As of November 2, a total of 16 cases of anthrax had been confirmed in the U.S., according to the Centers for Disease Control. Of those, four resulted in fatalities: one in Florida, one in New York City, and two in the Washington, D.C. area. In light of that disturbing news, you may be wondering what anthrax is exactly and what threat it poses to us.

Anthrax is an infectious disease that has been around for centuries and is found most commonly in farm animals. Humans can contract it three ways:

  • Ingesting the anthrax bacteria by eating bad food, such as tainted meat.
  • Handling infected material such as powder, soil, animal skins or hides.
  • Inhaling microscopic anthrax spores, which are invisible to the naked eye.

Anthrax can take anywhere from two days to two months to display symptoms. According to Allan Rosenfield, dean of the Mailman School of Public Health at Columbia University, "its initial symptoms are general symptoms, like the flu." Later symptoms can include shock, coma, respiratory failure and, ultimately, death, depending on which strain of the disease is contracted.

According to the Centers for Disease Control, 95 percent of anthrax cases are cutaneous, meaning they are contracted via physical contact with an infected material (soil, powder, animal skins, etc.). Only one in five such cases will result in death, if untreated. Until this latest outbreak of anthrax, medical experts believed that inhaling anthrax spores virtually always resulted in death. Now they are increasingly optimistic that early detection and treatment with antibiotics can substantially reduce the chance of death.

Very little is known about intestinally contracted anthrax, with estimates about the likelihood of death varying widely. No cases of intestinal anthrax have been reported in the U.S. as of November 2.

Rosenfield points out that, unlike the flu, anthrax is not contagious. "If I have anthrax, you cannot get it from me. But if we're both exposed to the same air, and anthrax is in the air, we may both come down with the disease, and it may take longer for you to get it than me."

Prevention of anthrax is possible with a vaccine. But you must take it consistently for 18 months to become fully protected. The vaccine is regulated by the government, which is developing it for wider public use.

The good news is that, once exposed, victims can be treated with an antibiotic known as ciproflaxin, or "Cipro," which has displayed a high rate of success in curing anthrax patients. Two of the people who tested positive for exposure to anthrax in Florida and New York reportedly took Cipro and are doing fine. In addition, other antibiotics are considered to be effective in fighting anthrax, including penicillin.

Don't run out to your local pharmacy and begin stockpiling antibiotics, though. Dr. Jim Walsh, a research fellow at the John F. Kennedy School of Government at Harvard University, has studied infectious diseases extensively and said, "Don't waste your money on this stuff. It's not going to make you any safer. There's so much misinformation out there that we're on the verge of hysteria. People are scared to death about anthrax when it really poses a very small threat."

There have been threats and attempts to use anthrax as a weapon in the past. During the Gulf War in 1991, the specter of anthrax warfare loomed over American troops in Iraq but never materialized. In 1995, a Japanese terror group piped anthrax into the Tokyo subway system several times with no effect. (The group did, however, later succeed by using the poison gas sarin.)

Infecting a population is not easy, according to Walsh. "It's not quite as simple as stealing a crop duster and putting a bio agent in it," he said. "It doesn't work like that. You need sophisticated equipment, and it's difficult to do."

Difficult, but not impossible. Which is why the U.S. government is doing everything in its power to prevent and prepare for even the smallest possibility of biological terrorism.

Anthrax Links

A wealth of information about what this deadly disease is and how it can be contracted is circulating on the Internet and elsewhere. Some of this information is false or inaccurate, however, especially the stuff being circulated via forwarded e-mail. All the more reason to get information from trustworthy sources.

A concise backgrounder on anthrax and other chemical or biological weapons is available from CBS News. CBS News is also reporting on the latest developments in the ongoing story.

For the latest official statements about anthrax, visit the Centers for Disease Control's anthrax page (www.bt.cdc.gov) or the agency's main page (www.bt.cdc.gov) to learn about our national preparedness and response plans.

The Department of Defense (www.anthrax.osd.mil) sponsors a site devoted to the anthrax vaccine.

Share your thoughts on the attacks in Afghanistan in You Tell Us.

[This story was updated on 11.02.01 at 5:04 P.M. ET]