About Anthrax

Key points

  • Anthrax can cause severe illness in both people and animals.
  • The bacteria that causes anthrax occurs naturally in soil worldwide.
  • People usually get anthrax from infected animals or contaminated animal products.
  • Call a healthcare provider immediately if you think you have been exposed to anthrax.
Illustration of how a dormant anthrax spore becomes active after entering a body, in this case a cow eating grass

Overview

Anthrax is a serious disease usually caused by Bacillus anthracis bacteria. It's found naturally in soil around the world and commonly affects livestock and wild animals. People usually get sick with anthrax if they come in contact with infected animals or contaminated animal products. People can breathe in anthrax spores, eat food or drink water contaminated with spores, or get spores in a cut or scrape in the skin.

Livestock and wild animals can become infected when they breathe in, eat, or drink spores in contaminated soil, plants, or water. These animals can include cattle, sheep, goats, antelope, and deer.

Anthrax is rare in the United States. However, occasional outbreaks do happen in wild and domestic grazing animals such as cattle or deer. In the United States, veterinarians recommend yearly vaccination of livestock in areas where animals have had anthrax in the past.

Most people will never be exposed to anthrax. However, there are jobs, hobbies, and activities that can put some people at higher risk of exposure.

Anthrax risk and prevention‎

Learn more about who's at risk of exposure and how to prevent anthrax.

Types

The type of illness a person develops depends on how anthrax enters the body: through the skin, lungs, or gastrointestinal system. All types of anthrax can cause death if they're not treated with antibiotics.

There are four types of anthrax:

Cutaneous anthrax happens when anthrax spores get into a cut or scape on the skin when a person handles infected animals or contaminated animal products like wool, hides, or hair. It mostly shows up on the head, neck, forearms, and hands. It's the most common form of anthrax infection, and it's also considered to be the least dangerous.

Recently, injection anthrax was identified in heroin-injecting drug users in northern Europe, but it hasn't been reported in the United States. Injection anthrax is similar to cutaneous anthrax and causes infection deep under the skin or in the muscle where the drug was injected.

Illustration of anthrax spores getting into a cut on the skin, causing cutaneous anthrax where it enters
Anthrax spores getting into a cut on the skin, causing cutaneous anthrax where it enters

Inhalation anthrax happens when a person breathes in anthrax spores. It's the deadliest form of the disease. People who work in places such as wool mills, slaughterhouses, and tanneries may breathe in the spores when working with infected animals or contaminated animal products. Inhalation anthrax starts primarily in the lymph nodes in the chest before spreading throughout the rest of the body.

Illustration of how anthrax spores are breathed into lungs, causing inhalation anthrax
Inhalation anthrax happens when people breathe in spores.

Gastrointestinal anthrax happens when a person eats raw or undercooked meat from an infected animal. It has rarely been reported in the United States. It affects the upper gastrointestinal tract (throat and esophagus), stomach, and intestines, causing a wide variety of symptoms.

Illustration of how gastrointestinal anthrax occurs through eating raw or undercooked meat from an infected animal.
Gastrointestinal anthrax occurs when a person consumes raw or undercooked meat from an infected animal.

New disease caused by anthrax toxin‎

Welder's anthrax is a newly identified and rare disease that has been found in several people who are welders or metalworkers. This disease causes severe pneumonia and can be fatal. If you are a welder or metalworker and you develop fever and chills with sudden cough, chest pain, difficulty breathing, or coughing up blood, see a healthcare provider immediately.

Symptoms

The symptoms of anthrax depend on the type of infection. Symptoms show up anywhere from 1 day to more than 2 months after you're exposed to the bacteria that cause anthrax. If you don't get proper treatment, all types of anthrax have the potential to spread through your body and cause severe illness and death.

Cutaneous anthrax

Photo of cutaneous anthrax infection on a person's hand showing the telltale black sores of anthrax infection.
Photo of cutaneous anthrax infection on a person's hand

Symptoms include:

  • Group of itchy, small blisters or bumps
  • Large amount of swelling around the sore
  • Painless sore commonly on the face, neck, arms, or hand that has a black center
    • Sore appears after the bumps have gone down
  • For injection anthrax, infected sores (abscesses) deep under the skin or muscle at the injection site

Inhalation anthrax

This posteroanterior (PA) chest x-ray was taken 4 months after the symptoms of anthrax started in a 46-year-old male.
The chest x-ray of a 46-year-old male four months after the onset of anthrax.

Symptoms include:

  • Fever and chills
  • Heavy sweats
  • Chest pain, cough, or shortness of breath
  • Confusion or dizziness
  • Nausea, vomiting, or stomach pains
  • Headache or body aches
  • Extreme tiredness

Gastrointestinal anthrax

Symptoms include:

  • Fever and chills
  • Swelling of neck or neck glands
  • Sore throat, hoarseness, and pain when swallowing
  • Nausea and vomiting, especially bloody vomiting
  • Diarrhea or bloody diarrhea
  • Headache
  • Red face and red eyes
  • Stomach pain and swelling
  • Fainting

If you've been exposed to anthrax

See a healthcare provider immediately and explain how you may have been exposed. It's important to get medical care as quickly as possible to have the best chances for a full recovery. Doctors can prescribe antibiotics to prevent you from getting sick, or as treatment if you're already sick.

There is no test to find out if you have been exposed to anthrax. Public health departments will have to do an investigation to see if and how you were exposed.