Anthrax is an acute infectious disease of animals that can be secondarily transmitted to humans. It is caused by a bacterium ( Bacillus anthracis ) that primarily affects sheep, horses, hogs, cattle, and goats and is almost always fatal in animals. The bacillus produces toxins that kill cells and cause fluid to accumulate in the body's tissues. Anthrax spores, which can survive for decades, are found in the soil, and animals typically contract the disease while grazing. Transmission to humans normally occurs through contact with infected animals but can also occur through eating meat from an infected animal or breathing air laden with the spores of the bacilli. The disease is almost entirely occupational, i.e., restricted to individuals who handle hides of animals (e.g., farmers, butchers, and veterinarians) or sort wool.
Anthrax is a rapidly progressing acute infection caused by spore-forming bacteria called Bacillus anthracis. Anthrax most commonly occurs in warm-blooded animals, especially goats, cattle, and sheep, but it can also infect humans. Anthrax spores can be easily produced in a dry form for biological weapons. Spores can survive many years in adverse conditions and still remain capable of causing disease. When inhaled by humans, these spores cause respiratory failure that can lead to death within a week.
Anthrax can make an excellent weapon of mass destruction. The spores may be used as a weapon in a variety of delivery systems. They can be produced in large quantities without sophisticated equipment. All it takes is a single breath of aerosolized anthrax to inhale enough spores to cause the disease. Then, if serious symptoms occur, it kills 99% of unprotected people. Even if a person with symptoms receives antibiotics, the death rate is still about 50%. Anthrax spores are odorless, colorless, and tasteless.