Diagnosis is usually only made after a death has been referred to the CJD Unit from hospitals or GPs. As the left-hand column shows, referrals have been holding steady. "Sporadic" CJD is the common form, usually found in people aged over 60. "Iatrogenic" is caused by the disease being introduced to the victim - mostly through treatment with human growth hormone. "Familial" cases occur in families which have a mutation of the PrP gene (see main text). "GSS" - Gerstmann-Straussler-Scheinker syndrome - is an extremely rare inherited disease also associated with PrP mutation.
The CJD Unit is convinced vCJD is a new phenomenon. One non-UK case has been discovered - retrospectively - in Lyons, bringing the total number of definite vCJD cases recorded to 12. The possibility that more might be out there is occupying many medics' time.