How Do Prion Diseases Spread

What Is A Prion Disease?

Prions are infectious agents which cause Creutzfeldt Jakob (CJD) disease in humans. They are not contagious, but they can spread from person to person through contact with infected brain tissue or other body fluids such as saliva, urine, feces and vomit. The most common route of transmission is via eating contaminated meat or consuming food that has been prepared using contaminated equipment.

The human form of CJD is called scrapie. Humans can become infected with this prion disease when they eat contaminated animal tissues or organs containing the prions.

Infected animals include sheep, goats, cows, pigs and deer. Other species of prion-contaminated animals include bats, mice and rats.

In addition to infecting humans, prions have been found in other mammals including monkeys and foxes. These animals do not develop CJD like humans do.

However, if these nonhuman primates come into contact with infected human tissue or other prions, they may contract CJD.

How Does Prion Disease Spread?

Human prions are transmitted from one individual to another through direct contact with infected brain tissue or other bodily fluid such as saliva, urine, feces and vomit.

Infected tissue may remain infectious for years if it is not exposed to extreme temperatures, sunlight, detergents or certain chemicals.

How Do Prion Diseases Spread?

When an individual is infected with the prion disease, the prions are transported throughout the body via blood and lymph. The infected prions then bind to the nervous system and cause irreversible damage, which eventually leads to death of brain cells.

The human form of the prion disease causes irreversible brain damage and neurodegenerative symptoms, which include:

Severe confusion

Loss of memory

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Perceptual disturbances

Personality changes

Psychotic behavior, such as depression or paranoia

Slurred speech

Spasticity and muscle rigidity

Generalized weakness

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Death from respiratory failure or cardiac arrest

Symptoms usually appear between four to seven years after initial infection.

How Are Prion Diseases Treated?

There is currently no treatment that can cure or reverse the damage of the prion disease. The most effective way to treat a prion disease is to provide pain medication and make sure the person is mentally comfortable. There are certain drugs which have been approved by the Food and Drug Administration (FDA) for treating Creutzfeldt-Jacob disease (CJD). Medicines may include:






If you suspect that you or a loved one has a prion disease, it is important to seek medical attention immediately. Early detection of the disease can be instrumental in slowing down the disease’s rapid spread.

Where Can I Find More Information About Prion Diseases?

You can learn more about prion diseases and sign up for email updates on CJD and human TSEs on the CDC’s website.



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