Todd Heisler © News ON THE RUN Deer scamper through the Rabbit Mountain open space in Boulder County, where a sampling of a small herd found about 20 percent of the animals infected with chronic wasting disease. Sharpshooters culled the herd, to the dismay of some Boulder County residents. All photography »

ON THE WEB ASK THE NEWS Reporters Lou Kilzer, Gary Gerhardt and Todd Hartman answer readers' questions concerning chronic wasting disease. Click here. INTERNET SITES A list of web sites the News uses to research chronic wasting disease and similar maladies. Click here. CWD FORUM Use our forum to discuss issues related to CWD -- from hunting to health concerns. Click here. MORE COVERAGE The News is the region's leading source on chronic wasting disease. Coverage includes archived stories about CWD. Click here.

A killer is on the loose.

As "mad cow" disease, it has taken more than 120 lives and devastated cattle farmers in England, Europe and Japan.

Now as chronic wasting disease in deer and elk, it threatens to cripple Colorado's hunting economy -- and possibly much more.

How concerned should we be?

Recent research points to an unsettling possibility. This family of diseases -- called transmissible spongiform encephalopathies (TSEs) -- may be more sinister than even pessimistic scientists first envisioned.

Once symptoms develop, each TSE is fatal, caused by a mutant protein called a prion. Spongiform vividly describes the diseased brain tissue: It is spongelike, filled with microscopic holes.

In laboratory tests, the National Institutes of Health found that a TSE can rest undetected in one animal before attacking another in a more virulent form.

There is no proof that chronic wasting disease can infect humans, but there is some evidence that it might be possible.

Continue »

Todd Heisler © News

END OF A GAME RANCH The remains of elk slaughtered on ranches in northeastern Colorado are burned just outside Livermore, near Fort Collins. Such mass cremations became commmonplace this year, as the government slaughtered more than 3,000 domestic elk in Colorado during the first five months of 2002 to contain chronic wasting disease. All photography »

TABLE OF CONTENTS

CHAPTER 1
A DISEASE RUN WILD
Colorado is the epicenter of chronic wasting disease, an emerging killer that is stalking wildlife, threatening the state's hunting economy, and creating turmoil for sportsmen, scientists and politicians alike. In recent months, biologists have discovered the disease spreading outside its endemic area in northeastern Colorado, jumping to the Western Slope and east across the Mississippi River.
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CHAPTER 2
THE MAD COW CONNECTION
Chronic wasting disease is among a family of fatal illnesses that includes mad cow disease in cattle, Creutzfeldt-Jakob disease in humans, and scrapie in sheep. Mad cow disease is believed to have evolved when cattle were fed meat and bone meal rendered from scrapie-infected sheep. Mad cow startled the world by crashing the species barrier into humans. More than 120 have died in England and Europe.
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CHAPTER 3
ELK TO THE SLAUGHTER
Nowhere has chronic wasting disease been more devastating than to the state's commercial elk ranches, where entire herds have been destroyed and incinerated. Some believe that transported commercial elk have spread the disease from one ranch to another, across state lines and into other countries.
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CHAPTER 4
WHILE DANGER SPREAD
Whether it was England's mad cow epidemic or Colorado's decades-long skirmish with chronic wasting disease, government reaction has been characterized by caution and denial. It wasn't until mad cow crossed into humans that alarms sounded across both fronts. Critics say that to this day research is lagging and proper safeguards are lacking.
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CHAPTER 5
A FAMILY GRIEVES
A young Utah wife and mother vividly recounts her husband's descent into Creutzfeldt-Jakob disease. Because of his youth, federal officials rushed to investigate whether his death might have been CWD-related. They determined there was no strong evidence to suggest that it was, but his wife remains skeptical.
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CHAPTER 6
WHAT LIES AHEAD?
The reach of CWD is expanding, and much about it remains unknown. But scientists and politicians have issued a call to arms, with urgent requests for better testing techniques, more diagnostic laboratory capacity, a greater understanding of how the disease spreads and more funding for preventative measures such as double fencing of game ranches. Some scientists, including a Nobel laureate, believe that understanding prion disease may eventually help unlock secrets about more prevalent human maladies, including Alzheimer's, Parkinson's and Lou Gehrig's.
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