Biological risk assessment

Introduction

Biological risk assessment is one of the key principles of biosafety. It is the process used to identify the hazardous characteristics of an infectious organism, the activities that could lead to exposure, the chances of contracting a disease after an exposure and the consequences of an infection. Risk assessment provides the necessary information to determine the appropriate biosafety measures (facility characteristics, microbiological practices, safety equipment, etc.).

To conduct a qualitative risk assessment, firstly all risk factors must be identified and explored. This is deduced from the tendency to increase or decrease the risk of infection. When not all information is available a conservative approach should be adopted, applying the precautionary principle: "When an activity is potentially dangerous to health and/or the environment the necessary preventive measures must be taken even if the cause-effect relationships have not been established scientifically". When working with GMOs it is also necessary to observe the "case-by-case" basis, by which an assessment must be made of the risks associated with the GMOs for each case, and the "step-by-step" principle, by which GMOs can only be released when the assessment of previous stages shows that there is no risk in passing on to the next stage (Spanish Law 9/2003).
 

What must be done?

Basically, biological risk assessment can be done in five stages. The PI is responsible for assessing the risk of a given experimental procedure, establishing the necessary biosafety level and, by means of the declaració d'activitats, submitting the results to the IBC for review.


Further information.

  1. Directrices para evaluar el riesgo biológico (INSST)
  2. Risk assessment (WHO 2020)
  3. Local Risk Assessment (PHAC 2017)
  4. Laboratory-Acquired Infection (LAI) Database (ABSA)
  5. Lentivirus Vector Fact Sheet (ABSA)

Microorganisms can be classified in different risk groups on the basis of the following factors:

-pathogenicity and lethality,
-virulence or attenuation,
-infection mechanism, infectious dose and transmission paths,
-concentration and scale,
-culture conditions,
-production of non-cellular derivatives, such as toxins and allergens,
-reproduction cycles and survival structures,
-host range
-degree of natural or acquired immunity of the host,
-resistance mechanism or sensitivity to antibiotics and to other specific agents,
-existence of suitable prophylaxis and therapies,
-existence of oncogene sequences,
-virus production by cell lines,
-parasitic properties.

This classification is based on normal conditions in the facility, possible effects on healthy individuals, and culture volumes typical of experimental or diagnostic procedures.

Systems of classification by risk group:

  1. Risk Group Database (ABSA) 
  2. Belgian classification 
  3. EPPO Global Database (quarantine pest)
  4. Biological agents (Annex III, Directive 2019/1833)
  5. Virus
  6. Bacteria
  7. Fungi
  8. Parasite
  9. Cell lines
     

The classification of biological agents (BA) by risk group (RG) is not always related to the required biosafety level (BSL). For example, in the risk groups the techniques used are not always taken into account. Defining the BSL gives the final manipulator an idea of the containment needed to safely manipulate the microorganism concerned since, as well as each microorganism's inherent characteristics, the system needs the requirements regarding facilities and operational, technical and physical factors linked to the manipulation of a particular agent. Thus, four biosafety levels (BSL) are defined.


Further information:

  1. BMBL6 section IV. Laboratory biosafety level criteria
  2. BMBL6 section V. Vertebrate animal biosafety level criteria