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Facts About Anthrax

Facts About Anthrax
Facts About Anthrax


Duke Health News Duke Health News

Anthrax is an infectious disease caused by the bacterium Bacillus anthracis. It most commonly occurs in animals including cattle, goats, sheep and antelopes. Humans who are exposed to infected animals or infected animal tissue can also develop anthrax.

There are three modes of anthrax transmission: inhalation, gastrointestinal and cutaneous. Humans can acquire anthrax by inhaling anthrax spores from contaminated animal products, by eating undercooked meat from infected animals, or by handling products derived from infected animals. It is extremely unlikely that cutaneous anthrax would spread between humans and inhalational and gastrointestinal anthrax have never been spread between humans.

Symptoms of anthrax usually occur within seven days of transmission, and vary depending on the mode of transmission.

Symptoms of inhalation anthrax generally resemble the flu. However, these symptoms may progress to cause shock and severe breathing problems. Inhalation anthrax usually leads to death.

Gastrointestinal anthrax results primarily from consumption of contaminated meat. Initial symptoms include vomiting, loss of appetite, nausea and fever followed by fever, vomiting of blood, abdominal pain, and severe diarrhea. Death occurs in 25 percent to 60 percent of intestinal anthrax cases.

Cutaneous transmission accounts for approximately 95 percent of anthrax infections and occurs when the anthrax bacterium enters a wound or abrasion on the skin. The infection initially resembles an insect bite (a raised itchy bump) and within one to two days develops into a vesicle and then a painless, black ulcer. Swelling of the lymph glands may also occur. Untreated, approximately 20 percent of cutaneous anthrax cases will lead to death. When treated with the appropriate antimicrobial therapy, deaths from this form of anthrax are rare.

Antibiotics can be effective in treating anthrax if treatment is begun in a timely manner. Anthrax can be fatal if untreated.

It is possible to immunize humans against anthrax through a series of injections. The Centers for Disease Control Advisory Committee on Immunization Practices recommends anthrax vaccination for people who work with anthrax in a laboratory, people who work with imported animal hides or furs that may contain anthrax, people who handle potentially infected animal products and military personnel working in areas with elevated risk for exposure to anthrax in the form of biological weapons.

Prophylactic antibiotics and vaccinations are recommended only for people who have been exposed to anthrax bacteria. However, there is no reason to use antibiotics or other treatments in people who have not been exposed to the bacteria. Anthrax patients cannot pass the bacteria to other people. It is not recommended that the general public be immunized against anthrax. The CDC also discourages the purchase of unnecessary medications or gas masks.

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