There have been 164 reported cases of vCJD, (the human form of BSE) in the UK since 1980, the date that BSE became present in the UK food chain. vCJD is a variant of Creutzfeldt-Jakob Disease, a fatal brain-deteriorating disease, for which there is currently no cure. In the majority of these reported cases, it is thought that vCJD has been transmitted through the consumption of infected beef, and that there have been relatively few cases up until now due to the species barrier between humans and cows. However, it has emerged that there is a real danger of becoming infected with vCJD through contaminated blood and the use of surgical instruments.
So far three patients in the UK are thought to have died after developing vCJD following transfusions of infected blood. The first case was reported in 2003. The blood donor, who had been healthy when he gave blood in 1996, later developed and then died of vCJD in 2000. In 2003, a recipient of that donor’s blood also died of vCJD. The second case was reported in 2004 and concerned a patient who died of causes unconnected with vCJD, but whose post mortem revealed the patient had been infected with the disease. The patient had received blood from a donor who had died of vCJD.
The death of a third patient following a transfusion of infected blood occurred this year. The patient’s symptoms appeared 7 years after having received the blood transfusion, while the donor’s symptoms had begun within 2 years of the blood donation. Following this latest case it has been revealed that the disease is very easily transmitted by blood.
Those most at risk of developing vCJD are patients who have received blood transfusions from donors who have later developed the disease. Patients thought to be at risk are being traced and contacted by their doctors and informed of certain precautions they need to take. Precautions include not donating blood, tissue or organs, and extra infection control being used when the patient undergoes surgery. The government has, in the past, introduced measures to lessen the risk of contracting vCJD through infected meat, for example by banning specified offal in human food.
It is, however, impossible to predict how many more cases of vCJD there will be. There could be more cases from exposure to meat products, before the ban on specified offal was introduced in 1989, if the incubation period is long. Also worrying is that there is currently no test to screen blood for vCJD, although there is a method of filtering the blood.
In addition to the risk of contracting vCJD through blood transfusions, there is a risk of being infected through the use of contaminated surgical instruments. This is particularly an issue in dentistry, as although instruments are sterilised between patients, this is not necessarily enough to destroy the prions which cause vCJD.