November 22, 2013 at 3:39 am #1075MikeKeymaster
In the search for answers about chronic wasting disease, hunters can
Keeping tabs on a mysterious disease.
By Cara Eastwood
Published in the Wyoming Tribune-Eagle
LARAMIE – With a razor-sharp scalpel clasped between her blue-gloved
fingers, lab technician Linda Cope carefully slices tiny pieces off
a lump of flesh that sits on a plastic cutting board.
Cope adds the sections to a small pile on a digital scale and
watches the weight creep up to 25 milligrams.
Once at the correct weight, she chops the small tissue pieces into
even smaller 2 millimeter cubes and then scoops the bits of flesh
into a vial containing water and tiny white porcelain beads.
When placed into a machine and spun at high speeds, the beads break
the flesh apart and help it dissolve into the water.
Then the technician removes the liquefied tissue from the vial and
puts it through several more steps to determine one question: Was
the animal infected with chronic wasting disease?
The fatal central nervous system disease found in mule deer, white-
tailed deer and Rocky Mountain elk causes the animals to lose body
control, exhibit odd behavior, increase drinking and urinating and,
eventually, to die.
The disease is not believed to be a danger to humans and has not yet
shown up in the meat of infected animals.
But the World Health Organization recommends not eating animals
infected with the illness, said Michelle Zitek, Wyoming Game and
Fish public information specialist.
In 1997 the Game and Fish Laboratory in Laramie began testing hunter-
harvested animals to gauge the extent of the disease in the state
and to let hunters know if their animals were infected. Since then,
the studies have continued annually.
With this year’s hunting season now in full swing, Cope and her
colleague Jessica Jennings are swamped with samples from hunter-
harvested animals from throughout the state.
Hank Edwards, wildlife disease specialist responsible for the
testing and mapping of chronic wasting disease data, says that by
the end of the season he and his staff will have tested more than
4,000 lymph nodes from mule deer, elk and whitetails.
The data will take months to analyze, he said, and any conclusions
about the status of the disease won’t be drawn almost until next
But with such a baffling disease, collecting any data at all helps
wildlife officials begin to understand it.
With their quick, reliable and sensitive Elisa test, lab staff gives
answers to hunters within only a few weeks – much faster than the
previous testing method.
But the disease’s mysterious origin makes it difficult to draw
conclusions about how fast it is spreading, Edwards said.
“It’s hard to say if we started seeing (chronic wasting disease)
because we started looking or because it was spreading,” he
said. “It’s probably a combination of both.”
Game and Fish officials craft a strategy each year on how to conduct
the chronic wasting disease survey, Edwards said.
“This year we tried to cover the whole state and also concentrate on
areas where we think the disease already exists in high
concentrations,” he said.
The southwestern corner near the Utah border will get special
attention. So will places where new cases have cropped up – like
Kaycee and Worland.
Hunter-harvested animals represent a random selection of deer and
elk, Edwards said, but the lab also tests road kills and animals
that Game and Fish staff kills as part of the “targeted
If a warden or a wildlife biologist sees an animal that is sick and
exhibiting symptoms of chronic wasting disease, the animal will be
killed and tested.
Hunters who see an animal that might be exhibiting signs of the
disease should contact the Game and Fish, Edwards said. There are
many diseases that look similar but are not chronic wasting disease,
Before the start of hunting season, lab staff assembled about 6,000
chronic wasting disease test kits containing head tags and small
sample containers. These went out to Game and Fish staff and meat
processors throughout Wyoming.
On the tag, hunters are asked to give specific information about
where the animal was killed. This is critical once the statewide
results come in and Edwards and his staff plot location points.
“Mostly we get ranches,” Edwards said, but that’s not specific
At check stations around the state, Game and Fish biologists give
hunters the option to take part in the free testing program. They
remove the lymph nodes of hunter-killed animals and label them with
sample and hunter numbers
Edwards said the goal is to get between 4,000 and 5,000 samples,
giving a good cross-section of the statewide deer and elk
Chronic wasting disease is a member of a group of diseases called
transmissible spongiform encephalopathies that are caused by
abnormal proteins, or “prions,” that attack the animals’ brains.
Even though scientists have yet to determine how the disease is
transmitted, they know that prions will appear in an animal’s lymph
nodes long before it starts to show the symptoms of chronic wasting
To increase the likelihood of finding prions, lab staff dissects the
lymph nodes into three sections after separating the tissue from any
skin or hair.
“In an early positive, the prions are randomly distributed in the
lymph node,” Edwards said. “As it gets to be a stronger positive, it
doesn’t make a hoot of difference where the sample comes from: The
prions are everywhere.”
On average, Edwards said, it takes about five hours to process one
sample and to determine a positive or negative result. With the
volume of samples coming through the lab, results take about four to
six weeks to appear on the Game and Fish Web site, he added.
“It’s all we can do to keep up with everything else we do here,” he
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