Bioterrorism Agents & Diseases

The Centers for Disease Control and Prevention's (CDC) Category A, B, & C Agents by Definition.

Category A Diseases/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
  • Require special action for public health preparedness
  • Result in high mortality rates and have the potential for major public health impact
  • Might cause public panic and social disruption

Category B Diseases/Agents


Second highest priority agents include those that:
  • Are moderately easy to disseminate
  • Require specific enhancements of CDC's diagnostic capacity and enhanced disease surveillance.
  • Result in moderate morbidity rates and low mortality rates

Category C Diseases/Agents


Third highest priority agents include emerging pathogens that could be engineered for mass dissemination in the future because of:
  • Availability
  • Ease of production and dissemination
  • Potential for high morbidity and mortality rates and major health impact