CLASSIFICATION OF PATHOGENIC MICROORGANISMS

Biological agents are classified according to risk groups and the biosafety level which are described later on in this section.  These classifications presume ordinary circumstances in the research laboratory, or growth in small volumes for diagnostic and experimental purposes.

The classifications of biological agents primarily reflect the judgments made on their inherent risks.  The agents listed in this Section were chosen because they seem to be frequently used in research and diagnostic activity.  Since no list can be all inclusive, if the agent you are working with or intend to work with is not listed, you are encouraged to classify your agent on the basis of similarity to those listed; risk groups for others will be identified on request to the Biosafety Officer.

As a general precaution, the risk group for agents should be raised when manipulation may result in the production of infectious aerosols. Agents of similar pathogenic characteristics not included in these lists should be considered in the same risk category.  It must also be understood that the lists presented in this Manual may not be complete - many agents are referred to in the literature by a variety of names and before assuming that an unlisted organism is classified in Risk Group 1, its characteristics, and pathogenicity must be verified in consultation with the Biosafety Officer.

Risk Group 1 AGENTS:

This Group consists of biological agents that pose low individual and community risk and are highly unlikely to cause disease in healthy workers or animals. The agents require Biosafety Level 1 containment.

Risk Group 2 AGENTS:

This Group consists of biological agents that under unusual circumstances can cause human illness.  Under normal circumstances, they are unlikely to be a serious hazard to laboratory workers, the community or the environment.  Laboratory exposures rarely cause infection leading to serious disease; effective treatment and preventive measures are available and the risk of spread is limited.

Risk Group 3 AGENTS

This Group consists of biological agents that usually cause serious human or animal disease, or which can result in serious economic consequences but are not ordinarily spread by casual contact from one individual to another.

Note: Laboratories engaging primary in the isolation and identification of HTLV or HIV may perform these activities in containment level 2 laboratories (physical requirements) using containment level 3 procedures and practices (level 2+).  All research and production activities require level 3 containment. Diseases are frequently treatable with anibacterial, antiviral, anti fungal and antiparasitic drugs.

Risk Group 4 AGENTS

This Group consists of biological agents that usually produce very serious human or animal disease, often untreatable, and may be readily transmitted from one individual to another, or from animal to human or vice-versa directly or indirectly, or by casual contact.

The Health Protection Branch of the Laboratory Centre for Disease Control in Ottawa, Canada has developed fact sheets similar to a chemical MSDS.  Unfortunately, these fact sheets are not available for all microorganisms.  Fact sheets are available for the organisms with links in red.