The pneumonic plague usually manifests after an incubation period of 2 to 3 days with fulminant pneumonia, malaise, high fever, cough, hemoptysis, and septicemia with ecchymoses, and extremity necrosis. The disease progresses rapidly, leading to dyspnea, stridor, cyanosis, and septic shock. Death is normally the result of respiratory failure and circulatory collapse [42] . The pneumonic plague is highly contagious via inhalational exposure or secondary hematogenous spread, and therefore the most likely form to be used in a bioterrorist attack. It is invariably fatal, unless treated within the first day of onset.