How do humans get affected by mad cow disease?

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.
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.
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.

Related Questions

What are the ways to get tested for mad cow disease?

Mad cow disease. The most common test is a brain biopsy but the patient must have symptoms of the disease before that is done. Read more...

How can I get tested for mad cow disease (crutzfeld-jakob) or dementia?

Well. For dementia, your family doctor, for mad cow...A neurologist, you will need a neurological exam, an eeg and especially a lumbar puncture done by a neurologist with experience in prion diseases. Read more...