Anthrax has been around for tens of thousands of years. Anthrax is a bacterial infection caused by Bacillus anthracis. Anthrax belongs to a group of bacteria that are capable of forming spores. A spore is a very resistant capsule that forms around the anthrax bacteria, similar to a seed. The spore allows anthrax to survive conditions that would normally kill bacteria, such as a low-nutrient environment, and extreme temperatures.

This ability to form spores is now being exploited by terrorists who have mixed anthrax spores in a very fine powder in order to spread anthrax through the air. If enough spores are inhaled from floating anthrax powder an infection can occur. When conditions are right, such as a moist environment with lots of nutrients (as is found in the human body), the anthrax bacteria will be triggered to multiply and an anthrax infection occurs. The anthrax bacterium releases deadly toxins that contribute to severe symptoms and death.

Anthrax is not transmitted by person-to-person contact, that is, it is not contagious. There are several forms of anthrax infections including skin (cutaneous), intestinal and inhalation (the most serious). Skin anthrax is the most common form of anthrax and occurs in people who have had contact with anthrax spores through a cut or scrape in the skin (either through handling animals or animal products that are contaminated with anthrax or by handling materials that have been intentionally contaminated). Intestinal anthrax occurs in people who have eaten improperly cooked meat from an animal that has been infected with anthrax. It is quite rare for meat to be contaminated with the bacteria that causes anthrax in North America. Therefore, intestinal anthrax is very rare on this continent. The most serious form of anthrax is inhalation anthrax, which occurs when anthrax spores are inhaled. Inhaled anthrax often causes death if not treated in the early stages. Therefore, it is very important to recognize the symptoms of this infection and seek immediate medical attention if they occur.

Anthrax obtained from natural sources is very rare. However, anthrax can be produced in laboratories and may be used as an agent of biological warfare. Anthrax, if used in this manner, can cause serious disease if the spores are inhaled.