Introduction

Bioterrorism (BT), the deliberate use of microbial agents or their toxins as weapons for political gain, continues to represent a persistent global threat due to the widespread availability of these substances and the opportunities for terrorists to deploy them against civilian targets. Although the potential deleterious consequences associated with exposure to biologic threat agents are high, the probability of exposure to these hazards is unknown – it remains in the unpredictable and malicious minds of terrorists. Therefore, a precise calculation of “risk” as it relates to BT is not possible. However, due to the potential for catastrophic sequelae, it is important for clinicians to understand the diagnostic and therapeutic approach to illnesses caused by agents of BT in order to mitigate the effects of an attack.

BT agents are considered weapons of mass terror because of their potential for large-scale morbidity and mortality. For example, one early model predicted nearly 200 000 casualties from a release of 50 kg of aerosolized anthrax spores upwind of a population center of 500 000. Based on more recent experience – the US anthrax attacks of 2001 resulted in 11 cases of systemic disease associated with 5 deaths – it is evident that even relatively small-scale events may cause mass terror.