Anthrax is caused by contact with Bacillus anthracis bacteria, and it commonly infects hoofed animals, including cows, sheep, and goats. There are three main entry points for humans: through cuts in the skin called cutaneous infections (mostly a problem for veterinarians and others who work with animals); by inhaling the anthrax spores (occurs most frequently when tanning hides or processing wool); or by eating meat contaminated with the bacteria.
A newly discovered way for anthrax to get into the body is through injection. This has been seen in northern Europe, mostly in people injecting heroin. To date, no case of this kind has been reported in the United States.
In 2001, anthrax spores sent through the U.S. Postal Service infected 22 people. Eleven survivors had confirmed cases of inhalational anthrax, and eleven had cutaneous infections.
The symptoms of anthrax vary depending on the way the bacteria were transmitted. Symptoms can take between 1 day and more than 2 months to appear. Symptoms of cutaneous anthrax usually appear 1 to 12 days after exposure. A cluster of itchy blisters or bumps—often found on the face, neck, arms, or hands—appears first, followed by a painless sore with a black center. There may be swelling surrounding the sore. Symptoms of inhalation anthrax include fever and chills, headache, shortness of breath, confusion or dizziness, cough, and chest pain. Symptoms of gastrointestinal anthrax include fever and chills, swelling of neck or neck glands, sore throat, painful swallowing, abdominal pain, bloody diarrhea, and nausea and vomiting. Symptoms of injection anthrax include fever and chills; blisters and bumps, followed by a painless sore with a black center where the anthrax was injected; swelling around the sore; and a deep abscess in the skin or muscle where the drug was injected. Although the symptoms of injection anthrax are similar to those of cutaneous anthrax, injection anthrax can spread throughout the body faster and can be harder to recognize and treat.
Most people with anthrax are treated with one or more antibiotics. Health care professionals will determine the best type of antibiotic to use based on the type of anthrax that has been diagnosed. Sometimes anthrax spores are activated inside the body. In those cases, antitoxins may be used to treat them.
In 2015, a new medication called ANTHRASIL™ was approved by the FDA for patients with inhalation anthrax. The drug contains antibodies that neutralize the effects of toxins produced by anthrax. ANTHRASIL is meant to be used in conjunction with antibiotics.
Clearly, the best way to prevent anthrax is to avoid exposure to the bacteria. If someone is exposed and does not yet have symptoms, preventive antibiotics may be given. A vaccine for anthrax is also available. It is typically given to laboratory or remediation personnel, some people handling animals or animal products, and military personnel at risk for exposure. The vaccine is given in a series of five doses.