Bacillus anthracis The causative agent of anthrax is a natural soil-dwelling organism.  There are at least 89 strains of B. anthracis which vary in virulence.  B. anthracis can form long-lived spores that are dormant, but re-activate when inhaled, ingested or come in contact with a skin lesion.  These are the three modes of infection.
Pulmonary anthrax – occurs when anthrax is inhaled.  It leads to flu-like symptoms followed by severe, often fatal, respiratory collapse.  This form is rarely treatable, even when caught early.
Gastrointestinal anthrax – occurs when humans eat anthrax inected meat.  This results in diarrhea, loss of appetite, inflamed intestines and vomiting of blood.  Gastrointestinal anthrax can be treated, but has a 25-60% mortality rate.
Cutaneous anthrax – occurs when anthrax spores come in contact with skin lesions.  It leads to an ulcer with a black center (an eschar) resembling black mold on bread.  It generally does not cause pain, but if left untreated can progress to toxemia and death.
Treatment includes large doses of antibiotics, orally and intravenously.  There is also an approved vaccine available to prevent the infection of anthrax.