Yersinia pestis is the microbe that causes bubonic plague, a blood disease that localizes in the lymph nodes, contracted when people are bitten by infected fleas. Since the dropping of fleas on a city seemed an impractical method of spreading plague, Cold War scientists in the Soviet Union decided to apply the model of anthrax to it, producing large quantities of dried bacteria. Inhaled Yersinia pestis causes pneumonic plague, a respiratory disease. Untreated cases generally result in death, and while the pneumonic form can be spread from person to person, the infection hazard is not thought to be extreme. The current thinking is that a bioterrorist would attempt to spread Yersinia pestis as an aerosol, and the same caveats apply as in the anthrax discussion.
Botulism, a food-borne illness caused by a family of toxins produced by the bacterium Clostridium botulinum, is also often mentioned as a potential agent of bioterror. Botulinum toxin gets a lot of press for being more lethal than sarin, but using it as a weapon for killing thousands—as opposed to a poison in potential assassinations or isolated cold-food contaminations—is problematic. The pessimists insist it can be suspended in air as a lethal dust or aerosol, but no reliable information suggests this is possible and practical.
Smallpox, a devastating viral illness, was eliminated as a naturally occurring disease in 1980 by the World Health Organization through vaccination and infection control. The only remaining stocks were in the United States and the Soviet Union. The Soviets, in what must be considered a crime against humanity, used their stock in a secret bioweapons project with the logic that it would make a good strategic weapon precisely because it had otherwise been eliminated. The man who is said to have helped create the weapon now works as a consultant on bioterror defense in northern Virginia. Is this a cause for outrage? Apparently not.
No one seems to know with any reliability whether, as the Soviet Union fell apart, it was able to maintain control of its stock of smallpox. There is no information on the effectiveness of the weapon or its reproducibility. There is no cure for smallpox, although the United States and other nations maintain aging stocks of vaccine of unknown reliability. Control of a sudden outbreak of smallpox would revolve around quick recognition, administration of an effective vaccine (which might be logistically difficult), and strict isolation of the infected. Speculating on casualties is merely depressing. Smallpox would be a truly suicidal weapon, since a reemergence of the virus, if it spread internationally, would certainly be devastating to third world nations. Terrorists would scarcely be immune.
