May 24, 2002

Spreading 'Mad Deer' Plague
Leaves U.S. Scientists Baffled

By ANTONIO REGALADO
Staff Reporter of THE WALL STREET JOURNAL
 

FORT COLLINS, Colo. -- There's trouble on the other side of the chain-link
fences surrounding the state government's Foothills Wildlife Research
Facility. The dusty pastures are ground zero for a deer-killing plague that
is frighteningly similar to mad-cow disease.

It was here that the condition, known as chronic wasting disease, or CWD,
was first identified decades ago, and where animal-management practices may
have fueled an epidemic. Now, scientists are conducting research in the
pens and laboratories here in their search for ways to stop it.

They are racing against a disease that has rapidly spread across eight
states and parts of Canada. The U.S. Department of Agriculture has called
CWD an "emergency." In Colorado, sharpshooters, some working from
helicopters, have slaughtered 10,000 deer in the past year trying to
contain its spread. Identified first only in captive animals, it has leapt
the fences, infecting a small but growing number of the nation's more than
20 million free-ranging deer.

Fears that CWD could devastate regional hunting and tourist economies have
sent states scurrying to Washington for financial aid. Last week, in
congressional hearings on the outbreak, Wisconsin Gov. Scott McCallum
pleaded for financial assistance and declared that CWD "is threatening our
way of life."

Brain tests following last fall's hunting season in Wisconsin suggested
that about 3% of white-tail deer are infected in a large region straddling
two counties. Those findings have generated shock waves in a state where
hunters killed 446,000 deer last year, generating more than $1 billion in
economic activity and countless venison dinners.

Much about the illness remains a mystery. A little-understood protein known
as a "prion," a form of which is behind mad-cow disease, causes chronic
wasting disease. In ways scientists don't yet fully grasp, prions enter the
brain and set off a chain reaction, causing some of the brain's own
proteins to assume an aberrant form. In humans, such rogue prion proteins
are blamed for a rare, naturally occurring human illness called
Creutzfeldt-Jakob disease, and a related disease linked to eating
contaminated beef from "mad cows."

 
There's no evidence that meat from deer or elk has infected humans. But
alarms have been raised recently over five unusual cases of brain-wasting
disease in young people living in the U.S., and researchers are probing the
cases for possible links.

One involves Doug McEwen, a 30-year-old hunter from Kaysville, Utah, who
died in 1999 of Creutzfeldt-Jakob disease. The condition is extremely rare,
and, when it occurs naturally, almost always strikes late in life. An early
onset has been one of the hallmarks of the disease linked to cattle. The
McEwen case caught the attention of activist groups that were lobbying for
stricter surveillance in the U.S. of mad-cow disease. The Center for Food
Safety, a consumer watchdog group in Washington, called Mr. McEwen's case
the first possible case of "mad deer" disease.

Researchers haven't been able to document a link. The Centers for Disease
Control and Prevention in Atlanta studied Mr. McEwen's case and those of
two other people 30 years old or younger who died of Creutzfeldt-Jakob
disease between 1997 and 2000. An analysis of their brain tissue ruled out
mad-cow disease as the cause. But two were hunters and one was the daughter
of a hunter, and all had regularly consumed elk or deer meat. Intrigued by
the possibility that wild game caused their disease, epidemiologists
quizzed family members about the victims' lifestyles and eating habits. But
researchers said they found "no strong evidence for a causal link" to CWD.

Mysterious Moves

Meanwhile, scientists in Fort Collins and elsewhere are conducting
federally funded tests to figure out how the animals are becoming infected.
In mad-cow, the disease source was traced to cattle feed containing bone
meal from contaminated livestock. But no one knows how CWD moves from
animal to animal. One thing is clear: The infectious agents are hard to
kill off. The grounds at the 35-acre Foothills facility have been dug up,
disinfected and even temporarily closed. Still, when the animals return,
they invariably lose weight, salivate copiously, behave oddly, and die.

"We know very, very little. We don't understand the transmission, we don't
understand the origin, we don't understand any of this," says Stanley
Prusiner, the University of California, San Francisco neurologist who won a
Nobel Prize for developing the prion hypothesis.

Chronic wasting disease has been around for at least 35 years, but until
the mad-cow outbreak, it was of interest to only a handful of wildlife
biologists. Elizabeth Williams was one of them. Just out of veterinary
school in 1977, she learned about the trouble researchers had been having
since the mid-60s at the animal research pens on the edge of Fort Collins.
The deer there were doing poorly in captivity, mysteriously losing weight
and dying. Biologists suspected a nutritional problem, or perhaps
poisoning, and termed the syndrome "chronic wasting."

Dr. Williams soon found the problem. Peering at thin slices of the animals'
brains through a microscope, she recalls seeing "a lot of lesions." The
sponge-like patterns of decay she found reminded her of a video she'd seen
as a student about the human cannibals of Papua New Guinea. An adventurous
scientist named D. Carleton Gajdusek had won a Nobel Prize for showing that
the ritual acts of eating human brains were causing a rare condition,
called spongiform encephalopathy, that was killing the islanders.

The deer were dying of something similar. Dr. William's classification of
CWD as a spongiform disease in 1977 was a career-making finding, although
CWD remained an obscure wildlife problem.

An early sign that CWD was infectious came two years later, when
veterinarians detected a case at another research facility in Sybille
Canyon, Wyo., about 120 miles northwest of Fort Collins. That site, a
jumble of open paddocks on a steep hillside, sometimes exchanged animals
with the Fort Collins pens.

Two years after the Sybille case turned up, biologists diagnosed the first
case in a wild animal -- a sick elk found in Rocky Mountain National Park.
It may never be known for sure if the disease actually started in the Fort
Collins pens, or was simply first identified there. "The pens are like
microscopes for mule deer," says N.T. Hobbs, an ecologist at the Colorado
State University, who now leads a major study of CWD funded by the federal
government. "Just because you see something, that doesn't mean you created
it."

The Foothills Wildlife Research Facility, Colorado's main center for
studying diseases of wild animals, is surrounded by a double ring of
eight-foot-high fencing, and none of the animals now being studied there is
ever allowed to leave alive. But security wasn't always so tight. For years
after Dr. Williams's findings about CWD, deer were often brought into the
pens to breed, then released back into the wild. The pens only had a single
fence line then, and especially during rutting season wild bucks would come
to the perimeter to nose with the females inside.

By 1985, however, it became clear that the Fort Collins pens and Sybille
Canyon had become deadly reservoirs of sickness. Whatever was causing CWD
was somehow loose in the dirt enclosures. That led to what Dr. Hobbs calls
a "grisly" clean-up effort at the Foothills facility. The deer, big horn
sheep and other animals being studied on site were all destroyed, and six
inches of topsoil hauled away. The out buildings were washed with bleach,
then left vacant for over a year. But when new deer were brought to the
Foothills pens, the disease came back too.

Today, both Fort Collins and Sybille Canyon are considered hopelessly
contaminated. Terry Kreeger, the Wyoming state veterinarian who lives at
Sybille with his family, says when an elk or deer dies of CWD, he hauls the
carcass in his pick-up truck to Dr. Williams's laboratory near Laramie. The
corpse is dissected and incinerated, but few other precautions are taken.
Dr. Kreeger, for instance, says he washes his truck out with a hose without
worrying about putting more prions into the environment. "This horse is
long out of the barn," he shrugs.

New Way to Spread

Initially, CWD had been spreading slowly, since wildlife in the main
infection area of about 20,000 square miles between Fort Collins and
Laramie were contained by natural barriers, such as the slopes of the Rocky
Mountains. But CWD's jump from deer into local elk gave the disease an
unpredictable new way to spread: via man-made transport as part of the
trade in elk. In 1996, CWD turned up on a commercial elk farm on
Saskatchewan, Canada. Three years later, elk-breeding operations in four
U.S. states had found sick animals as well.

At the time, commercial elk farming was booming among small ranchers
looking for new income. Elk require little food or space to thrive, and
ranchers can make money from their meat and antlers, which are sawed off in
the spring, then ground and sold as nutritional supplements. So-called
velvet antler is exported to Asia where it is considered an aphrodisiac,
and is also sold in U.S. chains such as General Nutrition Centers, where it
retails for about $17 an ounce.

Since 2000, only 259 farmed elk have died or been diagnosed with CWD,
according to the North American Elk Breeders Association. This is just a
small percentage of the 160,000 elk it estimates are in captivity on 2,300
U.S. and Canadian elk ranches. But the disease has an incubation period of
two to three years. Since 1998, elk farmers have destroyed 4,432 elk known
to be exposed to the sickness.

Some researchers speculate that the elk trade brought the disease to wild
deer in Wisconsin. Discovery of those infected animals sharply escalated
CWD concerns nationwide, because the new region of infection is so far from
where the disease was first identified. But the truth is, nobody knows.

Scientists in Colorado and Wyoming are now urgently trying to determine
just how CWD is spread, partly funded by a $2.2 million grant from the
National Science Foundation. At Sybille Canyon, researchers have infected
three young deer with CWD by feeding them the brains of deer that died of
the disease. Blood, saliva, feces and urine collected from the animals
every six months will be injected into the brains of laboratory mice to see
if they cause infection.

A separate set of experiments will confirm whether prions can lurk in the
environment, as the team suspects. At the Fort Collins pens, Michael
Miller, a Colorado Division of Wildlife biologist, has overseen the
construction of isolation rooms to test different theories. In one room,
two fawns are living alongside the decomposed carcass of a CWD deer. Others
are being reared in rooms that previously housed animals with CWD.

The unknowns worry some consumer advocates. "I think that we have to assume
the worst of CWD -- that it could be even more dangerous and costly than
mad cow because of its unique ability to spread through the environment and
animal to animal," says John Stauber, the author of "Mad Cow U.S.A.," a
book arguing the U.S. hasn't done enough to keep bovine spongiform
encephalopathy, as the disease is known formally, out of the country. "With
BSE there was a feeding loop that could be shut down. Here, it seems to
spread like a cold or the flu."

Some laboratory studies suggest CWD could theoretically infect people.
Byron Caughey, a prion researcher at the National Institutes of Health's
Rocky Mountain Laboratory in Hamilton, Mont., found that CWD prions could
convert human prion proteins to their deadly form in a lab dish. However,
the efficiency of such "conversion" was extremely low, evidence of a
substantial species barrier.

So far, few steps have been taken to reduce people's exposure to CWD
prions. In Colorado, where hunting and wildlife sightseeing generate nearly
as much economic activity as skiing, there are no special regulations
governing how deer carcasses are handled. Hunters in Fort Collins have been
asked to sever the head of any deer they bag and deposit it in a steel drum
outside the Division of Wildlife's offices across from the Holiday Inn. A
couple of weeks later, a state lab reports whether the kill was infected.

Margy Constantino, a Brooklyn native who makes her own bullets in the
basement of her ranch house near Fort Collins, says some hunters haven't
waited for test results before eating their kills. Ms. Constantino, who
lives in an area with rates of CWD as high as 15%, shot a buck through the
heart last year and waited about three weeks for results.

Though the results came back negative, she'd already had the animal
butchered in the meantime. Since the local butchers tend to give customers
ground meat made from pooled scraps, often there's no guarantee a hunter's
kill won't be mixed with that of an animal that turned up positive for CWD.

"The processor takes scraps and turns it into hamburgers," says Jim
Widmier, the proprietor of Arrow Dynamics, a shop in Fort Collins that
caters to bow hunters. "That is a scary situation. The hamburger and
sausage you get is going to be ground up with other people's."

Write to Antonio Regalado at antonio.regalado@wsj.com

Updated May 24, 2002