What is Anthrax?

Anthrax is an acute infectious disease caused by the spore-forming bacterium Bacillus anthracis. It is primarily a disease of sheep, goats, cattle and swine, but it can also infect humans. Symptoms of the disease usually occur within 7 days after exposure and will vary depending on how the disease was contracted. The three serious forms of human anthrax are cutaneous anthrax (skin), inhalation anthrax (nasal passages), and intestinal anthrax.

Cutaneous anthrax is the most common form of the disease and occurs when a person comes into contact with an infected animal and the bacterium enters a cut or abrasion on their skin. The skin infection begins as a raised itchy bump resembling an insect bite that develops into a skin bubble within 1 - 2 days and then a painless open sore with a black centre.

Inhalation anthrax occurs when the spores are inhaled through the nasal passages. Initial symptoms may resemble a common cold. After several days, the symptoms may progress to severe breathing problems and shock.

Intestinal anthrax is rare and more difficult to recognize. It is caused by eating contaminated food and results in acute inflammation of the intestinal tract. Symptoms include nausea, loss of appetite, vomiting, and fever followed by abdominal pain, vomiting of blood, and diarrhea.



A person who regularly handles products from infected animals is at a higher risk (i.e. wool, hides tanning/stretching).  A person cannot catch anthrax from someone who is infected with the disease. Therefore, there is no need to treat those around someone ill with anthrax (such as family, friends or co-workers) unless they were also exposed to the same source of the infection.


This page provides basic information only. It must not take the place of medical advice, diagnosis or treatment. Always talk to a health care professional about any health concerns.

Source:  Ontario Ministry of Health and Long-Term Care, Public Health Division.


For Further Information

Call the Infectious Disease Program: (807) 625-5900

or toll-free 1-888-294-6630

Health Topic
Diseases & Infections