Anthrax is an acute infectious disease caused by a bacterium called Bacillus anthracis. The bacteria form spores than can stay viable in the soil for perhaps hundreds of years. The bacterium may infect humans and animals. In humans, anthrax can cause infection in three body systems:
Anthrax infection in humans is rare in Canada. The latest BC case was seen in 2001. More recently, two people were infected in 2006 in Saskatchewan during an outbreak among animals (mainly cattle). All these people developed skin infections and recovered. Human cases of digestive and lung anthrax have never been reported in Canada.
Anthrax does not spread from person-to-person. It can spread in one of these ways:
- From infected animals or animal products.
- Humans can become infected with skin anthrax by handling products such as animal hides from infected animals.
- Digestive infections occur by eating undercooked meat from infected animals.
- Lung anthrax has been reported in factories where people breathe in spores from contaminated animal skins or wool.
Anthrax is most common in herbivores such as cattle, sheep, goats, and horses. These animals, when grazing, ingest anthrax spores that live in the soil and have recently been brought to the surface due to warm temperatures and/or heavy rainfall. Animals may also become infected by eating anthrax-contaminated feed. Anthrax outbreaks in animals occur worldwide.
In Canada, outbreaks have been reported in cattle in the western prairie provinces and in the free-ranging bison of the Northwest Territories.
Anthrax was deliberately prepared in a concentrated powder form and spread through the postal system in the United States in 2001 causing 22 cases of anthrax infection of the lungs and skin. To date, anthrax has not been used as a weapon in Canada.
Diagnosis of anthrax can be done in a number of ways, including:
- microscopic analysis of specimens
- culturing of specimens
- PCR testing
- ELISA testing of antibodies (Heymann 2008)
