Anthrax is caused by Bacillus anthracis. Humans acquire the disease directly from contact with infected herbivores or indirectly via their products. The clinical forms include:
- cutaneous anthrax (eschar with edema), from handling infected material (this accounts for more than 95 percent of cases);
- intestinal anthrax, from eating infected meat;
- pulmonary anthrax, from inhaling spore-laden dust.
Several other Bacillus spp, in particular Bacillus cereus and to a lesser extent Bacillus subtilis and Bacillus licheniformis, are periodically associated with bacteremia/septicemia, endocarditis, meningitis, and infections of wounds, the ears, eyes, respiratory tract, urinary tract, and gastrointestinal tract.