Anthrax is an infectious disease caused by bacteria called Bacillus anthracis. Infection in humans most often involves the skin, the gastrointestinal tract, or the lungs.

See also:

• Cutaneous anthrax
• Inhalation anthrax

Wool sorter's disease; Ragpicker's disease

Anthrax commonly affects hoofed animals such as sheep and goats, but humans who come into contact with the infected animals can get sick from anthrax, too. In the past, the people who were most at risk for anthrax included farm workers, veterinarians, and tannery and wool workers.

There are three main routes of anthrax infection:

• Cutaneous anthrax occurs when anthrax touches a cut or scrape on the skin.
• Inhalation anthrax develops when anthrax spores enter the lungs.
• Gastrointestinal anthrax occurs when someone eats anthrax-tainted meat. The disease usually develops within one week, and can affect the mouth, esophagus, intestines, and colon. The infection can spread to the bloodstream, and may result in death.

Anthrax may be used as a biological weapon or for bio-terrorism. In 2001, anthrax sent through the U.S. Postal Service infected 22 people; 7 survivors had confirmed cutaneous anthrax disease.

While at least 17 nations are believed to have a biological weapons program, it is unknown how many nations or groups are working with anthrax. Most bio-terrorism experts have concluded that it is difficult to use anthrax effectively as a weapon on a large scale.

• Cutaneous anthrax: Blister or ulcer that later forms a black scab, and is usually surrounded by a lot of swelling
• Inhalation anthrax: Begins with fever, malaise, headache, cough, shortness of breath, and chest pain; shock may occur in the second stage
• Gastrointestinal anthrax: Nausea and vomiting (the vomit may include blood), anorexia, and bloody diarrhea

The tests to diagnose anthrax depend on the type of disease suspected.

• If cutaneous anthrax is suspected, you may have a culture of the skin sore to test for the bacteria that causes anthrax.
• If inhalational anthrax is suspected, you may need a chest x-ray, blood cultures, sputum cultures, spinal tap for CSF culture, or gram stain. Samples may be sent to a special lab for more testing, including PCR, immunofluorescence, and immunohistochemistry.