Risk factors

Most cases of Creutzfeldt-Jakob disease occur for unknown reasons, and no risk factors can be identified. However, a few factors seem to be associated with different kinds of CJD:

• Age. Sporadic CJD tends to develop later in life, usually around age 60. Onset of familial CJD occurs slightly earlier, and vCJD has affected people at a much younger age, usually in their late 20s.
• Genetics. People with familial CJD have a genetic mutation that causes the disease. To develop familial CJD, a child must have one copy of the mutated gene, which is inherited from either parent. If you have the mutation, the chance of passing it on to your children is 50%.

• Exposure to contaminated tissue. People who've received infected manufactured human growth hormone, or who've had transplants of the infected tissues that cover the brain (dura mater), may be at risk of iatrogenic CJD.

  The risk of getting vCJD from eating contaminated beef is very low. In general, if countries are effectively implementing public health measures, the risk is virtually nonexistent. Chronic wasting disease (CWD) is a prion disease that affects deer, elk, reindeer and moose. It has been found in some areas of North America. To date, no documented cases of CWD have caused disease in humans.