Anthrax risk assessment

Mainly in response to the anthrax attacks in the United States, in 2002, the Centers for Disease Control and Prevention published a report entitled Crisis and Emergency Risk Communication (Reynolds, 2002). The report illustrates two prerequisites for successful risk communication credibility and trust. These two elements (Figure 11) may be highly important when dealing with uncertainty in exposure and risk assessment (Sjoberg, 2001). The prerequisites for credibility are accuracy of information and speed of release the main attributes of trust are empathy and openness. 

Anthrax remains both a serious public health hazard and a very real biological weapon threat. A deliberate release of an anthrax weapon in a populated area could have catastrophic implications. An economic model developed by the Centers for Disease Control and Prevention (CDC) suggested a cost of 26.2 billion to treat 100,000 people exposed to anthrax (Kaufinann et al., 1997). A risk assessment, provided at the end of this chapter, will serve to highlight the dangers of a realistic scenario involving anthrax spores. 

The distribution of B. anthracis endospores in mailings through the US Postal Service in the fall of 2001 served to ignite public awareness concerning anthrax as a weapon of mass destruction. Deliberate contamination of the mail resulted in 22 cases of anthrax (11 inhalational and 11 cutaneous). These mailings led to five deaths among the inhalational anthrax cases and an enormous economic burden associated with decontamination. The media coverage and public fallout unveiled the deficiencies in our current risk assessment of anthrax. 

The effects on public order, as well as economic and social effects, should be considered in an assessment of weaponized anthrax risk. Decontamination of the Hart... 

Koumikakis, B., Armour, S.J., Boulet, C.A., Spence, M., Parsons, B. (2001). Risk assessment of anthrax threat letters. Technical Report TR-2001-048 Defence Research Estahlishment Suf-field, Canada. 

Logistics. The committee observes that the supply chain provides a delivery mechanism for surreptitious chemical or biological attack. Our nation s recent experience with anthrax delivered through the U.S. mail system provides a relevant illustration of the disruption and psychological response that such an attack can cause. Food and water supplies offer similar delivery opportunities. Attacks by such means should be considered within the context of an overall risk assessment, since they could significantly degrade operational readiness. 

In silico models of anthrax release can be used to bridge the gap to help predict consequences of human exposure in the event of an outbreak or biological attack scenario. Several modeling studies have been published (Wein et al., 2003) in attempts to assess anthrax risk. The model of Wein et al. (2003) assumes a point-release of 1 kg of spores at a height of 100 m over a city of 10 million inhabitants. The effects on mortality of different antibiotic treatment strategies in an urbanized anthrax release are examined. This in silico biological weapon attack results in more than 100,000 deaths, given that both symptomatic and as)miptomatic persons receive antibiotics and the model incorporates availability and distribution parameters. In the base case, an approximation of... 

First, assess the probability of exposure. By doing so, clinicians can determine whether the patient is at risk for anthrax disease, whether to notify public health officials and law enforcement agencies and whether to begin preventive or curative... 

The effects on public order, as well as economic and social effects, should be considered in an assessment of weaponized antiirax risk. Decontamination of the Hart Senate Office Building in Washington, DC, required 7 months at a cost of 23 million. Decontamination of the postal facilities that processed the "anthrax letters" in Brentwood, DC, and Hamilton Township, NJ, required more than 1 year at a cost in excess of 100 million (Fernandez, 2002). The psychological effects of an anthrax attack could exceed the medical or economic effects, especially in the short term. Panic caused by seemingly random outbreaks of symptoms in apparently unrelated persons or events "could degenerate into panic, flight, communications breakdown, general societal dysfunction" (Wein et al., 2003). 

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