Variant Creutzfeldt-Jakob Disease (vCJD) in Canada

On May 2, 2007, the Canadian Food Inspection Agency (CFIA) announced the diagnosis of bovine spongiform encephalopathy (BSE) in a cow from British Columbia. This finding poses no new risk to human health as no part of the animal entered the human food or animal feed systems.

For information on BSE and food safety, please visit Health Canada's web site. Updates on CFIA's investigation on BSE are posted at http://www.inspection.gc.ca/.

• What is the risk to human health?
• What is CJD? What is vCJD?
• Are there other health impacts related to this issue?
• How do we know whether Canadians are contracting vCJD?
• Will we see cases of vCJD in Canada in the future?
• What does the recent study that found prions in mice organs mean for human health?

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Q. What is the risk to human health?

A. There is no increase in the risk to human health.

Variant CJD has been linked to eating contaminated beef products from animals infected with BSE in the large outbreaks occurring in Europe that peaked in the early 1990s. Since that time, the risk has diminished to the point where new human cases of the disease are rarely identified.

There has been one case of vCJD in Canada. However, this was related to this person's time living in the United Kingdom. There have been no cases linked to eating Canadian beef.

The development of vCJD in humans appears to have been related to slaughter practices and a large number infected cattle getting into the food chain. These differed from practices in both North America and parts of Europe, such as Switzerland, where in spite of several hundred BSE infected cattle, there were no human cases of vCJD.

Q. What is CJD? What is vCJD?

A. Creutzfeldt-Jakob Disease (CJD) is one of a small group of fatal diseases caused by infectious agents called prions (misfolded proteins). These attack the brain, killing cells and creating gaps in tissue. The disease is always fatal. There are two types of CJD: classical and variant.

Variant CJD is a new disease in humans linked to eating beef products from cattle infected with BSE. It attacks the central nervous system and is fatal if illness develops. It normally infects animals of the same or related species. Other prion diseases include Scrapie in sheep and Chronic Wasting Disease in deer and elk.

Classical CJD is a human prion disease. It is not linked to eating beef and is seen sporadically in populations around the world. The rate of CJD is approximately one per million people per year.

Q. Are there other health impacts related to this issue?

A. Unfortunately, due to the impact of BSE on the Canadian beef industry, farmers and others connected to it, have suffered the negative health problems, such as depression, that one would expect when stress levels increase and livelihoods are threatened.

Q. How do we know whether Canadians are contracting vCJD?

A. The Public Health Agency of Canada operates a comprehensive CJD surveillance system to monitor the instances of both classical and variant CJD across the country. The CJD surveillance system, considered one of the best in the world, involves national reporting through a toll-free line of all suspected cases of both classical and vCJD in Canada.

Q. Will we see cases of vCJD in Canada in the future?

A. In the UK, the number of people who become ill with vCJD remains low, with three becoming ill in 2003 and four in 2004. A low rate of new cases may continue for some time in those who were exposed during the outbreak in Europe. In countries that have experienced smaller outbreaks of BSE in cattle, in comparison to France and the UK, there have been no cases of vCJD and these smaller outbreaks have been larger than what we've seen in Canada. Although there are no guarantees, this experience indicates the risk from eating Canadian beef should be extremely small.

Q. What does the recent study that found prions in mice organs mean for human health?

A. The Public Health Agency has encouraged this type of research through its international partnerships on CJD and vCJD surveillance and has been looking closely at the issue of the transmission of CJD and vCJD through organs and tissues. We do know that prions could be present in any part of the body but the question is whether or not the protein will cause disease. Although this study is of interest, it does not cause an immediate concern for human health either through transmission of CJD through blood, organs and tissues or through the food supply, but does point to the need for continued research in this area. For further information on BSE and food safety, please visit the Health Canada web site at www.hc-sc.gc.ca/fn-an/securit/animal/bse-esb/index_e.html.