Bacillus anthracis is a pathogenic bacterium that is responsible for the Anthrax acute disease. The bacteria can form dormant endospores, which can survive for incredibly long periods of time, which can be inhaled or ingested by living animals, which cause the bacteria to reactivate and begin multiplying within the new host. In the wild, anthrax generally infects grazing animals, such as cows, goats and sheep, which inhale or ingest said spores while eating grass near the soil. Consumption of the flesh of an infected animal will spread anthrax, meaning that wild predators of these grazing animals also contract the disease in the wild.
Since 1881, when Louis Pasteur effectively vaccinated anthrax, outbreaks of the bacteria have decreased across the world, assisted by sanitary protocols, such as the sterilization of animal waste materials, and various programs dedicated to the eradication of the anthrax disease. However, the disease still occurs in outbreaks in wild animal populations, generally in developing countries without vaccination or veterinary programs protecting against it.
Anthrax can be produced in vitro in the spore state, resulting in the capacity for it to be produced en masse in a laboratory setting. Because of the hardy nature of the bacteria’s endospores, the anthrax disease can be used as biological weapon, and has a history of use as such. It was used first by Scandinavian freedom fighters against the Imperial Russian Army during its invasion of Finland during the first World War, planned for use in an operation by the British against German livestock during the second World War, and American stockpiles of weaponized anthrax existed until 1972.
The disease of pulmonary anthrax, or anthrax in the lungs, generally manifests first as cold or flu-like symptoms, followed by sudden respiratory collapse. Because of the sudden nature of the symptoms of pulmonary anthrax, doctors have been trained to discern anthrax from other causes of respiratory illness. Anthrax taken into the gastrointestinal tract, usually by eating infected meat is characterized by difficulty digesting and processing food, bloody vomit, severe diarrhea, and loss of appetite. After anthrax enters the bowels, it goes into the bloodstream, replicating itself more rapidly along the way. Historically, mortality rates for pulmonary anthrax are higher than gastrointestinal anthrax, with 92% for the former, and between 25% and 50% for the latter.
The third and final form of anthrax is cutaneous, or anthrax that manifests in the skin. A boil-like skin lesion occurs under a black eschar, or ulcer with a black center. The ulcer is painless, but necrotic and itchy at the site where the anthrax endospores entered the skin. This is caused when the spores of the bacilus anthracis bacteria bypass the outer layer of skin, generally through cuts. This form of anthrax is far less fatal, with an untreated mortality rate of 20%.