Last updated January 1, 2006

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This Q&A fact sheet addresses many common questions about anthrax. It is not a substitute for hands-on medical treatment. If you have a personal health concern, you should consult a physician.

What is anthrax?

Anthrax is a bacteria found naturally in soil as close to home as rural Texas, Oklahoma, and near the Mississippi River. Anthrax is also made in research and military labs. The scientific name for Anthrax is Bacillus anthracis.

How do humans get it?

Usually, they don’t. Most of what we know about anthrax comes from studying infected animals. In humans, natural cases of anthrax poisoning are very rare and are primarily a hazard for tanners, veterinarians, and other workers exposed to infected animals or animal parts. Not everyone exposed to anthrax contracts the disease.

There are three forms of Anthrax.  They correspond to how it enters the body:

  1. Skin: Microscopic anthrax spores (the inactive form of the bacteria) can get into the body through cuts in the skin, even tiny ones, after someone touches an object with anthrax on it—like animal tissue or a tainted letter.
  2. Lung: Spores can be breathed into the lungs. From there, spores make their way to the lymph nodes, where they turn into bacteria that release poisons into the surrounding tissue.
  3. Stomach: Spores can wind up in the digestive system after someone eats from a contaminated animal.

How dangerous is anthrax?

It depends on the strain of anthrax, how it’s contracted, and the age and health of the victim.

  1. Skin anthraxis the least dangerous form. Untreated, it kills only 5 percent to 20 percent of its victims, and if treated effectively with antibiotics, few deaths occur.
  2. Lung anthraxis much more dangerous. Before the fall 2001 outbreak, doctors estimated it would kill more than 80 percent of victims if left untreated. Since the mail attacks, doctors have learned that people who inhale spores can recover even if treatment starts after their symptoms appear.
  3. Ingested anthraxis also dangerous. Untreated, doctors think it would kill between 25 percent and 70 percent of its victims. But there’s never been a documented case in the United States, even during the fall 2001 scare.

Is anthrax contagious?

No. According to the Centers for Disease Control and Prevention, you can’t get it from someone who coughs next to you.

What are the symptoms?

Symptoms differ depending on how the disease is contracted:

  1. Skin anthrax starts with an itch. Later, small pimples form on the skin. Within two to six days, these sometimes turn into black sores.
  2. Inhaled anthrax leads to early symptoms much like those of the flu, the common cold, or other respiratory diseases.
  3. Ingested anthrax may cause nausea, fever, loss of appetite, vomiting (sometimes with blood), and abdominal pain.

A year after the fall 2001 anthrax letters, many of those infected were still suffering from symptoms including fatigue, shortness of breath, chest pains, and memory loss. The National Institutes of Health are planning a comparative study of the victims to learn more about the disease’s longer-term effects.

How is anthrax treated?

With antibiotics. Cipro is by far the best known, but penicillin and doxycycline have also been effective treating the forms contracted in the mailed letters. A May 2002 study said a treatment involving shots of vaccine plus a sixty-day regimen of several antibiotics is more effective than simply taking Cipro.

Scientists say a special enzyme developed by Rockefeller University biologists may also be an effective antidote, if injected quickly after the disease is contracted. But experts say that many more tests must be completed before the enzyme can be used as a drug.

Are there types of anthrax that don’t respond as well to antibiotics?

Probably. There are ways to modify anthrax genes to render the bacteria resistant to antibiotics.

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