Division of Disease Control and Health Protection

Creutzfeldt-Jakob Disease (CJD)

General Information

Creutzfeldt-Jakob disease (CJD) is a transmissible neurodegenerative disorder believed to be caused by an abnormal cellular prion protein. CJD is the most important member of a group of diseases known as the transmissible spongiform encephalopathies (TSEs). This group of diseases includes both human diseases, such as Kuru and new variant CJD, and a number of animal diseases.

Symptoms and Diagnosis

Hallmarks of the disease include rapid progression of dementia, often with gait and speech abnormalities, ataxia, and myoclonus (muscle jerks). A typical electroencephalogram (EEG) tracing is seen in 75% of CJD patients, which in conjunction with the clinical picture is considered to be diagnostic of CJD. However, confirmatory diagnosis of CJD requires histopathologic examination of brain tissue. A new test utilizing cerebral spinal fluid (CSF) has been developed that has both a high degree of sensitivity and specificity when combined with clinical and laboratory data. Image courtesy of the USDA

Outcome and Transmission

Typically, 90% of CJD patients die within 12 months of illness onset; with a mean survival time of 5 months. In approximately 85% of CJD patients, the disease is believed to occur spontaneously. In 5-15% of patients, CJD occurs as a familial disease and has been associated with point genetic mutations. Onset of CJD symptoms in sporadic and familial illness peaks between the ages of 60 and 70 years and is most common between the ages of 55 and 75 years. CJD is known to have been transmitted by contaminated neurosurgical instruments, EEG depth electrodes, corneal allografts, dura matter grafts and cadaveric human pituitary hormone.

History of CJD

In 1986, a newly recognized cattle disease, bovine spongiform encephalopathy (BSE) was reported in Britain. Due to the concern that the disease could spread to humans, the British government established the Spongiform Encephalopathy Advisory Committee (SEAC). In 1996 this SEAC announced 10 young Creutzfeldt-Jakob disease (CJD) patients (ages 16-39) with unusual clinical and neuropathogical features. As of December 31, 1998, a total of 35 cases of new variant CJD (nv-CJD) were identified in the United Kingdom and one in France. In the U.S., two cattle have tested positive for BSE – one in December, 2003, and the other in June, 2005. Neither of these cattle, however, entered the human food chain.

Current Issues

Concern has emerged regarding the safety of the blood supply and potential for transmission of CJD by transfusion. Tracking of blood donated by those in whom CJD subsequently developed has not uncovered the disease in recipients. While the risk for transmission is only theoretical, the potential that the agent for CJD may be blood borne has resulted in rejecting blood from people with a family history of CJD, history of receiving dura grafts or human growth hormone.

The Centers for Disease Control and Prevention began an active surveillance program for the new variant of CJD in April, 1996. In addition, a review of trends and incidence of CJD was done by a review of cause-of-death data from 1979 through 1994. The age-adjusted incidence of CJD death rates in the United States was similar to what has been reported in other areas of the world. The overall rate is 0.95 deaths per million, with approximately 98% of the death occurring among persons >45 years old.

CJD in Florida

In 2003, CJD was listed as a reportable disease within the state of Florida. Twelve cases were reported in Florida in 2004. Of these cases, 8 were male, and 4 were female. Affected patients ranged in age from 40 – 74 years old; the mean age of all patients was 63.3 years old.

References

• Holman C, Khan AS, Belay ED, Schonberger LB. Crutzfeldt-Jakob Disease in the United States, 1779-1994: Using National Mortality Data to Assess the Possible Occurrence of Variant Cases. Emerg Infect Dis 1996;2:333-7.

• Johnson RT, Gibbs CJ. Creutzfeldt-Jakob Disease and Related Transmissible Spongiform Encephalopathies. NEJM 1998;339:1994-2004

• Will RG, Ironside JW, Zeibler M, et al. A New Variant of Crutzfeldt-Jakob Disease in the UK. Lancet 1996;327:921-5.