Fig. 1. The IPF model.

Fig. 2. The process of model alignment.

Fig. 3. The comparison between BioWar scenarios with different dose dependency assumptions and the Sverdlovsk data.

Fig. 4. Comparison between IPF, BioWar and the US data for the percentage of infected population in the incubation stage.

Fig. 5. Comparison between IPF, BioWar and the Sverdlovsk data for the percentage of infected population in the incubation stage.

Fig. 6. Comparison between IPF, BioWar and the US data for the normalized fraction of infected population in the symptomatic stage.

Fig. 7. Comparison between IPF, BioWar and the Sverdlovsk data for the normalized fraction of infected population in the symptomatic stage.

Fig. 8. Mortality comparison between IPF, BioWar and the US data.

Fig. 9. Mortality comparison between IPF, BioWar and the Sverdlovsk data.

Table 1.

Alignment of model components between BioWar and IPF based on stages of disease progression

Table 2.

Model parameters and assumptions for the BioWar scenarios

Table 3a.

The mean and standard deviation of the lognormal distribution for the three stages of anthrax (dose-independent case)

Table 3b.

The mean of the lognormal distribution for the three stages of anthrax (dose-dependent case)

Low-dose case corresponds for the less than 4000 spores inhaled, high dose—greater than 12,000 spores inhaled, and medium case—between 4000 and 12,000 spores inhaled.

Table 4.

A comparison of the results between BioWar and IPF with the empirical data sets

^a The discrepancy in infected population between IPF and BioWar is due to the difference in the release mass of anthrax spores. IPF calibrates the infected population to empirical data and BioWar calculates it based on an attack scenario that the effective release mass is about 150 times of the Sverdlovsk case.
^b Empirical infection rate=infected population/the number of people taking anti-microbial prophylaxis or vaccinated.
^c Simulated infection rate=infected population/the exposed population. The exposed population refers to persons who are inhaled at least one anthrax spore.
^d Death rate=total number of deaths/infected population.
^e Stabilization time is the number of days that have elapsed when 99% of infected people either die or recover.
^f Approximately 10,300 persons completed a 60-day course of anti-microbial prophylaxis. This program is only applied to the people who met the following three factors: (1) the presence of an inhalational anthrax at a facility, (2) environmental specimens positive for B. anthracis in facilities along the path of a contaminated letter where aerosolization might have occurred, and (3) exposure to an air space known to be contaminated with aerosolized B. anthracis from an opened letter [5].
^g A voluntary immunization program vaccinated approximately 47,200 persons at least once. The voluntary immunization program using a live nonencapsulated spore vaccine was carried out for healthy persons 18 to 55 years old. Approximately 59,000 persons are eligible for the program and 80% were vaccinated at least once [14].