The recent case of two hunters who developed neurological diseases after consuming deer meat infected with chronic wasting disease has sparked concerns among scientists that ‘zombie deer disease’ could potentially transmit to humans, akin to how mad cow disease did.
Both hunters who ingested meat from deer known to carry chronic wasting disease, also known as “zombie deer disease,” experienced similar neurological conditions and subsequently passed away. This raises alarms regarding the potential transmission of the disease from animals to humans.
Chronic wasting disease (CWD), initially discovered in deer populations in northern Colorado and southern Wyoming in the 1990s, has since been identified in free-ranging deer, elk, and moose across at least 32 states throughout the continental United States, according to the U.S. Centers for Disease Control and Prevention (CDC).
Deer afflicted with CWD may colloquially be referred to as “zombie deer” due to the disease’s manifestation of symptoms such as weight loss, lack of coordination, stumbling, listlessness, drooling, and diminished fear of humans.
Scientists and health authorities have expressed concerns over the potential transmission of chronic wasting disease (CWD) to humans, similar to the outbreak of mad cow disease in the United Kingdom in the 1990s. A study conducted by Canadian scientists in 2022, based on research involving mice, suggested a risk of CWD transmission to humans.
Researchers at the University of Texas Health Science Center at San Antonio have highlighted a troubling case involving two deaths. These individuals consumed venison from a deer population known to be affected by CWD and subsequently developed sporadic Creutzfeldt-Jakob disease (CJD), a neurological disorder similar to CWD.
The second individual, aged 77, experienced “rapid-onset confusion and aggression,” according to the researchers, and passed away within a month despite receiving treatment.
“The patient’s history, including a similar case in his social group, suggests a possible novel animal-to-human transmission of CWD,” they wrote in the case report, presented earlier this month at the annual meeting of the American Academy of Neurology, and published in peer-reviewed journal Neurology.
The researchers did not disclose the locations where the affected individuals lived or hunted. However, the highest concentrations of chronic wasting disease (CWD)-infected deer are reported in Kansas, Nebraska, Wisconsin, and Wyoming, according to reports from the CDC and the US Geological Survey.
Due to the challenges in distinguishing between these diseases, the researchers clarified that this case does not constitute a confirmed instance of transmission. Nevertheless, they emphasized the importance of conducting further investigations into the potential risks associated with consuming CWD-infected deer and its implications for public health.
Chronic wasting disease, also known as “zombie deer disease,” is a prion disease characterized by a rare, progressive, and fatal neurodegenerative disorder that affects deer, elk, moose, and other animals, as outlined by the CDC. In prion diseases, abnormal folding of specific “prion proteins” leads to brain damage and other symptoms. These diseases, typically progressing rapidly and invariably fatal, can affect both humans and animals.
Creutzfeldt-Jakob disease (CJD) and its variant form (vCJD), which is a type of mad cow disease, are prion diseases observed in humans.
Mad cow disease serves as an illustration of a prion disease capable of transmission from cattle to humans, and certain researchers have drawn comparisons between “zombie deer disease” and it.
For instance, according to the Food and Drug Administration, in cases of mad cow disease, it typically took four to six years from infection for symptoms to manifest in cattle. Similarly, deer may exhibit an incubation period of up to two years before showing symptoms, as highlighted by the U.S. Geological Survey. Consequently, infected animals could appear healthy until symptoms such as weight loss emerge.