Chronic Wasting Disease was first observed among Colorado deer in 1967. Since then, the neurological disease has spread to 24 U.S. states and Canada.
There have been no reports of human contamination so far, but a recent Canadian study has once again sparked worries that the disease could be contracted by humans.
In a long-term study at the University of Calgary, 18 macaques were exposed to the disease in different ways, including injecting infected material straight to the brain; feeding infected meat; skin contact; and intravenously.
CWD Found To Infect Macaque Monkeys
For the experiment, researchers selected macaques, a species of monkey from Asia, because their genetic makeup is closer to that of human beings' in comparison to other animals.
A report states that to date, three out of the five macaques fed with 5 kilograms (11 lbs.) of infected deer meat over a period of three years tested positive for CWD. In humans, such diet is equivalent to eating a 7-ounce steak each month.
What's even more alarming is that two of the three monkeys fed with deer meat exhibited symptoms of the disease such as anxiety, ataxia, and tremors.
One macaque shed one-third of its body weight over a six-month period, while two animals that had infected matter injected into their brains also developed CWD.
"No one should consume animal products with a known prion disease," said Stefanie Czub, a prion researcher at the Canadian Food Inspection Agency, who presented the partial findings of the study in Edinburgh, Scotland last May 2017.
2004 CDC Study Relates Similar Results
In 2004, a study conducted by a team at the Centers for Disease Control and Prevention concludes that humans consuming infected meat are not safe from potential exposure.
Through an in vitro cell-free experiment, the team observed that CWD-associated prions can convert human prion protein, strongly proving that it is transmissible to humans. Despite this apparent observation, the lack of evidence still puts the risk of human transmission to a low level.
Moreover, the study claims it is possible for CWD to develop new strains targeting human beings due to the migration of infected deer.
What Is Chronic Wasting Disease?
The CDC classifies CWD as a prion disease that affects, deer, elk, reindeer, and moose. An infected animal could take more than a year before exhibiting symptoms, such as drastic weight loss or wasting and stumbling.
It can be contracted by animals of any age and is fatal to their health. Currently, there are no known treatments or vaccines for the disease.