Bioterrorism, or biological warfare, is defined as the intentional use of microorganisms or toxins derived from living organisms or viruses to cause death or disease in humans, other animals, or plants in civilian settings. Bioterrorism can occur by any of the previously described routes: fomites, vectors, infected animals, animal products, or emerging diseases.

To understand bioterrorism we will first review some basic definitions. Bioterrorism itself is the practice of using biological weapons for criminal violence. Biological weapons or agents of biological warfare are organisms or toxins produced by organisms that can be used against people, animals, or crops. This is in contrast to chemical weapons which are human-made poisonous substances that kill or incapacitate.

In veterinary medicine, we are also concerned about agroterrorism, which is a specific form of bioterrorism in which the biological weapons target animal or crop agriculture to cause economic damage and instability.

The consequences of bioterrorist attacks directed at humans differ considerably from consequences of agroterrorist attacks. The effects of an attack directed against public health would be measured in human morbidity and mortality and the costs associated with decontamination, surveillance, control, and eradication if possible. The effects of an attack directed at the health of livestock or poultry would be measured in animal morbidity and mortality and associated clean up costs as for human diseases. In addition, astronomical costs associated with disruption of animal and animal product exports would likely accrue. If the biological agent used were a zoonotic agent, both sets of costs would be incurred, and the situation could be far worse.

An example of agroterrorism can be found in World War I, when the German military allegedly used Bacillus anthracis, the causative agent of anthrax, to contaminate horses and mules in Mesopotamia and France.

Cieslak, Christopher G. Rj, Pavlin J. et al. Biological warfare: A historical perspective. JAMA 1997; 278:412-417.