Anthrax

What is anthrax?

Anthrax (pronounced “AN-thraks”) is an infectious disease caused by exposure to Bacillus anthracis bacteria. The bacteria are dormant, or inactive, in soil. Disease from anthrax mostly affects animals that graze on land that has the bacteria and is extremely rare in the United States.

People can become infected through inhaled bacteria spores, contaminated food or water, or skin wounds. Antibiotics are the first line of treatment for this potentially deadly infection. There are other treatments, including a vaccine.

Types of anthrax

The types of anthrax reflect the different ways the bacteria enter your body. Anthrax types include:

• Cutaneous (skin): Bacteria infect your body through a wound in your skin. Cutaneous anthrax is the most common and least deadly form. Veterinarians and people who handle animal wool, hides or hair are at the highest risk.
• Gastrointestinal: This type affects people who eat undercooked or raw meat from an infected animal. The bacteria affect your esophagus, throat, stomach and intestines. Gastrointestinal anthrax is rare in the United States. U.S.-based producers vaccinate livestock against anthrax and identify sick animals before slaughter.
• Inhalation: People who breathe in anthrax spores can develop this deadly form of anthrax. It can cause severe breathing problems and death. Inhalation anthrax is sometimes called woolsorter’s disease because people who work in wool mills — as well as slaughterhouse and tannery workers — may inhale spores from infected animals.
• Injection: People who inject heroin can get injection anthrax. This type is more common in northern Europe and hasn’t been reported in the United States. Injection anthrax causes infection deep under your skin or in muscle.

How common is anthrax?

Anthrax is found all over the world, although the disease is extremely rare in the United States. Disease outbreaks tend to occur in developing countries that don’t vaccinate livestock against the infection. These areas include:

• Caribbean islands.
• Central America.
• Central and Southwest Asia.
• South America.
• Southern and Eastern Europe.
• Sub-Saharan Africa.

Is anthrax a biological weapon?

A bioterrorism anthrax attack using anthrax spores is a possibility. In 2001, a U.S. military researcher mailed envelopes containing anthrax powder to members of Congress and the media. Five of the 22 people who developed cutaneous or inhalation anthrax died. Federal agencies continue to work to prevent future anthrax attacks.

What are the symptoms of anthrax?

Anthrax symptoms vary depending on the type. Symptoms typically appear within one week of exposure. Sometimes, signs of inhalation anthrax aren’t noticeable for two months. Depending on the type, symptoms include:

• Chest pain and trouble breathing.
• Fatigue.
• Fever and profuse sweating.
• Headache or muscle aches.
• Itchy blisters or bumps.
• Skin ulcer (sore) with a black center.
• Nausea and vomiting, abdominal pain and bloody diarrhea.
• Swollen lymph nodes.

What causes anthrax?

Bacillus anthracis bacteria cause anthrax. The bacteria produce spores that can live in the ground for years. Wild animals like deer, and livestock such as cattle or sheep, can inhale or ingest the dormant (inactive) spores while grazing.

After mixing with bodily fluids, anthrax bacteria activate, multiply and spread throughout your body. The bacteria cause a toxic, potentially deadly reaction. The same process happens to people who inhale, ingest or come into skin contact with the spores.

Is anthrax contagious?

Anthrax isn’t contagious like chickenpox or the flu. You can’t catch anthrax from being around someone who’s infected. Rarely, people develop cutaneous anthrax after coming into direct contact with another person’s infected skin lesion.

Who might get anthrax?

Certain people are more at risk for exposure to anthrax, including:

• Farmers and livestock handlers.
• Military members and travelers to countries known to have problems with anthrax.
• Researchers and laboratory workers who study the bacteria.
• Veterinarians who work with infected livestock.
• Wool mill, tannery and slaughterhouse workers.
• Drum makers who use animal hides.
• Heroin users.

What are the complications of anthrax?

Untreated anthrax can be deadly. Complications vary depending on the anthrax type:

• Cutaneous: Almost everyone who gets treated for cutaneous anthrax survives. About 20% of infected people who don’t get treatment die.
• Gastrointestinal: Approximately 60% of treated people survive. Without treatment, more than half of infected people die. Gastrointestinal anthrax can cause deadly brain and spinal cord swelling (meningoencephalitis).
• Inhalation: About 55% of infected people who receive treatment survive. That number drops to about 15% for people who aren’t treated.

How is anthrax diagnosed?

Depending on your symptoms and the anthrax type, your healthcare provider may conduct one or more of these tests:

• Biopsy of skin lesion.
• Blood tests.
• Chest X-ray.
• Computed tomography (CT) scan.
• Lab tests on poop (stool) or mucus.
• Lumbar puncture (spinal tap).

What is the treatment for anthrax?

Most forms of anthrax respond well to treatment. If you think you’ve been exposed, call your healthcare provider immediately. Fast treatment with antibiotics can stop the infection from developing. Anthrax treatments include:

• Antibiotics: Oral, injectable or intravenous (through your vein) antibiotics fight infection. You may need antibiotics for 60 days. Commonly used antibiotics include ciprofloxacin (Cipro®) and doxycycline (Doryx®).
• Antitoxins: These injectable antibody medications neutralize anthrax toxins in your body. Treatment typically includes antibiotics, too.
• Vaccine: A vaccine to prevent anthrax infection, BioThrax®, also treats infected people. Treatment involves three doses of the vaccine over four weeks. You’ll receive antibiotics at the same time.

How can I prevent anthrax?

The anthrax vaccine is 90% effective at preventing infection. The vaccine is only available to people between the ages of 18 and 65 who work in high-risk professions, such as farmers and livestock handlers, military members, researchers who study the bacteria, veterinarians and others as listed above. You receive five doses of the vaccine over 18 months. Afterward, you’ll need an annual booster shot. The vaccine also stops infection if you’ve knowingly been exposed to anthrax. In the United States, livestock that graze in anthrax-prone areas, such as certain parts of Texas, receive a different anthrax vaccine made for animals.

The anthrax vaccine isn’t available to the general public. If you’re traveling to an area known to have anthrax problems, you shouldn’t:

• Eat raw or undercooked meat.
• Handle or buy souvenirs made with animal hide or hair.
• Pet or touch animals.

What is the outlook (prognosis) for people with anthrax?

If you think you’ve been exposed to anthrax, call your healthcare provider to start antibiotics or other therapies immediately. Untreated anthrax can be deadly. Fast treatment can prevent severe infection and life-threatening symptoms, improving your odds of a full recovery.

When should I see my healthcare provider?

You should call your healthcare provider if you suspect you’ve been exposed to anthrax and you experience:

• Blood in respiratory secretions (coughing up blood).
• Blood in vomit or stool.
• Chest pain.
• Difficulty breathing.
• Diarrhea.
• Fever.
• Severe abdominal pain.

What questions should I ask my healthcare provider?

If you have anthrax, you may want to ask your healthcare provider:

• How did I get anthrax?
• What type of anthrax do I have?
• What’s the best treatment for me?
• Can I get the anthrax vaccine?
• What steps can I take to prevent getting anthrax again?
• Are my family members at risk for anthrax exposure?
• Should I look out for signs of complications?

A note from Cleveland Clinic

A diagnosis of anthrax is rare in the United States. People who work in certain professions or who travel to developing countries are more likely to be exposed to the bacteria that cause anthrax. If you work in a high-risk field, talk to your healthcare provider about getting the anthrax vaccine. Most people infected with anthrax recover after receiving prompt treatment with antibiotics or other therapies. Inhalation anthrax is deadlier and more difficult to treat. For these reasons, inhalation anthrax is considered a potential bioterrorism threat.