(1) Biological agents are microorganisms that cause disease in personnel, plants, or animals or cause the deterioration of material. Biological agents are divided into two broad categories; pathogens and toxins. (a) Pathogens are infectious organisms that cause disease or illness in their host and include bacteria, viruses, rickettsias, protists, fungi, or prions. (b) Toxins are biologically derived poisonous substances produced as by-products of microorganisms, plants, or animals. They can be naturally or synthetically produced. (2) Examples of biological agents and their associated diseases are Bacillus anthracis (anthrax), AIV H5N1 (avian influenza), Clostridium botulinum (botulism), Shigella species (food borne illness), Hantavirus (pulmonary syndrome), Legionella pneumophila (Legionnaire's disease), Histoplasma capsulatum (histoplasmosis), Yersinia pestis (bubonic and pneumonic plague), Variola virus (smallpox), Francisella tularensis (tularemia), and Ebola virus (viral hemorrhagic fever). (3) Infectious biological organisms represent one of the greatest potential threats due to their reproductive ability and the time delay from infection to symptom. An infectious biological attack may remain undetected for several days to weeks after release due to the incubation periods that biological agents may have. Diagnosis may be slow as many infectious agents have a slow onset and present with nonspecific symptoms that rapidly escalate in severity. Another compounding problem is that patients may simultaneously present in geographically separated areas. Depending on the pathogen, preventive measures and treatment will be difficult to implement due to factors such as large number of casualties, restriction of movement, and quarantine. Finally, first responders may be among the first casualties, rapidly overwhelming local and state support systems. (JCS/DoD, CBRNE CM (JP 3-41), 2006, p. I-6)