Scientists believe that Alzheimer’s disease may be transmittable through blood transfusions and medical accidents, in the same way as CJD (Cruezfeldt Jakob Disease). Researchers from University College London have said that it was possible that the “seeds of dementia” could be transferred from the brain tissue of one person to another.
The proteins that cause dementia are like a type called prions which can stick to metal surfaces, like surgical instruments and are resistant to conventional sterilisation. There has been research done on mice and monkeys which shows that the transmission of the Alzheimer’s protein is at least theoretically possible. When liquefied brain tissue from deceased Alzheimer’s patients was injected into the central nervous systems of the animals, they developed brain changes associated with the disease.
Although the risk is “low”, the researchers said that determining whether the proteins could be passed through medical instruments and metal surfaces should be a research priority. Professor Collinge, Director of Medical Research Council Prion Unit at University College London states “Alzheimer’s protein seeds could follow similar transmission pathways. The seeds will potentially stick to metal surfaces whatever the instrument is. With prions, we know quite a lot about that. Certainly, there are potential risks with dentistry where it’s impacting on nervous tissue, for example root canal treatments. No way is this suggesting Alzheimer’s is a contagious disease. You can’t catch it by living with someone who has Alzheimer’s disease or by being a carer”.
Chief Medical Officer, Professor Dame Sally Davies said “I can reassure people that the NHS has extremely stringent procedures in place to minimise infection risk from surgical equipment, and patients are very well protected.” Dame Sally Davies says that the Department of Health are monitoring the situation, but reassured the public that there was little risk.
Neuroscientist Professor John Hardy from University College London said: “with the previous mouse data, I think we can be relatively sure that it is possible to transmit amyloid pathology by the injection of human tissues, which contain the amyloid of Alzheimer’s disease”. Scientists at the University of Texas have discovered that it is possible to detect Alzheimer’s prions in the bloodstream years before sufferers get the disease, and they are hoping to develop a diagnostic test.
Written by Claire Collier