Deer disease researchers call on Creighton professor
His reputation as a world authority on the ecology of highly contagious disease particles known as “prions” landed Jason Bartz, PhD, on a University of Minnesota team studying chronic wasting disease (CWD) in deer.
Bartz, Creighton University’s associate dean for academic and faculty affairs and vice chair of medical microbiology and immunology at the Creighton University School of Medicine, will analyze field samples collected by researchers investigating an approximately 12-acre site in northern Minnesota where CWD-infected deer carcasses were illegally dumped.
Peter Larsen, PhD, assistant professor in the University of Minnesota’s Department of Veterinary and Biomedical Sciences and co-director of the Minnesota Center for Prion Research and Outreach, is leading the effort to measure the presence of prions in soil. These highly contagious particles can infect soil for up to two decades and can be detected by measuring their presence in animal urine, bones and hair.
The emergence of the illegal dump promises to be something of a biological Rosetta Stone, potentially revealing how long CWD prions can survive, how they spread, and whether plants and mushrooms are capable of absorbing and spreading them in addition to animals and rodents.
According to the Centers for Disease Control and Prevention, chronic wasting disease is universally fatal. There are no treatments or vaccines. It primarily affects deer, elk, reindeer, sika deer and moose and has been detected in Canada and the United States, Norway, Finland, Sweden and South Korea. Symptoms include drastic weight loss (wasting), stumbling, listlessness and other neurologic symptoms. No evidence of human transmission is known, though CDC information says that some studies have shown that non-human primates such as monkeys are at risk after eating CWD-infected meat.
“These studies raise concerns that there may also be a risk to people,” the CDC says. “Since 1997, the World Health Organization has recommended that it is important to keep the agents of all known prion diseases from entering the human food chain.”
Larsen says he met Bartz through a coalition of universities formed to address CWD issues.
“Our research interests proved so much in common that we were collaborating even before the dump site became available,” Larsen says. “When the dump site happened back in April it was all hands on deck. Jason is a world authority and expert on prion disease and the ecology of prions, and there are things he can do in his lab, experimentally, that we are nowhere near being able to do.”
Highly sensitive methodologies that can detect the presence of a tablespoon of CWD prions distributed across a body of water equivalent to 400 Olympic-sized swimming pools are key to the research effort.
“We are trying to figure out the extent of the contamination, if any, and if there is contamination, then trying to figure out ways to mitigate this so that it doesn't spread and pose a risk to wild deer in that area,” Bartz says. “In the laboratory, in experimental settings, there is evidence that plants can also spread these prions. Now that we have this proof of principle that something is possible, we are going into the field and asking the question: ‘Do we observe something in the field similar to what was determined in a laboratory setting?’”
Larsen says he believes his team’s research is “incredibly unique.”
“The research is so important and so novel because we are trying to understand the ecology of these prions in the wild so we can understand long term, through ecological testing, Where are the prions? Where are the hot spots?
“Are the rodents that live in the soil spreading prions around? Are the prions being incorporated into plants, into their leaves, perhaps into mushrooms, and even into grass? Are the prions circulating in dust? We know that you can go into a barn and find prions in dust. Are the prions moving through waterways? We know from our research into CWD in Colorado that prions can be picked up in water downstream of positive herds.”
The university consortium that brought Bartz and Larsen together is composed of basic scientists, field biologists and representatives of state and federal agencies concerned with chronic wasting disease.
“This year I was the chair of this consortium,” Bartz says. “We are a multidisciplinary group seeking to identify the major problems in the field, and once those problems are identified, figuring out how to solve them.”