Though biological weapons were outlawed in 1925 by the Geneva Convention and though research, development, and stockpiling of such weapons were forbidden by the Biological Weapons Convention in 1972, the threat of biological warfare has not been eradicated. A wide variety of agents have been considered as possible weapons. In addition to their devastating effect on the battlefield, some have potential for nosocomial spread in US hospitals that care for victims of biological warfare. The following is a brief review of the history of germ warfare, a description of selected agents under consideration, and a discussion of the potential impact of biological weapons on hospital infection control.

Biological warfare has been attempted many times in past centuries and is not a concept unique to the war in the Persian Gulf. Poisoning wells by throwing dead bodies into them was not uncommon in the Middle Ages. During the 14th century conflict in Crimea, plague victims were catapulted into the besieged city of Kaffa by the Tartar army. Whether aided by this or not, plague soon broke out and the city surrendered. Escaping citizens and returning soldiers soon spread the disease to much of Europe. In another example, blankets from smallpox victims were considered as potential weapons against American Indians by British colonial commanders in the 18th century. More recently, Japan purportedly investigated biological weapons to spread plague, cholera, yellow fever, and anthrax during World War II. Attempts in earlier centuries usually were unsuccessful due to the lack of knowledge about disease vectors and etiological agents. Only with the advent of modern microbiological techniques has intentional biological warfare been possible on an organized and vast scale.