As international travel and human encroachment into previously isolated areas have increased, so too has the potential for the emergence of new infectious diseases. Populations likely to be susceptible to new infectious diseases have also increased in size. The past three decades have seen outbreaks of diseases caused by parvoviruses, Nipah virus, circoviruses, and prions. Infectious pathogens such as these are formidable opponents; they can adapt to new hosts or cause variant diseases within new hosts. Many are also resistant to current inactivation techniques. In order to prevent or contain outbreaks, pathogens that emerge must be identified quickly and efficiently; research and ongoing global surveillance are therefore of primary importance. To effectively protect the blood supply and blood-based therapies, this research should include investigations into improved techniques for detection, screening, and viral inactivation, as well as into ways to reduce patient exposure to infectious pathogens via therapeutic agents. The proactive devotion of appropriate resources to infectious disease containment and prevention prior to an epidemic should be perceived as both essential public health policy and cost effective.