A team of researchers has reported that chronic wasting disease (CWD) can be transmitted through environments contaminated by whole carcasses or excrement of animals infected with the pathogen that causes CWD.
The research confirms long-held theories that CWD can be indirectly spread through environmental sources, in addition to direct interactions between infected and healthy mule deer.
Funded by the National Science Foundation (NSF) and the National Institutes of Health, the study results were published on-line last week in the journal Emerging Infectious Diseases. The authors are Colorado Division of Wildlife (DOW) veterinarians Michael Miller and Lisa Wolfe, Colorado State University (CSU) scientist Thomas Hobbs and University of Wyoming scientist Elizabeth Williams.
"Diseases like CWD are poorly understood and of rising concern," said Sam Scheiner, program director in NSFs division of environmental biology, which funded the research. "This study provides significant new information showing the potential for transfer of the infection through the environment after many months. The knowledge will substantially alter how we manage the disease in wild and domestic animals."
Based on anecdotal observations, "we have long suspected that CWD could be transmitted when healthy deer were exposed to excreta and carcasses of mule deer that had the disease," said Miller. "Our findings show that environmental sources of infection may contribute to CWD epidemics, and illustrate how potentially complex these epidemics may be in natural populations."
Added Williams, "Weve had a great deal of circumstantial evidence suggesting that indirect transmission occurs. The experimental findings show that we need to consider several potential exposure routes when attempting to control this disease."
Hobbs said the research could be important in helping to slow the spread of CWD.
"Ultimately, we want to develop models that predict the behavior of the disease," Hobbs explained. "For example, we would like to predict how prevalence changes over time in different areas of Colorado."
Hobbs said previous disease models have been based on animal-to animal contact as the sole source of infection and that disease prevalence was expected to decline as the number of infected animals is reduced.
"Our findings that contaminated environments can cause transmission means that these declines in infection rates may be much slower than would be predicted by models that only consider animal-to-animal transmission."
Miller said that while the research shows environmental contamination is possible in a captive setting, the impacts in the wild are still unknown.
The research confined healthy deer in three sets of separate paddocks. In the first set, healthy deer were exposed to another deer already infected with CWD; in the second set, deer were exposed to carcasses of deer that had died of CWD; in the third set, deer were confined in paddocks where infected deer had previously been kept.
A few of the healthy deer contracted CWD under all three exposure scenarios over the course of one year.
Chronic wasting disease is a fatal neurological ailment of elk, white-tailed deer and mule deer. Most researchers believe the disease is caused by an aberrant prion protein that misfolds in the brain, destroying brain tissues as it progresses. Clinical signs include lethargy, excessive salivation, loss of wariness of predators and slowly deteriorating body condition. The disease is always fatal and there is no known cure or treatment to prevent CWD.
Federal and state health officials have found no connection between CWD and human health. As a precaution, officials recommend that the meat of animals infected with CWD should not be eaten.
"Although live deer and elk still seem the most likely way for CWD to spread geographically, our data show that environmental sources could contribute to maintaining and prolonging local epidemics, even when all infected animals are eliminated," Miller said. He said the appropriateness of various culling strategies may depend on how quickly the CWD agent is added to or lost from the environment.
Cheryl Dybas | NSF
Statistical method developed at TU Dresden allows the detection of higher order dependencies
07.02.2020 | Technische Universität Dresden
Novel study underscores microbial individuality
13.12.2019 | Bigelow Laboratory for Ocean Sciences
The operational speed of semiconductors in various electronic and optoelectronic devices is limited to several gigahertz (a billion oscillations per second). This constrains the upper limit of the operational speed of computing. Now researchers from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany, and the Indian Institute of Technology in Bombay have explained how these processes can be sped up through the use of light waves and defected solid materials.
Light waves perform several hundred trillion oscillations per second. Hence, it is natural to envision employing light oscillations to drive the electronic...
Most natural and artificial surfaces are rough: metals and even glasses that appear smooth to the naked eye can look like jagged mountain ranges under the microscope. There is currently no uniform theory about the origin of this roughness despite it being observed on all scales, from the atomic to the tectonic. Scientists suspect that the rough surface is formed by irreversible plastic deformation that occurs in many processes of mechanical machining of components such as milling.
Prof. Dr. Lars Pastewka from the Simulation group at the Department of Microsystems Engineering at the University of Freiburg and his team have simulated such...
Investigation of the temperature dependence of the skyrmion Hall effect reveals further insights into possible new data storage devices
The joint research project of Johannes Gutenberg University Mainz (JGU) and the Massachusetts Institute of Technology (MIT) that had previously demonstrated...
Researchers at Chalmers University of Technology, Sweden, recently completed a 5-year research project looking at how to make fibre optic communications systems more energy efficient. Among their proposals are smart, error-correcting data chip circuits, which they refined to be 10 times less energy consumptive. The project has yielded several scientific articles, in publications including Nature Communications.
Streaming films and music, scrolling through social media, and using cloud-based storage services are everyday activities now.
After helping develop a new approach for organic synthesis -- carbon-hydrogen functionalization -- scientists at Emory University are now showing how this approach may apply to drug discovery. Nature Catalysis published their most recent work -- a streamlined process for making a three-dimensional scaffold of keen interest to the pharmaceutical industry.
"Our tools open up whole new chemical space for potential drug targets," says Huw Davies, Emory professor of organic chemistry and senior author of the paper.
12.02.2020 | Event News
16.01.2020 | Event News
15.01.2020 | Event News
24.02.2020 | Agricultural and Forestry Science
24.02.2020 | Earth Sciences
24.02.2020 | Agricultural and Forestry Science