Alzheimer's could be passed on through medical accidents

It would be theoretically possible to become infected with Alzheimer’s seeds through a blood transfusion, brain surgery, or invasive dental work, such as a root canal operation. Photo / iStock.

Alzheimer's disease may be transmissible through blood transfusions and medical accidents in the same way as Creuzfeldt Jakob Disease (CJD), scientists believe.

In a landmark finding, researchers at University College London said it was possible the "seeds" of dementia could be transferred from the brain tissue of one person to another.

Worryingly the proteins which cause dementia are a type called prions which can stick to metal surfaces, such as surgical instruments, and are resistant to conventional sterilisation.

It means that it would be theoretically possible to become infected with Alzheimer's seeds through a blood transfusion, brain surgery, or invasive dental work, such as a root canal operation. And because the incubation period can be up to 40 years, people could be unaware that they have been contaminated.

The Government's Chief Medical Officer Dame Sally Davies said the Department of Health was monitoring the situation but reassured the public that there was little risk.

British scientists stumbled on the discovery while studying the brains of eight people who died of CJD. All had developed the disease after being injected with human growth hormone taken from dead bodies between 1958 and 1985 when the practice was banned.

Unexpectedly, four of the patients had huge levels of amyloid beta protein - a sticky deposit which forms among brain cells and stops them communicating with each other properly in Alzheimer's patients.