Anthrax: From Antiquity and Obscurity to a Front-Runner in Bioterrorism

The earliest known writings about anthrax are from Egypt and Mesopotamia and date back to 5000 bc. The Book of Exodus in the Bible describes the Fifth plague killing the Egyptians' cattle and the Sixth plague, which may have been outbreaks of anthrax in humans. The early literature of Hindus, Romans, and Greeks contains descriptions of anthrax. Anthrax became the first human infectious disease with specific microbial etiology when B anthracis was used to fulfill Koch's postulate in 1877. The attenuated anthrax spore vaccine was first tested by Pasteur in 1881. In the early 1900s, improved industrial and animal husbandry hygiene and decreased use of potentially contaminated imported animal products caused a steady and significant decline in the number of cases in the developed world. This decline was aided further by the Sterne animal vaccine from the spore suspension by an avirulent nonencapsulated strain in 1939. This is the currently used animal vaccine. Anthrax in its natural form became an obscure disease in many parts of the world. Because of the ease with which B anthracis could be cultivated, it gained notoriety during World War I and World War II as a biologic weapon and was included in the offensive biologic weapons programs of Germany, Great Britain, the United States, and the USSR. Accidental release of anthrax spores from a biologic weapons facility in Sverdlovsk, Russia, caused the first documented outbreak from weapons grade B anthracis. The new age doomsday cult Aum Shinrikyo in Japan (1995) attempted to use anthrax spores along with other microbial agents to cause mass casualties, but all attempts failed. Larry Wayne Harris, a microbiologist in the United States, threatened to release "military grade anthrax" in Las Vegas, Nevada. He had obtained the veterinary vaccine strains of anthrax and was arrested when he openly talked about the use of biologic agents. The sensational media coverage of this event may have had the unintended effect of popularizing anthrax as a potential tool for terrorists. The first wave of anthrax hoaxes in the United States followed the report of this event. New legislation came into effect to ensure legitimate medical and scientific purposes for possession and transfer of biologic agents. The use of the US Postal Service to disseminate B anthracis intentionally in 2001 brought into focus the diversity of biologic threats. It also provided impetus and funding for research on microbial forensics, newer treatment modalities, and improved vaccines for anthrax. The scientific knowledge that has been gained using B anthracis potentially has a much wider application to infectious disease in general. To quote Albert Einstein: "In the middle of difficulty lies opportunity.".