Division of Ag researchers move ahead determining prevalence, distribution of Chronic Wasting Disease in state deer, elk
By Ryan McGeeney
U of A System Division of Agriculture
April 1, 2016
- CWD detected in deer in Newton County
- Experts working to determine prevalence
- CWD not transmissible between species
LITTLE ROCK — Researchers with the University of Arkansas System Division of Agriculture said this week that 18 out of 48 white-tailed deer tested in Newton County in March were found to have Chronic Wasting Disease, also known as CWD.
Don White, Jr., professor and wildlife ecologist for the Division of Agriculture, said that number was probably not representative of the disease’s actual prevalence in the state’s wildlife herds.
“Those samples we had contained what’s known as ‘focal sampling,’” White said. “Those animals were either road-killed or seemed to display the symptoms of CWD, so it’s not random, it’s not representative of the whole.”
White said the samples were collected by Arkansas Game and Fish Commission biologists.
CWD is a transmissible form of spongiform encephalopathy, which kills members of the deer family by altering proteins known as prions in the animals’ brains. Symptoms include weight loss to the point of emaciation, excessive salivation, loss of coordination and death. White said there is currently no vaccine for the disease, which results in 100 percent fatality.
White and he and Game and Fish Commission biologists had collected sample tissue from 265 deer within the Newton County surveillance zone, harvesting tissue post-mortem from the animals’ brain stem and lymph nodes, areas that tend to accumulate the proteins that cause CWD. The samples are being sent in batches to a veterinarian laboratory in Madison, Wis., which takes about 10-14 days to analyze them, White said.
Once all of the results from the 265 deer are available, prevalence of CWD in the population of deer within the surveillance zone can be determined. Once prevalence is known, researchers will begin working to determine the distribution of CWD in the general area where it has been detected.
By establishing the distribution of the disease, White said, researchers can begin to address areas where the disease is concentrated, which may require looking at some human practices, as well.
“Some researchers have seen a relationship between the presence of CWD and the density of the deer herd,” White said. “So the more animals per unit of space, the greater the prevalence of CWD. One approach may be to reduce deer density, and keep it low in those CWD-positive areas.
“CWD is transmitted from deer to deer via body fluids such as saliva, urine, and feces. Because deer feeding and baiting concentrate deer into small areas, perhaps we will need to address the issue of feeding and baiting in Arkansas,” he said. “But we really can’t develop a management approach to CWD until we know prevalence rates and the distribution of the disease in the state.”
Although various animals, and even humans, host their own specific versions of a transmissible spongiform encephalopathy (in humans, it is known as Creutzfeldt-Jacob Disease), the respective diseases aren’t transmissible between species.
Additionally, humans cannot contract CWD by ingesting mean from an infected deer.
“People in CWD-positive areas in Colorado, Wyoming, and Wisconsin have undoubtedly consumed millions of tons of venison over the past few decades,” White said. “A human has never contracted a TSE by eating deer or elk meat.”
Nevertheless, there are carcass-handling guidelines available for hunters concerned with coming into contact with animals that may be carrying CWD. Becky McPeake, professor and extension wildlife specialist for the Division of Agriculture, is currently finalizing a publication that outlines basic safety precautions, which include:
- Do not harvest animals exhibiting clinical signs of CWD or any other disease.
- When processing harvested game, hunters should wear gloved protection, and avoid contact with nervous system tissues.
- Don’t consume brain or organ meats, especially lymph nodes of the head of cervids.
- Bone out the meat, and make sure to minimize contact with the brain and spine, as they constitute the bulk of the nervous system where prions tend to concentrate.
- Dispose of all non-consumable parts securely and in a location where other cervids will not encounter the carcass (such as an approved landfill or buried at a depth of at least 6’).
- Cleaning processing equipment in a 50% chlorine bleach solution will destroy prions, but is very detrimental to most equipment. Standard cleaning with hot soapy water is typically sufficient, given the limited health risks to humans. Wipe down processing surfaces with the same solution on a clean cloth.
For more information on Chronic Wasting Disease or other animal health issues, contact your local Cooperative Extension Service agent or visit www.uaex.edu.
The University of Arkansas System Division of Agriculture offers all its Extension and Research programs and services without regard to race, color, sex, gender identity, sexual orientation, national origin, religion, age, disability, marital or veteran status, genetic information, or any other legally protected status, and is an Affirmative Action/Equal Opportunity Employer.
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Media Contact: Mary Hightower
Dir. of Communication Services
U of A Division of Agriculture
Cooperative Extension Service