A Colorado State University study is developing and evaluating a more sensitive test for chronic wasting disease – including the potential to test for infection in live animals, animal products and the environment – through a project funded by Denver-based Morris Animal Foundation.
The disease, which affects deer, moose and elk and is related to similar diseases in cattle and sheep, is a primary concern for hunters and wildlife ranchers and now affects wildlife in 19 states, 2 Canadian provinces and one Asian country.
Prions are rogue proteins that cause the family of diseases that include CWD. The diseases are known as spongiform encephalopathies. While this Morris Animal Foundation-funded study would be the first in several steps to develop and evaluate a potential new test, it will look at a method that shows promise in detecting a wider array of prions at lower levels than are currently detected.
The research into the potential test may allow detection of CWD prions in live animals, animal products and the environment.
“Developing this test may eventually lead to a more rapid and sensitive to test for CWD,” said Dr. Ed Hoover, a Colorado State University veterinarian and researcher with 30 years of experience in researching infectious diseases of animals. “But, just as significantly, it may lead to a substantial gain in our understanding of how prions spread, survive in natural habitats, and impact animal and public health.”
Currently, CWD can only be identified either by testing brain after an animal is deceased or by surgical sampling and testing lymphatic tissues. While researchers don’t know exactly how CWD is passed from animal to animal, CSU scientists discovered that body fluids such as saliva, blood, urine and feces harbor infectious prions. Animals can then be exposed by direct contact with an infected animal or by contact with a contaminated environment.
Current tests also don’t detect all levels of or kinds of infectious prions or prions in the environment, and the test being evaluated in this study has the potential to be developed into a process that would detect those prions.
The test is being researched in collaboration with Dr. Byron Caughey at the National Institutes of Health’s Rocky Mountain Laboratory in Hamilton, Mont. Caughey’s laboratory developed the strategy for the study. Hoover, Caughey and colleagues will focus first on determining if their proposed test detects prions in body fluids with greater sensitivity, accuracy and faster output than is currently possible.
It is unknown why an infectious prion from one species, such as deer or elk, can “jump” to infect another species, and the potential risk to other species such as cattle, or even humans, remains uncertain.