Since the September 11 terrorist attacks, there has been heightened public concern and anxiety about biological agents, specifically about anthrax. Anthrax continues to be the agent of choice for bioterrorism threats and hoaxes. These incidents usually involve the delivery of a suspicious package or letter containing a powdery substance. A note stating that the recipient has been exposed to anthrax may or may not be included.

Anthrax is an acute infectious disease caused by the spore-forming bacterium Bacillus anthracis. Anthrax most commonly occurs in hoofed mammals (such as farm animals) and can also infect humans.

Symptoms of disease vary depending on how the disease was contracted, but usually occur within 7 days after exposure. The serious forms of human anthrax are inhalation anthrax, cutaneous (or skin) anthrax, and intestinal anthrax.

Initial symptoms of inhalation anthrax infection may resemble a common cold. After several days, the symptoms may progress to severe breathing problems and shock. If untreated, inhalation anthrax can be fatal.

The intestinal disease form of anthrax may be caused by the consumption of contaminated food and is characterized by an acute inflammation of the intestinal tract. Initial signs of nausea, loss of appetite, vomiting, and fever are followed by abdominal pain, vomiting of blood, and severe diarrhea.

Direct person-to-person spread of anthrax is extremely unlikely, if it occurs at all. Therefore, there is no need to immunize or treat contacts of persons ill with anthrax, such as household contacts, friends, or coworkers, unless they also were also exposed to the same source of infection.

In persons exposed to anthrax, infection can be prevented with antibiotic treatment. Early antibiotic treatment of anthrax is essential–delay lessens chances for survival. Anthrax usually is treated with penicillin, doxycycline, and fluoroquinolones. An anthrax vaccine also can prevent infection. However, vaccination against anthrax is not recommended for the general public to prevent disease and is not currently available.

[Source: U.S. Centers for Disease Control, September 2001.]

For Credible or Implied Threat Situations (e.g., contact w/suspicious package or substance), Follow These Steps:

  1. Do not open the package, or shake or empty the contents.
  2. Get yourself and others out of the immediate vicinity and close off the room.
  3. Thoroughly wash hands and face with soap and water.
  4. Contact the local police by dialing 911.
  5. List all persons who physically handled the package and provide the list to the police.
[Source: Centers for Disease Control. "Updated Information About How to Recognize and Handle a Suspicious Package or Envelope." October 31, 2001.]


For more information on biological agents:


For more information on handling suspicious packages:


The following links provide some information about the proactive steps that the State of Colorado is taking to prepare for a terrorist type event: