Only weeks after the devastating terrorist attacks of September 11, 2001, Americans were further shaken by a series of highly suspicious exposures to the bacteria that causes anthrax, a potentially deadly disease. Dozens of individuals were exposed to spores of the bacteria after coming into contact with contaminated mail that was sent to various offices of the United States government and to several major American news organizations. Authorities investigating the incidents determined that the anthrax spores were mailed as acts of biological terrorism, which is widely referred to as bioterrorism. Officials stress that they have found no connection between the September 11 attacks and these acts of bioterrorism. But the timing of the anthrax mailings, coming so soon after September 11, reminded Americans that terrorists have many potential weapons at their disposal.

This special topic guide offers background information on anthrax and other potential agents of bioterrorism. It also provides overviews of immunization against diseases and treatment with antibiotics. In addition, the guide profiles the government agencies charged with investigating these incidents and preventing further exposure to biological hazards.

Anthrax and related issues
Anthrax is one of the oldest known diseases, and one of the first to be researched by pioneering bacteriologists of the 19th century. Anthrax is not a contagious disease; that is, it cannot be transmitted from person to person. The vast majority of anthrax cases are caused by infection through the skin. On the rare occasions when bacterial spores enter the lungs, they can cause the much deadlier inhalation form of the disease. The following articles from Encarta Encyclopedia offer background on anthrax, its history, behavior, and other related issues.

• Anthrax--an overview of the disease
• History of bacterial disease--including anthrax, plague, cholera, and other diseases
• Robert Koch--Nobel Prize-winner who discovered the cause of anthrax
• Louis Pasteur--microbiologist who developed the first effective vaccine against anthrax
• Bacteria that can cause human disease (chart)
• Disease terminology (chart)
• Smallpox--a viral disease considered another potential agent of bioterrorism
• Plague--a bacterial disease also considered a potential biological weapon

Fighting biological infection
Of the dozens of individuals exposed to the anthrax bacteria from the letters sent in the autumn of 2001, relatively few people actually became infected with anthrax. Doctors treat infected persons with antibiotics, which have proven effective in fighting the disease, particularly when they are administered early. The very rare inhalation form of anthrax is much more difficult to combat than the cutaneous form that is contracted through the skin.

Many people fearing possible exposure to anthrax bacteria in the future have requested supplies of antibiotics from their doctors to take as a precautionary measure. Health officials have warned, however, that antibiotics do not make people immune to the disease and may make them susceptible to other diseases. Moreover, if used inappropriately, antibiotics may actually cause the anthrax bacteria to develop a resistance to the drugs. The following articles from Encarta Encyclopedia offer more information on ways to fight biological infection:

• Antibiotics--used in the treatment of biological infection
• Immunization--stimulates resistance to disease in the human body
• Epidemiology--the study of the spread of diseases

Background on biological weapons
Although biological weapons were occasionally used to devastating effect in various wars of the 20th century, they have rarely been used by terrorists. The recent incidents of anthrax exposure illustrate, however, that terrorists could deliver biological weapons relatively easily, even through the U.S. Postal Service. The world reacted with shock and horror at these incidents, but analysts have long regarded biological weapons to be among the foremost threats to domestic and international security. The following article on Chemical and Biological Warfare, from Encarta Encyclopedia, offers background on:

• Biological warfare
• Delivery systems for chemical and biological agents
• Protection from chemical and biological attack
• International agreements to ban chemical and biological weapons
  

Government agencies
Various government agencies worked in concert to provide medical assistance to individuals who may have been exposed to the anthrax spores, to identify and isolate contaminated areas, to perform forensic studies that could identify the source of the bacteria, and to prevent future biological attacks from occurring. The following articles from Encarta Encyclopedia profile some of the principal agencies performing these functions:

• Centers for Disease Control and Prevention (CDC)--conducts research into the origin and occurrence of diseases, and develops methods for their control and prevention
• Department of Health and Human Services--administers a wide range of health care in the United States
• Food and Drug Administration--approves drugs that could be used in the treatment or prevention of illness, among other responsibilities

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