The CDC classifies potential bioterrorism agents into 3 categories: 1) A, 2) B, and 3) C. These categories are based on the agents' potential as weapons, such as their ability to be disseminated, transmitted, and to cause disease; the mortality rate; the expected impact on public health; and the potential for panic and social disruption [11, 12] . Category A agents, judged to have the greatest risk, include anthrax, plague, tularemia, smallpox, the hemorrhagic fever viruses, and botulinum toxin [11] . Most experts in the field believe that anthrax and smallpox would be the agents most likely to be used by terrorists [13] . Although these are the most easily fatal, terrorists could also reach their goals by simply causing illness on a large scale [10] . Category B agents are ones that would cause moderate morbidity and low mortality. Category C agents are pathogens in the emerging phase, [10] ( Table 1 ). The relative toxicity of selected agents for comparison is shown in Table 2 .