Brain & Nervous System More Neurological Diseases Mad Cow Disease in Humans Brain Disorder Becomes Deadly Over Time By Mary Kugler, RN Mary Kugler, RN, is a pediatric nurse whose specialty is caring for children with long-term or severe medical problems. Learn about our editorial process Mary Kugler, RN Medically reviewed by Medically reviewed by Diana Apetauerova, MD on November 04, 2019 linkedin Diana Apetauerova, MD, is board-certified in neurology with a subspecialty in movement disorders. She is an associate clinical professor of neurology at Tufts School of Medicine. Learn about our Medical Review Board Diana Apetauerova, MD on November 04, 2019 Print Creutzfeldt-Jakob disease made headlines in the year 2000 when an uptick of cases broke out in the United Kingdom. Those cases were linked to food contaminated with bovine spongiform encephalopathy (BSE), a prion disease that causes variant CJD, otherwise known as "mad cow" disease. The public has good reason to be concerned about the transmission of BSE to humans. Variant Creutzfeldt-Jakob disease, like the other types of Creutzfeldt-Jakob disease, is a rapidly progressing, always fatal neurological disorder. But the disease is very rare: It affects about one person in every one million per year worldwide; in the United States there are about 350 cases per year. The Centers for Disease Control and Prevention (CDC) monitors the incidence in the United States of all types of Creutzfeldt-Jakob disease. istetiana / Getty Images Different Types of Disease, Always Fatal There is no cure for Creutzfeldt-Jakob disease, which can occur in a person in one of three ways: About 10% to 15% of cases in the United States are inherited, resulting from a gene mutation. Most cases seem to appear sporadically, in someone who has no family history of the disease. A small percentage of cases occur through infection, by contact with infected brain tissue. There are documented cases that occurred as an unintended consequence of a medical procedure. Creutzfeldt-Jakob disease is not contagious in normal ways, like sneezing or coughing--there are no known cases of spouses or family members of an infected person contracting the disease. Contaminated Beef Products Cases of variant Creutzfeldt-Jakob disease seems to be linked to eating contaminated beef products in Europe. The same disease, when it occurs in sheep, is called "scrapie." It is believed that scrapie-infected sheep products were used in cattle feed, and that is how the cattle became infected. Scientists have found that what causes BSE, scrapie, and the Creutzfeldt-Jakob diseases is not a virus or bacteria as in other diseases, but a protein agent called a prion. The prion transforms normal proteins into infectious, deadly ones. Effects on the Brain Since Creutzfeldt-Jakob disease affects the brain, the symptoms it produces are neurological. It may start out subtly with insomnia, depression, confusion, personality and behavioral changes, and problems with memory, coordination, and sight. As it progresses, the person rapidly develops dementia and involuntary, irregular jerking movements called myoclonus. In the final stage of the disease, the patient loses all mental and physical functions, lapses into a coma, and eventually dies. The course of the disease usually takes one year. The disease generally affects people between the ages of 50 to 75 years, however, variant Creutzfeldt-Jakob disease has affected people at a younger age--even teenagers (the ages have ranged from 18 to 53 years old). Difficult to Diagnose There is not, as yet, a definitive medical test for diagnosing Creutzfeldt-Jakob disease, and confirmation of the disease can only be made after death through an autopsy. Since the disease is rare, some physicians might not even consider it as a diagnosis and might mistake the symptoms for other brain disorders like Alzheimer's or Huntington disease. Scientists suggest that new, sophisticated laboratory testing will in the future be able to detect the prions in an infected person's blood or tissues. Was this page helpful? Thanks for your feedback! Sign up for our Health Tip of the Day newsletter, and receive daily tips that will help you live your healthiest life. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Creutzfeldt-Jakob disease fact sheet. Revised August 13, 2019. Additional Reading "vCJD (Variant Creutzfeldt-Jakob Disease)." NCIDOD. 29 Nov 2006. Centers for Disease Control and Prevention. 28 Dec 2006 http://www.cdc.gov/ncidod/dvrd/vcjd. Collins, S., A. Boyd, A. Fletcher, M. F. Gonzales, C. A. McLean, C. L. Masters. "Recent advances in the pre-mortem diagnosis of Creutzfeldt-Jakob disease." J Clin Neurosci 7(2000): 195-202. Will, R., M. Zeidler, G. E. Steward, M. A. Macleod, J. W. Ironside, S. N. Cousens, J. Mackenzie, K. Estibeiro, A. J. Green, R. Knight. "Diagnosis of new variant Creutzfeldt-Jakob disease." Ann Neurol 47(2000): 575-582. Wilson, K., C. Code, M. Ricketts. "Risk of acquiring Creutzfeldt-Jakob disease from blood transfusions: Systematic review of case-control studies." BMJ 321(2000): 17-19.