Anthrax is an acute infectious disease caused by the spore-forming bacterium Bacillus anthracis. Anthrax most commonly occurs in hoofed mammals and can also infect humans. Symptoms of the disease vary depending on how the disease was contracted, but usually occur within 7 days after exposure. The serious forms of human anthrax are inhalation anthrax, intestinal anthrax, and cutaneous anthrax.

Initial symptoms of inhalation anthrax infection may resemble a common cold. After several days, the symptoms may progress to severe breathing problems and shock. Inhalation anthrax is often fatal.

The intestinal disease form of anthrax may follow the consumption of contaminated food and is characterized by an acute inflammation of the intestinal tract. Initial signs of nausea, loss of appetite, vomiting, and fever are followed by abdominal pain, vomiting of blood, and severe diarrhea.

Direct person-to-person spread of anthrax is extremely unlikely. Therefore, there is no need to immunize or treat contacts of persons ill with anthrax, such as household contacts, friends, or coworkers, unless they were also exposed to the same source of infection. In persons exposed to anthrax, infection can be prevented with antibiotic treatment. Early antibiotic treatment of anthrax is essential; delay lessens chances for survival. Anthrax is usually susceptible to penicillin, doxycycline, and fluoroquinolones. An anthrax vaccine can also prevent infection. Vaccination against anthrax is not recommended for the general public, however, and is not available.


If vaccine is available, all exposed persons (as determined by local and state health deparment) should be vaccinated with 3 doses of anthrax vaccine over 4 weeks. Start antibiotic prophylaxis immediately after exposure with ciprofloxicin (500mg per 12 hours) or doxycycline (100 mg per 12 hours). If strain is penicillin-susceptible, therapy can be modified to penicillin or amoxicillin. Antibiotic prophylaxis should be continued until 3 doses of vaccine have been administered; if vaccine is unavailable, antibiotics should be continue for 60 days.