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
Smart Data Transformation – Surfing the Big Wave
02.12.2016 | Fraunhofer-Institut für Angewandte Informationstechnik FIT
Climate change could outpace EPA Lake Champlain protections
18.11.2016 | University of Vermont
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
08.12.2016 | Power and Electrical Engineering
07.12.2016 | Health and Medicine
07.12.2016 | Life Sciences