National prion disease pathology surveillance center
Human prion disease
Acquired cases represent less than 1% of cases in the U.S. and include kuru, iatrogenic CJD, and variant CJD.
Types of Acquired CJD
A virtually extinct form of human prion disease of the Fore linguistic group of Papua New Guinea transmitted via ritualistic endocannibalism.
Mainly affected women and young children. Some incubation periods extended more than 50 years. Clinical presentation of ataxia and psychiatric disturbances.
Iatrogenic CJD (iCJD)
Acquired through contamination of neurosurgical instruments, corneal transplants, dura mater graft, or cadaver derived human growth hormone.
Age at onset depends on the age at exposure and on the incubation period (time from exposure to disease onset). Incubation periods and likelihood of developing disease depend upon source of infected tissue and route of exposure. Some incubation periods can last decades.
Clinical and pathological features are often indistinguishable from sCJD. Growth hormone cases show plaques.
Variant CJD (vCJD)
Exposure to bovine spongiform encephalopathy (BSE) (a.k.a., “mad cow disease”) through consumption of infected beef or blood or plasma transfusion.
Younger age at onset and longer duration than sporadic CJD. Psychiatric symptoms often seen at disease presentation. For blood or plasma transfusion, age at onset depends on the time of exposure. Neuropathologically characterized by the presence of florid plaques.
*There have been no known cases of vCJD acquired in the US. Of the 4 cases diagnosed by the NPDPSC, all were acquired outside the US.