About Variant Creutzfeldt-Jakob Disease (vCJD)

Key points

  • Variant Creutzfeldt-Jakob disease (vCJD) is a rare disease caused by a prion, an infectious protein.
  • It is linked to eating beef from cows infected with "mad cow disease."
  • It is always fatal, usually within 14 months of the first symptoms.
  • vCJD illnesses have been very rare since the early 2000s.
A photo illustration that shows a gloved scientist with a pipette superimposed over a drawing of a brain.

What it is

vCJD is a rare, fatal brain disease that occurs in people. It has been linked to eating meat from cows infected with another prion diseases, bovine spongiform encephalopathy (BSE). BSE is sometimes called "mad cow disease."

vCJD was first reported in the United Kingdom in 1996. Worldwide, there have been 233 people reported to have vCJD since its discovery. The vast majority of illnesses occurred in the United Kingdom in the late 1990s and early 2000s. There were also cases reported in Europe, Asia, the Middle East, the United States and Canada.

It can take years for someone to develop vCJD symptoms after they were exposed to BSE. But, once symptoms begin, it is always fatal. Most people with vCJD live with the illness for one to two years, with an average time of 13-14 months.

Signs and symptoms

As with other prion diseases, it takes a long time for people to get sick after contact with the prion. This timeframe can be 10 years or more.

People with vCJD have obvious psychiatric (mental, emotional, behavioral) symptoms. Often, this includes depression, anxiety and withdrawal.

They may also have a painful condition called dysesthesia. This may feel like itching, burning, pins and needles or other sensations on their body.

Later in the illness, patients typically have dementia and neurologic signs such as poor coordination.

Reported cases

Of the 233 vCJD illnesses reported since 1996, four vCJD illnesses have been reported in the United States. Three occurred between 2001 and 2006. A fourth had vCJD symptoms beginning in 2012.

It is believed that all four people with vCJD in the U.S. contracted the disease in another country. Two of the four patients had lived for decades in the United Kingdom. A third was born and raised in Saudi Arabia before coming to the United States. It's not clear where the fourth patient may have been exposed, but experts agreed it was likely outside the US.

A few more recent vCJD illnesses occurred in lab personnel and may have been exposed to prions in the lab.


There is strong evidence vCJD is caused when people eat meat from cows that were infected with Bovine Spongiform Encephalopathy (BSE).

BSE was first identified in the United Kingdom in the 1980s and cases peaked in the early 1990s. The first vCJD cases were reported in 1996.

Feeding cattle meat and bone meal from dead cows, some of which had BSE, contributed to the large U.K. outbreak.

Policies to prevent further exposure of animals and humans to BSE led to a dramatic decline in BSE cases. These included animal feed bans and the removal of infectious cattle tissues, such as the brain, from human food.

Scientists believe people may have eaten food potentially contaminated with BSE in the mid-1980s. vCJD cases started appearing about 10 years later. This matches the usual incubation period (the time between exposure and symptoms) for other prion diseases.


Preventing vCJD primarily involves avoiding BSE. Given the how rare BSE is and protective measures in place, there are no specific vCJD prevention measures needed now.


There is no specific test to diagnose vCJD while a patient is alive.

Healthcare providers look at a number of factors when deciding if someone has vCJD:

  • The patient's age
  • Their symptoms
  • Brain activity tests before death
  • Whether symptoms lasted more than one year
  • Whether another disease could have caused the illness.

To confirm the patient had vCJD, scientists must examine brain tissue gathered during an autopsy. They look for changes in the brain that are specific to vCJD.


There is unfortunately no cure for vCJD. No specific therapy slows or stops the disease's progression once symptoms begin.

Treatment involves providing supportive care to help make the person more comfortable as their illness progresses.

Similar diseases

Though they have very similar names, vCJD is not the same disease as Creutzfeldt-Jakob Disease. The latter is often called "classic CJD" to avoid confusion.

Both are caused by prions, misfolded proteins that clump together in brain tissue. As they do, they cause brain damage. Over time, the brain damage gets worse, eventually causing the person's death.

Some of the differences between the two diseases include:

  • vCJD typically affects a much younger age group (average age 28 vs 68)
  • vCJD has different initial symptoms (psychiatric/behavioral vs dementia).
  • The two diseases affect the brain differently.
  • vCJD causes death > one year after illness onset (vs. 4-5 months for CJD)