by EBSCO Medical Review Board
(Human Mad Cow Disease; vCJD)


Variant Creutzfeldt-Jakob disease (vCJD) is a type of prion disease that can cause death. Bovine spongiform encephalopathy (BSE) is a prion disease in cows. There is evidence that BSE can spread to humans. This results in vCJD. It is also known as mad cow disease.


It is believed that vCJD is caused by proteins called prions. Prions are normal proteins in the body. These prions may fold up in a way that is not normal. This can change them into the protein that causes the illness. The buildup of these prions may be linked to vCJD.

The Nervous System
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Risk Factors

Variant CJD is more common in younger people. Being around tissue that contains prions may raise the risk. This may happen from:

  • Eating beef from infected cows
  • Getting a blood transfusion from a person who had the disease


After a person is exposed, it can take up to 20 years until they feel sick. Problems get worse over time and include:

  • Early phase (0 to 6 months)—mental health problems, such as depression, anxiety , withdrawal, memory problems, and trouble speaking
  • Middle phase—nervous system problems, such as difficulty with walking and coordination, muscle jerking and stiffness, and a hard time speaking
  • Late phase—being unable to talk or move


The doctor will ask about your symptoms and health history. A physical exam will be done.

These tests may be done to learn more about the brain:

  • Blood tests
  • Electroencephalogram (EEG) to record the electrical activity of the brain
  • to test the fluid that protects the brain and spinal cord

Images may be taken with:

The only way to diagnose vCJD is for a doctor to look at the brain after a person has died.


There is no cure for vCJD. You will receive support and help easing discomfort.


The risk of this problem may be lowered by not eating beef products when traveling to places where BSE is a problem.


Creutzfeldt-Jakob Disease Foundation, Inc. 

National Institute of Neurological Disorders and Stroke 


Health Canada 

Public Health Agency of Canada 


Creutzfeldt-Jakob disease. EBSCO DynaMed website. Available at: Accessed January 25, 2021.

Creutzfeldt-Jakob disease fact sheet. National Institute of Neurological Disorders and Stroke website. Available at: Accessed January 25, 2021.

Geschwind MD. Prion Diseases. Continuum (Minneap Minn). 2015 Dec;21(6 Neuroinfectious Disease):1612-1638.

Mackenzie G, Will R. Creutzfeldt-Jakob disease: recent developments. F1000res. 2017;6:2053.

Revision Information

  • Reviewer: EBSCO Medical Review Board Rimas Lukas, MD
  • Review Date: 12/2020
  • Update Date: 01/25/2021