CHAPTER 3: Inhalational Anthrax – Issues in Dose–Response and Hazard Evaluation

Inhalational anthrax is rare in the industrial or normal public health context, but a real threat in the context of biological terrorism and warfare. The 2001 US anthrax letter attacks surfaced knowledge gaps in risk evaluation, which is needed for efficient planning of the immediate and long-term response to such an attack. This invoked large investments in research directed towards the development of models and methods for risk evaluation and their application in the analysis of response strategies to bioterror anthrax attacks. The dose–response experimental and modeling studies are reviewed in this chapter, with emphasis on their relevance to risk analysis, response planning, and mitigation of the effects of these attacks. They are focused on the following themes: (i) dose–response modeling of experimental animal data, with emphasis on nonhuman primates and other animal models frequently used as surrogates for the absent human data; (ii) dynamic modeling of multiple exposures, representing a realistic scenario for secondary exposure; (iii) modeling of the incubation period distribution; and (iv) risk analysis in special environments representing human exposure to inhalational anthrax in the industrial and bioterrorism contexts. The statistical methodologies, biological background and implications for risk assessment and outbreak response planning are discussed.