London School of Hygiene & Tropical Medicine

A paper published online today in the Royal Society journal Interface shows the future death toll from vCJD is likely to be far lower than originally anticipated because public health interventions that are already in place will have dramatically reduced the number of infections that could have occurred through blood transfusion.

In 2004, a study of 13,000 appendix and tonsil samples revealed that thousands of people may be unknowningly harbouring vCJD. Since then four people have contracted vCJD after receiving blood transfusions from donors who were carrying the disease, and the Department of Health has responded by banning people who received blood transfusions since 1980 from donating blood.

A team of researchers based at the London School of Hygiene & Tropical Medicine used mathematical models to explore scenarios in which a new vCJD epidemic carried by infected blood might develop, and also assessed the impact of public health interventions that have been implemented on its spread.

They found that public health interventions reduced the worst case scenario from 900 future deaths to 300. More reassuringly, considering only scenarios thought to be biologically plausible, the worst case with public health interventions as implemented would be around 50 future deaths.

Dr Paul Clarke, lead author of the paper, comments: 'Our findings indicate that a large scale epidemic of vCJD via blood transfusion running into thousands of cases is unlikely to occur, and that public health interventions such as the donation ban were timely and effective in limiting the scale of the epidemic'.
 

• Is there the potential for an epidemic of variant Creutzfeldt-Jakob disease via blood transfusion in the UK? by Dr P Clarke, Professor G Will and Dr AC Ghani (DOI: 10.1098/ rsif.2007.0216)