Prions:a threat to health security and the need for effective medical countermeasures

Prions are infectious conformations of certain naturally occurring proteins.These misfolded proteins can struc­turally alter healthy protein,creating misfolded copies that repeat the process and form protein aggregates that lead to neuronal cell death.Although years can pass from initial prion infection to clinical presentation of symp­toms,onset of symptoms is typically followed by rapid neurological decline resulting in death.Prion diseases have been characterized in animals ranging from sheep and cattle to cervids and humans,with notable cross-species infections such as the variant Creutzfeldt-Jakob disease.Thus,prions present a health risk with the potential to disrupt major food sources as well affect human health through animal to human and human to human trans­mission events.While human to human prion transmission is rare and the immediate risks for a prion-facilitated pandemic are low,prions are a class of pathogens for which we are underprepared.In addition,prions,and prion disease-like approaches,have also been discussed in the context of biological weapons and toxins,adding another layer of complexity surrounding biosecurity and biodefense.These threats underscore the need for increased scrutiny and research on prions.Here,pharmaceutical and nonpharmaceutical prion-specific interventions are discussed.Recent advances in prion therapeutic development are also briefly highlighted,and a set of policy rec­ommendations are given that aims to provide high level suggestions for the prevention and mitigation of prion diseases.

Preparing for a “dirty bomb” attack: The optimum mix of medical countermeasure resources

Background: In radiological emergencies with radionuclide incorporation, decorporation treatment is particularly effective if started early. Treating all people potentially contaminated("urgent treatment") may require large antidote stockpiles. An efficacious way to reduce antidote requirements is by using radioactivity screening equipment. We analyzed the suitability of such equipment for triage purposes and determined the most efficient mix of screening units and antidote daily doses.Methods: The committed effective doses corresponding to activities within the detection limits of monitoring portals and mobile whole-body counters were used to assess their usefulness as triage tools. To determine the optimal resource mix, we departed from a large-scale scenario(60,000 victims) and based on purchase prices of antidotes and screening equipment in Germany, we calculated efficiencies of different combinations of medical countermeasure resources by data envelopment analysis. Cost-effectiveness was expressed as the costs per life year saved and compared to risk reduction opportunities in other sectors of society as well as the values of a statistical life.Results: Monitoring portals are adequate instruments for a sensitive triage after cesium-137 exposure with a high screening throughput. For the detection of americium-241 whole-body counters with a lower daily screening capacity per unit are needed. Assuming that 1% of the potentially contaminated patients actually need decorporation treatment, an efficient resource mix includes 6 monitoring portals and 25 mobile whole-body counters. The optimum mix depends on price discounts and in particular the fraction of victims actually needing treatment. The costeffectiveness of preparedness for a "dirty bomb" attack is less than for common health care, but costs for a life year saved are less than for many risk-reduction interventions in the environmental sector.Conclusion: To achieve economic efficiency a high daily screening capacity is of major importance to substantially decrease the required amount of antidote doses. Among the determinants of the number of equipment units needed, the fraction of the potentially contaminated victims that actually needs treatment is the most difficult to assess. Judging cost-effectiveness of the preparedness for "dirty bomb" attacks is an issue of principle that must be dealt with by political leaders.