What is anthrax?

Anthrax (AN-thraks) is an infectious disease caused by exposure to Bacillus anthracis bacteria. The bacteria are dormant, or inactive, in soil. Anthrax mostly affects animals that graze on land that has the bacteria.

People can become infected through inhaled bacteria spores, contaminated food or water, or skin wounds. Antibiotics are the first line of treatment for this potentially deadly infection. There are other treatments, including a vaccine.

How common is anthrax?

Anthrax is found all over the world, although the disease is extremely rare in the United States. Disease outbreaks tend to occur in developing countries that don’t vaccinate livestock against the infection. These areas include:

  • Caribbean islands.
  • Central America.
  • Central and southwest Asia.
  • South America.
  • Sub-Saharan Africa.

Who might get anthrax?

Certain people are more at risk for exposure to anthrax, including:

  • Farmers and livestock handlers.
  • Military members and travelers to countries known to have problems with anthrax.
  • Researchers and laboratory workers who study the bacteria.
  • Veterinarians who work with infected livestock.
  • Wool mill, tannery and slaughterhouse workers.
  • Drum makers who use animal hides.
  • Heroin users.

What are the types of anthrax?

The types of anthrax reflect the different ways the bacteria enter the body. Anthrax types include:

  • Cutaneous (skin): Bacteria infect the body through a wound in the skin. Cutaneous anthrax is the most common and least deadly form. Veterinarians and people who handle animal wool, hides or hair are at highest risk.
  • Gastrointestinal: This type affects people who eat undercooked or raw meat from an infected animal. The bacteria affect the esophagus, throat, stomach and intestines. Gastrointestinal anthrax is rare in the United States. U.S. producers vaccinate livestock against anthrax and identify sick animals before slaughter.
  • Inhalation: People who breathe in anthrax spores can develop this deadly form of anthrax. It can cause severe breathing problems and death. Inhalation anthrax is sometimes called woolsorter’s disease because people who work in wool mills — as well as slaughterhouse and tannery workers — may inhale spores from infected animals.
  • Injection: People who inject heroin can get injection anthrax. This type is more common in northern Europe and hasn’t been reported in the United States. Injection anthrax causes infection deep under the skin or in muscle.

Is anthrax a biological weapon?

A bioterrorism attack using anthrax spores is a possibility. In 2001, a U.S. military researcher mailed envelopes containing anthrax spores to members of Congress and the media. Five of the 22 people who developed cutaneous or inhalation anthrax died. Federal agencies continue to work to prevent a future anthrax attack.

What causes anthrax?

Bacillus anthracis bacteria cause anthrax. The bacteria produce spores that can live in the ground for years. Wild animals like deer, and livestock such as cattle or sheep, can inhale or ingest the dormant (inactive) spores while grazing.

After mixing with bodily fluids, anthrax bacteria activate, multiply and spread throughout the body. The bacteria cause a toxic, potentially deadly reaction. The same process happens to people who inhale, ingest or come into skin contact with the spores.

What are the symptoms of anthrax?

Anthrax symptoms vary depending on the type. Symptoms typically appear within one week of exposure. Sometimes, signs of inhalation anthrax aren’t noticeable for two months. Depending on the type, symptoms include:

Is anthrax contagious?

Anthrax isn’t contagious like chickenpox or the flu. You can’t catch anthrax from being around someone who is infected. Rarely, people develop cutaneous anthrax after coming into direct contact with another person’s infected skin lesion.

Last reviewed by a Cleveland Clinic medical professional on 08/19/2020.


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