In 2001, a series of anthrax attacks through the mail on media and federal government offices killed five people and sickened 17. Government buildings in Washington D.C. were shut down; government agencies issued advisories on how to handle suspicious-looking packages; news and mailroom employees across the country began donning latex gloves to sort mail; Americans stockpiled antibiotics against public health officials’ advice; and worried citizens flooded hospitals with common cold symptoms or called law enforcement to report sightings of suspicious white powder (usually flour).

And public health departments were flooded with calls from a frightened public, everyone asking similar questions: How real is the threat? What are the symptoms? How can I protect myself?

Today the anthrax scare has died down, but some people — especially postal workers — may wonder what, if any, precautions they should take.

Here are some of the most commonly asked questions about anthrax, with responses drawn from interviews with experts on bioterrorism and information put out by the federal government’s Centers for Disease Control and Prevention and the Department of Health and Human Services.

What is anthrax?

Anthrax is an animal disease that has been around for thousands of years. It’s caused by a spore-forming bacteria, Bacillus anthracis, which live in the soil and on infected animals, such as cattle, sheep, goats, camels, antelope, and other hoofed animals. Spores can be found in pastures in most parts of the world. Like all other bacteria, you can’t sense anthrax — it’s invisible to the naked eye, odorless, and tasteless.

Anthrax is an infectious disease, but the good news is that it’s not contagious. In this case, “infectious” means that anthrax bacteria causes an infection, but one that’s not generally passed from person to person.

How are people exposed to anthrax?

About 95 percent of the world’s human anthrax cases are skin infections, usually the result of handling infected animal products, according to the CDC. Eleven of the 22 cases of anthrax reported in 2001 by people who handled contaminated mail were cutaneous anthrax and non-lethal. The bacteria enter the skin through a cut or abrasion. Many people who come down with cutaneous anthrax (the skin infection) are exposed to the bacteria from handling products made from infected animals, such as wool, hides, leather, or animal-hair items.

In rare instances, people handling contaminated animal products develop inhalation anthrax. As in the five lethal cases of anthrax in 2001, people may breathe in anthrax spores, which can release a toxin that can do fatal damage to the respiratory system and brain. Finally, if people eat raw or undercooked meat from animals infected with anthrax, the bacteria can invade the intestines.

Experts stress that anthrax in any form is rare in the U.S. From 1900 to 1978, there were only 18 documented cases of inhalation anthrax in the country. From 1944 to 1994, there were slightly more than 200 cases of cutaneous anthrax; the most recent pre-9/11 case was reported in North Dakota in August 2000: A man contracted the disease when he helped dispose of five cows that died of anthrax. To date, there have been no reports of the intestinal form ever occurring in the United States.

How dangerous is anthrax?

A: The degree of danger depends largely on how anthrax gets into your system. The cutaneous (skin) form responds well to antibiotics, and people usually recover if treated. Even among untreated people, survival rates are about 80 percent.

A lung infection caused by inhaling anthrax spores is far more dangerous, but rare because it’s difficult to disperse anthrax in the air effectively and it takes several thousand spores to cause a dangerous infection. Once established, inhalation anthrax is often fatal, according to the CDC. Nearly half of all deaths occur within 24 to 48 hours of serious respiratory symptoms. Without treatment, the ingested form is fatal in 25 to 60 percent of cases.

Fortunately, the type of anthrax being mailed was susceptible to antibiotics. An antibiotic-resistant strain of bacteria would have been far harder to treat, as would a virus.

How do you know if you have anthrax?

The symptoms of anthrax vary depending on which kind you have and usually appear within seven days of exposure.

The symptoms of inhalation anthrax resemble that of a common cold, marked by fever, coughing, and overall fatigue. After a few days, you may develop severe difficulty breathing and shock. Without antibiotic treatment, this form of anthrax is often fatal.

Symptoms of skin infection from anthrax include a rash with small fluid-filled bumps that look like spider or mosquito bites, swelling of the skin, swollen lymph glands, and fever. The red, raised bumps may form ulcers that develop a black area in the center as the skin dies (which is why anthrax gets its name from the same Greek root for anthracite, which is coal). Later, the ulcers may develop scabs that eventually fall off.

The CDC says symptoms are usually noticeable within seven days of exposure, but they can take up to 60 days to appear. That’s why people who are exposed to anthrax have to take antibiotics for at least two months.

Can anthrax be prevented?

An animal vaccine is available and widely used in countries where anthrax is common. This vaccine has been licensed for use in humans, and the CDC reports it to be 93 percent effective. At this time, however, the vaccine is in short supply and it has been set aside for use by people who handle animals, work in laboratories where anthrax is studied, or are in the military.

The vaccine is given in an initial course of three injections, two weeks apart, followed by booster shots at 6, 12, and 18 months and an additional booster every year after that.

Is there an approved treatment for anthrax?

Yes. Three types of antibiotics are approved for all types of anthrax infections: ciprofloxacin (Cipro), doxycycline, and penicillin. Other antibiotics can be effective as well. Because the disease is so serious, people who have been exposed to anthrax bacteria — whether or not they have symptoms — should take antibiotics for 60 days to reduce the risk the disease will develop or to halt its progression. Taking antibiotics will also minimize the chance of developing side effects, such as meningitis.

I work at the post office. What should I do if I receive a letter that I suspect contains anthrax?

First of all, don’t panic. It’s likely that you’re not dealing with anthrax. Don’t shake the suspicious letter or empty its contents, the CDC advises. Instead, put the envelope or package in a plastic container that can’t leak. (If you don’t have a container, cover the envelope with anything at hand — including a trash can or clothing — then leave the room and close the door.) If necessary, have someone cordon off the area to keep other people out. Next, wash your hands thoroughly and call 911 to notify the local police and FBI. If you’re at work, notify your building’s security official or your supervisor.

If you’ve spilled some of the powder, DON’T try to clean it up. Cover it with a piece of paper or towel, then leave the room and close it off so other people won’t come into contact with it. The CDC advises that you put any clothing that’s come into contact with the powder into a leak-proof bag or container, then wash your hands or shower with soap and water before calling 911.

How can I tell if a letter or package might contain anthrax?

The U.S. Postal Service says that characteristics of suspicious packages and letters include the following:

  • Excessive postage
  • Handwritten or poorly typed addresses
  • Incorrect titles, titles without names, and misspellings of common words
  • Oily stains, odors, and discolored envelopes
  • No return address
  • Excessive weight or a lopsided envelope
  • Protruding wires or aluminum foil
  • “Excessive security measures” such as string, masking tape, and so on
  • Letters marked “personal” or “confidential”
  • A city or state in the postmark that doesn’t match the return address

If you’ve received a suspicious letter or package, don’t try to open it. Instead, the U.S. Post Office advises you to isolate the piece of mail, evacuate the immediate area, and call a Postal Inspector to report that you’ve gotten a mail parcel that may contain chemicals or biological agents.

How hard is it to use anthrax as a biological weapon?

In the absence of an air attack, it’s quite difficult. It’s tricky to create spores in the lab, keep them from clumping together, and disperse them effectively. In Tokyo in 1993, the Aum Shinrikyo cult attempted to spread anthrax from a rooftop several times within a week without success — although the cult was well-funded and included experienced biologists.

In the event of an emergency, government health agencies plan to ship antibiotics from their stockpiles to wherever they are needed.

How can I find out more about anthrax and bioterrorism?

You can visit the federal government’s Centers for Disease Control and Prevention at, which will give you
the latest government advisories as well as updates on reported cases. You may also want to visit Johns Hopkins Bloomberg School of Public Healths Center for Civilian Biodefense Strategies.


Interview with Dr. Raymond Zilinskas, Monterey Institute of International Studies, Center for Nonproliferation Studies.

U.S. Department of Health and Human Services. Anthrax Preparedness: HHS Progress. May 2006.

Centers for Disease Control. Key Facts About Influenza and the Influenza Vaccine. September 2005.

Anthrax as a Biological Weapon, Thomas V. Inglesby, MD, et al. Journal of the American Medical Association, Vol. 281 No. 18.

An Anthrax Primer: NPR’s Science Desk Answers Some Frequently Asked Questions, National Public Radio online,

Use of Anthrax Vaccine in the United States: Recommendations of The Advisory Committee on Immunization Practices, US Department of Health and Human Services, CDC; Dec. 15, 2000/vol. 49/No. RR-15. Chemical – Biological Warfare Fact Sheet,” US Department of State, Washington, DC; 2001;

How to Handle Anthrax and other Biological Agent Threats, CDC, Oct. 12, 2001

General information on anthrax, CDC,

Questions and Answers about Anthrax Prevention and Treatment, October 10, 2001, U.S. Department of Health and Human Services,

Human anthrax associated with an Epizootic among livestock–North Dakota, 2000. Morbidity and Mortality Weekly Report, Aug 17, 2001

Questions and Answers about Anthrax, Frequently Asked Questions, CDC.

Investigation of Bioterrorism-Related Anthrax, United States: 2001: Epidemiological Findings. CDC; October 2002/vol. 8/No. 10.

Anthrax Fact Sheet 2002, Center for Civilian Biodefense Strategies, John Hopkins University.

Centers for Disease Control. Anthrax Q and A: Anthrax and Influenza. May 2003.

Johns Hopkins University Bloomberg School of Public Health. Preparedness Tips from the School of Public Health. March 2003.

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