 1 percent or more of the deer population.”
Having said that, state officials are encouraged by these results, he said.
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.
