[6] CWD is typified by chronic weight loss and clinical signs compatible with brain lesions, aggravated over time, always leading to death.

[7] In April 2024, it was revealed that two men from the same hunting group contracted Creutzfeldt–Jakob disease, prompting medical researchers to speculate transmission had occurred from consuming CWD-positive venison.

[11] In February 2003, the Centers for Disease Control published a report of "Fatal degenerative neurologic illnesses in men who participated in wild game feasts--Wisconsin, 2002".

"[12] In September 2003, Hoey pointed out that one of the three patients (the 55 year-old) "presented with a 3-month history of difficulty in writing and unsteadiness of gait, followed by dementia, speech abnormalities and myoclonic jerking.

Pathologic examination of the brain at autopsy 3 months later revealed widespread subcortical spongiform lesions consistent with CJD.

[14] The September 2018 discovery of CWD on a managed operation in Grenville-sur-la-Rouge Quebec prompted a wholesale slaughter of 3500 animals in two months before the enterprise shut down permanently.

[17] The quarantine around Grenville was still in place, and the ministry specifically prohibited (only) the "removal" from the quarantine "enhanced monitoring area" zone of "the head, more specifically any part of the brain, the eyes, the retropharyngeal lymph nodes and the tonsils, any part of the spinal column, the internal organs (including the liver and the heart), and the testicles.

Behavioral changes also occur in the majority of cases, including decreased interactions with other animals, listlessness, lowering of the head, tremors, repetitive walking in set patterns, and nervousness.

[22] The APHIS summarized it as:[3] Behavioral changes, emaciation, weakness, ataxia, salivation, aspiration pneumonia, progressive death.The cause of CWD (like other TSEs, such as scrapie and bovine spongiform encephalopathy) is a prion, a misfolded form of a normal protein, known as prion protein (PrP), that is most commonly found in the central nervous system (CNS) and peripheral nervous system (PNS).

The abnormality in PrP has its genetic basis in a particular variant of the protein-coding gene PRNP that is highly conserved among mammals and has been found and sequenced in deer.

[3] In white-tailed deer, polymorphisms at codons 95 (Q->H) and 96 (G->S) dramatically affect CWD progression and prion strain specification.

[28] Exposure between animals is associated with sharing food and water sources contaminated with CWD prions shed by diseased deer.

[32] Recent research on Rocky Mountain elk found that with CWD-infected females, many subclinical, a high rate (80%) of maternal-to-offspring transmission of CWD prions occurred, regardless of gestational period.

Modern news stories and anecdotal evidence from treating physicians suggest that a human may have contracted Creutzfeldt–Jakob disease via the consumption of squirrel brains infected with CWD.

It depended on voluntary minimum standards methodology, and herd certification programs to avoid interstate movement of the disease vector.

Introduced for the 2019 Minnesota hunting season, a no-cost deer carcass-incineration program was rolled out by Crow Wing County officials hoping to stem the spread of CWD in the region.

The voluntary program encourages both residents and visiting hunters to bring harvested deer carcasses to the county landfill east of Brainerd, Minnesota for incineration and disposal.

[22] In 2023, Minnesota funded a Center for Infectious Disease Research and Policy (CIDRAP) project to assemble 70 public health experts from around the world to devise a response plan for potential human spillover.

Michael Osterholm, an infectious disease expert at the University of Minnesota, stressed the urgency of preparedness, noting that the prion responsible for CWD is evolving and becoming more capable of infecting humans.

Despite these concerns, a 2022 study by the National Institutes of Health indicated that the likelihood of prions infecting human brain cells remains remote.

In addition, scientists use immunohistochemistry to test brain, lymph, and neuroendocrine tissues for the presence of the abnormal prion protein to diagnose CWD; positive IHC findings in the obex is considered the gold standard.

[21] Conventional CWD diagnostic strategies and seeded amplification methods for amplifying CWD prions in vitro include: immunohistochemistry (IHC), western blotting (WB), enzyme immunoassay (EIA), protein misfolding cyclic amplification (PMCA), and real time quaking-induced conversion (RT-QuIC).

However, experimental transmission of CWD into other ruminants by intracranial inoculation does result in disease, suggesting only a weak molecular species barrier exists.

By April 2016, CWD had been found in captive animals in South Korea; the disease arrived there with live elk that were imported from Canada for farming in the late 1990s.

Alabama (1), Arkansas (19), Colorado (27), Idaho (1), Illinois (19), Iowa (12), Kansas (49), Louisiana (1), Maryland (1), Michigan (9), Minnesota (7), Mississippi (9), Missouri (21), Montana (23), Nebraska (43), New Mexico (3), New York (1), North Carolina (1), North Dakota (7), Ohio (2), Pennsylvania (14), South Dakota (19), Tennessee (14), Texas (7), Utah (7), Virginia (10), West Virginia (5), Wisconsin (37) and Wyoming (22).

A case in October 2023 in Yellowstone National Park, Wyoming, whose ecosystem supports the greatest and most diverse array of large wild mammals in the continental US, was reported.

[57] In January 2024, British Columbia's surveillance program identified its first two positive deer samples from the Kootenay region of the province.

The guidelines contain information on identifying animals with CWD symptoms and instructions for minimizing the risk of contamination, as well as a list of supplies given to hunters to be used for taking and submitting samples from shot reindeer.

The export of live animals of the deer family to other countries has been temporarily banned as a precautionary measure to stop the spread of the CWD, and moose hunters are going to be provided with more instructions before the start of the next hunting season, if appropriate.

A 16-year old emaciated female moose was found in the municipality of Arjeplog in the county of Norrbotten, circling and with loss of shyness towards humans, possibly blind.