An infectious bacterial disease, characterized by a high fever, enlarged spleen, swelling of the throat in some animals, exudation of tarry blood, and resulting in death, anthrax may attack all domestic animals and man; it also affects numerous wild animals, and is most common among herbivora. It most commonly affects livestock, although it is occasionally transmitted to humans. It has three forms, affecting the skin (most common), the intestines or the respiratory tract. Anthrax bacteria [Bacillus anthracis] produce spores that are highly resistant to disinfectant and therefore remain viable long after the death of the animal, even adhering to the handicraft goods made from the skins.
Anthrax is a widespread disease, occurring in all parts of the world, but particularly in tropical and sub-tropical areas. In temperate climates, it occurs only spasmodically and affects fewer animals in each outbreak than are affected in the tropics. The disease is most commonly contracted by way of the mouth or alimentary system, and is most often soil-borne (and water-borne). It may be transmitted by birds or flies which have fed on infected animals or on carcasses and which subsequently infect the trees and shrubs which are eaten by herbivores, or (in the case of insects) directly infect by biting; the latter especially affect man. Animals that wallow in mud or dry soil may carry the infected soil from one place to another. Anthrax spores may also be carried by surface drainage or in wind-borne fragments of disintegrated carcasses. Occurrence of anthrax is influenced by climatic and ecological conditions. Rainy weather followed by hot days appears to be most favourable for the disease but it also frequently occurs during hot dry summers, or drought when animals are forced to graze close to the soil. Anthrax spores are very hard to destroy and may remain alive in the soil for 10 years after an outbreak. Worms are thought to contribute in the spread of the disease. It can be contracted sometimes as a result of breathing dust from affected animals (woolsorters' disease).
It was reported in 1997 that Russia developed a new variant of the anthrax toxin that is totally resistant to antibiotics and which could cause a catastrophe if it fell into the wrong hands.