Common questions about Creutzfeldt-Jakob disease.
Can you catch it from somebody?
It is not a 'catching' disease like measles or mumps. People who look after,
come into contact with, or eat off the same plate as those with CJD will not get
the disease any more frequently than members of the general public. Indeed, doctors
and nurses who would be expected to come into contact with people with the disease
are no more likely to develop CJD than anyone else.
Why did my friend or relative get CJD?
The truth is that no one knows. Without knowing what
causes the condition, we do not have an answer to this question.
However, a number of cases have occurred in particular circumstances with a logical
Some known causes of CJD
Some people who received treatment with human growth hormone developed CJD. In the past, growth hormone was obtained from the pituitary gland (a small gland at the base of the brain) of people who had died.
It is suspected that one or more people from whom the glands were obtained had died from CJD.
At that time it was not known that CJD could be passed on from one person to another in this way.
Since 1985 the hormone has been made artificially and there are now no risks of acquiring the
disease in this way.
Although there is no direct evidence that CJD is transmitted through blood transfusions, it is
now recommended as a precautionary measure that individuals who have received human
pituitary hormones or individuals with a family history of CJD should not act as blood
One case of CJD was described in an individual who contracted the disease after receiving
corneal transplants from someone who had died, to replace their own damaged cornea. Other
cases have occurred due to the implantation of human dura mater grafts at neurosurgery
(the dura mater is the tough outer membrane enclosing the brain and spinal cord). These
tragic medical accidents occurred at a time when it was now known that CJD could be
transmitted from one person to another in this way. No organs or tissues of any type
are now taken from people who have died from CJD for use in donations.
Four cases of CJD occurred in people who had undergone brain surgery and it is likely that
transmission of the infectious agent occurred from case to case by the use of contaminated
surgical instruments. It is now standard practice for all instruments used in neurosurgical
or eye operations on a patient with CJD to be destroyed.
Can you catch it from food or animals?
The classical form off CJD occurs at a relatively standard rate in all countries around the
world. One possible explanation for the cause of classical CJD is that it is transmitted to
humans when they eat meat or other products from animals infected by animal spongiform
encephalopathy. However, CJD occurs in countries where there is no scrapie or BSE and there is,
as yet, no evidence that this form of CJD is caused by transmission from animals. Studies have
not shown any common link between patients with CJD and there does not appear to be any increased risk through dietary or occupational exposure to sheep.
The cause of classical CJD is unknown, although one possible but unproven explanation is that
the disease results from a random and chance alteration of the form of the brain protein, prion
protein, which then multiplies and eventually causes disease. If this theory is correct,
classical CJD may not be due to any form of infection from the environment.
New variant CJD
Although the risk from eating meat from BSE affected animals has always been considered
to be remote, there has been a theoretical risk that some of us may have been exposed to
infection prior to the banning of many adult cattle tissues, including brain and spinal cord,
from the human food chain in November 1989.
Research carried out by the CJD Surveillance Unit in Edinburgh early in 1996 identified
a number of younger people, average age 28, in the UK with a new clinical pathological type
of CJD. Researchers believe that a new variant of the disease has been identified and that
there have now been 15 cases of this type of CJD in the UK and one case in France.
The new cases do not appear to be linked to known risk factors for CJD such as earlier
treatment with human growth hormone or exposure to surgical instruments contaminated with CJD.
It also seems that the new cases examined to date are not genetic in origin.
The occurrence of a new and unexplained form of CJD in a country with a high
incidence of BSE suggests the possibility of a causal link. Recent evidence has also
shown that the protein that accumulates in the brains of patients with the new variant
is different from other forms of CJD and similar to BSE. Although this is not proof,
the evidence strengthens the possibility that new variant CJD is caused by BSE. If
these cases have arisen as a result of eating infected animal tissue, given the probable
ten to twenty year incubation period, there may be many more people at risk.
Is the person with CJD in pain?
Individuals with CJD may sometimes feel discomfort from, for example,
sitting in one position too long, but there is no pain associated with the disease itself.
However, it is very distressing for others to see someone they care about seriously ill.
What can the medical profession do?
There are ways to alleviate some of the features which can accompany the illness.
For example, frequent changes of position of an immobile person are necessary to ensure
comfort and prevent the development of pressure sores. A catheter to drain urine is often
necessary if incontinence of urine is a problem. A catheter is a narrow rubber tube which
is painlessly inserted into the bladder. Sometimes the ability to swallow may be lost, and
then the patient can be fed via a tube through the nose or receive fluid by means of a plastic
needle in their vein (a "drip").
The shakiness or jerks which some patients experience can be treated with sedative
drugs or painkillers. The object is to keep the person with CJD as comfortable as possible
up to the time of death.