"A biological attack is the deliberate release of germs or other biological substances that can make you sick. Many agents must be inhaled, enter through a cut in the skin or be eaten to make you sick. Some biological agents, such as anthrax, do not cause contagious diseases. Others, like the smallpox virus, can result in diseases you can catch from other people." This document outlines what to do in the event of biological threat.
Michigan State University Criminal Justice Resources Home Page: http://www.lib.msu.edu/harris23/crimjust/bioterr.htm