Case Studies in Infection
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Page updated 9 October 2007
Ordinary person-to-person transmission of CJD in any form has not been recorded.
There are several known instances worldwide of patient-to-patient transmission following neurological procedures on classical CJD, the use of human pituitary growth hormone to treat dwarfism, dura mater patches and corneal transplantation. The only likely source of infection from cases of classical CJD is implanted nervous tissue.
It is presumed that vCJD is acquired by eating contaminated food of bovine origin from an affected animal. This risk is currently assessed as being very low.
In addition, vCJD prion is known to involve the lymphoreticular system early in the course of incubation. The number of asymptomatic individuals harbouring the prion is not known. Therefore vCJD is of particular concern as an infection risk. Any procedure involving either the lymphoreticular system or nervous system of a patient with vCJD is regarded as a risk for transmission. Blood and blood products could be contaminated with vCJD prions and a recent report suggests that at least three incidents of transfer from donor to recipient has occurred. In the UK , all products involving human plasma are sourced from non-UK donors, and blood from transfusion is routinely leucodepleted. Organs or tissue for transplantion are not taken from any cases with suspect or proven CJD of any form. Avoiding unnecessary procedures on patients who have, or might have any form of spongiform encephalopathy is the most certain way of preventing iatrogenic infections.