Bioterrorism is the use of biological agents, such as pathogenic organisms or agricultural pests, for the expressed purpose of causing death or disease, to instill a sense of fear and panic in the victims as well as to intimidate governments or societies for political, financial, or ideological gain.

Of all the possible biological agents, the Center for Disease Control and Prevention has identified the following Type A and Type B agents as biological agents requiring greater planning and preparedness. For an explanation of biological agent types, please see the Agent Classification Section.

Type A Agents: Greatest Potential

• Anthrax (Bacillus anthracis)
• Botulism (Clostridium botulinum toxin)
• Plague (Yersinia pestis)
• Smallpox (variola major)



Transmission electron micrograph of Ebola virus (date unknown)

• Tularemia (Francisella tularensis)
• Viral Hemorrhagic Fever (filoviruses, such as Ebola and Marburg, and arenaviruses, such as Lassa and Machupo)

Type B Agents

• Brucellosis (Brucella species)
• Food Safety Threats (i.e., Salmonella species, Escherichia coli 0157: H7, Shigella)
• Glanders (Burkholderia mallei)
• Melioidosis (Burkholderia pseudomallei)
• Psittacosis (Chlamydia psittaci)
• Q Fever (Coxiella burnetii)
• Ricin Toxin (from Ricinus communis)
• Straphylococcal enterotoxin B
• Typhus fever (Rickettsia prowazekii)
• Viral Encephalitis (alphaviruses such as Venezuelan equine encephalitis, eastern equine encephalitis, and western equine encephalitis)
• Water Safety Threats (i.e., Vibrio cholerae, Cryptosporidium parvum)