anthrax

The Columbia Encyclopedia, 6th ed.
Save to active project

anthrax

anthrax (ăn´thrăks), acute infectious disease of animals that can be secondarily transmitted to humans. It is caused by a bacterium (Bacillus anthracis) that primarily affects sheep, horses, hogs, cattle, and goats and is almost always fatal in animals. The bacillus produces toxins that kill cells and cause fluid to accumulate in the body's tissues.

Anthrax spores, which can survive for decades, are found in the soil, and animals typically contract the disease while grazing. Transmission to humans normally occurs through contact with infected animals but can also occur through eating meat from an infected animal or breathing air laden with the spores of the bacilli. The disease is almost entirely occupational, i.e., restricted to individuals who handle hides of animals (e.g., farmers, butchers, and veterinarians) or sort wool.

In the cutaneous, or skin, form of the disease, which is not usually fatal to humans, the bacillus enters the skin through a scratch, cut, or sore. Pustules occur on the hands, face, and neck; if the disease is not treated with antibiotics, the bacteria can migrate to the blood vessels, causing septicemia (blood poisoning) and death. Gastrointestinal anthrax is more likely to be fatal. Nausea, vomiting, and fever can be followed by abdominal bleeding, tissue death, and septicemia. Pulmonary, or inhalation, anthrax begins with flulike symptoms and ultimately causes lesions in the lungs and brain. It is rarer, but is usually fatal if not treated early. Because of this, individuals without symptoms who have been exposed to inhaled anthrax are treated with antibiotics for 60 days.

Anthrax is a well-known, ancient disease; the fifth plague visited upon the Egyptians in Genesis (see plagues of Egypt) resembles the disease. Pure cultures of the anthrax bacillus were obtained in 1876 by Robert Koch, who demonstrated the relationship of the microbe to the disease. Confirmation of the bacillus as the cause of anthrax was provided by Louis Pasteur, who also developed a method of vaccinating sheep and cattle against the disease. Anthrax is now uncommon in the United States because of widespread vaccination of animals and disinfection of animal products such as hides and wool.

Anthrax spores have been used experimentally by various nations as a biological warfare agent, but effective delivery of anthrax to a population is difficult, and such use is now banned by international convention. Because anthrax has been tested as a biological weapon, the United States has developed a vaccine for military use, but it requires several injections and annual boosters. An accidental release of anthrax from a military laboratory near Sverdlovsk (now Yekaterinburg) in the Soviet Union resulted in 68 deaths from pulmonary anthrax in 1979. In 2001 a number of people in the United States were exposed to spores that were sent through the mails and contracted anthrax; several persons died. Although these bioterror attacks occurred shortly after the terrorist attacks on the World Trade Center and the Pentagon, it did not appear to be linked to them.

S. D. Jones, Death in a Small Package (2010).

Notes for this article

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
Loading One moment ...
Project items
Notes
Cite this article

Cited article

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

Cited article

anthrax
Settings

Settings

Typeface
Text size Smaller Larger
Search within

Search within this article

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

While we understand printed pages are helpful to our users, this limitation is necessary to help protect our publishers' copyrighted material and prevent its unlawful distribution. We are sorry for any inconvenience.
Full screen

matching results for page

Cited passage

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

Cited passage

Welcome to the new Questia Reader

The Questia Reader has been updated to provide you with an even better online reading experience.  It is now 100% Responsive, which means you can read our books and articles on any sized device you wish.  All of your favorite tools like notes, highlights, and citations are still here, but the way you select text has been updated to be easier to use, especially on touchscreen devices.  Here's how:

1. Click or tap the first word you want to select.
2. Click or tap the last word you want to select.

OK, got it!

Thanks for trying Questia!

Please continue trying out our research tools, but please note, full functionality is available only to our active members.

Your work will be lost once you leave this Web page.

For full access in an ad-free environment, sign up now for a FREE, 1-day trial.

Already a member? Log in now.

Are you sure you want to delete this highlight?