US EPA

7216026 

Journal Article 

THE VALUE OF RISK MODELLING TO SUPPORT BLOOD SAFETY POLICY DECISIONS 

Cobain, TJ; , 

2010 

NOVA SCIENCE PUBLISHERS, INC 

HAUPPAUGE 

TRANSFUSION: THINK ABOUT IT 

151-170 

WOS:000284123700011 

The contamination of blood supplies in France and Canada by HIV in the 1980's resulted in a severe loss of public confidence in blood transfusion worldwide The ensuing focus by Governments on establishing 'Zero' risk blood supplies has lead to the incremental implementation of donor screening strategies in the form of new tests and donor deferrals Each additional measure leads to a shrinking pool of eligible donors and places increasing pressure on the sufficient supply of blood and blood productsBalancing the risk of safety and sufficiency is complex One useful risk assessment tool is mathematical modelling increasingly used within the blood sector to estimate the risk associated with specific interventions In this chapter two 'case studies' are used to illustrate the value of robust risk modelling to inform blood safety decision makingThe first considers the threat posed to the Australian blood supply from variant Creutzfeldt-Jakob (vCJD) disease A mathematical model was developed to quantitate the then theoretical risk of vCJD transmission from a blood donor and compare it with the predicted increase in incidence of known pathogens resulting from the need to recruit an additional 50,000 first time donors, who are known to have higher viral incidence rates The latter risk was associated with a proposed new donor deferral strategy which would indefinitely defer donors who had resided in the UK for a cumulative period of 6 months or more within the risk period The model output indicated that the risk of vCJD transmission by blood was greater than that from the additional recruitment of first time donors and this data informed the eventual Australian policy decision to implement a vCJD deferral for residence in the UKThe second case considers the strategy of testing donors at risk of malaria exposure and re-instating them for cellular component production earlier than the original deferral period This strategy delivers a significant efficiency gain in terms of cellular blood components but potentially increases the risk of transfusion transmitted malaria A mathematical model was developed to quantitate the risk differential between the existing deferral for 1-3 years versus deferral for a minimum period of 4 months with subsequent malaria antibody screening The model predicted a negligible risk increase of 1 in 6 million for a transmission involving P falciparum, the most important species in terms of recipient mortality This novel risk modelling provided important evidence supporting the eventual implementation of a malaria antibody testing strategy in Australia 

Cobain, TJ; 

978-1-61668-969-8