Anthrax is a serious illness caused by a microbe that lives in soil, called Bacillus anthracis. It became famous in 2001 when anthrax was used as a biological weapon and sent in the United States mail. The anthrax attack resulted in five deaths and 17 illnesses, making it one of the worst biological attacks in the U.S. But anthrax is uncommon in the United States.

What Causes Anthrax?

Anthrax illness is more common in farm animals than people. You can get anthrax through indirect or direct contact by inhaling, touching, or ingesting Bacillus anthracis. You can come into contact with anthrax in two ways:


You can get anthrax by touching farm animals or game animals infected with anthrax. You can also become infected by inhaling it. In addition, you can get anthrax by eating undercooked meat from animals infected with anthrax.

Biological Weapon

Anthrax can be used as a biological weapon. However, this is very rare—there has not been an anthrax attack in the United States since the 2001 attack.

Who Is at Risk for Anthrax?

You have an increased risk of getting anthrax if you:

  • work with anthrax in a laboratory
  • work with livestock as a veterinarian (not likely in the U.S.)
  • handle animal skins from areas with a high risk of anthrax (not in the U.S.)
  • handle game animals
  • are in the military on duty in an area that carries a high risk of anthrax exposure

What Are the Symptoms of Anthrax?

Symptoms of anthrax exposure depend on the mode of contact. Symptoms include:

Cutaneous (Skin Contact)

If you get anthrax through the skin, you may get a small, raised sore that is itchy. It usually looks like an insect bite. The sore quickly develops into a blister. It then becomes a skin ulcer with a black center. Neither the sore, blister, or ulcer cause pain. Cutaneous anthrax symptoms usually develop within one to five days of exposure.

Gastrointestinal (Ingestion)

Symptoms of gastrointestinal anthrax usually develop within a week of exposure. Symptoms of anthrax ingestion include:

  • nausea
  • loss of appetite
  • fever
  • swelling in the neck
  • bloody diarrhea
  • severe abdominal pain


Symptoms of inhalation anthrax may develop in two to 45 days of exposure, but usually develop within a week. Symptoms of inhaling anthrax include:

  • cold and flu symptoms
  • sore throat
  • fever
  • achy muscles
  • cough
  • shortness of breath
  • fatigue
  • shaking
  • chills
  • vomiting

How Is Anthrax Diagnosed?

Tests to diagnose anthrax include:

  • blood tests
  • skin tests
  • stool samples
  • spinal tap (a procedure that tests a small amount of the fluid that surrounds the brain and spinal cord)
  • chest X-ray
  • CT (computed tomography) scan
  • endoscopy (a test that uses a small tube with an attached camera to examine the esophagus or intestines)

If your doctor detects anthrax in your body, the test results will be sent to a public health laboratory for confirmation.

How Is Anthrax Treated?

Treatment for anthrax depends on whether you have symptoms. Treatments include:

Preventive Treatment After Exposure (No Symptoms)

If you are exposed to anthrax, but have no symptoms, your doctor may give you preventive treatment. Preventive treatment consists of antibiotics and the anthrax vaccine.

Treatment for Anthrax After Exposure (With Symptoms)

Anthrax is treated with antibiotics for 60 days.

What Is The Long-Term Outlook?

Anthrax is treatable with antibiotics if caught early. The problem is that many people do not seek treatment until it is too late to treat. Without treatment, the chances of death from anthrax go up. Untreated, your odds for dying of cutaneous anthrax are 20 percent. If you have gastrointestinal anthrax, your chances are 50 percent. The odds of dying from inhaling anthrax are extremely high.

How Can I Prevent Anthrax?

You can reduce your risk of anthrax by doing the following:

Avoid Infected Animals and Animal Products

You should avoid contact with animals and animal products in countries with a high rate of anthrax, or countries that do not routinely vaccinate farm and herd animals for anthrax. You should also avoid eating meat in these countries.

Anthrax Vaccine

The only FDA-approved anthrax vaccine is the BioThrax™ vaccine. It is available to the general public. The anthrax vaccine is given to people who work in situations that put them at high risk of contact with anthrax, such as military personnel and scientists. The U.S. government has a stockpile of anthrax vaccine in case of a biological attack or other type of exposure. The anthrax vaccine is 91 percent effective in humans after two vaccinations.