Variant Creutzfeldt-Jakob Disease (vCJD) is the human form of Bovine Spongiform Encephalopathy (BSE). It was first reported in the United Kingdom (UK) in 1996. It is thought to be contracted by eating bovine meat products infected with an abnormal prion protein. This is generally accepted as being the same agent that causes
Q. What is variant Creutzfeldt-Jakob Disease (vCJD)?
vCJD is the human form of Bovine Spongiform Encephalopathy (BSE). It was first reported in the United Kingdom (UK) in 1996. It is thought to be contracted by eating bovine meat products infected with an abnormal prion protein. This is generally accepted as being the same agent that causes BSE.
Q. What are the risks associated with contracting vCJD?
The main risk associated with contracting vCJD is dietary exposure to meat or meat products infected with BSE. This could have occurred through residing in the UK in the years 1980 to 1996, or from consuming infected meat or meat products in Ireland, either imported from the UK or from Irish sources, before all control measures were in place. The National CJD Advisory Group commissioned research on vCJD risk in the Republic of Ireland. This concluded that the likelihood of future cases occurring in Ireland from the above sources is extremely small.
Other possible risks include:
- Receiving a blood transfusion from a donor who was well at the time of the donation but later developed vCJD
- Having certain operations where instruments are used that were previously used on a patient who later went on to develop vCJD. This is a possible risk even if the instruments used are thoroughly cleaned and sterilised after surgery.
Q. How many cases of vCJD have there been in the UK or elsewhere?
To date there have been 227 cases of vCJD worldwide, 3 of which were due to blood transfusion, the rest were probably caused by eating contaminated meat products. 176 of these cases, including the 3 transfusion transmitted cases, were in the UK, 27 in France and 4 in Ireland.
Q. Are people who lived in the UK between 1980 and 1996 at risk of contracting vCJD?
The risk of contracting vCJD through travelling and living in the UK in this period is considered to be low. It should be noted that in the UK where tens of millions of people were potentially exposed to vCJD through eating infected food, there have only been 176 cases of the disease to date.
Q. What is significant about residence in the UK in the period 1980 to 1996?
This period covers the epidemic of BSE in cattle in the UK that occurred in the years 1980 to 1996. The first cases of BSE in cattle in the UK were reported in 1986. Scientists believe the incubation period for the disease in cattle is about five years, so BSE most likely first appeared in cattle around 1980. It is thought that BSE occurred in cattle that were fed meat and bone meal from other animals.
The UK introduced a ban on feeding meat and bone meal to cattle in 1988, and subsequently introduced a series of measures to reduce the risk of humans being exposed to infection. These measures have been fully implemented since 1996.
Q. What areas in the UK are included for the purposes of this deferral policy?
The areas are Northern Ireland, England, Scotland, Wales, the Channel Islands and the Isle of Man.
Q. What is the relevant period?
The relevant period is the sum total of all time spent in the above areas between 1 January 1980 and 31 December 1996, including brief trips, weekend visits, attending college, holidays, work or periods of residence.
Q. What else has the IBTS done to reduce the risk of transmission of vCJD by blood transfusion?
Since the first cases of vCJD were reported in the UK in 1996, the IBTS has taken a number of precautionary steps including:
- From November 1999 the removal of most of the white cells from blood (white cells are considered by experts to be a potential source of infection).
- The National Blood Users Group issued guidance to all doctors in January 2001, setting out best practice for blood usage in surgical patients.
- From April 2001, people who spent 5 years or more in the UK between 1 January 1980 and 31 December 1996 were excluded from donating blood.
- From October 2002 people who had previously received blood transfusions outside the Republic of Ireland were excluded from donating blood in Ireland.
- The importation of plasma from BSE free countries.
- From May 2004 people who had spent 3 years or more in the UK between 1 January 1980 and 31 December 1996 were excluded from donating.
- From May 2004 people who had received blood transfusions in the Republic of Ireland (other than autologous transfusions) since 1 January 1980 were excluded from donating.
- From November 2004 people who had spent 1 year or more in the UK between 1 January 1980 and 31 December 1996 were excluded from donating blood.
- From November 2004 people who had certain operations in the UK since 1 January 1980 were excluded from donating. These include neurosurgery, eye surgery, laser eye treatment, appendectomy, tonsillectomy, adenoidectomy, splenectomy and lymph node biopsy.
- From October 2006 people who had root canal treatment in the UK since 1 January 1980 were excluded from donating unless their dentist had used only single use disposable files and reamers
- From 2009 importation of fibrinogen made from US-sourced plasma to replace cryoprecipitate made from Irish plasma.
Q. Why did the IBTS exclude people who had received blood transfusions in Ireland?
This was introduced as a precautionary measure in May 2004 in response to the first transmission of vCJD by blood transfusion in the UK. The donor was well at the time of donation but later developed vCJD.
Q. I received a blood transfusion in the Republic of Ireland since January 1980. Does this mean I could develop vCJD?
On the available evidence, the risk to patients from blood and blood products in the Republic of Ireland is extremely small and may be zero. This risk is far outweighed by the potential medical consequences of not receiving blood when it is required.
Q. Can blood donors get vCJD by donating blood?
No absolutely not. The materials used for every donation are new, sterile and disposable and are used only once. Giving blood carries no risk of catching vCJD.
Q. Is there a test for vCJD?
There is no blood test available for the disease at present and while there are a number of companies working on developing a test, it will be a few years before one will be available. So there is no way of screening blood donations for the presence of vCJD at present.
Q. How can I help?
We each have a one in four chance of needing a blood transfusion in our lifetime. The IBTS must collect 3,000 units of blood every week to meet patients’ needs. So we are asking you if you can continue to donate, to donate regularly and to encourage others to become blood donors. Every donation saves lives and your donation is needed now more than ever.
Q. I can no longer donate as a result of these measures. Will I ever be eligible to donate again?
If you are excluded from donating because of these measures we would like to say thank you for your valuable support over the years. As new scientific evidence emerges we will review our decision. If we reverse our decision in the light of new evidence we will get back in touch with you.