person, triggering public panic and requiring special public health precautions.
Many public health officials believe that anthrax is the bioweapon of greatest concern—although in the case of the 2001 anthrax mailings in the United States there was less morbidity and mortality than many feared would occur. The infection is caused by Bacillus anthracis, a bacterium that forms spores. Anthrax does not spread from person to person but rather by hard-coated bacterial spores that spring to life under the right conditions. Anthrax can cause skin lesions and gastrointestinal disease. Inhalation anthrax is the rarest form of the infection—and may be the most difficult to treat.
Another disease of concern is smallpox, a serious, contagious, and sometimes fatal infection. Smallpox was officially declared eradicated from the globe in 1980, after an 11-year WHO vaccination campaign—the first human disease to be eliminated as a naturally spread contagion. Once the disease was gone, routine vaccination of the general public was stopped. Today, the virus remains only in laboratory stockpiles. But in the aftermath of the events of September and October 2001, concern has grown that the smallpox virus might be used as an agent of bioterrorism.
Another threat—the botulinum toxin—is the most lethal compound known. The nerve toxin is produced by the bacterium Clostridium botulinum. Researchers estimate that as little as a gram of aerosolized botox could kill more than 1.5 million people.
NIAID is developing tools to detect and counter the effects of a bioterrorist attack, including vaccines to immunize the public against diseases caused by bioterrorism agents, diagnostic tests to help first responders and other medical personnel rapidly detect exposure and provide treatment, and therapies to help patients exposed to bioterrorism agents regain their health.
Awareness of disease threats fostered by changing patterns of human existence and behaviors is the first step toward mitigating their effects. The following section explores what we can do, individually and collectively, to address risks posed by this evolving relationship between humans and microbes.