A: Highest priority

Bacillus anthracis, causing anthrax

Botulinum toxin from Clostridium botulinum, causing botulism

Yersinia pestis, causing plague

Francisella tularensis, causing tularemia

Variola virus, causing variola major (classic smallpox)

Viral hemorrhagic-fever (VHF) viruses:

• Arenaviruses, causing Lassa fever and New World VHFs (Machupo, Junin, Guanarito, and Sabia hemorrhagic fevers)

• Bunyaviridae, causing Crimean Congo hemorrhagic fever and Rift Valley fever

• Filoviridae, causing Ebola virus disease and Marburg virus disease

• Flaviviridae, causing yellow fever, Omsk hemorrhagic fever, and Kyasanur Forest disease

B: 2nd highest priority

Brucella species, causing brucellosis

Epsilon toxin of Clostridium perfringens, causing food poisoning

Salmonella sp, causing food poisoning; Escherichia coli 0157:H7 infection; and Shigella, causing shigellosis

Burkholderia mallei, causing glanders

Burkholderia pseudomallei, causing melioidosis

Chlamydia psittaci, causing psittacosis

Coxiella burnetii, causing Q fever

Ricin toxin from Ricinus communis, causing different symptoms depending on type of exposure

Staphylococcal enterotoxin B, causing staphylococcal food poisoning and other symptoms depending on type of exposure

Rickettsia prowazekii, causing typhus fever

Alphaviruses causing viral encephalitides (for example, Venezuelan, eastern, and western equine encephalitides)

Vibrio cholerae, causing cholera; Cryptosporidium parvum, causing cryptosporidiosis; and other agents, causing other waterborne diseases

C: 3rd highest priority

Nipah virus, hantavirus, coronaviruses, and influenza viruses capable of causing pandemic influenza

Other agents associated with emerging infectious diseases