Anthrax

Anthrax [AN-thracks] is a bacterial disease that mainly affects animals. In rare cases, it can spread to people and cause life-threatening illness.
Anthrax is most common in areas where people raise livestock and where public health programs are lax. Animals get anthrax by grazing on soils contaminated with anthrax spores. Anthrax in people is usually the result of a work-related exposure to infected animals or contaminated animal products.
To prevent anthrax, avoid contact with livestock and animal products when in countries where anthrax is common. A vaccination is available for people at high risk for work-related exposures.

What is anthrax?

Anthrax is mainly a disease of animals. In rare cases, it can spread to people and cause life-threatening illness.

What is the infectious agent that causes anthrax?

Anthrax is caused by Bacillus anthracis, a bacterium that lives naturally in certain types of soil. The bacterium produces spores. Spores are hardy forms of the bacterium that can survive in soil or on contaminated objects for years.

Where is anthrax found?

Anthrax is found worldwide but is most common in areas where people raise livestock and where public health programs are lax. Materials contaminated with anthrax spores can reach any country in the world.

How do people get anthrax?

Animals get anthrax by grazing on soils contaminated with anthrax spores. People get anthrax by touching infected animals or animal products, such as wool, hides, leather, or hair products (especially goat hair). The bacteria get into the body through a break in the skin. In rare cases, people can get anthrax by breathing in anthrax spores from contaminated soil or animal products or by eating undercooked meat from infected animals.

What are the signs and symptoms of anthrax?

In the body, anthrax spores produce a powerful toxin (poison) that causes the signs and symptoms of illness. The signs and symptoms vary depending on how a person was infected.

Infection by skin contact: Most cases occur by skin contact. Skin infection begins as a raised itchy bump that looks like an insect bite. Within 1-2 days, it develops into a boil-like sore and then a painless ulcer with a characteristic dark (dying) area in the center. The infection can also cause swelling of the lymph glands near the site. About 20% of untreated cases will result in death. With proper treatment, deaths from this type of anthrax are rare.

Infection by inhalation: People who get anthrax by breathing in spores have symptoms that are like a common cold. After several days, the symptoms can progress to severe breathing problems and shock. This type of anthrax usually results in death in 1-2 days after the start of severe symptoms.

Infection by ingestion: Intestinal infections from eating contaminated meat are rare. The infection causes severe inflammation of the intestinal tract. The first signs are nausea, loss of appetite, vomiting, and fever, followed by abdominal pain, vomiting of blood, and severe diarrhea. Intestinal anthrax results in death in 25% to 60% of cases.

How soon after exposure do symptoms appear?

Symptoms usually appear within 7 days.

How is anthrax diagnosed?

Anthrax is usually diagnosed by isolating the bacterium from the blood, skin lesions, or respiratory discharges.

Who is at risk for anthrax?

When anthrax affects humans, it is usually due to a work-related exposure to infected animals or their products. Workers who are exposed to dead animals and animal products from countries where anthrax is common can become infected.

There is little risk to most U.S. travelers to other countries. The greatest risk comes from handling rugs and handicrafts made from goat skin or goat hair. Spores can live indefinitely in wool, blankets, and other animal products.

What is the treatment for anthrax?

People with anthrax should be treated promptly with antibiotics. To be effective, treatment should be started early. If left untreated, the disease can be fatal.

How common is anthrax?

Anthrax is most common in animals in agricultural regions of the world. Anthrax is rare in humans. An estimated 20,000 to 100,000 cases occur yearly worldwide, mostly in developing countries. Anthrax is very rare in the United States and in other countries where animals are inspected before and after slaughter. Anthrax is also rare in U.S. travelers, although certain handicrafts might be contaminated and should be avoided.

Is anthrax a new or emerging infectious disease?

Because of the wide use of animal anthrax vaccines, anthrax is only a minor health problem around the world. However, lapses in local control programs can have serious consequences. Almost 10,000 cases were reported in an outbreak in Zimbabwe in the late 1970s. Hundreds of cases occur each year in several African countries.

How can anthrax be prevented?

When traveling to countries where anthrax is common and vaccination levels of animal herds are low, avoid contact with livestock and animal products. Avoid eating meat that has not been properly slaughtered and cooked. Do not buy items made of goat hair or goat skin.

An anthrax vaccine has been licensed for use in humans. The vaccine is reported to be 93% effective in protecting against anthrax infection from skin contact. The vaccine is currently approved only for healthy men and women ages 18-65 years. Pregnant women should not be vaccinated.

Vaccination is recommended for:

Persons whose work can expose them to imported animal hides, furs, bonemeal, wool, animal hair (especially goat hair), and bristles
Persons whose work in diagnosing or investigating anthrax cases might bring them into contact with anthrax spores
Note: Because anthrax is considered to be a potential agent for use in biological warfare, the Department of Defense is implementing systematic anthrax vaccination of all U.S. military personnel beginning in Summer 1998. Military personnel should contact their chain of command with questions about the vaccine and its distribution.

Where can I find more information about anthrax?

Agencies

CDC, NCID, Division of Bacterial and Mycotic Diseases, Meningitis and Special Pathogens Branch

Websites

http://www.cdc.gov/ncidod/dbmd/anthrax.htm

Information regarding anthrax and the recent bioterrorism activities is available at:

http://www.bt.cdc.gov/

This fact sheet is for information only and is not meant to be used for self-diagnosis or as a substitute for consultation with a health-care provider. If you have any questions about the disease described above, consult a health-care provider.