Biological terrorism is the intentional release of a biological agent in order to inflict harm on the general public and cause social disruption. Biological agents consist of bacteria, viruses or toxins made from living organisms that can cause deadly diseases in people, livestock and crops.

It is important to know only a small number of biological agents are viable as terrorist weapons. Most potential agents cannot survive outside of narrow temperature ranges, and are too rare or difficult to grow.

If officials detect a biological threat, they will provide the public with information and guidance based on the specific circumstances of the attack.

Category A Diseases and Agents

The U.S. public health system and primary healthcare providers must be prepared to address various biological agents, including pathogens that are rarely seen in the United States. High-priority agents include organisms that pose a risk to national security because they:

• Can be easily disseminated or transmitted from person to person.
• Result in high death rates and have the potential for major public health impact.
• Might cause public panic and social disruption.
• Require special action for public health preparedness.

Category A Agents Include:

• Anthrax
• Botulism
• Pandemic Flu
• Plague
• Smallpox
• Tularemia
• Viral Hemorrhagic Fevers

Category B and C Diseases and Agents

Category B agents are the second highest priority agents and include those that:

• Are moderately easy to disseminate
• Result in moderate infection rates and low death rates
• Require specific enhancements of CDC’s diagnostic capacity and enhanced disease surveillance.

Category C agents are the third highest priority agents and include emerging pathogens that could be engineered for mass dissemination in the future because of:

• Availability
• Ease of production and dissemination.
• Potential for high infection and death rates and major health impact.