Anthrax is a disease caused by Bacillus anthracis, a germ that lives in soil. Many people know about it from the 2001 bioterror attacks. In the attacks, someone purposely spread anthrax through the U.S. mail. This killed five people and made 22 sick.

Anthrax is rare. It affects animals such as cattle, sheep, and goats more often than people. People can get anthrax from contact with infected animals, wool, meat, or hides. It can cause three forms of disease in people. They are:

• Cutaneous, which affects the skin. People with cuts or open sores can get it if they touch the bacteria.
• Inhalation, which affects the lungs. You can get this if you breathe in spores of the bacteria.
• Gastrointestinal, which affects the digestive system. You can get it by eating infected meat.

Antibiotics often cure anthrax if it is diagnosed early. But many people don't know they have anthrax until it is too late to treat. A vaccine to prevent anthrax is available for people in the military and others at high risk.

Anthrax is a serious infectious disease caused by gram-positive, rod-shaped bacteria known as Bacillus anthracis. It occurs naturally in soil and commonly affects domestic and wild animals around the world. People can get sick with anthrax if they come in contact with infected animals or contaminated animal products. Anthrax can cause severe illness in both humans and animals.

Anthrax is not contagious, which means you can’t catch it from another person like the cold or flu.

How people get infected with anthrax

People get infected with anthrax when spores get into the body. When anthrax spores get inside the body, they can be “activated.” The bacteria can then multiply, spread out in the body, produce toxins, and cause severe illness.

This can happen when people breathe in spores, eat food or drink water contaminated with spores, or get spores in a cut or scrape in the skin. It is very uncommon for people in the United States to get infected with anthrax.

Certain activities can also increase a person’s chances of getting infected.

How animals get infected with anthrax

Domestic and wild animals can become infected when they breathe in or ingest spores in contaminated soil, plants, or water. These animals can include cattle, sheep, goats, antelope, and deer. In areas where domestic animals have had anthrax in the past, routine vaccination can help prevent outbreaks.

Where anthrax is found

Anthrax is most common in agricultural regions of

• Central and South America,
• sub-Saharan Africa,
• central and southwestern Asia,
• southern and eastern Europe, and
• the Caribbean.

Anthrax is rare in the United States. However, sporadic outbreaks do occur in wild and domestic grazing animals such as cattle or deer. Anthrax is more common in countries that do not have programs that routinely vaccinate animals against anthrax. In the United States, veterinarians recommend yearly vaccination of livestock in areas where animals have had anthrax in the past.

The type of illness a person develops depends on how anthrax enters the body. Typically, anthrax gets into the body through the skin, lungs, or gastrointestinal system. All types of anthrax can eventually spread throughout the body and cause death if they are not treated with antibiotics.

Cutaneous anthrax

Cutaneous anthrax is the most common form of anthrax infection, and it is also considered to be the least dangerous. Infection usually develops from 1 to 7 days after exposure.

When anthrax spores get into the skin, usually through a cut or scrape, a person can develop cutaneous anthrax. This can happen when a person handles infected animals or contaminated animal products like wool, hides, or hair. Cutaneous anthrax is most common on the head, neck, forearms, and hands. It affects the skin and tissue around the site of infection.

Without treatment, up to 20% of people with cutaneous anthrax die. However, with proper treatment, almost all patients with cutaneous anthrax survive.

Inhalation anthrax

Inhalation anthrax is considered to be the most deadly form of anthrax. Infection usually develops within a week after exposure, but it can take up to 2 months.

When a person breathes in anthrax spores, they can develop inhalation anthrax. 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 from infected animals. Inhalation anthrax starts primarily in the lymph nodes in the chest before spreading throughout the rest of the body, ultimately causing severe breathing problems and shock.

Without treatment, inhalation anthrax is almost always fatal. However, with aggressive treatment, about 55% of patients survive.

Gastrointestinal anthrax

Gastrointestinal anthrax has rarely been reported in the United States. Infection usually develops from 1 to 7 days after exposure.

When a person eats raw or undercooked meat from an animal infected with anthrax, they can develop gastrointestinal anthrax. Once ingested, anthrax spores can affect the upper gastrointestinal tract (throat and esophagus), stomach, and intestines, causing a wide variety of symptoms.

Without treatment, more than half of patients with gastrointestinal anthrax die. However, with proper treatment, 60% of patients survive.

Injection anthrax

This type of infection has never been reported in the United States.

Recently, another type of anthrax infection has been identified in heroin-injecting drug users in northern Europe.

Symptoms may be similar to those of cutaneous anthrax, but there may be infection deep under the skin or in the muscle where the drug was injected. Injection anthrax can spread throughout the body faster and be harder to recognize and treat. Lots of other more common bacteria can cause skin and injection site infections, so a skin or injection site infection in a drug user does not necessarily mean the person has anthrax.

Throughout history, from biblical times to modern day, many sicknesses have been described with symptoms that resemble anthrax. Although we cannot know for sure whether these earliest reports of illness were, in fact, anthrax, many researchers believe that they were.

Naturally Occurring Anthrax

Anthrax Used as a Biological Weapon

People get infected with anthrax when spores get into the body. When this happens, the spores can be activated and become anthrax bacteria. Then the bacteria can multiply, spread out in the body, produce toxins (poisons), and cause severe illness.

People get anthrax by:

• Breathing in spores,
• Eating food or drinking water that is contaminated with spores, or
• Getting spores in a cut or scrape in the skin.

Anthrax is NOT contagious. You cannot catch anthrax from another person the way you might catch a cold or the flu. In rare cases, person-to-person transmission has been reported with cutaneous anthrax, where discharges from skin lesions might be infectious.

Certain activities can increase the chances of getting anthrax

Working with infected animals or animal products

Most people who get sick from anthrax are exposed while working with infected animals or animal products such as wool, hides, or hair.

Inhalation anthrax can occur when a person inhales spores that are in the air (aerosolized) during the industrial processing of contaminated materials, such as wool, hides, or hair.

Cutaneous anthrax can occur when workers who handle contaminated animal products get spores in a cut or scrape on their skin.

Eating raw or undercooked meat from infected animals

People who eat raw or undercooked meat from infected animals may get sick with gastrointestinal anthrax. This usually occurs in countries where livestock are not routinely vaccinated against anthrax and food animals are not inspected prior to slaughter.

In the United States, gastrointestinal anthrax has rarely been reported. This is because yearly vaccination of livestock is recommended in areas of the United States where animals have had anthrax in the past, and because of the examination of all food animals, which ensures that they are healthy at the time of slaughter.

A newly discovered type of anthrax is injection anthrax. This type of anthrax has been seen in northern Europe in people injecting heroin. So far, no cases of injection anthrax have been reported in the United States.

Most people will never be exposed to anthrax. However, there are activities that can put some people at greater risk of exposure than others.

Anthrax is not contagious, which means you can’t catch it from another person like the cold or flu.

Laboratory professionals

Laboratory workers who handle anthrax may be at risk for being exposed if proper safety precautions aren’t followed.

People who handle animal products

Although rare, people can get anthrax after having contact with infected animals or their products, such as wool, hides, or hair. For this reason, people in certain occupations, like veterinarians, farmers, livestock producers, and others who handle animals and animal products may have an increased risk of exposure.

Mail handlers, military personnel, and response workers

Certain workers could be exposed to anthrax in the event of a bioterrorist attack, either during the attack or when responding to the emergency. Workers who could be at risk include mail handlers (if spores are sent through the mail), law enforcement personnel, healthcare workers, decontamination workers, and critical infrastructure workers who could be exposed to airborne (aerosolized) spores, depending on how the spores were spread.

Travelers

Anthrax can be found naturally in soil and commonly affects domestic and wild animals around the world, but it is most common in agricultural regions of Central and South America, Sub-Saharan Africa, Central and southwestern Asia, Southern and eastern Europe, and the Caribbean. Travelers should be mindful of what they eat and handle, as well as the souvenirs they bring home. Avoid eating raw or undercooked meat, and avoid contact with livestock, animal products and animal carcasses. Vaccination against anthrax is not recommended for travelers and is not available for civilian travelers.

The symptoms of anthrax depend on the type of infection and can take anywhere from 1 day to more than 2 months to appear.  All types of anthrax have the potential, if untreated, to spread throughout the body and cause severe illness and even death.

Cutaneous anthrax symptoms can include:

• A group of small blisters or bumps that may itch
• Swelling can occur around the sore
• A painless skin sore (ulcer) with a black center that appears after the small blisters or bumps
  • Most often the sore will be on the face, neck, arms, or hand

Inhalation anthrax symptoms can include:

• Fever and chills
• Chest Discomfort
• Shortness of breath
• Confusion or dizziness
• Cough
• Nausea, vomiting, or stomach pains
• Headache
• Sweats (often drenching)
• Extreme tiredness
• Body aches

Gastrointestinal anthrax symptoms can include:

• Fever and chills
• Swelling of neck or neck glands
• Sore throat
• Painful swallowing
• Hoarseness
• Nausea and vomiting, especially bloody vomiting
• Diarrhea or bloody diarrhea
• Headache
• Flushing (red face) and red eyes
• Stomach pain
• Fainting
• Swelling of abdomen (stomach)

Injection anthrax symptoms can include:

• Fever and chills
• A group of small blisters or bumps that may itch, appearing where the drug was injected
• A painless skin sore with a black center that appears after the blisters or bumps
• Swelling around the sore
• Abscesses deep under the skin or in the muscle where the drug was injected

Injection anthrax symptoms are similar to those of cutaneous anthrax, but injection anthrax can spread throughout the body faster and be harder to recognize and treat than cutaneous anthrax. Skin and injection site infections associated with injection drug use are common and do not necessarily mean the person has anthrax.

Doctors in the United States rarely see a patient with anthrax. CDC guidance and case definitions are available to help doctors diagnose anthrax, take patient histories to determine how exposure may have occurred, and order necessary diagnostic tests.

If inhalation anthrax is suspected, chest X-rays or CT scans can confirm if the patient has mediastinal widening or pleural effusion, which are X-ray findings typically seen in patients with inhalation anthrax.

The only ways to confirm an anthrax diagnosis are:

• To measure antibodies or toxin in blood
• To test directly for Bacillus anthracis in a sample
  • blood
  • skin lesion swab
  • spinal fluid
  • respiratory secretions

Samples must be taken before the patient begins taking antibiotics for treatment.

If you think you may have been exposed to anthrax, you need to go to a doctor right away and explain why you think you may have been exposed. Doctors can prescribe antibiotics to prevent you from getting sick. There is no test a doctor can give you that determines if you have been exposed to anthrax. The only way exposures can be determined is through a public health investigation.

If you already have symptoms of anthrax, it’s important to get medical care as quickly as possible to have the best chances for a full recovery.

Anthrax is NOT contagious. You cannot catch anthrax from another person the way you might catch a cold or the flu. In rare cases, person-to-person transmission has been reported with cutaneous anthrax, where discharges from skin lesions might be infectious.

Doctors have several options for treating patients with anthrax, including antibiotics and antitoxin. Patients with serious cases of anthrax need to be hospitalized. They may require aggressive treatment, such as continuous fluid drainage and help breathing through mechanical ventilation.

For people who have been exposed to anthrax but do not yet have symptoms, certain antibiotics can be used to prevent illness from developing.

Antibiotics

All types of anthrax infection can be treated with antibiotics, including intravenous antibiotics (medicine given through the vein). If someone has symptoms of anthrax, it’s important to get medical care as quickly as possible to have the best chances of a full recovery. Doctors will select antibiotics that are best for treating anthrax and that are best for the patient based on their medical history.

Antitoxin

When anthrax spores get inside the body, they can be “activated.” When they become active, anthrax bacteria can multiply, spread out in the body, and produce toxins—or poisons. Anthrax toxins in the body cause severe illness.

After anthrax toxins have been released in the body, one possible treatment is antitoxin. Antitoxins target anthrax toxins in the body. Doctors must use antitoxin together with other treatment options.

Currently, there are a few types of antitoxins that can be used for treating anthrax.

Anthrax is rare, and most people will never be exposed to it. There is a vaccine licensed to prevent anthrax, but it is only recommended for routine use in certain groups of at-risk adults (for example, some members of the military and laboratory workers).

For people who have been exposed to anthrax but do not yet have symptoms, certain antibiotics can be used to prevent illness from developing.

Preventing anthrax during travel

Visitors to areas where anthrax is common or where an outbreak is occurring in animals can get sick with anthrax if they have contact with infected animal carcasses or eat meat from animals that were sick when slaughtered. They can also get sick if they handle animal parts, such as hides, or products made from those animal parts, such as animal hide drums. If you are visiting these areas, do not eat raw or undercooked meat and avoid contact with livestock, animal products, and animal carcasses.

International travelers should be aware of regulations concerning (and restrictions against) the importation of prohibited animal products, trophies, and souvenirs. For more information, see CDC’s Yellow Book.

Preventing anthrax from animal hides

Imported animal hides have been associated with a number of anthrax cases in the United States. Cases have occurred in drum makers using these hides. Cases have also occurred in people who have handled or been near the drums or in the environment where they were made. Some imported hides may contain anthrax spores, and although this is rare, there is no way to test for the presence of spores on hides.

To protect against anthrax spores, be sure to use hides that came from:

• Animals from the United States
• Animals that were imported with an international veterinary certificate showing that they have undergone the appropriate government inspection

Antibiotics can prevent anthrax from developing in people who have been exposed but have not developed symptoms. Antibiotics work in two main ways, by killing the anthrax or by stopping the anthrax from growing. When the anthrax can’t grow anymore, it dies. Two of the antibiotics that could be used to prevent anthrax are:

• Ciprofloxacin
• Doxycycline

Each of these antibiotics offers the same protection against anthrax. Anthrax spores typically take 1 to 7 days to be activated, but some spores can remain inside the body and take up to 60 days or more before they are activated. Activated spores release toxins—or poisons—that attack the body, causing the person to become sick. That’s why people who have been exposed to anthrax must take antibiotics for 60 days. This will protect them from any anthrax spores in their body when the spores are activated.

Anthrax spores can take up to 60 days or more to be activated in the body

Anthrax Vaccine Adsorbed (AVA) protects against anthrax. It does not contain any anthrax bacteria and cannot give people anthrax. It is not typically available to the general public. The vaccine is approved by the Food and Drug Administration (FDA) for two different situations: routine occupational use (before possible exposure) and post-event emergency use (after possible exposure).

Routine occupational use (before possible exposure)

Anthrax vaccine is approved for use in three groups of adults 18 to 65 years of age who may be at risk of coming in contact with anthrax because of their job.

These at-risk adults will receive the vaccine before exposure:

• Certain laboratory workers who work with anthrax
• Some people who handle animals or animal products, such as some veterinarians
• Some members of the United States military

To build up protection against anthrax, these groups should get 5 shots of anthrax vaccine over 18 months. To stay protected, they should get annual boosters. The shots are injected into a muscle (intramuscular).

People who should NOT get the anthrax vaccine for routine occupational use include:

• Pregnant women.
• Anyone who has had a serious allergic reaction to a previous dose of anthrax vaccine.
• Anyone who has a severe allergy to any component of the anthrax vaccine.
• Anyone with severe allergies, including allergy to latex, should tell their doctor.

Anyone with a moderate or severe illness might be asked by their doctor to wait until they recover to get the vaccine. People with mild illness can usually be vaccinated.

Post-event emergency use (after possible exposure)

In November 2015, FDA also approved the vaccine for use after exposure to anthrax for people 18 through 65 years of age. In certain situations, such as a bioterrorist attack involving anthrax, anthrax vaccine might be recommended to prevent the disease in people after they have been exposed to the anthrax germs.

If this were to happen, people who were exposed would get 3 shots of anthrax vaccine over 4 weeks plus a 60-day course of antibiotics.

During an emergency, the only people who should not get the anthrax vaccine after possible exposure are those who have had a serious allergic reaction to a previous dose of anthrax vaccine. These people would receive the 60-day course of antibiotics only.