- Touching and hugging
- Sharing meals
- Caring for someone at home
- Some surgery and instruments
- Certain tissues in hospitals
- Blood and organ donation rules
People ask this quietly, often feeling guilty for asking. It is a fair question, and the answer is clear enough to rely on.
Can it spread in a home or a hospital room?
There is no evidence that CJD spreads through ordinary day to day contact. Prion diseases are not infectious in the usual way. They do not pass through the air, and the UK and US support organisations both say there is no increased risk from contact with a person who has the illness, including close and intimate contact. Holding a hand, helping with washing, sharing a room and eating together are all safe.
The word “prion” means a misfolded protein. It is not a bacterium or a virus, which is why the usual ideas about infection do not fit.
Carers do not need special precautions. The one standard piece of advice is for anyone who might touch the person’s blood, such as a nurse dressing a wound: wear gloves and follow the same precautions used with every patient.
So how has it ever passed between people?
Through a small number of specific medical routes, now very rare.
The largest group of cases came from human growth hormone made from the pituitary glands of people who had died, used before the mid 1980s. Other cases followed grafts of dura mater, the membrane that covers the brain, and corneal transplants from donors whose illness had not been recognised. A few cases before 1976 were linked to instruments used in brain surgery, and none of that kind have been reported since decontamination procedures were improved.
Variant CJD, the form linked to BSE in cattle, has been passed by blood transfusion on a small number of occasions in the UK. Blood and plasma explains the donor rules that follow from this.
These routes involve brain or nervous tissue, or blood in the case of variant CJD, entering another person’s body. They have nothing in common with living alongside someone.
Which parts of the body carry the prion?
Health agencies describe the brain, spinal cord and eyes as the tissues with high infectivity. This is why hospitals take extra care with certain procedures and instruments, and why a post mortem examination is done with precautions. It does not change anything about day to day care. Surgery and instruments explains what hospitals do.
What about after a death?
Guidance for funeral staff differs depending on whether a post mortem has been carried out. Where one has not, there is no reason to discourage touching or kissing the face. Where one has, relatives are advised to avoid that contact. The funeral director and the hospital can say what applies.
What about food and animals?
Variant CJD came from eating beef from cattle with BSE. Sporadic CJD, the most common form, is not caused by any other prion disease and has no known cause. Food and BSE covers the history and the controls, and Myths and facts takes the common worries one by one. The Exposure and safety hub lists the rest.
For any question about a specific exposure, a past operation or a transfusion, the GP or treating team can ask the national surveillance service on your behalf.