Cause of Anthrax
When a person becomes infected with anthrax, the disease is caused by a bacterium known as Bacillus anthracis. The type of anthrax a person develops depends on how the bacteria enter the body. For example, gastrointestinal anthrax is caused by eating meat contaminated with anthrax bacteria or their spores. Cutaneous anthrax infections occur when the anthrax bacteria enter a cut or abrasion on the skin. Inhalation anthrax occurs by breathing in the anthrax bacteria or spores.
The cause of anthrax is the bacterium known as Bacillus anthracis. This type of bacteria can cause an anthrax infection:
- On the skin (known as cutaneous anthrax)
- In the lungs (known as inhalation or pulmonary anthrax)
- With the intestines (known as gastrointestinal anthrax).
Bacillus anthracis is a bacterium that lives in soil. The anthrax bacterium is different from many other bacteria because it can form spores, a survival tactic that has allowed it to survive for extended periods under the harshest of conditions. A Bacillus anthracis spore is very hardy; it is able to withstand extreme heat, cold, and drought without nutrients or air. When environmental conditions are favorable, the spores will germinate into thriving colonies of bacteria. For example, a grazing animal may ingest spores that begin to grow, spread, and eventually kill the animal. The bacteria will form spores in the carcass and then return to the soil to infect other animals in the future. Bacillus anthracis is an aerobic bacterium, meaning that it needs oxygen to survive and grow.
As mentioned above, regardless of the type, the cause of anthrax is Bacillus anthracis. However, how the anthrax bacteria enter the body will determine the type of anthrax.
Cutaneous anthrax infections occur when the anthrax bacteria enter a cut or abrasion on the skin. This may occur when a person handles contaminated wool, hides, leather, or hair products (especially goat hair) of infected animals.
Inhalation anthrax is caused by breathing in the anthrax bacteria or spores.
Gastrointestinal anthrax is caused by eating meat contaminated with anthrax bacteria or their spores.