Anthrax is an acute infectious disease caused by the spore-forming bacterium Bacillus anthracis .
It most commonly occurs in warm-blooded animals, but can also infect man. Anthrax spores can be produced in a dry form for biological warfare which may be stored and ground into particles. When inhaled by humans these particles cause respiratory failure and death within a week. A skin lesion evolving over 2 to 6 days from a papule, through a vesicular stage to a depressed black eschar. A brief prodrome resembling a viral respiratory illness followed by a development of hypoxia and dyspnea.