During the anthrax scare of 2001, when envelopes containing the deadly bacteria were mailed to locations throughout the country, 22 people were infected with the disease. Five eventually died.
The incident, occurring shortly after the Sept. 11 terrorist attacks, underscored the vulnerability of the United States to bioterrorism. Those responsible for the anthrax scare have never been found.
But has our preparedness improved since then? According to many experts, the answer is no.
And anthrax is only one of several bacteria and viruses that could be used in a bioterrorist attack.
"Anthrax is easier to come by and people have used it recently," said Kyle Olson, vice president of CRA, a consulting firm specializing in bioterror under contract to the Department of Homeland Security.
Referring to the anthrax scare of 2001, Olson said, "He/she/they are still out there and may be biding their time and making more. If you can make a little, you can make a lot. That's a scenario that has a lot of people bothered."
The Centers for Disease Control and Prevention classifies six pathogens as Class A bioterrorism agents: smallpox, plague, botulism, tularemia, hemorrhagic fever and anthrax.
Michael Greenberger, director of the University of Maryland Center for Health and Homeland Security in Baltimore, explains that the Class A pathogens share some common traits: they can be easily spread, all of them can be deadly, and even a small dose could cause widespread damage and fear throughout a populated area.
To address these concerns, the CDC in 1999 began to develop the Strategic National Stockpile, a nationwide system of storage facilities with equipment and supplies to address an emergency like a bioterrorist attack.
The SNS would supplement efforts by state and local agencies to respond to a public health emergency. And by most accounts, the stockpile has the equipment to do so.
"The SNS is in pretty good shape," said Olson. "There are multiple stockpiles in numerous sites around the country of drugs, antibiotics, medical equipment, even things like gloves and tongue depressors."
How these SNS supplies might reach their intended population, however, is a matter of some concern.
"It's one thing to say that stockpile is in good shape -- it's another thing to say that the preparations for using the stockpile are in good shape," said Olson.
"Very few places in the U.S. have plans for using [the SNS] in place. There are some good efforts, but by and large the majority of American cities do not have good plans or plans that have been tested," said Olson.
Olson and Greenberger note that a handful of cities, like Denver, Seattle and Chicago, have tested some portion of their emergency plans, and say tests are now being planned for other large cities.
But Greenberger said that in large cities like Chicago, "things did not go well."
"The major problem with the stockpile is that once it gets to the field, there are no plans to distribute the medications from the stockpile once they arrive on the scene," he said.
Charles Schable, director of Terrorism Preparedness and Emergency Response for the CDC, believes great improvement in coordinating the distribution of emergency supplies and medication has been made in recent years.