Manbir Online .... Creutzfeldt-Jakob Disease

Creutzfeldt-Jakob Disease ("CJD") is a rare, fatal brain disorder which causes a rapid, progressive dementia and associated neuromuscular disturbances

Incidence of this disease is One in per million people per year.
Affects both men and women of diverse ethnic backgrounds usually between the ages of 50 to 75 years. The disease occurs world wide.

Cause of the Disease
There had been much debate on the cause of the disease. Now it is accepted that that a transmissible agent is responsible for causing Creutzfeldt-Jakob Disease, as shown by experiments involving the injection of CJD-affected brains into the normal brains of healthy animals. The identification of this transmissible agent has been the subject of much scientific inquiry and debate.

The agent responsible is either a slow virus or Prion.

In 1996, scientists confirmed that they had discovered a new strain or variant of the disease among young people This is now referred to as vCJD.

The emergence of vCJD came after the biggest ever epidemic of BSE in cattle. Since that epidemic was in the UK and most vCJD victims lived in the UK, most scientists believed the two were linked.

They say the most likely cause of vCJD in humans was eating BSE-infected beef between the years of 1986 and 1989, when contaminated meat probably got into the food chain in large quantities.

Mode of Transmition of the disease

There appear to be three general categories for classifying the means through which CJD may be acquired.
First, the disease can occur sporadically.
Second, the disease can be inherited.
Third, the disease can be transmitted through infection.

Sporadic Creutzfeldt-Jakob Disease

Sporadic CJD refers to those cases in which there is no known infectious source and no evidence of the disease in the prior or subsequent generations of the patient's family. Most CJD cases occur sporadically, thereby leaving their origins a mystery.

Inherited Creutzfeldt-Jakob Disease

Approximately 10 to 15 per cent of CJD cases are inherited. These familial cases exhibit a mutation in the gene coding for the prion protein. Genetic factors are thought to be responsible for the elevated numbers of CJD cases in some communities in Czechoslovakia and Chile, as well as among Libyan-born Jews.

Creutzfeldt-Jakob Disease Through Infection

Although CJD can be aquired by a transmissible agent it is not a contagious disease. The family members do not have increased risk of contacting the disease.
Iatrogenic transmission of CJD has occurred in cases involving
corneal transplants,
implantation of electrodes in the brain,
duramater grafts,
contaminated surgical instruments
and the injection of natural human growth hormone derived from cadaveric pituitaries.

Thus, one may become infected with CJD from direct contamination with infected neural tissue.

Studies are currently being conducted to determine if CJD is
transmitted to humans through blood. The infectious agent has been found in blood but there have been no documented cases of blood transmission of CJD in humans.

In Britain, scientists and politicians have struggled to ascertain if there is a connection between bovine spongiform encephalopathy ("BSE") and CJD. BSE or "mad cow disease" was initially discovered in Britain in 1986 and thought to have resulted from the use of cattle feed containing ground offal from scrapie-infected sheep.
It is now believed that here was a possible link between BSE and CJD. This new acknowledgement arose from the identification of an apparently new strain of CJD which was discovered in 10 people under the age of 42, including some teenagers. Additionally, five of the people were associated with the meat and livestock industry. Scientists decided that the most likely explanation for this unusual outbreak was the consumption of beef from diseased cattle before 1989, when regulations were adopted for the disposal of potentially infectious cattle offal, including brains, and the use of sheep entrails as feed ceased.

How many people have died of vCJD in the UK?

The official figure for the number of people who have died from vCJD since 1995 is over 80. Two others have died in the Irish Republic and in France.

Several other people in the UK have developed the disease and are currently being nursed. Because the incubation period for the disease could be 15 or 20 years, we do not know how many more of us could also eventually fall ill.

Scientists believe they will not have a clear idea of whether the final figure will be a few hundred or a few thousand, or many thousands, until the end of the year 2002.

Some members of the population appear to be more at risk than others. Most of those who have so far died are young. This is baffling the scientists.

Scientists believe if people are going to get the disease they will, in nearly all cases, already be incubating it.

They believe very little if any contaminated beef is now reaching the food chain. Therefore, there is very little individuals can now do.

However, if large quantities of the adult population are to develop vCJD, the government wants to ensure the disease does not spread unnecessarily across the population.

They have recommended contact lenses used by opticians for tests should not be re-used. They have taken measures to ensure blood is safe.

And they've recommended surgical instruments in certain operations should not be re-used.