NR ATOB
AU Molesworth,A.M.; Bone,A.; Gill,N.; Purcell,M.; Comer,P.J.
TI Variant Creutzfeldt-Jakob disease and blood products: risk assesment methods, assumptions and public health implications in the United Kingdom.
QU International Conference - Prion 2005: Between fundamentals and society's needs - 19.10.-21.10.2005, Congress Center Düsseldorf - Poster Session: Human prions, risk of blood products, and therapy HUMAN-25
PT Konferenz-Poster
AB
In the UK, certain patients who can be identified as having had potential exposure to the vCJD agent through blood transfusion or treatment with particular UK-sourced plasma-products, are informed of their exposure so that, where appropriate, special precautions can be taken to reduce the likelihood of onward transmission of vCJD in the health-care setting. Recipients of certain plasma-products derived from UK-donors (used by the UK plasma-product manufacturers until 1998) are considered 'at-risk of vCJD for public health purposes' if their exposure to potential infectivity exceeds 0.02ID50 - the exposure that carries a potential risk of vCJD infection of 1%. This is the risk of infection in addition to the general risk borne by individuals in the UK population through dietary exposure to the BSE agent. Below the threshold dose the benefit to public health is considered too uncertain and the anxiety caused to individual patients too great to warrant the informing of patients and the implementation of public health precautions.
The potential vCJD infectivity in blood products was estimated by a risk assessment process. This reviewed experimental research on blood infectivity together with information on how products are manufactured to estimate the potential infectivity of batches of plasma-products derived from a donation from someone incubating vCJD. In the absence of complete evidence concerning transmission of vCJD infection, it was necessary to base the risk assessment on a number of assumptions relating to the infectivity of blood, processing and the susceptibility of recipients to infection, so that the resulting exposure estimates are likely to be pessimistic. While a precautionary approach to the management of potential iatrogenic transmission has been judged to be appropriate in the UK context; the benefits achieved by this approach and the public health precautions implemented have yet to be determined.
IN Die Autoren legen ihre überwiegend nicht sehr realistischen, zur mathematischen Bewältigung einer Risikoabschätzung fast ohne bekannte Parameter aber kaum vermeidbaren und meistens eher pessimistischen Annahmen offen, mit denen sie versuchten, durch Blutprodukte einem auch für britische Verhältnisse außerordentlichen nvCJK-Risiko ausgesetzte Patienten zu ermitteln, bei denen der erhoffte Nutzen eine Patienten-Information über ihr Risiko das zu befürchtende Risiko und den Streß überwiegt, die solche Informationen auslösen können. Berücksichtigt wurden dabei nur Blutprodukte, die aus 23 Blutspenden von 9 Menschen gewonnen wurden, bei welchen später nvCJK diagnostiziert wurde. So fanden sie gut 5000 Risiko-Patienten, die nun beobachtet und hoffentlich gut betreut werden.
AD A.M.Molesworth, A.Bone, N.Gill, Health Protection Agency Centre for Infections, London UK; M.Purcell, P.Comer, DNV Consulting, London UK
SP englisch
PO Deutschland