Wildlife experts investigate spread of ‘zombie deer disease’

A white-tailed deer afflicted with chronic wasting disease — also frequently referred to as “zombie deer disease” — will appear abnormally thin, move sluggishly, and salivate excessively. There is no cure: chronic wasting disease (CWD) is contagious and always fatal, and it has been detected with increasing frequency in Virginia and other states, raising concerns about effects on the deer population.

Virginia Tech professor and wildlife health expert Luis Escobar will be leading a study to determine the risk of CWD transmission in Virginia. He answered questions about the disease, what the study will do and how it is being funded.

Q: Where has chronic wasting disease been detected?

“In North America, species known to be susceptible to natural infection include elk, white-tailed deer, mule deer, black-tailed deer, moose, and the red deer, which is not native to the continent. All of these are mammals in the deer family, or cervids. In the U.S., chronic wasting has been detected in free-ranging cervids in 29 states. In Virginia, CWD has been detected in white-tailed deer in the north and southwest areas of the commonwealth.”

Q: How does CWD spread and what are the symptoms?

“CWD is caused by infectious proteins causing fatal neurodegenerative diseases. Infected deer can transmit the pathogen by direct contact — for example, through saliva — or by contaminating the environment. As examples, infected feces or urine or an infected carcass can contaminate grass.  Transmission can occur before symptoms appear, as early as six months after the infection. The infection causes hyperexcitability, or increased activity, in the early stages. Advanced symptoms include severe loss of weight, excessive salivation, behavioral changes such as decreased activity, and weakness followed by death.”

Q: How severe is the threat to the white-tailed deer population?

“Some studies suggest a large potential threat to wildlife conservation due to deer mortality and effects on genetic diversity in populations affected by CWD. Efforts to prevent spread of the disease include regular culling, which could impact deer abundance in the affected regions but seems to be effective.”

Q: What research will your team conduct into the spread of chronic wasting disease?

“Thanks in part to a $30,000 gift from Virginia Hound Heritage, our team, which includes Virginia Tech professor of deer ecology and animal movement Brett Jesmer, will be able to undertake an extensive investigation into CWD transmission risk across Virginia. The goal of this project is to estimate the paths, direction, and extent of future CWD spread in white-tailed deer. The team will use molecular tools to generate information of likely spread of the disease in unprecedented detail in Virginia.”

Q: Can humans or pets get CWD?

“To date, CWD only has been found in white-tailed deer and other cervids.”

About Escobar
An assistant professor with Virginia Tech’s Department of Fish and Wildlife Conservation, Luis Escobar conducts research focused on the application of ecology and epidemiology to study the distribution of infectious diseases in fish and wildlife. His laboratory explores methods for investigating links between global change and disease emergence. He has won awards for his research, which has included studying disease transmission from vampire bats to other species in Colombia, and studying the effects of the tuberculosis vaccine on COVID-19. Read more about him here.

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