Organism or Agent:

Category A and B pathogens

UCSF Occupational Health Services:

415-885-7580 (work hours, 8am to 5pm)

Exposure Hotline Pager: 

415-353-3898 (24 hours)

Office of Environment Health & Safety:

415-476-1300 (work hours) 

UCSF Police Department:

415/476-1414 or 9-911 (In case of emergency, 24 hours)

EH&S Public Health Officer:   

415-514-3531(work hours)

Biosafety Officer 415-514-2824 (work hours)

University of California San Francisco

Environmental Health And Safety/Biosafety

Exposure Reporting Procedure

for Category A and B Pathogens

The US Department of Health and Human Services, National Institute of Allergy and Infectious Diseases (NIAID) categorizes potential bioterrorism and emerging disease pathogens into three categories depending on the agent’s virulence, morbidity, and mortality risk – Category A, B, and C priority pathogens. This document concerns Category A and B agents used in research laboratories.

Category A priority pathogens are defined by the NIAID ad organisms or biological agents that pose the highest risk to natural security and public health. They are relatively easy to disseminate and transmit from person-to-person, result in high mortality rates, and require special public health preparation and intervention.

Category B priority pathogens are defined by the NIAID as organisms or biological agents that are moderately easy to disseminate, and have moderate morbidity and low mortality risk for healthy individuals. These pathogens also require enhanced diagnostic and disease surveillance.

The Centers of Disease Control (CDC) has also created a list of bioterrorism agents/diseases; however the NIAID list includes and stresses pathogens used in biomedical research.

Reporting Exposures to UCSF Exposure Hotline

All exposures to Category B pathogens are reported to the Exposure Hotline, which is forwarded to the UCSF Public Health Officer.

The UCSF Public Health Officer records and investigates the exposure and takes the following actions:

  • Determines whether the exposure involved Category A or B agents
  • Evaluates any potential exposure risk to members of the public
  • Notifies the UCSF Occupational Health Services (OHS) and Biosafety Officer immediately of any additional agents or information related to exposure that may be relevant to the case.
  • Identifies modifications to laboratory procedures or equipment to mitigate the possibility of a similar exposure occurring.
  • If needed, requests the Department Safety Advisor (DSA) for the lab and biosafety officer to follow up on safe laboratory procedures or provide retraining.

If a potential exposure to members of the public is identified, the UCSF Public Health Officer, in collaboration with the Medical Director of UCSF OHS and Biosafety Officer, will follow the protocol outlined in the Communicable Disease Management and Emergency Response Plan.

A report with redacted information will also be presented to the UCSF Institutional Biosafety Committee (IBC) at the first meeting following the exposure, if the UCSF Public Health Officer, Medical Director of UCSF OHS, and Biosafety Officer deem necessary.

Reporting Exposures to the SF Department of Public Health (SFDPH)

The UCSF Public Health Officer, in consultation with the Medical Director of the UCSF OHS, will determine if the reported exposures requires SFDPH Communicable Disease Control reporting.

If a report is required, the UCSF Public Health Officer will investigate the exposure as described above and prepare a summary of the incident and investigation. This exposure summary report will be provided to the UCSF Biosafety Officer and Medical Director of the UCSF OHS, who will complete the reporting requirements to SFDPH Communicable Disease Control. The exposure summary report will also be presented at the first UCSF IBC meeting following the exposure.

Category A Pathogens

The lists below group all NIAID Category A pathogens by type:


Bascillus anthracis

Yersinia pestis (plague)

Francisella tularensis (tularemia)

Viral Hemorrhagic Fevers:


  • Junin virus
  • Machupo virus
  • Guanarito virus
  • Chapare virus
  • Lassa virus
  • Lujo virus


  • Hantaviruses (that cause Hanta Pulmonary syndrome)
  • Rift Valley Fever
  • Crimean Congo Hemorhagic Fever


  • Dengue virus


  • Ebola virus
  • Marbug virus


Variola major (smallpox)

Other related pox viruses


Clostridium botulinum (botulism)


Category B Pathogens

The lists below group all NIAID Category B pathogens by type:


Burkholderia pseudomallei (melioidosis)

Coxiella burnetii (Q fever)

Brucella species (brucellosis)

Burkholderia mallei (glanders)

Chlamydia psittaci (Psittacosis)

Typhus fever (Rickettsia prowazekii)

Food & Waterborne Pathogens:



  • Caliciviruses
  • Hepatitis A


  • Cryptosporidium parvum
  • Cyclospora cayatanensis
  • Giardia lamblia
  • Entamoeba histolytica
  • Toxoplasma gondii
  • Naegleria fowleri
  • Balamuthia mandrillaris


  • Microsporidia

Mosquito-borne Encephalitis Viruses:

West Nile virus (WNV)

LaCrosse encephalitis (LACV)

California encephalitis

Venezuelan equine encephalitis (VEE)

Eastern equine encephalitis (EEE)

Western equine encephalitis (WEE)

Japanese encephalitis virus (JE)

St. Louis encephalitis virus (SLEV)

Zika virus (ZIKV)


Ricin toxin (Ricinus communis)

Epsilon toxin (Clostridium perfringens)

Staphylococcus enterotoxin B (SEB)

For Questions and Additional Information

UCSF Public Health Office
Office of Environmental Health and Safety
Phone: (415) 514 – 3531
Box: 0942

UCSF Occupational Health Services
Phone: 415-885-7580

Fax: 415-514-5614


NIAID Emerging Infectious Diseases/Pathogens:

CDC Bioterrorism Agents/Diseases (A to Z):

CDC Bioterrorism Overview:

SFDPH List of Reportable Diseases