The Manitoba Wildlife Federation will soon be launching an awareness campaign to educate the public on Chronic Wasting Disease, otherwise known as CWD. It is a sister disease to Bovine Spongiform Encephalopathy (BSE) or ‘mad cow disease’ and is in the group of diseases known as Transmissible Spongiform Encephalopathy (TSE) and has now been confirmed in at least six species of deer.
TSE’s have repeatedly emerged and all of the largest epidemics have been documented in domestic or captive animals, such as in domestic cattle (BSE), on mink farms (TME), domestic sheep (Scrapie) and CWD having originally presented itself in captive deer and elk on game farms. The unique factor of CWD is that it has established itself significantly in wild big game species, such as deer, elk and moose.
Rob Olson, Managing Director for the Manitoba Wildlife Federation, says researchers are now calling CWD an insidious and dire disease, and the greatest conservation challenge of our future.
“This is due to the fact that it is not caused by bacteria or a virus,” says Olson, “but a misshapen protein, a prion, that is folded incorrectly, and replicates rapidly in a host, like a deer, and displaces the healthy proteins. It attacks different parts of the body of the deer but causes degeneration of the brain and is always fatal.”
CWD is thought to have started in the late 1960’s in Colorado, quite possibly through a scrapie infected sheep either on shared pastures or in captivity somewhere along the front range of the Rocky Mountains in the United States. From there it is believed CWD-infected animals were unknowingly transported from game farms in South Dakota into Canada, near Lloydminster, Saskatchewan.
Presently, CWD has been confirmed in 24 US states, South Korea, Norway and 3 Canadian provinces. Olson says it is imperative we do everything we can to prevent CWD from crossing Manitoba’s borders, as it is extremely contagious and not easily killed.
There is no known cure for CWD, nor is there a vaccine. It has been shown to persist and remain infectious in the environment, including in clay-based soils that can increase its infectivity up to 680 times. Carcasses of dead CWD-affected animals create contaminated “super-sites”. The prions are extremely resilient, and are known to resist all forms of sterilization, including disinfectants, alcohol, formaldehyde, radiation, freezing, and incineration with temperatures exceeding 600 degrees Celsius.
Transmission of the disease occurs through blood, urine, and saliva in live animals through animal to animal contact, soil to animal, mother-to-offspring, as well as exposed plants or other surfaces including tools or instruments. Most recent evidence shows the infective agent of CWD is taken up through the root system of plants growing in contaminated soils, with transfer to stem and leaves. This has possible ramifications for domestic animals.
Rob Olson says the disease has not jumped the species barrier into humans, or domestic animals, but the possibility still remains, as the disease may evolve like ‘mad cow disease’ did when BSE was thought to affect cattle only. Olson says they are nervous about this because estimates are between 10,000-15,000 CWD infected deer are consumed by hunters every year in North America. “But you can't easily tell if it’s infected so that can create opportunities for infection. It creates opportunities for the prions to change and to jump that species barrier into humans.”
Rob reminds us of what all transpired when BSE broke out. “We all remember the border being closed and what that did to Canada’s cattle producers. So, can you imagine the implications if CWD jumped the species barrier to cattle from a trade perspective? It would be devastating to our economy.”
“If this would ever jump to a person, like ‘mad cow’, the implications would be astronomical. So, the stakes are really high. We need to contain this now, and buy the scientists time to find a cure and ways around it before it jumps a species barrier into a domestic animal, or into humans. We have to act now.”
A recent study in 2009 out of the University of Calgary, researchers fed 5 Macaques monkeys CWD-affected meat and 3 of the monkey became infectious. Macaque monkeys share most of same DNA as humans and this has increased the cause for concern.
Olson says the biggest thing they can do right now is educate the public on the grave ramifications on Manitoba wildlife, Ag industry and safety when it comes to human consumption of affected meat. “We need to stop this disease from crossing the borders into Manitoba.”
Researchers of CWD state “CWD is now deemed to be the largest-ever mass of infectious prions in global history, and experts sum up the threat (to wildlife, agriculture, our economies, and potentially to human health) in two words: “insidious and dire.”
They add a sobering statement: “Current policy and apathy toward the levels of CWD consumption by people has been described as ‘one of the most outrageous human susceptibility experiments in history.’”
The MWF are taking steps to keep CWD out of the province. The following is their mandate on the critical needs at this time:
1. “Contain the geographic spread of CWD by enacting and enforcing an immediate ban on the movement of all live cervids, all potentially CWD-infected carcasses, animal parts, products, exposed equipment, trailers, or other sources of infectious materials.”
2. “Mandate and implement for hunters, convenient, cost-free, rapid testing of all animals harvested from CWD-affected areas.”
3. “Ensure that no CWD-infected material reaches the food or feed chains, and that it is instead properly disposed of.”
4. “Establish and fund accountable research and science-based policy to protect public interest (health, wildlife and related industries, agriculture, our economies and communities).”
The Manitoba Wildlife Federation will be implementing a formal awareness campaign in mid-August. You can visit their website for further details, and the ongoing research data soon on CWD at www. mwf.mb.ca.