Biological Risk Groups

In many countries, including the United States, biological agents are categorized in Risk Groups (RG) based on their relative risk. Depending on the country or organization, this classification system might take the following factors into consideration:

  • Pathogenicity of the organism
  • Mode of transmission and host range
  • Availability of effective preventive measures (e.g., vaccines)
  • Availability of effective treatment (e.g., antibiotics)
  • Other factors

It is important to understand that biological agents are classified in a graded fashion such that the level of hazard associated with RG1 being the lowest and RG4 being the highest. The University follows the NIH Guidelines categorization of Risk Groups as follows:

  • RG1 – Are not associated with disease in healthy adult humans or animals
  • RG2 – Are associated with disease which is rarely serious and for which preventative or therapeutics is often available
  • RG3 – Are associated with serious or lethal human disease for which preventative or therapeutics may be available
  • RG4 – Are associated with lethal human disease for which preventative or therapeutics are not readily available

Microorganisms and their associate RG designation commonly used at UVA can be found at the American Biological Safety Association (ABSA) website.

Note: Risk Groups are not the same as Biosafety Levels. Please see the Biosafety Levels web page for more information.