What is Anthrax?

Anthrax is an acute infectious disease caused by the spore-forming bacterium Bacillus anthracis. Anthrax most commonly occurs in warm blooded animals, but can also infect humans. Anthrax is most common in agricultural regions where it occurs in animals. These include South and Central America, Southern and Eastern Europe, Asia, Africa, the Caribbean, and the Middle East.

Who gets Anthrax?

When anthrax affects humans, it is usually due to an occupational exposure to infected animals or their products. Workers who are exposed to dead animals and animal products (industrial anthrax) from other countries where anthrax is more common may become infected with Bacillus anthracis. Anthrax in animals rarely occurs in the United States. Most reports of animal infection are received from Texas, Louisiana, Mississippi, Oklahoma and South Dakota.

How is Anthrax spread?

Anthrax infection can occur in three forms: cutaneous (skin), inhalation, and gastrointestinal. Bacillus anthracis spores can live in the soil for many years and humans can become infected with anthrax by handling animal products from infected animals or by inhaling anthrax spores from contaminated animal products. Anthrax can also be spread by eating undercooked meat from infected animals. It is rare to find infected animals in the United States.

What are the symptoms of Anthrax?

Symptoms of disease vary depending on how the disease was contracted, but symptoms usually occur within seven days. Cutaneous: Most anthrax infections occur when the bacterium enters a cut or abrasion on the skin, such as when handling contaminated wool, hides, leather or hair products (especially goat hair) of infected animals. Skin infection begins as a raised itchy bump that resembles an insectbite but within 1-2 days develops into a vesicle and then a painless ulcer, usually 1-3 cm in diameter, with a characteristic black necrotic (dying) area in the center. Lymph glands in the adjacent area may swell. About 20% of untreated cases of cutaneous anthrax will result in death. Deaths are rare with appropriate antimicrobial therapy. Inhalation: Initial symptoms may resemble a common cold. After several days, the symptoms may progress to severe breathing problems and shock. Inhalation anthrax usually results in death in 1-2 days after onset of the acute symptoms. Intestinal: The intestinal disease form of anthrax may follow the consumption of contaminated meat and is characterized by an acute inflammation of the intestinal tract. Initial signs of nausea, loss of appetite, vomiting, fever are followed by abdominal pain, vomiting of blood, and severe diarrhea. Intestinal anthrax results in death in 25% to 60% of cases.

How soon do symptoms occur?

Symptoms of anthrax usually appear within 7 days after coming into contact with Bacillus anthracis bacteria.

How is Anthrax diagnosed?

Anthrax is diagnosed by isolating Bacillus anthracis from the blood, skin lesions, or respiratory secretions or by measuring specific antibodies to Bacillus anthracis in the blood of suspected cases.

What is the treatment for Anthrax?

Doctors can prescribe effective antibiotics. Usually penicillin is preferred, but erythromycin, tetracycline, or chloramphenicol can also be used. To be effective, treatment should be initiated early. If left untreated, the disease can be fatal.

How long is an infected person infectious to others?

Direct person-to-person spread of anthrax most likely does not occur.

Should an infected person be excluded from work or school?

Since direct person-to-person spread of anthrax most likely does not occur, an infected person need not be excluded from work or school.

How can Anthrax be prevented?

An anthrax vaccine for use in humans is available in the United States. It is indicated for individuals who come in contact in the workplace with imported animal hides, furs, bonemeal, wool, animal hair (especially goat hair), and bristles; and for individuals engaged in diagnostic or investigational activities which may bring them into contact with anthrax spores.

More about Anthrax

• Surveillance Case Definitions