How do humans get affected by mad cow disease?

Dementia...: Mad cow disease is called creutzfeldt-jakob disease or spongiform encephalopathy in humans. It is contracted by exposure to infected animal, typically by injestion. Clinical features vary but severe cases present with feature of rapidly worsening dementia.

Eat the meat: Mad cow disease is a "slow virus" which enters the brain and then causes an ultimately fatal ending. One of the chief ways of acquiring this agent is to eat it. The same virus has been transmitted through bone grafts, corneal transplants, blood product contamination.

Variant CJD: Is the human form of bovine spongioform encephalopathy which can be transmitted by eating contaminated beef, especially ground beef and by blood transfusion. There have been been no cases acquired in the usa.

Variant CJD: Is the human form of bovine spongioform encephalopathy which can be transmitted by eating contaminated beef, especially ground beef and by blood transfusion. There have been been no cases acquired in the usa.