Anthrax is caused by the bacterium Bacillus anthracis .
It is a disease of sheep, cattle, horses, goats, and swine. Human infection, though rare, is an occupational disease of farm workers, veterinarians, and tannery and wool workers. In the cutaneous form, the infection is transmitted through a break in the skin. After lesions form and the dead tissue and crusts fall off, infection may spread through the bloodstream and cause shock , cyanosis , sweating , and collapse . The incidence is 1 out of 100,000 people.