Anthrax is a rare but serious illness caused by a spore-forming bacterium, Bacillus anthracis. Anthrax mainly affects livestock and wild game. Humans can become infected through direct or indirect contact with sick animals.
There's no evidence that anthrax is transmitted from person to person, but it's possible that anthrax skin lesions may be contagious through direct contact. Usually, anthrax bacteria enter the body through a wound in the skin. You can also become infected by eating contaminated meat or inhaling the spores.
Signs and symptoms, which depend on how you're infected, can range from skin sores to vomiting to shock. Prompt treatment with antibiotics can cure most anthrax infections. Inhaled anthrax is more difficult to treat and can be fatal.