Anthrax

Overview

What is anthrax?

Anthrax (AN-thraks) is an infectious disease caused by exposure to Bacillus anthracis bacteria. The bacteria are dormant, or inactive, in soil. Anthrax mostly affects animals that graze on land that has the bacteria.

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.

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.
  • Sub-Saharan Africa.

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 types of anthrax?

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

  • Cutaneous (skin): Bacteria infect the body through a wound in the skin. Cutaneous anthrax is the most common and least deadly form. Veterinarians and people who handle animal wool, hides or hair are at highest risk.
  • Gastrointestinal: This type affects people who eat undercooked or raw meat from an infected animal. The bacteria affect the esophagus, throat, stomach and intestines. Gastrointestinal anthrax is rare in the United States. U.S. 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 the skin or in muscle.

Is anthrax a biological weapon?

A bioterrorism attack using anthrax spores is a possibility. In 2001, a U.S. military researcher mailed envelopes containing anthrax spores 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 a future anthrax attack.

Symptoms and Causes

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 the 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.

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:

Is anthrax contagious?

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

Diagnosis and Tests

How is anthrax diagnosed?

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

Management and Treatment

How is anthrax managed or treated?

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 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 the 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.

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.

Prevention

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. 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 should not:

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

Outlook / Prognosis

What is the prognosis (outlook) 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.

Living With

When should I call the doctor about anthrax?

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 doctor?

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 is 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.

Last reviewed by a Cleveland Clinic medical professional on 08/19/2020.

References

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Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy