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U.S. Government Lists of
Bioterrorism Agents and Diseases

The U.S. government has created several, overlapping, lists of viruses, bacteria, toxins, and diseases that could threaten the health and safety of the public, animals, and plants. Although the contents of the different lists are similar, the purpose of the three lists, described below, vary.

The viruses, bacteria, and toxins on the Select Agents List are federally restricted through regulation of their possession, use, and transfer. Two agencies, the Centers for Disease Control and Prevention (CDC) and the Animal and Plant Health Inspection Service (APHIS), which protect and promote the health of humans and animals and plants, spearhead the Select Agent Program for the Department of Health and Human Services (HHS) and the Department of Agriculture (USDA), respectively. The agencies ensure that restrictions, such as registration with the CDC or APHIS of entities possessing the agents and completion of a Federal Bureau of Investigation security risk assessment form, are in place. They also determine what is categorized as a select agent by using the following criteria:

  • The effect that exposure to the agent or toxin has on human, animal, or plant health, or on animal or plant products;
  • How the agent or toxin transfers to humans, animals, or plants and how contagious, virulent, and toxic it is;
  • The effectiveness and supply of treatments and vaccines for any resulting disease; and
  • Any other criteria deemed critical such as susceptibility of specific age groups.

The CDC has another list, its Bioterrorism Diseases/Agents List, which is not associated with any Congressional mandate or federal regulations. It simply groups diseases, viruses, bacteria, and toxins that target humans into three different categories: A, B, and C. Category A agents present a great threat to public health and national security and:

  • Have high rates of transmission and/or fatalities;
  • Can have a great impact on public health since few health professionals have experience with the agents; and
  • Can potentially cause social disruption or a panicked public response.
Category B agents:
  • Spread with moderate ease;
  • Cause moderate rates of disease with low death rates; and
  • Necessitate specific lab capabilites and disease monitoring by the CDC.
Category C agents, which include emerging viruses, bacteria, and toxins, could be modified for dissemination due to:
  • Availability;
  • Easy production and spreading; and
  • Potentially high infection and/or death rates.

The National Institute of Allergy and Infectious Diseases (NIAID) is responsible for the Category A, B, and C Priority Pathogens List, a third lists of viruses, bacteria, and toxins. Although its categorical structure is modeled after the CDC's Bioterrorism Diseases/Agents List, its purpose is to prioritize the Institute's biodefense research and funding on specific viruses, bacteria, and toxins.

HHS Select Agents and Toxins (PDF)
Abrin Cercopithecine herpesvirus 1 (Herpes B virus)
Coccidioides posadasii Conotoxins
Crimean-Congo hemorrhagic fever virus Diacetoxyscirpenol
Ebola virus Lassa fever virus
Marburg virus Monkeypox virus
Reconstructed replication competent forms of the 1918 pandemic influenza virus containing any portion of the coding regions of all eight gene segments (Reconstructed 1918 Influenza virus) Ricin
Rickettsia prowazekii Rickettsia rickettsii
Saxitoxin Shiga-like ribosome inactivating proteins
South American Hemorrhagic Fever viruses Tetrodotoxin
Flexal Guanarito Junin
Machupo Sabia  
Tick-borne encephalitis complex (flavi) viruses Variola major virus (Smallpox virus) and
Variola minor virus (Alastrim)
Central European Tick-   borne encephalitis Far Eastern Tick-   borne encephalitis Kyasanur Forest disease
Omsk Hemorrhagic Fever Russian Spring and Summer encephalitis
Yersinia pestis

USDA Livestock Select Agents and Toxins (PDF)
African horse sickness virus African swine fever virus
Akabane virus Avian influenza virus (highly pathogenic)
Bluetongue virus (Exotic) Bovine spongiform encephalopathy agent
Camel pox virus Classical swine fever virus
Cowdria ruminantium (Heartwater) Foot-and-mouth disease virus
Goat pox virus Japanese encephalitis virus
Lumpy skin disease virus Malignant catarrhal fever virus
(Alcelaphine herpesvirus type 1)
Menangle virus Mycoplasma capricolum/ M.F38/M. mycoides Capri
(contagious bovine pleuropneumonia)
Mycoplasma mycoides mycoides
(contagious bovine pleuropneumonia)
Newcastle disease virus (velogenic)
Peste des petits ruminants virus Rinderpest virus
Sheep pox virus Swine vesicular disease virus
Vesicular stomatitis virus (Exotic)

USDA Plant Select Agents and Toxins (PDF)
Candidatus Liberobacter africanus Candidatus Liberobacter asiaticus
Peronosclerospora philippinensis Ralstonia solanacearum race 3, biovar 2
Schlerophthora rayssiae var zeae Synchytrium endobioticum
Xanthomonas oryzae pv. oryzicola Xylella fastidiosa (citrus variegated chlorosis strain)

Overlapping (Human and Livestock) Select Agents and Toxins (PDF)
Bacillus anthracis Botulinum neurotoxins
Botulinum neurotoxin producing species of Clostridium Brucella abortus
Brucella melitensis Brucella suis
Burkholderia mallei (formerly Pseudomonas mallei) Burkholderia pseudomallei (formerly Pseudomonas pseudomallei)
Clostridium perfringens epsilon toxin Coccidioides immitis
Coxiella burnetii Eastern Equine Encephalitis virus
Francisella tularensis Hendra virus
Nipah virus Rift Valley fever virus
Shigatoxin Staphylococcal enterotoxins
T-2 toxin Venezuelan Equine Encephalitis virus

CDC Bioterrorism Diseases/Agents (PDF)
Category A Diseases/Agents
Anthrax (Bacillus anthracis) Botulism (Clostridium botulinum toxin)
Plague (Yersinia pestis) Smallpox (variola major)
Tularemia (Francisella tularensis) Viral hemorrhagic fevers (filoviruses [e.g., Ebola, Marburg] and arenaviruses [e.g., Lassa, Machupo])
Category B Diseases/Agents
Brucellosis (Brucella species) Epsilon toxin of Clostridium perfringens
Food safety threats (e.g., Salmonella species, Escherichia coli O157:H7, Shigella) Glanders (Burkholderia mallei)
Melioidosis (Burkholderia pseudomallei) Psittacosis (Chlamydia psittaci)
Q fever (Coxiella burnetii) Ricin toxin from Ricinus communis (castor beans)
Staphylococcal enterotoxin B Typhus fever (Rickettsia prowazekii)
Viral encephalitis (alphaviruses [e.g., Venezuelan equine encephalitis, eastern equine encephalitis, western equine encephalitis]) Water safety threats (e.g., Vibrio cholerae, Cryptosporidium parvum)
Category C Diseases/Agents
Emerging infectious diseases such as Nipah virus and hantavirus

NIAID Category A, B, and C Priority Pathogens (PDF)
Category A
Bacillus anthracis (anthrax) Clostridium botulinum
Yersinia pestis Variola major (smallpox) and other pox viruses
Francisella tularensis (tularemia)
Viral hemorrhagic fevers
   LCM, Junin virus, Machupo
     virus, Guanarito virus
   Lassa Fever
   Rift Valley Fever
Category B
Burkholderia pseudomallei Coxiella burnetii (Q Fever)
Brucella species (brucellosis) Burkholderia mallei (glanders)
Ricin toxin from (Ricinus communis) Epsilon toxin of Clostridium perfringens
Staphylococcus enterotoxin B Typhus fever (Rickettsia prowazekii)
Chlamydia psittaci (psittacosis)  
Food and Waterborne Pathogens
   Diarrheagenic E.coli
   Pathogenic Vibrios
   Shigella species
   Listeria monocytogenes
   Campylobacter jejuni
   Yersinia enterocolitica
   Hepatitis A
   Cryptosporidium parvum
   Cyclospora cayetanensis
   Giardia lamblia
   Entamoeba histolytica
Additional viral encephalitides
West Nile Virus
California encephalitis
Japanese encephalitis Virus
Kyasanur forest Virus
Category C
Emerging infectious diseases such as Nipah virus and additional hantavirus
Tickborne hemorrhagic fever viruses
Crimean-Congo Hemorrhagic fever virus
Tickborne encephalitis viruses
Yellow fever Multi-drug resistant TB
Influenza Other Rickettsias
Rabies Severe acute respiratory syndrome-associated coronavirus (SARS-CoV)
Prions Chikungunya virus
Antimicrobial resistance, as related to engineered threats Innate immunity, defined as the study of non-adaptive immune mechanisms that recognize, and respond to, microorganisms, microbial products, and antigens
Antimicrobial resistance excluding research on sexually transmitted organisms such as:
Bacterial vaginosis
Hemophilus ducreyi
Human immunodeficiency virus
Trichomonas vaginalis
Chlamydia trachomatis
Hepatitis B virus
Human papillomavirus
Hepatitis C virus
Neisseria gonorrhea
Granuloma inguinale
Herpes Simplex virus
Treponema pallidum

Select Agent Rules

APHIS-CDC Select Agent Security Documents

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