Creutzfeldt-Jakob disease and variant Creutzfeldt-Jakob disease - including symptoms, treatment and prevention
These are progressive fatal infections of the brain caused by an infectious protein particle called a prion. These diseases are some of a group of brain infections known as Transmissible Spongiform Encephalopathies (TSE).
Creutzfeldt-Jakob disease and variant Creutzfeldt-Jakob disease are notifiable conditions1
How Creutzfeldt-Jakob disease is spread
Creutzfeldt-Jakob disease (CJD) is a very rare illness, affecting about one person per million population worldwide, and has been recognised for about 80 years. In almost all cases the source of infection is not apparent – these are called sporadic cases.
Some cases (a small number) are the result of a genetic abnormality and run in families.
An even smaller number have been linked to medical treatment, such as use of human pituitary hormones, corneal transplants or neurosurgery.
Since 1995 a new disease similar to classic CJD has been recognised, known as variant Creutzfeldt-Jakob disease (vCJD). To date there have been about 150 probable or proven cases, most of which have occurred in the United Kingdom. It is believed almost all of these cases are related to a massive epidemic of Bovine Spongiform Encephalopathy (BSE), commonly known as 'mad cow disease', in the United Kingdom which peaked in 1992 to 1993. People became infected by eating cattle products contaminated with the BSE prion.
There have been recent reports of transmission of vCJD by blood transfusion.
Signs and symptoms
Most cases of classic CJD occur in people over 50 years of age. Symptoms include:
- rapidly progressive dementia
vCJD has several important differences from CJD:
- It affects much younger people. The average age of death of people with classic Creutzfeldt-Jakob disease is 68 years, but for vCJD it is 28 years. We do not yet know the reason for this.
- It generally begins with different symptoms from Creutzfeldt-Jakob disease, with psychiatric and sensory disturbances being prominent.
The diagnosis is suggested by:
- clinical symptoms
- electroencephalogram (EEG) - recording of the electrical activity of the brain
- brain scans - such as magnetic resonance imaging (MRI).
Currently, diagnosis of CJD can only be confirmed by laboratory examination of brain material (usually after death).
Diagnosis of vCJD can also be made by biopsy of the tonsils.
(time between becoming infected and developing symptoms)
For CJD, from 15 months to more than 30 years.
Unknown for vCJD because it is a new disease, but thought to be also from years to decades.
(time during which an infected person can infect others)
Routine social or community contact with a person with CJD or vCJD carries no risk of spread. Infected brain tissue is infectious before and after onset of symptoms.
Currently there is no available vaccine or treatment and these conditions appear to be always fatal.
- Strict adherence by health care institutions to infection control guidelines for the management of surgical equipment.
- Body tissues or blood from people with symptoms suggestive of CJD or vCJD must not be used for transplantation or transfusion
- Human-derived pituitary hormone products are no longer used for treatment and people who have received them must not donate blood. These people should also notify hospitals that they have been treated with human pituitary hormones if they are going to have head or spine surgery.
- Livestock herds infected with BSE are slaughtered and incinerated, and animals with symptoms suggestive of BSE are not permitted to enter the food chain.
- Beef from countries where BSE is known to occur is subject to quarantine.
- Rules on the composition of livestock feeds must be adhered to.
1 – In South Australia the law requires doctors and laboratories to report some infections or diseases to SA Health. These infections or diseases are commonly referred to as 'notifiable conditions'.