Terrorism is the use of force or violence against persons or property in violation of the criminal laws of the United States for purposes of intimidation, coercion or ransom. Biological agents are organisms or toxins that can kill or incapacitate people, livestock, and crops. Three basic groups of biological agents are most likely to be used as terrorism, and they are bacteria, viruses, and toxins. These biological agents could be spread to residents of McKinney by being sprayed into the air, by infecting animals that carry the disease to humans and by contaminating food and water.
The smallpox virus was wiped out in 1949, but since there are samples of the virus kept in two approved labs in the United States and Russia the concern for its use as a weapon still exists. A case of smallpox today would be the result of an intentional act.
Smallpox infections can be transferred by having prolonged face-to-face with a person who has smallpox, by coming into direct contact with infected bodily fluids or objects such as bedding or clothing and by exposure to an aerosol release of smallpox.