Creutzfeldt-Jakob disease (CJD) originates from an infectious agent that infected sheep, which crossed the species barrier to bovines to cause bovine spongiform encephalopathy, then eventually was acquired by humans. Changes in the rendering of livestock carcasses allowed the pathogen to survive and contaminate meat and bone meal in livestock feed, amplifying infection to epidemic proportions. Export of contaminated meat and bone meal and live cattle incubating the disease caused the spread of bovine spongiform encephalopathy to other countries. Bovine spongiform encephalopathy caused variant Creutzfeldt-Jakob disease that entered into the human food chain. CJD is a disease primarily affecting the nervous system. Worldwide it affects one out of 1 million people, most between 50 and 70 years of age. A marker of the disease is an abnormal protein called a prion that accumulates in the brain of people who have CJD. Transmission of CJD between people is rare, and the agent that causes the disease is thought not to be highly contagious.
CJD can occur suddenly without any apparent cause; such cases are called sporadic. The disease may be passed on in families or may be transmitted by contact with contaminated tissue from humans or animals. The disease progresses quickly within the body and is always fatal; most people with CJD die within four to six months.
Practical ways to eradicate a disease, such as Creutzfeldt-Jakob disease, involves a join effort all around the world. First, farmers everywhere must report cattle that show symptoms of Mad Cow disease and to stop importing and exporting meat from infested countries. This is not all, people around the world must also be careful about which foods they eat and how they cook their meat. Also, governments and policy-makers must protect public health by taking known information and design restriction and regulations pertaining to the type of feed cattle intended for slaughtering receive and the meat we receive from foreign countries. Eliminating the main source, sheep and cattle, would be the most practical solution today. A few years ago this might not have been so. There are also other techniques that we can use to test for CJD such as a spinal tap, which can be used to stop the transfer of tainted blood between transfusions (filtered blood). Today, these tactics are the most practical in terms of eliminating the most common type of the disease, new variant CJD.