DON'T TAKE CWD
FOR GRANTED, PENN STATE EXPERTS ADVISE
UNIVERSITY PARK, Pa. -- Scientists in Penn State's College
of
Agricultural Sciences expected chronic wasting disease (CWD) to show up
in deer in the Northeast eventually, but they didn't anticipate that it
would appear on Pennsylvania's northern doorstep this spring after being
discovered in a deer that was fed to 350 people.
But that's what happened
in Verona, N.Y., where a donated deer --
processed into venison that ended up in chili, meatballs and sausage
served to attendees at a volunteer fire department game banquet in March
-- later tested positive for CWD. Subsequent testing revealed that four
more domesticated deer in two captive herds kept just east of Syracuse
were infected by the disease.
Even though there is no evidence that humans are affected
by CWD --
or even that livestock other than deer or elk are vulnerable to the
disease -- the finding shook wildlife and food-safety officials in both
Pennsylvania and New York. It marks the first time CWD has been found
east of Illinois, and the herds containing the infected animals were
less than 100 miles north of the Pennsylvania border.
"CWD has not been linked to
human illness," says Catherine Cutter,
assistant professor of food science, who specializes in the processing
of meat from deer and other wild game. "But the Centers for Disease
Control and Prevention recommends against eating meat from deer infected
with CWD. We advise hunters to use common sense and take some basic
precautions in handling harvested deer."
David Wolfgang, senior research associate in veterinary
science,
points out that scientists don't yet know exactly how the disease is
transmitted. "The agents that cause CWD are neither bacteria nor
viruses, but are hypothesized to be prions, infectious proteins," he
says. "The disease causes a deer's brain and nervous system to slowly
accumulate the abnormal prions and eventually to begin to deteriorate.
Although CWD is a fatal disease among deer and elk, research suggests
that humans, cattle and other domestic livestock are resistant to
natural transmission. While the possibility of human infection remains a
concern, it is important to note there has never been a case of humans
contracting CWD."
Wolfgang noted that the disease, which appeared in
Colorado in the
late 1960s and has spread east and south since then into 11 states, has
not jumped between species. At the National Prion Disease Pathology
Surveillance Center at Case Western Reserve University, experiments in
transgenic mice are under way to determine the likelihood of the disease
jumping from deer to humans.
The ramifications of CWD coming to the Northeast -- and
perhaps
ultimately Pennsylvania -- are very serious, according to Gary San
Julian, professor of wildlife resources. "When chronic wasting disease
was discovered in Wisconsin two years ago, the sale of hunting licenses
dropped as hunters reacted to what they perceived as a threat," says San
Julian. "Sales rebounded after that, but it shows the economic impact
this disease can have on a state such as Pennsylvania, with a strong
hunting heritage, if it is discovered here."
New York officials are taking the outbreak seriously --
they killed
all 20 deer on the two farms where the disease was discovered,
quarantined several other nearby deer farms, and they plan to kill more
than 400 deer to collect samples to see whether the disease has spread
into the wild. But the circumstances surrounding the New York CWD cases
are especially worrisome, San Julian explained, boosting chances CWD
might break containment.
"One of the farms where the infected deer was
discovered does more
than raise deer -- it also takes in wild deer for rehabilitation and
releases them back into the wild," San Julian says. "It is a concern,
depending how injured or orphaned animals were handled. The prospect of
CWD being in the wild a short distance north of Pennsylvania worries
hunters and conservation agency officials here alike. Containing this
disease could cost millions of dollars at a time when agency funds are
tight."
States where CWD has been discovered have issued
recommendations
for hunters to follow when handling deer carcasses. Although CWD is not
in Pennsylvania, Cutter suggests that Keystone State hunters consider
taking the following precautions:
--Avoid butchering, processing or consuming venison from
an animal
that appeared sick in any way. "Steer clear of deer that appear
emaciated, wobbly or display an unnatural lack of fear," she says.
--Wear rubber or latex gloves when handling venison and
processing
deer. "That's a wise practice even if you aren't worried about CWD,"
she
says.
--Don't cut into the brain, spinal cord, spinal column or
lymph
nodes when butchering.
--If possible, hang deer by hind legs with head down when
butchering. "Most cattle and livestock processed in this country are
hung with the head down," Cutter says. "That prevents brain and
spinal
fluids from contacting the meat."
--Use a knife and debone all venison. "Cutting bone
could expose
meat to nerve tissue," Cutter says.
--Once you are finished processing, clean all knives and
utensils
thoroughly with warm, soapy water, and then soak them for a few hours in
a 50 percent solution of bleach and water. "Strong chlorine solutions
have been shown to greatly decrease the infectivity of prions, the
infectious agents of CWD found in the nerve tissue of infected animals,"
she says.
--Properly dispose of brain, spinal cord, spleen, tonsils and
other
organs. "Appropriate disposal depends on what state you are in,"
Cutter
explains. "In Pennsylvania, you should seal the remains in plastic trash
bags and be certain they are disposed of in a lined landfill that is not
exposed to runoff and doesn't leach into groundwater. That describes
most municipal landfills."
EDITORS: Contact Catherine Cutter at (814) 865-8862 or by e-mail at
cnc3@psu.edu; Gary San Julian at (814) 863-0401 or by e-mail at
jgs9@psu.edu; or David Wolfgang at (814) 863-5849 or by e-mail at
drw12@psu.edu.
Writer/Editor
Jeff Mulhollem
(814) 863-2719
>jjm29@psu.edu