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About prion diseases

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What prion diseases are

A prion is a type of protein found in the central nervous system (the brain and the spinal cord) of humans and animals.

For reasons still unknown, normal prion proteins can change into an abnormal infectious form.

These infectious prions convert more and more prion proteins to the abnormal form, eventually causing disease by damaging the brain and central nervous system.

Prion diseases can affect both humans and animals.

Although prion diseases are rare, they are always fatal. These diseases are not completely understood and researchers are still working to discover treatments.

Types of prion diseases

Disease Which animals it affects Programs in place
Bovine spongiform encephalopathy (BSE) (also known as mad cow disease) Cattle (Bovine) Bovine spongiform encephalopathy surveillance program
Scrapie Sheep and goats National scrapie surveillance program
Chronic wasting disease Deer, moose, elk and reindeer

Prion diseases in humans

Disease Surveillance program in place
Creutzfeldt-Jakob disease Creutzfeldt-Jakob disease surveillance system (Public Health Agency of Canada)
Variant Creutzfeldt-Jakob disease Creutzfeldt-Jakob disease surveillance system (Public Health Agency of Canada)

What current research tells us

Classical bovine spongiform encephalopathy (also known as mad cow disease) is believed to spread to humans via beef contaminated with abnormal bovine spongiform encephalopathy prions.

To date, no direct evidence suggests that scrapie or chronic wasting disease may spread to humans. However, scientific uncertainty remains for zoonotic (animal to human) and cross-species transmission.

Animal studies suggest that chronic wasting disease prions could infect some types of non-human primates under experimental conditions. Experts continue to study whether this disease has the potential to infect other animals or humans and if so, under what circumstances. Infection would likely occur through:

Organizations that work to protect Canadians against prion diseases

Federal, provincial and territorial governments have taken measures to reduce human exposure to food or other consumable products potentially contaminated by prions. Through surveillance and other types of testing, animals known to be infected are prevented from entering the commercial food chain.

In Canada, the control of prion diseases is a joint responsibility that necessitates close collaboration among all levels of government, industry and the public.

Canadian Food Inspection Agency

  • lead federal agency for food animal prion disease surveillance and control
  • conducts inspections and has monitoring and testing programs in place to prevent, control and respond to the spread of some animal diseases in Canada such as BSE and scrapie
  • ensures that food safety risks are managed by licensed operators in federally inspected establishments

Public Health Agency of Canada

Health Canada

  • assesses the risks animal diseases may pose to human health through the consumption of health products and food
  • develops regulations and policies to mitigate these risks
  • provides information to help Canadians make informed decisions

Indigenous Services Canada

  • supports communications with Indigenous populations and community leaders about prion diseases

Environment and Climate Change Canada

  • protects and conserves Canada's natural heritage and ensures a clean, safe and sustainable environment
  • supports work on prion diseases in wildlife under federal jurisdiction, in particular the risk of transmission of chronic wasting disease to caribou populations listed under the Species at Risk Act

Agriculture and Agri-food Canada

  • provides support for engagement and communication with stakeholders in the Canadian agriculture and agri-food sector

Parks Canada

  • protects and presents significant examples of Canada's natural and cultural heritage
  • works with provinces and territories and other federal departments to mitigate the impacts of chronic wasting disease on national parks and national historic sites

Provincial and territorial governments

  • are responsible for many aspects of animal disease management, including:
    • wildlife health
    • licensing and response to disease in game farms (where applicable)
    • surveillance programs
    • intra and inter-provincial movement controls

Canadian Wildlife Health Cooperative

  • is a university-based, inter-agency partnership that pools the resources and expertise of:
    • Canada's Colleges of Veterinary Medicine
    • government departments and agencies at all levels
    • non-government agencies
  • works to reduce the ecological and economic costs and impacts of wild animal diseases in Canada
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