How does anthrax invade a host?

Anthrax invades a host either through inhalation of anthrax spores while handling infected animals or animal products such as wool, hides or hair, or when spores gain access into the body through a cut or scrape on the skin from such infected materials

Also eating raw or undercooked meat from infected animals and other spore-contaminated foods and drinks may bring about infection with a form of anthrax called gastrointestinal anthrax.

Once spores get into the body, they are activated and become anthrax bacteria, which multiply, spread in the body and produce toxins that cause severe illness.