Anthrax is a severe bacterial infection caused by the bacterium Bacillus anthracis, predominantly affecting animals such as cattle, sheep, horses, mules, and certain wildlife. While humans and pigs generally show significant resistance to the disease, human infection can occur if spores of B. anthracis enter the body through contact with infected animals or contaminated animal products, insect bites, ingestion, or inhalation. These spores, when aerosolized, can be used for biological warfare and bioterrorism.The most prevalent form of anthrax in humans is cutaneous anthrax, which presents as a localized skin infection with a central black ulcer surrounded by significant swelling. Inhalation anthrax, also known as woolsorters' disease, involves severe bleeding into the chest, rapidly evolving into a systemic infection with a high mortality rate. Gastrointestinal anthrax is less common but similarly deadly.Anthrax manifests in various forms. The pulmonary form occurs when a large quantity of anthrax spores is inhaled, often in enclosed spaces shielded from sunlight, which quickly kills the spores. If left untreated, pulmonary anthrax is usually fatal. The intestinal variant results from consuming meat tainted with anthrax. However, most human anthrax cases arise from skin contact with contaminated animal products. Historically, cutaneous anthrax was prevalent among those handling infected animals, such as farmers, woolsorters, tanners, brushmakers, and carpetmakers.The characteristic sign of skin anthrax is a carbuncle, a cluster of boils that ulcerates. Typically, this lesion has a hard, black center, surrounded by red inflammation, resembling a burning coal, which is the origin of the name "anthrax," derived from the Greek word for coal. Cutaneous anthrax is treated with antibiotics like ciprofloxacin (Cipro). Pulmonary anthrax requires immediate intravenous antibiotics, such as penicillin combined with streptomycin.A vaccine exists for those at high risk, including military personnel, but the only anthrax vaccine produced in the USA currently faces production standardization challenges.Regarding bioterrorism, the US General Accounting Office (GAO) noted in 1999 that while anthrax was a "possible" biological threat, acquiring a virulent strain and deploying it effectively would be challenging. However, anthrax became a definitive bioterrorism agent in the autumn of 2001 when it was distributed through the US mail, marking its emergence as a significant 21st-century threat.
