Diseases : 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 seven 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 one to two 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 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.


Giving preventative antibiotics to a person exposed to anthrax may prevent infection. Early antibiotic treatment (within 24 hours) is essential since any delay lessens the chance for survival. The decision to offer preventative antibiotics to those persons exposed is dependent upon the level of exposure.

An anthrax vaccine may also prevent anthrax disease. However, Health Canada advises that there is no need to vaccinate anyone who has not been exposed to the disease.

Further Information

Anyone with concerns should consult their physician or their local public health unit.


The information provided is subject to change. The information was collated from the following three sources :

1. Chin, J. "Control of Communicable Diseases Manual". 17th Edition. 2000. American Public Health Association: Washington D.C.
2. Health Canada website
3. Centers for Disease Control and Prevention website

*Advice on the most up-to-date treatment should be sought from a clinical expert.

January 2003

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