Top Priority Bioterrorism Threat Agents
U.S. Centers for Disease Control and Prevention*
CATEGORY A
High-priority agents that pose a risk to national security because they can be easily disseminated from person to person, cause high mortality with potential for major public health impact, might cause public panic and social disruption, and require special action for public health preparedness.
Category A agents
- Bacillus anthracis (anthrax)
- Clostridium botulinum toxin (botulism)
- Francisella tularensis (tularemia)
- Variola major (smallpox)
- Yersinia pestis (plague)
- Filoviruses
- Ebola virus (Ebola hemorrhagic fever)
- Marburg virus (Marburg hemorrhagic fever)
- Arenaviruses
- Junin virus (Argentinian hemorrhagic fever) and related viruses
- Lassa virus (Lassa fever)
CATEGORY B
Second highest priority agents include those that are moderately easy to disseminate, cause moderate morbidity and low mortality, and require specific enhancements of public health diagnostic capacity and enhanced disease surveillance.
Category B agents
- Alpha viruses
- Eastern and western equine encephalomyelitis viruses (EEE, WEE)
- Venezuelan equine encephalomyelitis virus (VEE)
- Brucella species (brucellosis)
- Burkholderia mallei (glanders)
- Coxiella burnetii (Q fever)
- Clostridium perfringens (epsilon toxin)
- Ricin toxin from Ricinus communis
- Staphylococcal enterotoxin B
A subset of Category B agents includes pathogens that are food or waterborne. These pathogens include but are not limited to the following.
- Cryptosporidium parvum
- Escheria coli
- Salmonella species
- Shigella dysenteriae
- Vibrio cholerae
CATEGORY C
Third highest priority agents include emerging pathogens that could be engineered for mass dissemation in the future because of availability, ease of production and dissemination, potential for high morbidity and mortality and major health impact.
Category C agents
- Hantaviruses
- Multidrug-resistant tuberculosis
- Nipah virus
- Tickborne encephalitis viruses
- Tickborne hemorrhagic fever viruses
- Yellow fever
- Influenza (pandemic)
Preparedness for List C agents requires ongoing research to improve disease detection, diagnosis, treatment, and prevention.
* Adapted from the California Dept. of Health Services Bioterrorism Surveillance and Epidemiologic Response Plan.
