Biological Warfare

Biological warfare is the use of living organisms (e.g., bacteria, virus) or biochemical agents (e.g., chemical neurotoxins) as strategic military weapons to cause harm in humans, animals, or plants. In contrast to bioterrorism, biological warfare is considered the governmentsanctioned use of biological weapons to attack a clearly defined military force or civilian population. These agents can be classified into six distinct groups; bacteria, viruses, rickettsiae, chlamydia, fungi, and biological toxins.

Bacteria (by itself or genetically engineered) can be used to produce disease that often can be treated with antibiotics. These are small organisms that can be easily grown on solid supports or liquid media. Viruses, however, require a living host in which to reproduce and are dependent on the cells they infect. Viruses sometimes can be destroyed using antiviral compounds, however, there is a limited supply of these compounds and only a few types available. Rickettsiae are organisms with similar characteristics common to bacteria, as they are susceptible to antibiotics, require oxygen, and have cell membranes. Rickettsiae are also similar to viruses in that they require a host to grow and reproduce. Chlamydia are parasites that cannot produce their own energy sources. Fungi can live without oxygen, are non-photosynthetic species, utilize decaying vegetable matter as their food source, and form spores. Toxins can be synthetic (chemical agents) or derived from poisonous substances produced by living plants, animals, or microorganisms. Toxins have an important advantage over pathogens as they are not alive and, therefore, they are more stable and easier to produce and distribute.

The degree at which these biological weapons become threatening involves several characteristics such as the level of infectiousness, toxicity, virulence, pathogenicity (ability to cause infectious disease), stability, and how easily they are transmitted from one species to the next.