BROOKINGS, S.D. – A South Dakota State University scientist is doing research that could lead to a live animal test for chronic wasting disease.
The fatal illness, for which there is no known cure, attacks the central nervous system of deer and elk, causing the infected animals to waste away.
Alan Young, associate professor of veterinary science, said developing a culture system for CWD could lead to an early stage diagnosis. Current tests can be done only on dead animals’ brains.
“As far as progress goes, we’re still a few years away from an actual diagnostic assay,” he said.
Young’s research is part of a joint effort between the Center for Infectious Disease Research and Vaccinology and the private research company Rural Technologies Inc.
It focuses on transmissible spongiform encephalopathies, or TSEs, a group of diseases caused by abnormal levels of complex proteins called prions.
The most-well-known form of TSE is bovine spongiform encephalopathy, better known as mad cow disease, which struck Britain in the 1980s.
Two cows have been found with the illness in the United States.
The human form is variant Creutzfeld-Jakob disease, which is believed to have originated from eating infected beef.
TSEs are typically discovered when prions are found in brain tissue during a postmortem test.
But the abnormal proteins also exist in lymph nodes, tonsils and immune cells in the bloodstream.
The problem is the levels are so low, they’re hard to detect, Young said.
His team was able to overcome the problem by focusing on a particular class of immune cells called follicular dendritic cells.
The method involves taking tissues out of an animal and throwing them on a cell type already susceptible to infection.
“Then if you see infection, you know the animal has the disease,” he said.
Although Young’s research is focused on CWD, he hopes the technology will translate to other prion diseases, such as mad cow.
The ultimate beneficiaries of a commercial CWD test will be hunters, game farms and wildlife managers, said Chris Mateo, operations manager for Rural Technologies.
The company is working under a $750,000 small business grant from the U.S. Department of Defense and hopes to have CWD blood test kits ready to sell within two to three years.
Mateo said testing kits, which might retail for $20 to $35, would be marketed to the diagnostic laboratories certified to test for CWD and the country’s captive herd farmers.
There are an estimated 150,000 elk on 2,300 farms and an estimated 550,000 deer on 11,000 farms in the United States, he said.
“They can buy the kit, or send the samples to a diagnostic lab,” Mateo said.
Steve Griffin, a biologist with the South Dakota Department of Game, Fish and Parks, said a live animal test would benefit those tending to captive herds – but not necessarily wildlife officers.
“It’s going to be very helpful for the captive industry. But for the wild animals, it’s not going to help you at all,” Griffin said. “Because you can’t go out and capture every wild animal and test it to see if it’s positive or not.”