This issue collects some of the finest scientists, physicians, and scholars to present the relationship between emerging natural threats and the deliberate use of biological agents, laboratory aspects of select agents and biosurety, clinical and pathologic differential diagnosis of potential pediatric bioterrorism agents, medical strategies to handle mass casualties caused by the use of biological weapons, updates viral hemorrhagic fevers, unusual agents such as fungal, and food borne agents including protozoal and helminthic, biological toxins from bacterial and marine organisms, and bioregulators. Update on molecular methods of detection, diagnosis, and characterization of biological threat agents are included. The clinicopathologic aspects of animal and zoonotic diseases of bioterrorism is wholly updated as is the impact on genomics and proteomics on biological threat agents. This issue also provides whole new immunologic approach to the management of select agents. Lastly, and very importantly, the anatomic laboratory and forensic aspects of biological threat agents is carefully reviewed.