The Kansas Department of Wildlife and Parks reported a total of 10 chronic wasting disease (CWD) occurrences from among almost 2,700 deer tissue samples collected and submitted for lab analysis by KDWP in recent months.
Eight of the CWD-positive deer tissue samples had been reported earlier by KDWP, and two additional “positives” were recently confirmed in the final batch of samples submitted for lab analysis, according to Shane Hesting, KDWPs wildlife disease coordinator.
A total of 2,693 tissue samples were collected by the department throughout the 2008 hunting seasons. Included in that total of samples collected were nine elk; none of the elk samples tested positive for CWD. KDWP has conducted annual sampling of deer and elk since 1996 to help track the occurrence of CWD.
“Emphasis was placed on obtaining more samples in northwest Kansas to assess the prevalence and distribution of the disease, since that area is adjacent to past CWD occurrences in neighboring states and is the only area of Kansas where it has been documented,” Hesting said.
“About 20 percent of the total samples collected in Kansas were from that 12-county area,” he added. “Therefore, the increased number of detections may be the result of more intensive sampling combined with the natural spread of the disease.”
All ten deer confirmed as CWD-positive were white-tailed deer taken by hunters in northwest Kansas. Of the CWD-positive deer confirmed by KDWP, five came from Decatur County, two from Sheridan County, two from Rawlins County, and one from Cheyenne County.
CWD had been documented previously in Kansas. During the 2007 season, three Decatur County whitetails were confirmed as CWD-positive. The first detection in a wild Kansas deer was a white-tailed doe killed by a Kansas hunter in 2005 in Cheyenne County. Prior to that, CWD was detected in a captive elk in Harper County in 2001.
Although research is underway, there is currently no vaccine or other biological method of preventing CWD. The only tool is to prevent the spread of CWD to new areas, because once the infective particle (an abnormal prion) is deposited into the environment – either through an infected carcass or from a live animal – it may exist for a decade or more, capable of infecting a healthy deer.
Despite the recent occurrences, the likelihood of finding CWD in a wild deer harvested in Kansas is small. That small likelihood decreases even more the farther from northwestern Kansas the deer lived. In recent years, numerous cases of CWD have been documented in neighboring areas of Colorado, Nebraska and Wyoming.
CWD is a fatal illness to infected deer and elk. Humans have never been known to contract the disease. CWD is a member of the group of diseases called transmissible spongiform encephalopathies (TSEs). Other diseases in this group include scrapie in sheep and goats, bovine spongiform encephalopathy (BSE or mad cow disease) in cattle, and Cruetzfeldt-Jacob disease in people. None of the ten CWD-positive deer from the 2008 seasons exhibited any outward symptoms of CWD that are common in the terminal stages of the disease.
CWD is a progressive, fatal disease that results in small holes developing in the brain, giving it a sponge-like appearance under the microscope. Decreased brain function causes the animal to display neurological symptoms such as depression, droopy head, staggering, loss of appetite, and a lack of response to man. The continuing deterioration of the brain leads to other symptoms such as weight loss, drooling, and excessive thirst. Caution is advised because of unknown factors associated with prion diseases, but no human health risks have been discovered where CWD occurs.
The symptoms of CWD include loss of body weight, stumbling, holding the head at an odd angle, circling, non-responsiveness to people, and pneumonia.
